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·HYPOTENSION
Shock and
Cardiocirculatory
Failure
By PAUL G WEIL, MD PHD
Director of Transfusion Service
Royal Victoria Hospital
Montreal Canada
J B LIPPINCOTT COMPANY
Philadelphia and Montreal

·This material was published in
American Practitioner and Digest of Treatment for
March 1955 Copyright 1955 by J B Lippincott Company
PUBLISHED IN Book FORM
JUNE 1955
THIS BOOK IS FULLY PROTECTED BY COPYRIGHT AND WITH THE
EXCEPTION OF BRIEF PXCERPTS FOR REVIEW NO PART OF IT
MAY BE REPRODUCED IN ANY FORM WITHOUT THE WRITTEN
PERMISSION OF THE PUBLISHERS
Distributed in Great Britain by
Pitman Medical Publishung Co Limited
London
Library of Congress
Catalog Card Number
55 9162
PRNTED IN TIIE UNITED STATES OF AMERICA

·INTRODUCTION 4 sudden fall in blood pressure is a common occurrence in many conditions It is a symptom found at the bedside in the operating room and in the emergency ward Whether due to blood loss cardiac arrhythmia or vasomotor paralysis it must be dealt with promptly to prevent the changes that may lead to death from severe or prolonged hypotension Treatment to be effective must be based on an understanding of the mechanisms involved in the development of hypotension Recognition of its causes and a knowledge of the methods and the drugs available for the restoration of normal blood pressure are of equal importance in therapy Shock is no longer an enigma The cause and the treatment of traumatic or surgical shock are now well known and as a consequence its morbidity and mor tality have been reduced greatly However the sub ject is so important that even the well established facts about shock need re emphasis and repetition thermore the experience of the past few years has added new knowledge Hypotension during surgical operation is a comnion occurrence Turther improvement in preoperative and postoperative care depends on an understanding of the factors other than blood loss that may be re sponsible for a fall in blood pressure The effects of anesthetic medication and procedures of operation itself especially in the elderly and those with cardio vascular disease the use of blood fractions and substitutes norepinephrine and other drugs are some of ·Introduction the more recent advances that require consideration Many new facts about hypotension from laboratory and clinical studies have accumulated in recent years Some of them are to be found in monographs on shock others in textbooks and journals of cardiology medicine surgery and anesthesia Therefore it was considered worth while to bring together in a single volume as many of these facts as would be helpful in the clinical management of any patient who suddenly develops low blood pressure. Its incidence and ur gency especially among the increasing number of older patients undergoing major surgery are further reasons for presenting the established facts about the problem so that the causes of hypotension may be bet ter known and its treatment improved Most of the material presented herein has been de rived from experiences in the clinical investigation and treatment of peripheral circulatory failure at the Royal Victoria Hospital over the past 15 years These have formed the basis but the experiences of others also have been drawn upon They are too numerous to mention but the bibliography contains the most recent and complete review articles The combined experience of many who have investigated and treated shock and cardiocirculatory failure presented in a concise form in its practical aspects for clinicians has been the aim of the author in this treatise Acknowledgment is gratefully made to Miss Helen Gates secretary Miss Ruth Baldry research tech nician of the Royal Victoria Hospital Transfusion Service for assistance in the preparation of the manu script and to Miss Helen MacArthur of the Depart ment of Medical Illustration RVH ·CONTENTS 1 REGULATION OF THE NORVAI BLOOD PRESSURE Systolic Diastolic 9 8 2 CAUSES OF HYPOTENSIOV 5 7 7 7 8 10 11 11 19 3 SHOCK Causes Diagnosis and Clinical Features Physiopathology Consequences Pathologic Anatomy Prevention of Shock Treatment of Shock I aboratory Aspects of Transfusion Transfusion Reactions and Complications Blood Derivatives Blood Substitutes Plasma Loss Dehydration 4 PERIPHERAL VASCULAR DILATATION Anesthesia Surgical Procedures Adrenocortical Hormones in Treatment of Shock Abdominal Emergencies Infection Drugs 20 26 29 91 32 35 35 42 46 46 48

·V111
Contents
4 PERIPHERAL VASCULAR DILATATION-(Continued)
Controlled Hypotension During Surgery 49
Orthostatic Hypotension
51
5 CARDIOGENIC HYPOTENSIOV
53
Endocardial Causes
53
Pericardial Causes
55
Cardiac Arrhythmias
55
Conclusion
61
INDEX
71

·REGULATION OF THE NORMAL BLOOD PRESSURE Blood pressure is regulated by a combination of factors having to do with the maintenance of the diastolic pressure and the production of systolic pressure The latter is primarily dependent on the amount of blood ejected by the left ventricle with cach systole The resistance of the aorta to the blood entering it also plays a part The diastolic pressure 18 maintained by the resistance of the peripheral vascular system and to a lesser extent by the heart rate The stroke volume or cardiac output per ventricu lar systole depends on the amount of blood that flows into the left ventricle from the lesser circulation The amount of blood that enters the pulmonary circuit in turn depends on the venous return to the right auricle The factors on which this depends are the blood volume and the peripheral blood flow The resistance of the aorta to the blood flow during systole is determined by the size and the elasticity of the aorta This central resistance as it is called is increased by rigidity of the aortic walls A decrease in the capacity of the aorta also increases central re sistance Peripheral resistance is directly related to the calı ber of the capillaries the venules and most impor 1 ·2 Hypotension tant the arterioles It is regulated by three mecha nisms (1) nervous impulses (2) hormonal agents and (3) the inherent tone of arteriolar smooth muscle An increase in intravascular pressure sets up impulses mediated through the autonomic pathways arising in the aortic arch and the carotid sinus which reach the vasomotor and cardiac centers in the medulla Effer ent impulses originating in these centers slow the heart rate and decrease arteriolar resistance thereby lowering both systolic and diastolic blood pressure The humoral agents that affect blood pressure are principally those of the adrenal gland cortical as well as medullary and the posterior pituitary Ar ceriolar tone is probably an inherent property of the vascular musculature which is only modulated by neural and humoral mechanisms Because diastolic pressure falls as the duration of diastole is lengthened it is also dependent on heart The rate of the heart is regulated by the same nervous and humoral mechanisms that control periph eral resistance ie autonomic impulses and adreno medullary secretion as described above Thus there is a close integration of peripheral and central fac tors maintaining the level of the blood pressure within the normal range In the innervation of the heart the sympathetic system mediates the accelerator impulses the agus the inhibitory ones The carotid sinus reflex 10 slowing of the heart when blood pressure rises has been mentioned already Another important reflex in the homeostatic control of blood pressure is that whereby an increased venous return to the right auri cle increases heart rate

·Regulation of the Normal Blood Pressure
The main factors regulating the level of normal
blood pressure are summarized below
Cardiac Output
| Venous Retur
Blood Volume
SYSTOLIC
Central Resistance
Elasticity of Aorta Walls
Capacity of Aorta
Peoppheval u Blood Flow
Peripheral Resistanre
1 Caliber of Arterioles
Nervous Impulses
Humoral Agents
DIASTOLIC
Heart Rate
Nervous Impulses

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·2
CAUSES OF HYPOTENSION
There are many causes of hypotension but they all
act in one of three ways to produce the fall in blood
pressure The mechanisms of its production are (1)
a reduction in blood volume (2) peripheral vascular
dilatation and (3) failure of the heart or cardiogenic
In most cases only one mechanism is usually involved
in other cases however there may be several espe
cially in the later phase if the hypotension is not
treated properly With the exception of infection the
mechanism of the manifold causes of hypotension is
known and the treatment is both definitive and effec
tive if instituted early The principal causes of hypo
tension are as follows
1 Reduced blood volume
Hemorrhage
Plasma loss
Dehydration
2 Peripheral vascular dilatation
Anesthesia
Surgical procedures
Drugs
Infections
3 Cardiogenic
Valvular lesions
5

·6
Hypotension
Pericardial damage
Disturbances in rate and rhythm
Myocardial ischemia
Cardiopulmonary

·3
SHOCK
CAUSES
The most common of all causes of acute hypoten
sion is hemorrhage The terms shock collapse
and peripheral circulatory failure have been used
to describe the condition that supervenes following a
reduction in blood volume The term shock itself
has been qualified further depending on the circum
stances of its causation as wound or traumatic shock
and surgical shock It is also known as hypovolemic
oligemıc secondary and hemorrhagic shock
The less common causes of oligemic shock are a loss
of plasma as in burns or a loss of water and electro
lytes in dehydration in these conditions as in hem
orrhage there is a reduction in circulating blood
volume
He is appre
DIAGNOSIS AND CLINICAL FEATURES
The clinical features of the fully developed state of
shock are well known The patient complains of
feeling cold and of insatiable thirst
hensive and in pain which may not be severe The
temperature is subnormal the skin feels cold and is
covered with sweat Pallor and in severe shock mot
tied cyanosis of the skin of the extremities is present
There is a delay in filling of the vessels of the skin
blanched by pressure The pulse is usually rapid and
7

·8 Hypotension easily compressible The blood pressure is lon and may be unobtainable Diagnosis of shock 2s not difficult However the recognition of the factors responsible for it is often difficult Since hemorrhage is the main factor in the great majority of cases one must know under what circumstances and to what extent blood loss has re sulted in or may lead to shock Hemorrhage may be either external or internal it may be due to injury it may occur during or follow ing operation or it may be spontaneous The large amounts of blood that may be lost postpartum in cer lain operations and after severe injuries have been shown many times Blood loss from gastro intestinal lesions such as esophageal varices duodenal ulcer and carcinoma is common and may be exsanguinating The swelling of soft tissues or the presence of dull ness on percussion over body cavities as useful as an indication of the extent of hemorrhage There is a correlation between wound size and blood loss in those with trauma to the extremities A patient with I of his own fist s volume of tissue damaged has small blood loss with I to s moderate and between 3 and 5 a large blood loss amounting 10 50 per cent of the blood volume in the first few hours of injury As a further guide to treatment it may be assumed that if the systolic pressure is below 100 approximately one third of the blood volume has been lost In an avec age size patient this would amount to about 1500 cc. PHYSIOPATHOLOGY Hermodynamics In shock due to fluid loss there 13 a decreased cardiac output sesulting from inadequate filling of the ventricles because of a diminished venous ·Shock 9 return There is no significant change in hemoglobin or hematocrit levels in shock from hemorrhage except hours later However when the reduction in blood volume is due to plasma loss or dehydration there is hemoconcentration early The metabolic changes in shock are consequent to the anoxia resulung from deficient circulation There is an acidosis with a fall in CO2 An impaired renal function is manifested by a rise in plasma NPN and a decreased formation of urine Acute renal failure the so called lower nephron nephrosis may supervene as discussed later Impairment of liver function may occur with serious consequences in terms of its role in protection against sepsis as mentioned elsewhere Vasoconstriction Experimentally it has been shown that the kidney and the liver also contribute to the state of shock by the elaboration of humoral factors in profound shock the kidney produces a vasoconstrictor principle called VEM and the liver a vasodilator material called VDM As the animal approaches the stage of irreversible shock VDM ap pears in the blood in increasing amounts It has been shown to be identical with iron containing protein ferritin In animals made resistant to damage by previous graded exposures there is a decrease in the blood VDM Furtherinore there is an increase in the inactivation of VDM by Iner slices obtained from Tesistant rats The VEM VDM mechanism concerns only the smaller vessels and is a result of shock in the experimental animal Certain compensatory phenomena accompany shock Vasoconstriction causes a pallor of the skin and con tributes to the oliguria Vasoconstriction of the ves sels of the skin makes blood available to more vital ·10 Hypotension regions At the same time constriction of the renal vessels may have an ultimately harinful effect on the excretory function of the kidney as described later It may mask severe hemorrhage in the earliest stages by its maintenance of blood pressure at or near the normal level Hemodilution The other physiologic change of a compensatory nature is hemodilution As blood pres sure falls extracellular fluid in the extravascular spaces flows into the capillaries thereby increasing the blood volume Whereas vasoconstriction and its effect on blood pressure are immediate hemodilution is a slower process taking several hours to achieve a significant effect. Furthermore in dehydration hemo dilution may not occur Neither of these compeni satory mechanisms is effective in severe shock and never must be relied upon to take the place of treat ment CONSEQUENCES The consequences of severe or untreated shock are several Some of the more serious of them are acute renal failure myocardial infarction cerebral throm bosis and irreversible or delayed shock Myocardial infarction and cerebral thrombosis are more likely to occur in the elderly and in individuals with coronary or cerebral arteriosclerosis Delayed shock is a term used to describe the fatal form in which after restoration of normal blood pres sure by transfusion following an initial period of severe or prolonged hypotension the blood pressure steadily declines and the patient dies although the blood volume may be normal or cien above nor inal The cause is unknown but schere infection and ·Shock 11 massive hemorrhage inadequately treated either sepa rately or in combination are important contributory factors The term irreversible shock has crept into clini cal usage where it has no place It belongs in the experimentalist s vocabulary where it means that shock has been produced in such a way (amount of blood removed length of bleeding period etc) that the animal cannot recover when all the removed blood is replaced Often the term has been used to describe therapeutic failure in patients who have been treated for shock Its clinical usage should be discouraged not only for the reasons just mentioned but also because it is dangerous in that it may lead to the neglect of opportunity for effective therapy PATHOLOGIC ANATOMY The findings of the pathologist will seldom olfer any clues at a clinicopathologic conference held to discuss the pathogenesis of the condition in cases of death due to shock Except for the typical patho logic findings of the consequences and the complica tions of the syndrome such as cerebral thrombosis myocardial infarction or lower nephron nephrosis there is no characteristic pathologic anatomy The organs may be pale and bloodless of transfusions were inadequate or they may be congested in those dying of delayed shock despite adequate replacement PREVENTION OF SHOCK It is almost an understatement to assert that surgi cal shock could be considered as a preventable dis The factors that have combined to bring this about are several The cause blood loss as well ease ·12 Hypotension known Its recognition is relatively simple Blood has become available in adequate amounts and trans fusions have been made safe Measurement of Blood Loss The only reliable clin ical guide in the prevention and the treatment of shock is the frequent determination of blood pressure In operations in which blood loss may be severe or in patients in whom it is important that a normal blood pressure be maintained (cardiac arteriosclerotic elderly etc) the actual determination of blood loss by simply seiglung the blood soaked sponges is a valuable method for estimating the amount of blood to be transfused Anemia In many patients with chronic disease there is often an anemia associated with infection malignancy or malnutrition Such patients usually have a reduced total blood volume They withstand operation poorly and may develop shock following a small amount of blood loss of the anemia is not cor rected before operation The usual practice in such cases is to give repeated small transfusions (500 cc) of whole blood or red cell suspensions for several suc cessive days before operation Dehydration of equal importance is the correction of dehydration in patients about to be operated on in whom blood volume may be reduced because of vomiting diarrhea or other causes of depletion of water and electrolytes Coagulation Defects Defects in the clotting med: anism of the blood must be sought in the history and in special cases such as jaundice actual tests for defi ciencies in coagulation must be carried ou Excessive hemorrhage at operation due to such conditions as ·Shock 13 hemophilia and hypoprothrombinemia usually can be anticipated and prevented Anesthesia The importance of anesthesia is discussed elsewhere in the presence of existing or im pending shock the choice of the anesthetic agent and its use demand great care The use of the anesthetic and oxygen are the responsibility of the anesthetist His is also the duty of detecting the early sign of shock-hypotension--by frequent determination of the blood pressure Surgical Technic Careful surgical technic both in the gentle handling of tissue and in the use of hemo. stasis is important in minimızıng hemorrhage The practice of leaving severed vessels to bleed by not tying off or otherwise stopping hemorrhage should be condemned Such practice is wasteful of blood and invites postoperative shock Re operation A fall in blood pressure at the be ginning of an operation usually is not due to blood loss It may be cardiogenic but is most likely to be due to one of the factors responsible for peripheral vascular dilatation usually anesthesia Hypotension occurring later in the operation is most often due to hemorrhage but may be due to any of the various factors mentioned and only a knowledge of the pa tient and the circumstances of the operation will provide the answer as to the most likely cause However when shock occurs several hours after the completion of the operation anesthesia as a cause may be ex cluded There remains to be considered cardiogenic causes or blood loss The most common is hemor Thage from a loose ligature a ruptured vessel unde tected at operation or capillary oozing In such cases ·14 Hypotension transfusions will have only a temporary effect in re storing the blood pressure Immediate re operation must be seriously considered for control of hemor rhage in patients who develop hypotension following operation and in whom the blood pressure cannot be restored and maintained by transfusion The use of vasoconstrictor drugs may only delay the necessary and inevitable operation beyond the point of no return In elderly arteriosclerotic patients other rarer causes of hypotension such as myocardial infarction or pul monary erabolism must be ruled out by clinical and electrocardiographic methods The importance of maintaining the blood pressure as nearly as possible within the normal range before during and after the operation in patients in tlie older age groups is emphasized in younger indi viduals with normal cardiovascular systems a sudden and even proſound decrease in blood pressure is not usually serious if it is self limited or corrected by ap propriate therapy However transient and moderate declines in blood pressure in the elderly or in those Ruth coronary or cerebral arteriosclerosis may lead to the serious consequences mentioned previously The prevention of such accidents is the joint responsibility of internist anesthetist and surgeon Carclul pre operative assessment of cardiovascular status and prep aration smooth induction and even course of anes thesia as well as the skill and the judgment of the surgeon are necessary to guide such patients safely through the stress of a major surgical operation TREATMENT OF STOCK Transfusion The treatment of shock is transfusion Enough blood must be administered to restore and maintain blood volume Not only are large amounts ·Shock 15 frequently needed but it must be given as soon as possible and rapidly The know how of transfu sion cannot be overemphasized Treatment is deter mined neither by one s impression of the amount of blood lost which is usually an underestimation nor by the large amounts which may have already been transfused but only by the response of the patient to operat a blood 00 pressurs co 60 40 blood 1500 (ca) 4000 3300 3000 2.500 2000 blood loss blood cplacement 1900 1000 $ BOO 0 25 3 35 1 152 time (hours) Fic 14 This illustrates (1) the large amount of blood that may be lost at operation in this case a pneumonec tomy for pulmonary tuberculosis (2) the development of shock during operation because of failure to maintain blood replacement pan passu with blood loss as shown in line 0-a and (3) the proper treatment of shock by immediate rapid and adequate replacement of blood as shown by line a-b ·14 Hypotension transfusions will have only a temporary effect in re storing the blood pressure Immediate re-operation must be seriously considered for control of hemor rhage in patients who develop hypotension following operation and in whom the blood pressure cannot be restored and maintained by transfusion The use of vasoconstrictor drugs may only delay the necessary and inevitable operation beyond the point of no return In elderly arteriosclerotic patients other rarer causes of hypotension such as myocardial infarction or pul monary embolism must be ruled out by clinical and electrocardiographic methods The importance of maintaining the blood pressure as nearly as possible within the normal range before during and after the operation in patients in the older age groups is emphasized In younger indı viduals with normal cardiovascular systems a sudden and even profound decrease in blood pressure is not usually serious if 14 15 self limited or corrected by ap propriate therapy However transient and moderate declines in blood pressure in the elderly or in those 11th coronary or cerebral arteriosclerosis may lead to the serious consequences mentioned previously The prevention of such accidents is the joint responsibility of internist anesthetist and surgeon Careful pre operative assessment of cardiovascular status and preparation smooth induction and even course of anes thesia as well as the skill and the judgment of the surgeon are necessary to guide such patients safely through the stress of a major surgical operation TREATMENT OF SHOCK Transfusion. The treatment of shock is transfusion Enough blood must be administered to restore and maintain blood volume Not only are large amounts ·Shock 17 sive hemorrhage requiring large amounts of blood to restore blood pressure to normal adequate transfu sions may not be given for fear of overloading the circulation Such fears are unfounded if the level of the blood pressure is taken as the guide for estimat ing the amount of blood to be infused Only after the blood volume and the blood pressure have been restored to normal is it likely that further transfu sions will overload the circulation when the nor mal blood volume as reflected by a normal blood pressure has been achieved and maintained the need for rapid transfusion is no longer present Then the transfusion may be continued at a slower rate If the patient has been overtransfused the transfu sion should be stopped immediately and a phlebot omy should be performed Enough blood should be withdrawn to cause a disappearance of the signs of circulatory overloading which are a fullness of the Yeins of the neck râles at the lung bases and ulti mately frothy sputum ie pulmonary edema Blood must not be withheld on the mistaken no tion that transfusion by raising blood pressure may increase or cause a resumption of bleeding If hypo tension persists despite transfusion it indicates that the cause is other than or in addition to blood loss myocardial infarction Transfusions must be continued until the bleeding has been controlled in those cases in which shock is due to continuing blood loss INTRAVENOUS TRANSFUSION Usually transfusion is given into the veins of the antecubital fossa but any accessible one may be used in massive or continuing hemorrhage it may be necessary to transfuse into sev ·18 Hypotension eral veins simultaneously and to increase the speed of the transfusion by applying pressure to the flow of blood from the transfusion bottle In the severely shocked patient with cold extreinities and collapsed perspheral vessels it is necessary to do a cut down at once without losing valuable time searching for veins in the usual locations INTRA ARTERIAL IRANSFUSION Sometimes intra arterial transfusion via the radial artery is used when resuscitation by intravenous transfusion fails How ever evidence is accumulating that it is not the route but the rate of transfusion that is the important fac cor in treating the severely shocked patient Ancillary Measures Besides transfusion other an allarv measures are used The control of hemorrhage 15 obviously of prime importance Pain and apprehension are allayed by morphine 10 mg (gr 1/6) given intravenously rather than intramuscularly be cause of the impaired absorption due to circulatory depression The morphire may be combined with 10 mg barbiturate To combat infection antibiotics should be given especially if shock is due to injury of the abdominal cavity or perineal region A good combination is penıcıllın 1 000 000 V and streptomycin 1 Gm re peated at 6-hour intervals Vasoconstrictor drugs such as norepinephrine are useful in certain cases where peripheral vascular dila tation contributes to the reduced blood volume eg hemorrhage with sepsis Body temperature should be maintained but the excessive application of heat should be avoided be cause it causes vasodilatation ·Shock 19 Except in those cases with cerebral or cardiopul monary complications or injuries patients in shock should be placed in the head low position to shift blood from the lower parts of the body thereby in creasing the circulation to the vital organs the brain the heart the liver and the kidneys Patients in shock should be moved as little as possible to mint mize the stimulation of peripheral vasodilatory re flexes LABORATORY ASPECTS OF TRANSFUSION The treatment of hemorrhagic shock with transfu sion and the importance of administering the blood as soon as possible after blood loss rapidly and in sufficient amounts have been discussed previously Without describing in detail the laboratory aspects of transfusion ie collection preservation grouping crossmatching of blood certain ones should be men tioned Only group specific blood may be used ie group A Rh negative blood for a group A Rh negative patient In some instances of limited supplies of blood or emergency situations group O blood can be given to individuals of any group and those who belong to group AB may receive blood of any group Only Rh negative blood may be given to Rh negative females to minimize the possibility of incompatible transfusion reaction and hemolytic disease of the new born The responsibility of the laboratory staff in the per formance of the necessary tests prior to transfusion 15 unique in laboratory medicine The results of most laboratory tests are used to corroborate a clinical diag plosis Any discrepancy between the clinical and the ·20 Hypotension laboratory findings can be checked by repeating the tests or taking a new look at the patient before treat ment is begun However an error in technic inter pretation or labeling by the staff of the transfusion service may result in a serious or even fatal transfusion reaction TRANSFUSION REACTIONS AND COVPLICATIONS The incidence of transfusion reactions and their oc currence in spite of the greatest care in collecting grouping crossmatching and transfusion of blood af ford a constant reminder that transfusions should be administered only when definitely indicated Incompatible or Hemolytic Reaction The most serı ous of all is that known as an incompatible or hemo lytic reaction which occurs when a patient gets the wrong blood (usually a group o patient receives group A blood) It is due much more often to care lessness by those responsible for administering the blood rather than to laboratory errors SYMPTOMS The symptoms are chill increased tem perature and pulse restlessness dyspnea pain in the chest or the lumbar region and circulatory collapse followed later in severe cases by jaundice and renal failure Since the earliest manifestations are those complained of by the patient eg a feeling of chilli ness or pains in the back extra care must be exercised in giving transfusions to those under general anes thesia PATHOGENESIS The pathogenesis of the renal fail ure known as lower nephron nephrosis that may fol low a hemolytic transfusion reaction is probably simi lar to that of profound or prolonged shock The ·Shock 21 factors involved may be summarized as lowered blood pressure vasoconstriction of renal vessels and a re duced renal blood flow TREATMENT may be divided into the following phases (1) The importance of preventing such accı dents by constant vigilance to make sure that the patient gets the right blood (2) If in spite of such efforts the patient gets the wrong blood a knowledge of the clinical features of a reaction should lead to an immediate cessation of the transfusion if there is someone by the side of the patient who will recognize the reaction and stop the transfusion If in doubt that a transfusion reaction is taking place stop the transfusion (3) After having stopped the transfusion determine if it really is a hemolytic reaction by obtaining a specimen of the patients blood and sending it to the laboratory for regrouping and crossmatching (4) The patient should be given sodium lactate to al kalırıze the urine and should receive glucose to pro vide fluid for diuresis (5) During the last phase the aim of treatment is to maintain a balance between fluid intake and output and the acid base equilibrium until renal function returns to normal Until such time it is important not to force fluids otherwise pul monary edema may develop A useful rule is to give every 24 hours an amount equal to that excreted in the previous 24 hours plus 500 to 1000 cc, for in sensible loss Pyrogenic Reactions The incidence of pyrogenic reactions has been greatly reduced since the introduc tion of disposable donor and transfusion sets which are pyrogen free The symptoms are those of a hemo. lytic reaction The treatment is to stop the transfu ·$10n 22 Hypotension Since it is impossible on the basis of symptoms to differentiate between a pyrogenic and a hemolytic reaction all reactions following the transfusion of whole blood or red cell suspensions should be re garded as due to incompatibility until proved to be otherwise Allergic reactions sometimes occur The usual man ifestation is urticaria They are not serious The treatment is symptomatic Edema There is no evidence that even in large transfusions of 10 or more bottles of blood given over a short period of time the citrate has any toxic effect or causes a clinıcally significant change in the coagu lation of the recipients blood However the sodium radical which is not excreted rapidly may cause water retention and pulmonary edema In large transfu sions in the elderly or those with cardiorenal disease this complication must be guarded against Intra venous solution of saline should be used sparingly in such patients who are receiving large amounts of blood Since the ratio of diluent to blood is approxi mately 1 to 3 a transfusion of 4 liters contains slightly more than I later of diluent with about 20 Cm of sodium citrate In such patients it may be beneficial to use 1 bot tle of packed cells for every 3 or 4 bottles of whole blood to avoid circulatory overloading and pulmo If pulmonary edema develops treatment by immediate phlebotomy ys expedited by using a blood donor bottle of the vacuum containing kind Embolism caused by the introduction of air in the transfusion nerer should occur It is necessary to use specially prepared transfusion sets containing fine nary edema ·Shock 23 mesh filters to remove particulate matter which might be the cause of embolism in transfusing whole blood packed cells or plasma Jaundice There are three causes of jaundice fol lowing transfusion (1) hemolysis of donor cells prior to transfusion (2) hemolysis of donor cells after trans fusion due to incompatibility and (3) homologous se rum hepatitis PRETRANSFUSION HEMOLYSIS The least important in its clinical implications is that due to hemolysis of the donor cells either before or immediately after transfusion The hemolysis is due to the early death of the cells because of improper storage or handling of blood ie their life span has been so shortened that the cells are moribund when they are transfused Blood is taken out of the blood bank to the wards or the operating theater It may be left standing at room temperature for several hours and then returned unused The same blood may be crossmatched again and taken out for another patient If this sort of thing happens 2 or 3 times and the blood has not been cared for properly the red cells reach senility earlier than the date of obsolescence stamped on the bottle When such blood is transfused massive bemolysis and jaundice may occur There are usually no other manifestations such as precede the appear ance of jaundice in the next type to be discussed The prevention of this complication is the responsibility of everyone who orders a blood transfusion or handles a bottle of blood Post TRANSFUSION HEMOLYSIS Causes of Jaundice By far the most important of the causes of jaundice following transfusion is known as the hemolytic or ·$ion 22 Hypotension Since it is impossible on the basis of symptoms to differentiate between a pyrogenic and a hemolytic reaction all reactions following the transfusion of whole blood or red ce'l suspensions should be te garded as due to incompatibility until proved to be otherwise Allergic reactions sometimes occur The usual man ifestation is urticaria They are not serious The treatment is symptomatic Edema There is no evidence that even in large transfusions of 10 or more bottles of blood given over a short period of time the citrate has any toxic effect or causes a clinically significant change in the coagu lation of the recipients blood However the sodium radıcal which is not excreted rapidly may cause water retention and pulmonary edema In large transfu sions in the elderly or those with cardiorenal disease this complication must be guarded against Intra venous solution of salıne should be used sparingly in such patients who are receiving large amounts of blood Since the ratio of diluent to blood is approxi mately 1 to 3 a transfusion of 4 liters contains slightly more than 1 liter of diluent with about 20 Gm of sodium citrate In such patients it may be beneficial to use 1 bot tle of packed cells for every 3 or 4 bottles of whole blood to avoid circulatory overloading and pulmo nary edema If pulmonary edema develops treatment by immediate phlebotomy is expedited by using a blood donor bottle of the vacuum containing kind Embolistn caused by the introduction of air in the transfusion never should occur It is necessary to use specially prepared transfusion sets containing fine ·Shock 25 utmost importance in transfusing such patients that the Rh type be determined accurately and blood transfused only after crossmatching Rare Factors and Afultiple Transfusions The last group of incompatibilities is that due to a combina tion of rare factors (eg hell) and multiple transfu sions The recipient whose cells do not contain one of the factors is given by chance blood that does have that particular factor he deselops antibodies to it and during a subsequent transfusion of blood containing the same factor he has a hemolytic reaction This may also happen to an Rh negative patient who receives multiple transfusions of Rh positive blood However when supplies of Rh negative blood are limited it may be justifiable to transfuse male patients with Rh positive blood of transfusion is im perative but with female patients the risks of such a procedure must be weighed more carefully (As mentioned already Rh positive blood cannot be given under any circumstances to a patient who has antı bodies to the Rh factor) Rh positive blood given to an Rh negative female may sensitize her so that even years later in her first pregnancy the infant if Rh positive may have hemolytic disease also be dangerous to transfuse the Rh negative woman with Rh positive blood in large amounts for if she ever has been sensitized during pregnancy she may respond to the transfusion with the production of antibodies sufficient to hemolyze the transfused cells and cause jaundice To prevent this type of jaundice it is necessary that the laboratory be informed if the patient is a recipient It may ·26 Hypotension of multiple transfusions because incompatibilities due to such factors can be detected only by special grouping and crossmatching procedures Homologous Serum Jaundice Finally the third cause of jaundice is not a hemolytic process but a hepatitis which is caused by a virus transmitted in the blood the plasma or the serum of the donor Although the morbidity is low the mortality is high It may be differentiated from the preceding type of jaundice by its late appearance on an average of 60 days following transfusion and by the various tests used to distinguish between hemolytic and nonhemo lytic jaundice The prevention of the disease is ren dered all the more difficult because of (1) the preva lence of carriers who are also actual or potential blood donors (2) the absence of any test for the ex clusion of such donors and (3) the lack of any method for destroying the virus in bank blood The blood derivatives albumin gamma globulin and fibrinogen have been rendered free of the virus in their prepa ration recent reports would indicate BLOOD DERIVATIVES Red Cell Suspensions Besides whole blood various fractions and products of whole blood are available They may be preferable or supplementary to whole blood in certain conditions Red blood cell suspen sions or packed cells as they are often called are use ful in the treatment of hemorrhage in the elderly or in those with cardiorenal or cardiopulmonary disease in such patients the use of whole blood in large amounts because of the contained diluent of antı coagulant and preservative may overload the circu lation Packed cells which contain only a minimal ·Shock 27 amount of diluent may be used to increase the hemo globin content of the circulating blood without the addition of excess amounts of fluid Usually they are prepared by allowing the blood to stand undisturbed for several hours and drawing off the supernatant plasma or they may be obtained more quickly by centrifuging If means are not available for the ster ile preparation of packed cells they may be obtained by standing the transfusion bottle head down for several hours and after the cells have settled admin istering only the first half of its contents In trans fusing packed cells the same precaution in respect to sterility freshness compatibility etc should be observed as for whole blood Their preparation has been simplified by the introduction of the Fenwal blood pack Platelet Suspensions The treatment of shock due to hemorrhage resulting from deficient platelets has been improved recently by the introduction of meth ods for the preservation of platelets for transfusion Even fresh blood drawn in the ordinary way contains no appreciable number of thrombocytes Hemor rhage from thrombocytopenia is often uncontrollable by ordinary transfusions If blood is drawn into plasuc bags or glass containers coated with silicone the platelets may be preserved long enough to effect cessation of bleeding in such cases provided that the blood is transfused immediately A simple procedure used at the Royal Victoria Hospital is as follows (1) the patients blood is grouped (?) a blood sample is obtained from a donor of the same group as the pa tient (3) the donors and the patients blood is cross matched (4) if compatible the donor is bled into a Fenual plastic bag or a Baxter bottle coated with ·28 Hypotension silicone (5) the patient is transfused immediately after the donation has been completed Plasma In addition to the cellular components of blood used in the treatment of hemorrhage there are several plasma fractions that are useful Albumin was prepared for the United States Armed Forces during World War II for the emergency treat ment of shock It is a valuable substance for this purpose since it is the plasma protein which normally maintains colloid osmotic pressure in the blood Its administration provides a rapid method of treating shock because it quickly shifts extravascular fluid into the circulation It must be used with extreme cau tion in patients suspected of being dehydrated and in such patients its use must be accompanied by intra venous saline In the concentration commercially available for intravenous use it is five times as effec tive as an equal amount of plasma ie 100 cc of albumin is equivalent to 500 cc of plasma as a plasma expander Albumın is also used to reduce cerebral edema and to provide metabolic requirements in se vere burns Fibrinogen The remaining plasma protein frac tion used in transfusion treatment of hemorrhage is fibrinogen More and more cases of bleeding due to a coagulation defect resulting from hypofibrinogene mia are being reported Fibrinogen administration is often the only means of restoring the fibrinogen level to normal and correcting the coagulation defect in such cases The diagnosis of hypofibrinogenemia must be considered in the presence of hemorrhage oc curring in cases of metastic carcinoma of the pros tate and the pancreas severe liver disease toxemia ·Shock 29 and Rh isosensitization with a dead fetus It is also to be suspected in severe hemorrhage occurring dur ing major lung surgery The most important how ever from all aspects is premature separation of the placenta Clinically the condition should be suspected in obstetric patients who continue to bleed from the vagina despite repeated transfusions of even freshly drawn blood and other measures usually employed to stop hemorrhage The patients blood can be tested for fibrinogenopenia by the following procedure (I) with draw 3 cc of blood (2) incubate at 37 for 30 min utes (3) if no clot appears the fibrinogen level is at a critically low level Fibrinogen is now commercially available as Parenogen supplied by Cutter Labora tories Every maternity hospital should maintain an adequate stock for emergency use Usually bleeding can be controlled by the infusion of 4 mg BLOOD SUBSTTTUTES Originally called blood substitutes it is now custom ary to refer to the substances which increase blood vol ume as plasma expanders extenders or augmenters There is no substitute for blood when large amounts are needed However in cases where amounts rang ing from 500 to 1500 cc of blood are ordinarily used plasma expanders may be substituted for blood emergency situations their use is often a life saving measure during the time necessary to start a transfu sion Their use in these circumstances justifies their being called blood substitutes They comprise a variety of substances of animal or plant origin or synthetically produced They all have ·Sucrose 30 Hypotension a common physical property similar to that of albu min-of holding fluid in the vascular system Dextran is a polysaccharide derived from the fermentation of Polyvinyl pyrrolidone (PVP) is a synthetic polymer made from acetylene Gelatin is derived from an animal and pectin from a plant source They are all reliable and safe substitutes Clinical experiences with these substances have demonstrated that they do not give rise to reactions of any kind Recently it has been found that following the admin istration of more than 1000 cc of Dextran in any one infusion there may be an increased bleeding tendency as revealed by Jaboratory studies It has not been shown to be of clinical significance and the exact mechanism is unknown They restore and maintain blood pressure in cases in which blood loss does not exceed 1500 cc In pa tients with severe or prolonged bleeding as men tioned previously it is necessary to use whole blood Even in such cases however they may be used to supplement limited supplies of blood In many cases a substitute alone will prevent shock Most blood transfusions are given for operations re quiring from 500 to 1500 cc of blood replacement It is in this type of case that the substitutes have an important role as blood sparing agents They fave other advantages too Their use will lessen the incidence of serum hepatitis due to trans fusion of blood containing the virus of the disease Similarly the incidence of reactions due to transfu sion of incompatible or contaminated blood will be decreased The danger of sensitization to the Rh and related factors by blood transfusion in female patients ·Shock 31 and the development of hemolytic disease of the new born is also reduced PLASMA LOSS Burns Reduction of the blood volume from loss of plasma most commonly occurs in cases of burns The loss of plasma from the damaged capillaries in the burned regions of the body leads to an actual re duction in the blood volume The injury also pro duces psychic and physical stinul that cause periph eral vascular dilatation and a reduction in effective blood volume Hemoconcentration is a constant feature of severe burns The determination of the degree of hemocon centration by hemoglobin or hematocrit studies is of great value in estimating the reduction in plasma vol ume and the amount of plasma to be transfused Hemoconcentration studies as a guide to therapy are likewise of value in other conditions in which a re duction in blood volume is that of plasma loss or loss of water and electrolytes Crush Syndrome A condition in which shock is usually present accompanied by hemoconcentration is the crush (compression traumatic) syndrome which follows compression injuries to the extremities When the compression is released plasma transudes into the tissue from damaged capillaries distal to the compres $ion Acute Purulent Exudation Shock due to a reduc tion in plasma volume is also to be found in condi tions in which there is acute purulent exudation such as empyema and peritonitis A rare condition in which plasma loss may be considerable is pemphigus ·32 Hypotension In intestinal obstruction especially when accompa nied by local circulatory stasis as in mesenteric tlironi bosis there may be a diffusion of plasma into the peritoneal cavity and the bowel lumen with resultant reduction in plasma volume Obstruction In strangulating obstruction of the small bowel particularly if it involves a large seg ment reduction in blood volume may be great Moreover distension of the abdomen may impede the venous return from the lower extremities Dehydra tion due to vomiting present in such cases is also an important factor contributing to the reduction in plasma volume Treatment The treatment of shock due to these causes is the infusion of plasma The various plasma substitutes described have been used with good effect In the treatment of severe burns blood transfusion also should be given because of the anemia which be comes manifest when the hemoconcentration disap pears Intestinal obstruction must be treated with saline infusion as well as plasma to replace the fluids lost by vomiting DEHYDRATION A reduction in blood volume occurs in dehydration Loss of water and electrolytes in excessive amounts from the skin the gastro intestinal tract or via the kidneys and insufficient intake of fluid gre a clinical picture characterized by dryness of the mouth flushed skin increased temperature oliguria and low blood pressure Hemoconcentration is usually present but may be masked by the coexistence of anemia Espe cially in the elderly there may be psychologic changes with restlessness delirium stupor or excitement Salt ·Shock depletion may be extreme from vomiting diarrhea gastro intestinal fistula and gastric suction In the low salt syndrome sometimes occurring in patients with congestive heart failure treated with mercurial diuretics in diabetic coma and in adrenocortical in sufficiency circulatory collapse may be profound De hydration in infants and children may be rapidly fatal Treatment The correction of the electrolyte im balance that may result from dehydration is often more difficult than the correction of the dehydration itself The clinical biochemical aspects of the prob lemn such as the tendency for an acidosis to develop if sodium is lost in excess of chlorides (pancreatic ileal jejunal secretion and urine) or for an alkalosis to develop if chloride is lost in excess of sodium (gas tric secretion) lie outside the scope of the present dis cussion However the treatment of dehydration re solves itself into the restoration of reduced blood yol ume by intravenous infusion of NaCl in the first in stance and only later in the correction of electrolyte imbalance by the use of modified solutions ISOTONIC NACL or normal salıne probably is given most frequently It is used for patients with dehydra tion resulting from yomiting and in those in whom it is necessary to replace aspirated gastro intestinal fluids Hypotonic NaCl infusion is used in simple water deprivation in hypoalbuminemia and in any condition where the immediate need is water replace ment without increasing the osmotic pressure of the plasma or raising the serum sodium level Such a solution is obtained by the simultaneous infusion of a solution of dextrose in water and normal saline HYPERTONIC NACL is used in conditions such as the ·34 Hypotension low salt syndrome in which the large volume of 150 tonic solution required to raise the low sodium level might cause circulatory overloading This solution because of its hypertonicity draws water from the intracellular into the extracellular tissue causing de hydration of the cells of impaired renal function does not permit the excretion of excess sodium For these reasons hypertonic salıne solutions must be used cau tiously SOLUTIONS CONTAINING POTASSIUM such as Ringers Hartmans Darrows are used for treatment of de hydration due to diarrhea or other conditions in which there is a loss of secretion from the lower gastrointestinal tract and in diabetic acidosis In such cases there is a loss of potassium of significant amounts in addition to the loss of other electrolytes Other intra venous solutions containing all the electrolytes found in normal human plasma je sodium chloride cal cium magnesium and potassium have been introduced recently ·4 PERIPHERAL VASCULAR DILATATION The nervous regulation of vascular tone through out the whole circulatory system or any of its parts may be interfered with by a variety of agents drugs procedures infections psychic and other stimuli to produce vasodilatation and resulting hypotension They are mediated by one of tho mechanisms either inhabition of vasoconstriction or initiation of vasodılator activity or both In the past hypotension due to vascular dilatation has been called neurogenic or primary shock ANESTHESIA Next in importance to hemorrhage as a cause of hypotension during surgery is the anesthesia itself Anesthetic agents besides blocking painful stimuli and relaxing the musculature have certain unde sirable effects paralysis of vasomotor tone interfer ence with the conduction mechanism of the heart and the deleterious effects of anoxia on the myocar dium and the medullary centers controlling circula tion and respiration $5 ·36 Hypotension Prcanesthetic Medication Either because of an in creased sensitivity of the patient or an overdosage preanesthetic medication with avertin barbiturates morphine etc may cause a lowering of the blood pressure Operation should be deferred in such cases unul the blood pressure rises of its own accord or is restored to normal with vasoconstrictor drugs if im mediate operation is imperative Ether and Pentothal Sodium Rapid induction with ether or Pentothal Sodium may produce hypoten sion due to uncompensated peripheral vasodilatation Lightening the depth of anesthesia usually suffices for the return of the blood pressure to normal levels Or it may be necessary to interrupt the anesthesia for a short time and administer oxygen under pressure As a general rule vasopressors are used with conduction anesthesia Cocaine when used as a local anesthetic has been known for years as a potentially dangerous drug be cause of the collapse and even death that occasionally followed its use Now it is rarely used except as a topical agent in weak concentrations and combined with a vasopressor in eye operations and bronchoscopic examination Pituitrin preparations have been reported to cause a severe fall in blood pressure in patients anesthetized with cyclopropane Care must be taken not to inject oxtocin or other pituitrın preparations in obstetric patients until after the anesthesia has worn off With these as with all other anesthetic agents and premedication drugs it must be remembered that they interfere with the normal balance between vasocon strictive and vasodilator influences on the one hand ·Peripheral Vascular Dilatation 37 and on the other the reflexes which slow or increase the heart rate There sometimes results an increase but more often a decrease in blood pressure of the two hypotension is by far the more important The significance of the various forms of tachycardia brady cardia and other arrhythmias is considered later Spinal Anesthesia Spinal anesthesia (pontocaine etc) causes a reduction in blood pressure because of the paralysis of the vasomotor mechanism with dilata tion of the vascular bed below the level of anesthesia The time of appearance of hypotension due to this mechanism is usually shortly after the induction of anesthesia either before or at the beginning of the operation The prevention and the treatment of hypotension due to spinal anesthesia depends on the use of ephedrine gr 3/4 to 1 1/2 before the spinal puncture is made and a vasopressor drug such as neo synephrine or norepinephrine of hypotension develops following injection of the anesthetic drug As men tioned elsewhere epinephrine is not used because of its harmful effects on the heart in susceptible indı viduals or in those anesthetized with cyclopropane or related anesthetic agents Cyclopropane has been shown to cause the most sudden and dangerous of all forms of hypotension namely that of ventricular fibrillation and cardiac standstill Its mode of action is considered to be due to its sensitization of the heart to irregularities in duced by reflex stimulation via the autonomic nerv ous system or by the direct action of epinephrine on the cardiac conduction system Trichlorethylene and ethyl chloride may act in the same way as cyclopropane to produce cardiac irregularities Chloroform ·BP 200 01 Apr 9 11 12 6 La Ap 20 6 22 + Apr 11 + e ati rep lomy S . 12 150 rectomy OUT 30) AN phedningen e PA ++ Gt AT m.net Dem 1 Nup com Neon wlope pana TE 100 blood Larg 5 005 poos Gynephr SA 100 Blood blood 42.33 song Blood 3000 1000.cc blood annat. Ompus) ·FIG 24 This illustrates (!) shock following spinal anesthesia and its treatment with Neosynephrine º the development of shock after operation in this case a nephrectomy for left renal calculi (3) the failure of blood transfusion to maintain blood pressure (4) the necessity of reoperation to look for and control bleeding in this case a ruptured splenic pedıcle torn during the nephrectomy (5) the development of shock following the second operation due to insufficient blood replace ment 39 ·Hypotension content of blood returns to normal the stimulation ceases and the blood pressure falls As already discussed incompatible transfusions may cause collapse The early symptoms of such a resc tion eg pain in the back and a feeling of chilliness will be absent she patient is unconscious from a general anesthetic but the presence of a chill wall warn that a transfusion reaction may be taking place However if both a general anesthenc and a muscle relaxing drug such as curare have been used there will be none of the usual symptoms (pain) or signs (rigor) of an incompatible transfusion reaction Un der these circumstances however tachycardia tachyp nea an increased bleeding tendency or a fall in blood pressure may indicate that an incompatible blood is being transtused But they are unreliable manifesta trons it is better to rely on extra precautions to make certain that the proper blood is administered to such patients SURGICAL PROCEDURES Position of Patient There are surgical procedures and manipulations during operation that of them seles cause a fall in blood pressure apart from blood loss and anesthesia Stimulation of sasodepressor re flexes induces vasodilatation and hypotension Pos furing the patient in certain positions as in the use of the kidney bar or the jacknife position may cause a drop in blood pressure which may be corrected by change of posture and the injection of a vasocon strictor drug Visceral Manipulation Operations on the thoracic ·in blood pressure Peripheral Vascular Dilatation 43 the abdominal or the pelvic organs also may cause re flex vasodilatation and a lowering of blood pressure The hypotension is not related to the slowing of the heart which is a secondary response to the vasodilata tion "The decreased blood pressure due to these fac tors is usually transient and sell limited However in the presence of other causes of hypotension such as hemorrhage these reflexes through their additive elfect on the blood pressure may assume unusual im portance It can be corrected by the use of vasocon Strictors In operations on the neck during intubation or during thoracentesis the vasovagal reflex may be acti vated as shown by a slowing of the pulse and a fall Unlike the peripheral vascular type just described it is of cardiogenic origin and may be prevented or abolished by atropine and similarly acting drugs which prevent the vagus from responding to such stimuli During operations for the removal of a pheochromocytoma or a diseased kidney causing hypertension hypotension may result because of the sudden cessa tion of secretion of epinephrine or hypertensin In such operations it is now routine to use norepineph tine or other vasopressor drugs during the operative and the immediate postoperative periods Interference with Vasoconstrictor Mechanism In patients undergoing the second stage of sympathec tomy and splanchnicectomy for hypertensive cardiovascular disease hypotension during the operation may result from interference with the vasoconstrictor mechanism of the lower spinal segments unless a vaso. pressor agent is used It is frequently necessary in ·Hypotension such patients to continue the intravenous administra tion of norepinephrine or similar drugs during the postoperative period to present a fall sa blood pres sure due to uncompensated vascular dilatation in the lower limbs Vasopressor Drugs As this and preceding sections have shown the vasopressor drugs are very valuable antishock substances In certain conditions such as those just described and during spinal anesthesia they are specific antagonists to shock in others such as hemorrhage they may be useful adjunctne agents In still others such as myocardial infarction severe infection etc to be discussed later they may be of benefit and should be used to treat the accompanying shock ADRENOCORTICAL FIORVOVES IN TREATMENT OF SELOCK These substances hate special value in the treat ment of shock in the following circumstances (1) op erations involving removal or interference with secre tion of pituitary and adrenal giands og Cushings disease (2) operations on patients who have been un der long term treatment with cortisone and (3) Addi son s disease in the first type of case the sudden with drawal of adrenocortical secretion may precipitate collapse In the second type patients whose adrena cortical activity has been suppressed by long continued treatment cannot respond to the sudden increased demand of the added stress of operation Peripheral circulatory collapse and hypoglycemia result In both cases treatment consists of giving cortisone in ade quate doses from 100 to 200 mg daily before and ·Peripheral Vascular Dilatation 45 after operation gradually reducing the dosage in the postoperative period During operation it may be necessary to treat with intravenous cortisone Blood transfusions and vasoconstrictors are also indicated The occurrence of collapse in patients with adrenocortical insufficiency when infection or trauma super venes is treated with cortisone intramuscularly and intravenously As mentioned above shock may also occur in patients under long term treatment with cortisone who develop infection or receive an injury or undergo an operation Such an eventuality must be guarded against in patients with arthritis asthma dermatitis or others receiving cortisone for long pe riods Evidence of its use must be specifically sought in taking the history of such patients prior to opera tion Under such circumstances as well as during the course of any intervening illness the cortisone should be increased in all such cases when shock is either present or may be anticipated it is well to support the circulation by using norepinephrine or other vaso constrictors and to give blood transfusions or other blood volume expanders during the critical phases Patients who are chronically ill may not show an adequate response to an added stress In rare in stances in those with an undetected adrenocortical insufficiency the stress of illness injury or operation may also cause collapse The diagnosis in such cases can be confirmed by determining the eosinophilic re sponse But except in these and the previous cases mentioned where cortisone is specifically indicated it has no use in the prevention or the treatment of shock ·46 Hypotension ABDOMINAL EMERGENCIES Many patients with signs of an acute abdomen have an addition the signs of shock The collapse may be extreme in those with snfection of the peri toneal cavity as described later But eser in patients with early minimal or absent peritoneal contamina tion signs of shack are usually present Perforation of a viscus eg ruptured duodenal ulcer empyema of the gallbladder acute peritonius splenic infarc ton etc usually are accompanied by collapse Other visceral disturbances in which shock may be a prom nent feature are torsion of a testicle renal or ureteral colc a twisted ovarian cyst In all of these condi tions the treatment of the collapse is the treatment of the underlying condition by surgery vasoconstric fors antibiotics and mussons of blood and fluid INFECTION Wounds The profound effects of contaminated wounds especially those of the abdominal cavity on the blood pressure of severely injured casualties fuas been known since IVorld War 1 and intensively stud sed since World War I In such cases collapse may be seiere despre minimal reducron in actual blood volume and may persist even after adequate replace ment as measured by blood solume determinations Bacteremia Peripheral circulatory collapse also may occur in various fulminating infections accom panied by a bacteremia with the pneumococcus me ningococcus streptococcus and gram negatuse bacilfs The severe shock that is usually fatal folloning trans fusion with contaminated blood or plasma belongs in thu Category The arculatory depression fre ·47 Peripheral Vascular Dilatation quently found in cases of peritonitis and intestinal obstruction in spite of correction of fluid balance is probably of a similar nature Although the mechanism of the vascular collapse 15 still uncertain it is thought to be due to peripheral vascular dilatation in which the venules are chiefly involved It has been shown that it is not due to re duced blood volume It is not considered to be due to cardiac impairment although a direct action on the heart as well as on the peripheral vasculature by the bacterial toxins cannot be excluded TREATMENT 15 most unsatisfactory The use of wide spectrum antibiotics early and in large amounts (eg Penıcıllın with Streptomycın) may be helpful and always should be instituted The replacement of blood plasma water and electrolytes in cases in which blood volume is reduced by a loss of one or more of these constituents of the circulation is ex tremely important Vasoconstrictors may be of ben efit and always should be administered Contaminated Infusion Fluids The prevention of shock due to the infusion of contaminated blood or plasma requires special mention Since the danger of contaminants is always present blood or plasma should be used only when indicated Blood before being administered should be checked for hemolysis and for a characteristic vermilion hue imparted to the inner surface of the bottle on shaking which indi cates contamination The use of plasma stored in the liquid state is fraught with the danger of shock Not only may it be impossible to recognize contaminaled plasma but even plasma stored in the cold may contain contami ·48 Hypotension nants that grow at low temperatures The use of dried or frozen plasma reconstituted or chaned im mediately before being used and the plasma expand ers as discussed elsewhere talminimize the incidence of shock due to contaminated plasma The preparation of plasma and red cell suspensions demands the most careful technic and sterile precau tions since these materials which are excellent bac tersal culture media may be stored for a considerable period before being used I a transfusion for any reason has to be stopped a safe rule to follow is that the same bottle of whole blood plasma red-cell sus pension or any other intravenous solution should not be used again if more than an hour has elapsed be tween the first attempt and the next because of the danger of contamination DAUGS Hypertension Drugs recently introduced for the relief of hypertension may produce in some instances marked lowering of the blood pressure They may be classified according to their mode of action as (1) the ganglionc blocking agents tetraethyl ammonium and Hexamethonium (2) centrally acting sympathetic drugs hydralazine (Apresoline) dihydrocrgocornine (DHO) and Veratrum (3) peripherally acting sym pacholytic depressants Dibenamine and Priscoline The final common pathway of action of all of these drugs (and sodium nitrate) is peripheral vascular paralysis The vasomotor collapse responds to the vasoconstrictor drugs such as norepinephrine Bc cause of its cardiac effects and the underlying cardiac disease that may be present in cases in which these ·Peripheral Vascular Dilatation 49 hypotensive drugs are used epinephrine is contra indicated Barbiturate overdosage and poisoning with o her drugs or loxic agents is almost invariably accompa nied by collapse The treatment of the collapse is as important as the removal of the drug by stomach washing or neutralization of its effect with an antı dote Although there is no reduction in actual blood volume blood trans[usion in addition to the use of vasoconstrictors may be lıfe saying Oxygenation of the tissue must be achieved not only by restoring the Circulation but also by artificial respiration Anaphylactic reactions of which hypotension is a manifestations may be so rapidly fatal that no treat ment is of any avail However in many instances they can be prevented Penicillın is known to cause such reactions when given by injection to allergic individuals Manifestations of allergy always should be inquired into before injection of any drug or for eign substance whenever possible in the case of penicillin its oral rather than intramuscular admin 2stration is the one of choice When a drug an antı biotic a foresgni serum or any agent that may cause such a reaction is used epinephrine always must be at hand ready for instant vse to Counteract the fall in blood pressure CONTROLLED I{YPOTENSION DURING SURGERY The use of controlled hypotension during surgery has been recommended by some anesthetists as a val vable method in suitably selected patients undergoing certain operacions The advantages according to its advocates are that hemorrhage is lessened thereby ·Hypotension permitting more rapid technic and a better view sn a relatively bloodless field Induction There are several means of inducing hypotension which may be used Spinal anesthesia and Hexamethonium paralyze the vasoconstrictors of the lower spinal segments Hypothermia by refrigera tion or phenothiazine derivatises is also used Besides the possible harmful effects of hypotension the pheno thiazine drugs such as Largactil may cause liver dam age Sall anocher method of reducing blood pressure us by phlebotomy or rather arteriotomy whereby the patient is bled sato a closed system the blood can be reinfused quickly sf the seed arises If this method is used the patient must be postured in the head down position and blood replacement must keep step with blood loss Because of the removal of the norma tensive homeostatic mechanism of vasoconstriction when spinal anesthesia or Hexamethonium are used ulting the patient into the head up position by caus ing a further pooling of blood in the lower part of the body may further reduce the blood pressure to dangerously low levels The loss of even small amounts of blood may have a similar effect Complications The major complications of this form of preventing blood loss during surgery are reactionary hemorrhage from bleeding vessels not de tected and ligated at operauon acute renal farlure thrombosis of cerebral coronary or retinal vessels leading to hemiplegia myocardial infarction or blind ness and death The contraindications are many and include the elderly arteriosclerotic hypotensive or hypertensive individuals and all patients in whom 16 may be anticipated that blood replacement and oxy ·Peripheral Vascular Dilatation 51 genation may be difficult or in whom blood loss may be large Even its proponents point out that it is a potentially hazardous method which should only be used in carefully selected cases by skillful and ex perienced anesthetists ORTHOSTATIG HYPOTENSION A clinical entity characterized by orthostatic hypotension vertigo hypohydroses impotency bladder dysfunction and relatively slow cardiac rate has been described This is considered to be due to disturb. ances in the autonomic nervous system as manifested by the impairment in both vasoconstrictor and vaso dilator components The hypotension is a reflection of the failure of vasoconstriction in some parts of the body to compensate for vasodilatation in others and also to the absence of reflex tachycardia The lesion responsible for the defect in autonomic func tion is thought to be situated in the hypothalamus Postural hypotension may occur also in patients with organic nervous diseases such as myasthenia gravis neurovascular syphilis subacute combined scle rosis and the various neuropathies due to vitamin de ficiency Specific treatment of the disease process it self and symptomatic treatment of the hypotension by the usual measures of abdominal binders and elastic Stockings should be undertaken The increase of blood volume by increased daily intake of sodium chloride and the use of vasoconstrictor drugs such as ephedrine may be helpful Other forms of orthostatic hypotension include those due to large varicosities or angsomata of the extremities and phlegmasia dolen caerulens Stand

·52 Hypotension
ing for long periods of time without moving the
muscles of the legs sufficiently to aid the return venous
flow may cause a selere fa}} in blood pressure with
syncope In the aged and those convalescent from a
long or debilitating illness orthostatic hypotension
may result from the deficient support to the vascu
lature afforded by the weakened musculature Treat
ment consists of progresssve esercises abdomnal bind
ers and cphedrine

·5 CARDIOGENIC HYPOTENSION Hypotension resulting from a reduced cardiac out put secondary to diminished venous return (second ary shock) or reduced peripheral resistance (primary shock) has been discussed already A third cause of sudden lowering of the blood pressure is that due to the heart itself Cardiac output may fail because of permanent structural changes due to disease processes (rheumatic fever arteriosclerosis etc) or transient functional influences (anoxia during anesthesia tachy cardia etc) ENDOCARDIAL CAUSES A sudden fall in blood pressure due to aortic or mitral stenosis may occur during exertion or the stress incident to surgical operation The increased meta bolic demands of the body are met ordinarily by an increase in the blood supply to the tissues through an increase in both peripheral vasodilatation and car diac output However in aortic or mitral stenosis the cardiac output cannot increase because of the im pediment to the flow of blood through the constricted valves The increased peripheral vasodilatation re mains unopposed and hypotension ensues Furthermore in patients with aortic or mitral steno- 53 ·54 Hypotension Sis reflex tachycardia brought on by such stimul as exertion and operative procedures (incubation vis ceral manipulation etc) shortens the diastolic filling time Diminished cardiac output results which in turn leads to a fall in blood pressure The recognition of this cause of hypotension during surgery depends on an adequate preoperatre history and physical examination The occurrence of syn cope on exertion and the presence of the character astic systolic thrill and murmur at the base of the heart are the principal diagnostic features The mur mur of aortic stenosis is heard best at the end of ex piration with the parent leaning well forward In patients with mitral stenosis the characteristic apical diastolic murmur and a history of rheumaus fever are rarely absent In contrast with those with aoruc stenosis it usually occurs in the younger age τσμp Treatment When blood pressure falls dusing op eration in such patients 11 may be restored by (1) moeasures which increase peripheral resistance 16 norepinephrine and (2) those which decrease heart rate such as prostigmine The latter drug augthen's the infuence of the agus in slowing the heart Atropine scopolamine and similarly acting vagal de pressant drugs should not be used preoperatnely Pain apprehension asıxsety and excitement which in crease the heart rate should be avoided and such sumuli eliminated by the use of morphine and bas bicurales preoperatively Many patients with mitral or aortic stenosis can be benefited now by cardiac surgery Dufing opera uon on the heart itself the above considerations apply with even greater force ·Cardiogenic Hypotension 55 cardiac output PERICARDIAL, CAUSES Large pericardial effusions of sudden onset often cause severe compression of the heart and a decrease in the venous retura resulting in a diminution of The effusion may be hemorrhagic due to trauma or serous due to infections usually rheumatic fever or more rarely tuberculosis The symptom complex of cardiac tamponade us pathogno monic and consists of a rapid decline in blood pressure with dyspnea and engorgement of the cervical veins and the liver On percussion the area of car diac dallness is increased Auscultation reveals de creased heart sounds and often the presence of a peri cardial friction rub A roentgenogram shows a diffuse enlargement of the cardiac shadow Electrocardio graphically there is a decreased amplitude of the QRS complex (Fig 3) مالستالين wh b) a normal FICURE 3 Treatment consists of pericardial paracentesis of ligation of a ruptured vessel is required surgical inter vention is necessary CARDIAC ARRHYTHMIAS Disturbances in cardiac rate and rhythm or cardiac arrhythmias as they are called are frequent manifesta ·56 Hyporession tion of structural changes in the beast due to discase During operation when factors such as anora che toxic effects of anesthetic agents or stimul arising from the handing of scera way be active arrhyth mas may start as a result of such functional factors in a normal heart in either case whether due to permanent pathologic changes or transient physio logic influences the arrhythmia may lead to hyporea sion If the cause is not removed quickly or if the proper drugs are not used immediately the lowered blood pressure may lead to dire consequences Nost of the archychmias that may occur during operation and are serious enough to cause hypotension can be recognized readily and treated It is important there fore that surgeon and anesthetist as well as internese be familiar with them Classification It ss customary ta classiły the cardiac arrhythmias according to whether the disturbance (in rate or rhythm) is that of impulse sottration or im pulse conduction A depression of the normal rhythm inmated at the sinys node may result in sinus brady cardia or sinus arrest which of sufficiently prolonged may cause hypotension and in rare instances sudden death Originally called by Sir Thomas Lewys the vasovagal syndrome the mechanism resulung in fall of blood pressure dizziness and syncope is due to a wide variety of Caccors including psychic stimula digt talis certain infectious diseases (influenza virus pneu monia typhoid) catonid sinus pressure and anesthesia The clectrocardiogram as characteristic consisting of a prolongation of normal complexes as shown as Fig ure 4 In operations especsally in the region of the neck

·Cardiogenic Hypotension
57
hah
FIGURE 4
that may stimulate the carotid sinus reflex and induce
vagal slowing atropine banthine or similarly acting
parasympatholytic drugs should be administered pre
operatively to paralyze the vagus
Tachycardia Paroxysmal tachycardia of auricular
or ventricular origin is a disturbance of impulse ini
tration in which the arrhythmia is initiated in an
ectopic focus in either the auricle or the ventricle or
more rarely the auriculoventricular node If the
chycardia persists long enough there may result a
decrease in cardiac output and a fall in blood pres
sure
AURICULAR TACHYCARDIA In paroxysmal auricular
tachycardia the auricular and the ventricular rates
are regular and constant varying from 150 to 250
per minute The electrocardiographic evidence con
sists of absent or abnormal P waves with otherwise
normal complexes (Fig 5)
VENTRICULAR TACHYCARDIA Ventricular parox
ysmal tachycardia is a less common but more serious
hahahahah
FIGURE 5

·58 Hypotension form of arrhythmix It may occur under a variety of circumstances Among the drugs that may cause at are even those which are used for the treatment of heart disease such as digitalis quinidine and procaine amide hydrochloride (Pronestyl) Others are Dılan tin tetraethylammonium chloride and the central nervous stimulant used in the treatment of barbitu rate poisoning sikethamıde (caffeine amphetamine coramine mixture) Potassium intoxication such as may occur fol lowing an incompatible transfusion reaction or in acute renal failure may cause arrhythmsas Potas ssum honever when sts level in the blood has been depressed below normal as a result of overdosage of digitalis is useful as an antiarrhythmic agent for the treatment of the digitalis induced arrhythmias Anxiety has been shown to cause ventricular tachy cardia It has been suggested as a possible explana tion for cases of sudden death in individuals with normal hearts Cardiac catheterization may be a cause of serious arthylhraras Several cases of premature ventricular systoles ventricular tachycardia and fibrillation have been reported following this procedure it is not uncommon in patients with severe myocardial disease especially after myocardial infarction The occurrence of ventricular arrhythmias during major surgery is apparently on the increase They occur not only in those with diseased but also in those with normal hearts and in the young as well as in the old Arrhythmias of ventricular origin arse dur ing operations in the thorax on pulmonary and car diac structures and sn the region of the great ressels ·Cardrogenic Hypotension 59 with their multiple cardio-inhibitory and accelerator reflex potentials They also occur in operations in other areas and on other systems of the body No single factor is responsible for the arrhythmia However the combination of factors that conspire to cause ventricular arrhythmias and lead to the dreaded ventricular fibrillation and cardiac arrest may be sum marized as follows the patient especially when some degree of heart disease is present the anesthesia-mul tiple agents depth of anesthesia intubation anoxia the operation-especially cardiac and thoracic surgery Of all the factors anoxia and an accentuated vasovagal reflex are perhaps the most important Diagnosis The diagnosis of ventricular tachycar dia is usually difficult without the aid of the electrocardiogram However it should be suspected at the bedside or in the operating room in patients who show failure of vagal stimulation to produce an ef fect a jugular pulse rate slower than the ventricular rate irregularities of length of cycle and changing intensity of the first heart sound The electrocardio gram is as in Figure 6 Treatment Procaine amide (Pronestyl) is a valu able drug for the control of ventricular arrhythmia It may be given orally intramuscularly or intrave nously When given intravenously it may cause hypo vi FIGURE 6 ·att anti 60 Hypotension tension if too large a dose is used the dose should not exceed 100 mg per minute Norepinephriae will counterati the hypotensive effects of Pronestyl over dosage By mouth the usual dose u 200 to 500 mg repeated in 2 hours but much larger doses may be needed in emergency situanons it is best to use the intravenous rouie cautiously and to have norep nephrine handy Quinidine much older than Pronesty! arrhythmic drug especially in the creacment of auricu iar fibrillation is also a valuable agent for the treat meni of the ventricular variety It may be adminis tered intravenously with safety of certain precautioris are observed The drug in the form of the lactarc is dilured 28 100 cc of glucose and administered at the rate of 2 c. per minute Frequent ECGs are taken so that the infusion may be stopped at the first evi dence of toxicit) and so that it may be discontinued immediately after normal rhythm has been restored Digitalss the oldest of all annarrhythmic drugs has a more limited field of usefulness in the therapy of this disorder However in the treatment of the emer gencies due to auricular fibrillation either acute che culatory collapse or congestive failure certain intra venous preparations are of great value Lanatoside C acetyl strophanthidin and ouabain are the intravenous digitalis preparations most commonly used in emer gencies because of thest rapidity of action and rapid elimination Quabain is used at the Royal Victoria Hospital for such cardiac emergencies in a dosage of 05 mg follaned unhin an hour by 0 23 ng it needed as an intravenous soluison of 100 cc of glucose con taining the drug ·Cardiogenic Hypotension 61 The routine preoperative use of quinidine or Pro nestyl to prevent arrhythmias occurring is inadvisable because of their depressant effect on the myocardium and the consequent increased susceptibility to cardiac arrest Their use should be reserved for the treat ment of arrhythmias as they arise when by intravenous or intracardiac injection they act immediately Digi talis may be dangerous if used in the presence of ven tricular fibrillation Ventricular Fibrillation CAUSES One of the most serious of the cardiac arrhythmias is ventricular fibril lation It is an irregularity of increased rate due to the continuous initiation of impulses by an ectopic focus in either ventricle (Fig 7) The causes are coro. nary arteriosclerosis digitalis intoxication anesthesia especially cyclopropane in excess and other factors leading to anoxia during operation as already men tioned It may be preceded by ventricular tachycardia and if not treated immediately it may terminate fa tally in cardiac arrest Therefore the prompt recog nition and treatment of hypotension as a manifesta tion of this form of cardiac arrhythmia is of utmost importance DIAGNOSIS A sudden and profound fall in blood pressure during an operation always should arouse suspicion of ventricular fibrillation or cardiac arrest mm FIGURE 7 Why ·62 Hypotension However the other causes of acute hypotensionblood loss vagal arrest vascular dilatation-should be considered first It may be that only by an ECG tracing can ventricular fibrillation or standstill be confirmed or ruled out Or it may be that to wait for confirmatory evidence of the ECG is to wait too long There are dangers in both courses of action Opening the chest with its attendant trauma and in fection may place an unsupportable burden on an already seriously all patient On the other hand delay in doing just that may jeopardize his chances for survival TREATMENT A middle course would seem to be as wise as it is valorous and consists of the following procedure for the treatment of cardiac arrest (1) Re move excess anesthesia by hyperventilation with oxy gen (2) Compress the heart from without the thorax through the diaphragm (3) Inject 10 cc Caci 10 per cent or 1 cc. epinephrine 1 1000 into the left ventricle through the chest wall In many cases this will suffice to restore normal rhythm The treatment of ventricular fibrillation is less sat isfactory than that for cardiac arrest It consists of (1) The intracardiac injection of 10 cc procaine 10 per cent to produce standstill and then manual com pression to maintain circulation until the heart beats normally (2) Return of normal heart beat is aided by CaCl and epinephrine (3) If the chest has been opened the aorta should be compressed to help main tain cerebral and coronary circulation and also aid in the flow of the intraventricularly injected drugs into the coronary circulation (4) The use of an elec ie ·Cardiogenic Hypotension 63 trical defibrıllator may be required if these measures fail Throughout the period during which resuscitative measures are being applied to the heart artificial res piration must be given also to ensure adequate oxy genation and transfusions continued at a more rapid rate to maintain an adequate venous return to the heart Heart Block The disturbances of impulse conduc tion that are important in causing hypotension are sinoauricular block and auriculoventricular block The former is an interference in the transmission of the impulse originating in the sinoauricular node The physiopathology of this arrhythmia is the same as for sinus bradycardia and sinus arrest described previously In sinoauricular block however the in terference in impulse transmission is due to struc tural changes in the heart Not only the manifesta trons but also the diagnosis and the treatment are those already described for sinus arrest Auriculoventricular block is an interruption of im pulse conduction at the AV node It may be tem porary when occurring during infection or anesthesia or permanent due to arteriosclerosis syphilis rheu matic fever or hypertension Complete heart block gives rise to the phenomenon known as the Stokes Adams syndrome This consists of episodes of hypotension syncope and convulsions due to ventricular asystole Although the SA node imitates normal im pulses they are blocked at the AV node Since they are not conducted into the ventricles the latter ini tiates its own rhythm in an ectopic focus either in ·64 Hypotension ah he FICURE 8 the preser the junctional tissue or in the left or the right sen tricle At times ventricular asystole takes place (Fig 8) Cardiac arrest may occur also in heart block due to disease of the auriculoventricular conduction system or to carotid sinus hypersensitivity The treatment of heart block consists of the administration of ephed rine epinephrine and related compounds Atropine may be useful in dımınishing vagal sensitivity In of heart block quinidine and Pronestyl are dangerous drugs and should not be used because they may induce fibrillation of the ventricle by de pressing the basic idioventricular pacemaker But as already mentioned in patients with previously normal conductoe mechanisms who develop ventricular fibril lation eg during surgical operation quinidine or Pronestyl is the drug of choice In complete block the rate usually averages about 40 per minute and the rhythm is regular Electrocardiographically the P waves have no uniform uime relationship to the QRS complexes which are aber rant The prevention of attacks is aided by ephed rine During an attack norepinephrine is used intra venously Myocardial Infarction The term medical shock has been used frequently to describe the clinical fea tures of severe myocardial infarction Present are all ·Cardiogenic Hypotension 65 blood 160 operation cyclo pressure 140 120 My 100 150 80 60 40 20 pulse 160 140 120 100 4 1 2 3 time(hours) FIC 94 The deleterious effects of preoperative medica tion with atropine in a case of mitral stenosis with hemolyuc anemia in which a splenectomy was performed Atropine prevented the vagus from counteracting the effects on the heart rate of the sympathetic stimuli induced by the opera tion Tachycardia ensued sith engorgement of the lesser circulation which was followed by inadequate filling of the leſt sentricle and hypotension ·64 Hypotension ہمالیہ he FICURE 8 the junctional tissue or in the left or the right sen tricle At times ventricular asystole takes place (Fig Cardiac arrest may occur also in heart block due to disease of the auriculoventricular conduction system or to carotid sinus hypersensitivity The treatment of heart block consists of the administration of ephed rine epinephrine and related compounds Atropine may be useful in diminishing vagal sensitivity In the presence of heart block quinidine and Pronestyi are dangerous drugs and should not be used because they may induce fibrillation of the ventricle by de pressing the basic idioventricular pacemaker But as already mentioned in patients with previously normal conductive mechanisms who develop ventricular fibril lation eg during surgical operation quinıdıne or Pronestyi is the drug of choice In complete block the rate usually averages about 40 per minute and the rhythm is regular Electrocardiographically the P waves have no uniform time relationship to the QRS complexes which are aber rant The prevention of attacks is aided by ephed During an attack norepinephrine is used intra venously Myocardial Infarction The term medical shock has been used frequently to describe the clinical fca tures of severe myocardial infarction Present are all rine

·Cardiogenic Hypotension
69
REFERENCES
1 Conference on Shock Syndrome Ann New York Acad.
Sc 55 345 1952
2 Days H A Shock and Allied Forms of Failure of the
Circulation New York Grune & Stratton 1949
s Frank Howard A Present-day concepts of shock New
England J Med 249 445 486 1953
4 Green Harold D ed Shock and Circulatory Homeosta
SIS Transactions of the first and second Macy con
ferences New York Josiah Macy Jr Foundation
1951 1952
5 Judson Walter E Hypotension physiologic mecha
nisms and treatment M Clin North America 37
1313 Sept 1953
6 Pulaskı E War wounds New England J Med 249
890 932 1953
7 Richards D W Nature and treatment of shock Cir
culation 9 606 1954
8 Weil PG Shock and blood transfusion in H E Mose
ley ed Textbook of Surgery St Louis Mosby
1952 Chap IV

·68 Hypotension TREATMENT Therapy consists of oxygen rapid act ing digitalis preparations and norepinephrine The operation des ised by Trendelenberg for treatment of pulmonary embolus has had very little success Per sistence in the use of symptomatic treatment espe cially vasoconstrictors may be rewarding Cardiopulmonary Causes Patients with pulmonary hypertensive disease may have episodes of hypotension during exercise or excitement At such times the in crease in pulmonary arterial pressure stimulates a vagal reflex resulting in slowing of the heart and arteriolar dilatation with a fall in systemic arterial pressure Other pulmonary causes of cardiocirculatory failure are acute cor pulmonale such as that due to tension pneumothorax or mediastinal shift due to hemor rhage etc pleural shock from therapeutic pneumothorax or thoracentesis and hyperventilation CONCLUSION The management of shock because of its emergency nature has been compared with the therapy of dia betic coma in that it is not enough to start treatment write orders and return later to see how the patient 15 progressing Some instances of cardiocirculatory failure present the most serious of all emergencies Probably no other conditions demand such resource fulness close supervision and sense of urgency during the entire period of treatment The effects of anoxia are so serious that in severe shock the period during which transfusions and other resuscitative measures may be effective is often measured only in minutes occasionally even in seconds but almost never in hours ·INDEX Achromycin therapy shock 40-41 Albumin as blood derivative 28 Allergy from transfusion 22 Anemia preoperative transfusions to prevent shock, 1? Anesthesia choice and use in prevention of shock 13 as etiologic factor fall in blood pressure at beginning of operation 13 hypotension from 39-49 cocaine 36 cyclopropane 37 41 ether 6 medication preanesthetic, uh Pentothal Sodium 36 pituitran preparations 36 37 prevention 41 spinal hypotension from 37 39 Antibiotics as therapy bacteremia 47 shock 40 to combat infection 18 Anxiety ventncular tachycardia from 58 Aorta resistance to blood flow central I mechanisms ? peripheral 1 2 Arrest cardiac 64 sinus hypotens on from 56 Arrhythmias cardiac arrest cardiac 64 cardiopulmonary causes 68 classification 56 57 fibrillation ventricular 61 63 heart block 63 64 hypotension from 55-68 infraction myocardial 6468 tachycardia See Tachycardia Artertotomy reduction of blood pressure by 50 Atropine therapy card ac arrese of prenperative ad nını trat on in mi tral stenosis with bemolytic anemia deleterious effects 65 Bacteremia hypotens on from 46-47 treatment 47 71 ·72 Index Barbiturate therapy in shock control of pain and apprehension 18 Block heart auriculaventricular 63 64 complete 63 hypotension from 63-64 sinoauricular 63 Blood coagulation defects preoperative anticipation to prevent shock 12 13 derivatives 26 29 albumin 28 fibrinogen (Parenogen) 28 29 plasma 28 suspensions platelet 27 28 Ted cell 26-27 dilution in shock 10 incompatibility as transfusion reaction 20 21 42 pathogenesis 20 21 rare factors and muluple transfusions 25 26 Rh factor 21 2 symptoms 90 42 treatment 21 loss at operation charts 15 16 measurement for prevention of shock 12 pressure diastolic maintenance maintenance in older age groups importance of 14 normal regulation 1 3 summary of factors 3 systolic production 1 Rh factor incompatibilities due to 24 22 subxutuios 29 31 advantages 30 31 transfusion See Transfusion Yolume reduction dehydration See Dehydration hemorrhage See Hemorrhage Brachycardia sinus hypotension from 6 Cardiogenic hypotension 53 69 cardiac arrhythias 55 69 arrest cardiac 61 cardiopulmonary causes 68 classification 56 57 fbrillation entricular 61 63 heart block 63 64 infarction myocardial 64 68 tachycardia Sec Tachycardia ·Index Cardiogenic hypertension-(Continued) Quses endocardial 53 51 treatment 54 pericardial 55 Catheterization carduc as cause of anbythmia 58 Causes of hypotens on 5 6 cardiogenic See Cardiogenic hypotension peripheral vascular dilatation See Peripheral vascular dilata tion reduced blood volume See Shock Chloroform as anesthetic agent hypotension from 37 41 Coagulation defects preoperative anticipation to prevent shock 12 13 Cocaine as local anesthetic agent bypotension from 36 Control of hypotension during surgery 49 51 complications 50 51 contraind cations 50 51 induction 50 Cortisone therapy for shoch operative or postoperative 44-45 Cyclopropane as anesthet c agent with piluitrin preparations hypotens on from 36 Dehydration from diarrhea reduction of blood volume from 34 preoperative correction to prevent shock 12 reduct on of blood volume from 3 34 treatment 33 34 Naci hypertonic 33 34 isotonic 33 solutions contain ng potass um 84 role in produang shock with hemoconcentration 40 from yomt ng reduction n plasma volume 32 Digitalis therapy nfarction myocardial 68 tachycard a ventricular 61 Drugs as therapy for hypertension produang hypotension 48-49 hypotension from 43-49 anaphylactic reactions 49 barb tu ate overdosage and po soning 49 vasopressor for bypotension in operative or postoperative periods 37 43 41 Edema from transfus on 22 Embolism from transfus on introduct on of air 22 23 Empyema shock due to reduction n plasma yolume 31 3 Ephedrine therapy card ac arrest 64 Epinephnge therapy cardiac arrest 64 ·74 Index Ether as anesthetic agent hypotension from 30 Ethyl chlonde as anesthetic agent hypotension from 37 Fibrillation ventricular 61 63 causes 61 diagnosis 61 62 treatment 62 63 Fibrinogen (Parenogen) as blood derivatiye 28 29 Heart arrest 61 block hypotension from 63-64 infarcuon myocardial 64 68 innervation 2 Hemodilution in shock 10 Hemolysis post transfusion jaundice from 2396 causes 23 24 rare factors and multiple transfusions 2.26 Rh factor 25 26 prevention 24 pretransluston jaundice from 23 Ilerophila preoperative anupation to prevent shock 12 13 Hemorrhage minimal from careful surgrcal technic in preven ton of shock 13 postoperative hypotension from 13 re-operation for correction of 14 Hemostasis careful surgical technic in prevention of shock 13 Hormones adrenocortical in treatment of shock 44 45 Hypertension drug therapy hypotension from 48 49 Hypoprothrombinemia preoperative anticipation to prevent shock 12 13 Infection hypotension from bacteremia 46-47 treatment 47 contaminated infusion fluids 47-48 wounds 46 role in produang shock with hemoconcentration 40 Jaundice after transfusion 23 OG causes 23 G hemolysis post transfusion 23 26 pretransfusion 23 rare factors and mulupie transfusions 23 24 Rh factor 24 25 XTUD homologous " prevention 24 ·Index 75 Morphine therapy in shock control of pain and apprehension 18 Neosynephrine as therapy shock after spinal anesthesia 38 39 Norepinephrine therapy hypotension during operation 54 infarction myocardial 68 in shock 18 40-41 tachycard a ventncular 60 Obstruction intestinal shock due to reduction in plasma volume 32 Orthostatic hypotension 51 52 Oxygen therapy infarction myocard al 68 Paracentesis pencardial for hypotension 55 Parenogen (fibrinogen) as blood derivative 29 Pemphigus shock due to reduction in plasma volume 31 Penicillin therapy anaphylactic reactions with hypotension 49 bacteremia 47 shock 40 41 for infection 18 Pentothal Sodium as anesthetic agent hypotension from 36 Peripheral vascular dilatation causing hypotension 3, 52 abdominal emergencies 46 adrenocortical hormones in treatment of shock 44-45 anesthes a See Anesthesia hypotension from control dunng surgery 49 51 compl cations 50 51 contraindications 50 51 induction 50 drugs 48 49 infection, 46-48 bacteremia 46-47 treatment 47 contaminated infusion fluids 47 48 wounds 46 orthostatic 51 5% surgical procedures 49 44 interference with vasoconstrictor mechanism 43-44 manipulation of viscera 42 43 position of patient 42 treatment vasopressor drugs 41 Periton tus shock due to reduction in plastoa volume 31 Pituitrin preparations wth cyclopropane as anesthetic agent, hypotension from 36 37 ·76 Index Plasma as blood derivative 28 contamination hypotension after infusion 47-48 expanders 29 $1 loss 31 $2 causes burns 31 crush syndrome 31 exudation purulent acute 31 32 obstruction 32 vomiting dehydration from 32 shock from 31 32 treatment 92 Poncocaine as anesthetic agent hypotension from 37 Position ficad low in shock 19 Posture hypotension from 512 Potassium intoxication ventricular tachycardia from 58 59 Procline anaide (Proneseyl) therapy tachycardia ventricular 59 60 Prostigmine therapy hypotension during operation 54 Pyrogenic reactions from transfusion 21 22 Quinidine therapy tachycardia ventricular 60 Re operation in prevention of shock 13 14 Shock 7 34 anatomy pathologic li causes failure to compensate blot loss with adequate se placement charts 34 35 clinical features 7 8 consequences 10 11 definition 7 delayed 1011 diagnosis 78 IrTeversible 31 medical 61-67 physiopathology 8 10 hemodilution 10 metabolic changes 9 vasoconstriction 9 10 prevention 11 14 antiapation of coagulation defects 12 13 carelul surgical technic 13 choice and use of anesthetic agent 13 correction of dehydration 1? measurement of blood lose 12 ·Index 77 Shock-(Continued) prevention (Continued) preoperative transfusions in anemia 12 re operation 13 14 treatment 14 19 adrenocortical hormones 44 15 apallary measures 18 19 transfusion 14 18 charts 15 16 intra arterial 18 intravenous 10 overloading the circulation 16 17 signs 17 Steno is mitral with hemolyuc anemia deleterious effects of pre Operative med cation with atropine 65 Stokes Adams syndrome 63 64 Streptomycin therapy bacteremia 47 Streptomycin therapy shock 40 41 for infection 18 Surgical procedures hypotension from 42 44 interference with va oconstrictor mechanism 43 41 position of patient 42 treatment vasopressor drugs 44 visceral mampulation 42-43 Surgical technic carefut in prevent on of shock 13 Tachycardia 57 61 from atropine preoperative administrat on in m tral stenosis with bemolytic anemia 60 auricular 57 compensating in m tral stenosis hypotension from 66 ventricular 57 61 causes 58 59 d agnosis 59 etiology 58 59 inadence 58 59 treatm nt 59 61 Transfusion contam nated Au ds hypotension from 47-48 nadequate dunng operation hypotension from 66 intra arterial for shock 18 intravenous for shock 17 18 laboratory aspects 19 20 muluple and rare factors jaund cel om 2n react ons and complicat ons 2026 allergy 92

·78 Index
Transłuşton (Continued)
reactions and complications--Conusued)
edcma 22
embolism 22 23
sncompatibility 20 21
pathogenesis 20 21
symptoms 20
treatment 23
jaundice See Jaundice
pyrogenic 21 22
1ests pnor to 19 20
as treatment for shock 1418
overloading the arculation 16-17
Trichlorethylene as anesthetic agent hypotension from 37
Urucaria from transfusionss 22
Vasoconstriction in shock 9 10
Vasoconstrictor drugs as therapy sa shock 18
Vasovagal syndrome 56
Wounds infection hypotension from 18

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