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Evaluation of the Cardiac Status of the Poor Risk Patient
Evaluation of the Cardiac Status of the Poor Risk Patient DAVID I. RUTLEDGE
ff
ONE of the striking features of modern surgery is the increased age of the average patient coming to surgery in a general hospitaL When one reflects on the advances in surgery wherein the problems of infection, technique and anesthesia have gradually been solved it is obvious that the major problem now confronting the surgeon, once the diagnosis is established, is "What kind of a risk is the patient?" The causes of the increased age of patients coming to surgery are not pertinent to this discussion, but because of the increased age, the cardiovascular system is assuming a primary role when the risk is to be evaluated. Fortunately for the patient, it is rarely necessary for the cardiologist to say "You need surgery but your heart won't stand it." One of the first steps should be to evaluate the patient for known cardiovascular defects. This should begin with a careful history to elicit any symptoms of cardiovascular disease; next, the physical examination with particular reference to the size and rhythm of the heart and the presence or absence of murmurs. Any signs of congestive failure or diminished myocardial reserve are very important in this regard. As far as laboratory procedures are concerned, it is important to know the hemoglobin value and to be certain that it is within the normal range. A roentgenogram of the chest should be carried out and an electrocardiogram, although not absolutely essential, is desirable. A negative electrocardiogram or chest roentgenogram may be exceedingly useful from a comparative standpoint if postoperative complications develop. This does not mean that every patient coming to surgery must have an electrocardiogram, but if there is any question as to the cardiac status of the patient, electrocardiography should be carried out. If no signs of cardiovascular disease are detected, it is fair to assume that the risk of the patient is the risk of the surgical procedure itself. Modern anesthesia, with its abundant oxygen supply, is not likely to make a latent cardiac condition a problem. When the physician is confronted with a cardiac patient in whom sur597
598
David I. Rutledge
gical intervention is contemplated, there are a number of factors which should influence the decision. It is assumed that the skill of the surgeon and of the anesthesiologist is the greatest that is available. The first of these factors is, how does the surgical condition influence the future of the patient? It is obvious that if the patient has a cancer or perforated ulcer, the cardiac condition immediately assumes a secondary role but what about the gallbladder that produces moderate symptoms, or an asymptomatic hernia? In such cases the risk of surgery must be carefully weighed. The physician might also ask how the surgical condition affects the cardiac status. I have in mind particularly cholecystitis in the presence of coronary artery disease. The second factor is, what is the life expectancy of the patient without operation? I know of nothing more difficult to estimate than the life expectancy in heart disease. If the surgical condition is creating a problem, the physician is entitled to take considerable risk. The question, what is to be accomplished by surgery, also needs to be answered. If the operation is to be purely palliative, there should be definite need for palliative measures. Finally, what are the risks of operation and what steps can be taken to reduce them? It is this subject that is the primary concern of this paper. CONGENITAL HEART DISEASE
The group with congenital heart disease is not large considering the over-all incidence of heart disease, and fortunately most of these patients are not poor operative risks. Nevertheless, this is an important group because a great deal can be done for many of these patients. Patients with coarctation of the aorta and patent ductus arteriosus are, in general, good operative risks. There may be certain problems at the time of surgery but usually these are technical and managed without difficulty by the experienced surgeon. If a patient with patent ductus arteriosus has subacute bacterial endocarditis, this condition should be corrected with antibiotics if possible, and a period of two to three months allowed to elapse after the blood stream becomes sterile. Also, if there is any evidence of left ventricular failure this should be corrected before surgical intervention is contemplated. The condition of patients in the cyanotic group, primarily the tetrology of Fallot, is somewhat more alarming, but even so, these patients are amazingly good operative risks. This is because the anesthetist can administer oxygen in high concentration along with the anesthetic agent. There are various degrees of cyanosis with tetrology of Fallot and in general the risk increases with the cyanosis. When the anastomosis is satisfactorily performed there is little to fear so far as the anesthesia is concerned, but if for technical reasons it is impossible to complete the anastomosis, these patients do not tolerate well the major risk of opening the thoracic cavity. One of the hazards in this type of operation is the
Cardiac Status of Poor Risk Patient
599
danger of intravascular clotting. With the cyanosis these patients tend to have an increased hemoglobin and red blood cell count with markedly increased viscosity of the blood. There is no satisfactory way of diminishing this tendency with anticoagulants and yet keep the patient safe from excessive bleeding in the postoperative period. The physician should be certain, however, that the patient is well hydrated both before and after operation. RHEUMATIC HEART DISEASE
I shall not discuss here the rheumatic patient who is to undergo valvular surgery, as this subject is being covered elsewhere in this volume. A well compensated rheumatic heart is not a contraindication to surgery and usually does not increase the risk of operation. Precautions should be exercised in the presence of infection. When auricular fibrillation is present it is presumed that this condition will be under digitalis control. Patients with mitral stenosis and regular rhythm sometimes have difficulty if tachycardia develops as the right ventricle pumps more blood into the pulmonary circulation than can return through the stenotic mitral valve. Sudden death is always a possibility in patients with aortic stenosis. I know of no good way of combating this but the surgeon should inform the patient's relatives of the danger in advance. Patients with rheumatic heart disease and congestive heart failure should be properly prepared for surgery. If possible, surgery should not be undertaken for a period of three to six weeks from the time compensation is restored. Preparation should consist of sodium restriction, adequate rest, proper use of digitalis, and the use of mercurial diuretics to eliminate excessive fluid in the body. If mercurial diuretics are to be used for any length of time, the electrolyte balance should be carefully determined. Some patients with rheumatic heart disease are known to have paroxysmal episodes of fibrillation or flutter. The prophylaetic liSP, of quinidine should be considered in the presence of such a history. THYROCARDIACS
Formerly, the thyrocardiac ,vas one of the great problems ill surgery of the thyroid gland. However, these patients respond so well to the various antithyroid drugs that at the present time this condition does not constitute a contraindication to surgery. In fact, operation prociw:cti a highly desirable effect on the myocardium. When these patients are properly prepared, the mortality rate is 2 per cent, as compared with the mortality rate of 10 per cent before antithyroid drugs were available. For the last three years tracheotomy has been performed routinely at operation on all thyrocardiac patients and no death has occurred during this interval of time.
600
David I. Rutledge HYPERTENSION AND CORONARY DISEASE
Patients with hypertension and coronary disease constitute the largest group and one of ever-increasing importance. It is in this group that operations on the gallbladder, the prostate or for repair of hernia are performed with increasing frequency. Although each individual case must be evaluated, certain generalizations can be made. 1. Hypertension, even if severe, increases little the risk of major surgical procedures. 2. Operation should not be attempted in the presence of congestive heart failure. This does not mean that the heart failure cannot be corrected and the necessary surgical procedure carried out later. Again, a waiting period of three to six weeks after heart failure is corrected is desirable. 3. Surgery should not be attempted within ninety days of a coronary thrombosis. Here again, emergency procedures may have to be carried out. It is estimated that about ninety days are required for an infarct to completely heal. The heart will tolerate surgical intervention better after that has been accomplished. 4. Surgery should be limited in scope. The surgeon should carry out the indicated procedure and finish as quickly as possible. Extending the operation or undertaking procedures not contemplated, which might be justified in an ordinary individual, should be discouraged in this group of patients. 5. Arrhythmias, primarily auricular fibrillation, should be controlled. Practical Stcps to Reduce the Risk of Operation
I should like to consider next the risks of surgery and steps that can be taken to lessen them when surgical intervention is necessary. It is assumed that the patient will have a suitable preoperative medication before going to the operating room. It is advisable to have the anesthetist talk to the patient the night before surgery so that he can allay any anxiety in so far as possible. Most patients express more concern about the anesthesia than about the operative procedure. In general, the risks can be divided into three groups. The first is cardiac arrhythmias. Extrasystoles are one of the most commonly encountered arrhythmias in anesthesia, and especially if cyclopropane is used. If the extrasystoles are infrequent, nothing need be done about them. If they become frequent, administration of cyclopropane should be stopped because of the danger of producing ventricular tachycardia. If the ventricular extrasystoles become so frequent that the presence of ventricular tachycardia seems imminent, steps should be taken to control them. Either quinidine or Pronestyl is useful in this situation. Occasionally a true ectopic arrhythmia such as paroxysmal auricular
Cardiac Status of Poor Risk Patient
601
or nodal tachycardia will develop. Fortunately, most of such arrhythmias are of short duration. If they are persistent they can usually be controlled by pressure on the vagus nerve. If the attack persists, the use of either quinidine or Pronestyl should be considered. In general, quinidine is more useful for the arrhythmias arising in or above the A-V node. Auricular fibrillation and auricular flutter are somewhat more serious and common than the foregoing. Established auricular fibrillation that is properly controlled presents no problem but the heart that suddenly develops this arrhythmia during the surgical procedure presents an unfortunate situation. This complication is particularly prone to develop during operations on the chest. Probably the drug most effective in controlling auricular fibrillation and flutter is quinidine sulfate. Certain contraindications to the use of quinidine should be borne in mind. The first of these is a known idiosyncrasy to quinidine or quinine, the second is chronic auricular fibrillation, the third is congestive heart failure, and the fourth is heart block, either partial, complete or bundle branch block. For the most part, however, quinidine can be administered with relative safety. The method of administration needs some discussion. It should be remembered that quinidine is rapidly excreted and so the oral route is practical only in short procedures. The drug can be given along with the preoperative medication in such cases and not infrequently we do so. Quinidine is available in ampules for parenteral injection; if its use is thought to be desirable, it can be injected intramuscularly one hour before operation. It can also be used intravenously, but this will rarely be necessary. The dose is 0.5 to 0.6 gram (6 to 9 grains). If the operation is prolonged, a second dose can be given three hours later in the operating room. Pronestyl is a derivative of procaine and is especially useful in controlling ventricular premature beats or ventricular tachycardias. Pronestyl can be given orally or intravenously. The intravenous dose is 2 cc. (200 mg.) per minute, the required dose being between 2 and 10 cc. Sometimes the blood pressure may drop alarmingly when the drug is given intravenously. When the danger of congestive heart failure exists, these patients should be prepared for surgery by restriction of sodium preceding the operation and if there is any indication of retain~ fluid it is wise to administer a mercurial diuretic the day before operation. We use Thiomerin, a mercurial diuretic that can be given subcutaneously in doses of 1 to 2 cc. Considerable caution should be exercised in regard to the matter of intravenous fluid in the postoperative state. Surgeons need to recall that a liter of saline solution contains 9 grams of salt, and in these days of low sodium diets we are talking in terms of milligrams. Saline should be avoided during and after operation, and 5 per cent dextrose should be used instead. Even this should be administered slowly and probably not to exceed 2 liters in the first twenty-four hours. An edi-
602
David I. Rutledge
torial* in the New England Journal of Medicine contained a pertinent statement in this regard, "That which is lost, whether it be whole blood, water, chloride or protein, should be replaced as accurately as possible, no more, no less." The routine administration of digitalis preparations before operation is still a debated question. The disadvantage of the use of digitalis routinely is its tendency to produce arrhythmias, especially if cyclopropane is to be employed. The only patients whom we routinely digitalize in the absence of definite indications are middle-aged or elderly patients with carcinoma of the esophagus. These patients often have troublesome tachycardia in the postoperative period. Whenever there is any doubt regarding the myocardial reserve I prefer to digitalize and avoid the use of cyclopropane. Perhaps the greatest hazard of all and the one most difficult to prevent or manage when it occurs is acute coronary insufficiency, possibly with myocardial infarction. In many cases it cannot be prevented. However, certain precautions should be taken. One might ask how the presence of myocardial infarction is recognized when the patient is under anesthesia. The anesthetist usually suspects this condition when the blood pressure continues to drop, resisting all attempts to elevate it, and the pulse rate increases. Certain precautions should be taken in an attempt to avoid acute coronary insufficiency: (1) If anemia is present, it should be corrected preoperatively with transfusions, if need be, since anemia is one of the important predisposing factors. (2) If undue bleeding is expected the anesthetist should be prepared and not hesitate to administer blood in the operating room. (3) High concentrations of oxygen should be maintained during anesthesia. This procedure is routine with most anesthetists. (4) An attempt should be made to avoid wide swings in blood pressure, particularly hypotension. For this reason, spinal anesthesia should be used with considerable caution. The choice of anesthetic agents should be left to the anesthesiologist. It is important that the cardiologist not presume to tell the anesthetist what agent to use. The anesthetist should use the agent he is most skillful in handling. Anesthesia for cardiac patients will be discussed in another portion of this volume. THE MANAGEMENT OF CARDIAC EMERGENCIES DEVELOPING IN THE OPERATING ROOM
1. Extrasystoles are a common cause of concern to the anesthetist. If they occur only occasionally, nothing need be done about them. If they become frequent, administration of cyclopropane should be stopped if it is being used. As has been stated previously, quinidine or Pronestyl can be used if alarm arises.
* Cardiac contraindications to surgical procedures. New England J. Med. 241: 282 (Aug. 18) 1949.
Cardiac Status of Poor Risk Patient
603
2. A gradUally dropping blood pressure with an increased pulse rate usually means that the anesthesia is too deep. If it is lightened, the situation is usually corrected. If lightening the anesthesia does not correct the situation, one of the pressor drugs may be used to elevate the blood pressure. 3. Paroxysmal tachycardia has been discussed previously. 4. Carotid sinus syncope may occur during operations about the neck, especially the thyroid gland, and is a frightening experience. All pressure and tension should immediately be released. Procaine, 1 per cent, should be infiltrated into the region of the sinus before the operation is resumed. 5. Cardiac arrest is one of the most distressing situations to confront the surgeon and the anesthetist. The surgeon should check for the presence of pressure in the region of the carotid sinus, as many cases of cardiac arrest are actually carotid sinus syncope. Artificial respiration should be continued by the anesthetist, which can be done easily with the use of modern anesthetic machines. Epinephrine, 0.5 cc. of a 1: 1000 solution, in 5 cc. of 1 per cent procaine, should be injected into the left ventricle. Most important is the immediate,institution of cardiac massage. If the chest is open this can be done very quickly and efficiently. Occasionally the heart can be successfully massaged through the diaphragm but usually it is done more effectively if the chest is open. Cardiac massage should be continued; in one of our cases the heart resumed beating after twenty minutes and the patient made an uneventful recovery.
ff
ONE of the striking features of modern surgery is the increased age of the average patient coming to surgery in a general hospitaL When one reflects on the advances in surgery wherein the problems of infection, technique and anesthesia have gradually been solved it is obvious that the major problem now confronting the surgeon, once the diagnosis is established, is "What kind of a risk is the patient?" The causes of the increased age of patients coming to surgery are not pertinent to this discussion, but because of the increased age, the cardiovascular system is assuming a primary role when the risk is to be evaluated. Fortunately for the patient, it is rarely necessary for the cardiologist to say "You need surgery but your heart won't stand it." One of the first steps should be to evaluate the patient for known cardiovascular defects. This should begin with a careful history to elicit any symptoms of cardiovascular disease; next, the physical examination with particular reference to the size and rhythm of the heart and the presence or absence of murmurs. Any signs of congestive failure or diminished myocardial reserve are very important in this regard. As far as laboratory procedures are concerned, it is important to know the hemoglobin value and to be certain that it is within the normal range. A roentgenogram of the chest should be carried out and an electrocardiogram, although not absolutely essential, is desirable. A negative electrocardiogram or chest roentgenogram may be exceedingly useful from a comparative standpoint if postoperative complications develop. This does not mean that every patient coming to surgery must have an electrocardiogram, but if there is any question as to the cardiac status of the patient, electrocardiography should be carried out. If no signs of cardiovascular disease are detected, it is fair to assume that the risk of the patient is the risk of the surgical procedure itself. Modern anesthesia, with its abundant oxygen supply, is not likely to make a latent cardiac condition a problem. When the physician is confronted with a cardiac patient in whom sur597
598
David I. Rutledge
gical intervention is contemplated, there are a number of factors which should influence the decision. It is assumed that the skill of the surgeon and of the anesthesiologist is the greatest that is available. The first of these factors is, how does the surgical condition influence the future of the patient? It is obvious that if the patient has a cancer or perforated ulcer, the cardiac condition immediately assumes a secondary role but what about the gallbladder that produces moderate symptoms, or an asymptomatic hernia? In such cases the risk of surgery must be carefully weighed. The physician might also ask how the surgical condition affects the cardiac status. I have in mind particularly cholecystitis in the presence of coronary artery disease. The second factor is, what is the life expectancy of the patient without operation? I know of nothing more difficult to estimate than the life expectancy in heart disease. If the surgical condition is creating a problem, the physician is entitled to take considerable risk. The question, what is to be accomplished by surgery, also needs to be answered. If the operation is to be purely palliative, there should be definite need for palliative measures. Finally, what are the risks of operation and what steps can be taken to reduce them? It is this subject that is the primary concern of this paper. CONGENITAL HEART DISEASE
The group with congenital heart disease is not large considering the over-all incidence of heart disease, and fortunately most of these patients are not poor operative risks. Nevertheless, this is an important group because a great deal can be done for many of these patients. Patients with coarctation of the aorta and patent ductus arteriosus are, in general, good operative risks. There may be certain problems at the time of surgery but usually these are technical and managed without difficulty by the experienced surgeon. If a patient with patent ductus arteriosus has subacute bacterial endocarditis, this condition should be corrected with antibiotics if possible, and a period of two to three months allowed to elapse after the blood stream becomes sterile. Also, if there is any evidence of left ventricular failure this should be corrected before surgical intervention is contemplated. The condition of patients in the cyanotic group, primarily the tetrology of Fallot, is somewhat more alarming, but even so, these patients are amazingly good operative risks. This is because the anesthetist can administer oxygen in high concentration along with the anesthetic agent. There are various degrees of cyanosis with tetrology of Fallot and in general the risk increases with the cyanosis. When the anastomosis is satisfactorily performed there is little to fear so far as the anesthesia is concerned, but if for technical reasons it is impossible to complete the anastomosis, these patients do not tolerate well the major risk of opening the thoracic cavity. One of the hazards in this type of operation is the
Cardiac Status of Poor Risk Patient
599
danger of intravascular clotting. With the cyanosis these patients tend to have an increased hemoglobin and red blood cell count with markedly increased viscosity of the blood. There is no satisfactory way of diminishing this tendency with anticoagulants and yet keep the patient safe from excessive bleeding in the postoperative period. The physician should be certain, however, that the patient is well hydrated both before and after operation. RHEUMATIC HEART DISEASE
I shall not discuss here the rheumatic patient who is to undergo valvular surgery, as this subject is being covered elsewhere in this volume. A well compensated rheumatic heart is not a contraindication to surgery and usually does not increase the risk of operation. Precautions should be exercised in the presence of infection. When auricular fibrillation is present it is presumed that this condition will be under digitalis control. Patients with mitral stenosis and regular rhythm sometimes have difficulty if tachycardia develops as the right ventricle pumps more blood into the pulmonary circulation than can return through the stenotic mitral valve. Sudden death is always a possibility in patients with aortic stenosis. I know of no good way of combating this but the surgeon should inform the patient's relatives of the danger in advance. Patients with rheumatic heart disease and congestive heart failure should be properly prepared for surgery. If possible, surgery should not be undertaken for a period of three to six weeks from the time compensation is restored. Preparation should consist of sodium restriction, adequate rest, proper use of digitalis, and the use of mercurial diuretics to eliminate excessive fluid in the body. If mercurial diuretics are to be used for any length of time, the electrolyte balance should be carefully determined. Some patients with rheumatic heart disease are known to have paroxysmal episodes of fibrillation or flutter. The prophylaetic liSP, of quinidine should be considered in the presence of such a history. THYROCARDIACS
Formerly, the thyrocardiac ,vas one of the great problems ill surgery of the thyroid gland. However, these patients respond so well to the various antithyroid drugs that at the present time this condition does not constitute a contraindication to surgery. In fact, operation prociw:cti a highly desirable effect on the myocardium. When these patients are properly prepared, the mortality rate is 2 per cent, as compared with the mortality rate of 10 per cent before antithyroid drugs were available. For the last three years tracheotomy has been performed routinely at operation on all thyrocardiac patients and no death has occurred during this interval of time.
600
David I. Rutledge HYPERTENSION AND CORONARY DISEASE
Patients with hypertension and coronary disease constitute the largest group and one of ever-increasing importance. It is in this group that operations on the gallbladder, the prostate or for repair of hernia are performed with increasing frequency. Although each individual case must be evaluated, certain generalizations can be made. 1. Hypertension, even if severe, increases little the risk of major surgical procedures. 2. Operation should not be attempted in the presence of congestive heart failure. This does not mean that the heart failure cannot be corrected and the necessary surgical procedure carried out later. Again, a waiting period of three to six weeks after heart failure is corrected is desirable. 3. Surgery should not be attempted within ninety days of a coronary thrombosis. Here again, emergency procedures may have to be carried out. It is estimated that about ninety days are required for an infarct to completely heal. The heart will tolerate surgical intervention better after that has been accomplished. 4. Surgery should be limited in scope. The surgeon should carry out the indicated procedure and finish as quickly as possible. Extending the operation or undertaking procedures not contemplated, which might be justified in an ordinary individual, should be discouraged in this group of patients. 5. Arrhythmias, primarily auricular fibrillation, should be controlled. Practical Stcps to Reduce the Risk of Operation
I should like to consider next the risks of surgery and steps that can be taken to lessen them when surgical intervention is necessary. It is assumed that the patient will have a suitable preoperative medication before going to the operating room. It is advisable to have the anesthetist talk to the patient the night before surgery so that he can allay any anxiety in so far as possible. Most patients express more concern about the anesthesia than about the operative procedure. In general, the risks can be divided into three groups. The first is cardiac arrhythmias. Extrasystoles are one of the most commonly encountered arrhythmias in anesthesia, and especially if cyclopropane is used. If the extrasystoles are infrequent, nothing need be done about them. If they become frequent, administration of cyclopropane should be stopped because of the danger of producing ventricular tachycardia. If the ventricular extrasystoles become so frequent that the presence of ventricular tachycardia seems imminent, steps should be taken to control them. Either quinidine or Pronestyl is useful in this situation. Occasionally a true ectopic arrhythmia such as paroxysmal auricular
Cardiac Status of Poor Risk Patient
601
or nodal tachycardia will develop. Fortunately, most of such arrhythmias are of short duration. If they are persistent they can usually be controlled by pressure on the vagus nerve. If the attack persists, the use of either quinidine or Pronestyl should be considered. In general, quinidine is more useful for the arrhythmias arising in or above the A-V node. Auricular fibrillation and auricular flutter are somewhat more serious and common than the foregoing. Established auricular fibrillation that is properly controlled presents no problem but the heart that suddenly develops this arrhythmia during the surgical procedure presents an unfortunate situation. This complication is particularly prone to develop during operations on the chest. Probably the drug most effective in controlling auricular fibrillation and flutter is quinidine sulfate. Certain contraindications to the use of quinidine should be borne in mind. The first of these is a known idiosyncrasy to quinidine or quinine, the second is chronic auricular fibrillation, the third is congestive heart failure, and the fourth is heart block, either partial, complete or bundle branch block. For the most part, however, quinidine can be administered with relative safety. The method of administration needs some discussion. It should be remembered that quinidine is rapidly excreted and so the oral route is practical only in short procedures. The drug can be given along with the preoperative medication in such cases and not infrequently we do so. Quinidine is available in ampules for parenteral injection; if its use is thought to be desirable, it can be injected intramuscularly one hour before operation. It can also be used intravenously, but this will rarely be necessary. The dose is 0.5 to 0.6 gram (6 to 9 grains). If the operation is prolonged, a second dose can be given three hours later in the operating room. Pronestyl is a derivative of procaine and is especially useful in controlling ventricular premature beats or ventricular tachycardias. Pronestyl can be given orally or intravenously. The intravenous dose is 2 cc. (200 mg.) per minute, the required dose being between 2 and 10 cc. Sometimes the blood pressure may drop alarmingly when the drug is given intravenously. When the danger of congestive heart failure exists, these patients should be prepared for surgery by restriction of sodium preceding the operation and if there is any indication of retain~ fluid it is wise to administer a mercurial diuretic the day before operation. We use Thiomerin, a mercurial diuretic that can be given subcutaneously in doses of 1 to 2 cc. Considerable caution should be exercised in regard to the matter of intravenous fluid in the postoperative state. Surgeons need to recall that a liter of saline solution contains 9 grams of salt, and in these days of low sodium diets we are talking in terms of milligrams. Saline should be avoided during and after operation, and 5 per cent dextrose should be used instead. Even this should be administered slowly and probably not to exceed 2 liters in the first twenty-four hours. An edi-
602
David I. Rutledge
torial* in the New England Journal of Medicine contained a pertinent statement in this regard, "That which is lost, whether it be whole blood, water, chloride or protein, should be replaced as accurately as possible, no more, no less." The routine administration of digitalis preparations before operation is still a debated question. The disadvantage of the use of digitalis routinely is its tendency to produce arrhythmias, especially if cyclopropane is to be employed. The only patients whom we routinely digitalize in the absence of definite indications are middle-aged or elderly patients with carcinoma of the esophagus. These patients often have troublesome tachycardia in the postoperative period. Whenever there is any doubt regarding the myocardial reserve I prefer to digitalize and avoid the use of cyclopropane. Perhaps the greatest hazard of all and the one most difficult to prevent or manage when it occurs is acute coronary insufficiency, possibly with myocardial infarction. In many cases it cannot be prevented. However, certain precautions should be taken. One might ask how the presence of myocardial infarction is recognized when the patient is under anesthesia. The anesthetist usually suspects this condition when the blood pressure continues to drop, resisting all attempts to elevate it, and the pulse rate increases. Certain precautions should be taken in an attempt to avoid acute coronary insufficiency: (1) If anemia is present, it should be corrected preoperatively with transfusions, if need be, since anemia is one of the important predisposing factors. (2) If undue bleeding is expected the anesthetist should be prepared and not hesitate to administer blood in the operating room. (3) High concentrations of oxygen should be maintained during anesthesia. This procedure is routine with most anesthetists. (4) An attempt should be made to avoid wide swings in blood pressure, particularly hypotension. For this reason, spinal anesthesia should be used with considerable caution. The choice of anesthetic agents should be left to the anesthesiologist. It is important that the cardiologist not presume to tell the anesthetist what agent to use. The anesthetist should use the agent he is most skillful in handling. Anesthesia for cardiac patients will be discussed in another portion of this volume. THE MANAGEMENT OF CARDIAC EMERGENCIES DEVELOPING IN THE OPERATING ROOM
1. Extrasystoles are a common cause of concern to the anesthetist. If they occur only occasionally, nothing need be done about them. If they become frequent, administration of cyclopropane should be stopped if it is being used. As has been stated previously, quinidine or Pronestyl can be used if alarm arises.
* Cardiac contraindications to surgical procedures. New England J. Med. 241: 282 (Aug. 18) 1949.
Cardiac Status of Poor Risk Patient
603
2. A gradUally dropping blood pressure with an increased pulse rate usually means that the anesthesia is too deep. If it is lightened, the situation is usually corrected. If lightening the anesthesia does not correct the situation, one of the pressor drugs may be used to elevate the blood pressure. 3. Paroxysmal tachycardia has been discussed previously. 4. Carotid sinus syncope may occur during operations about the neck, especially the thyroid gland, and is a frightening experience. All pressure and tension should immediately be released. Procaine, 1 per cent, should be infiltrated into the region of the sinus before the operation is resumed. 5. Cardiac arrest is one of the most distressing situations to confront the surgeon and the anesthetist. The surgeon should check for the presence of pressure in the region of the carotid sinus, as many cases of cardiac arrest are actually carotid sinus syncope. Artificial respiration should be continued by the anesthetist, which can be done easily with the use of modern anesthetic machines. Epinephrine, 0.5 cc. of a 1: 1000 solution, in 5 cc. of 1 per cent procaine, should be injected into the left ventricle. Most important is the immediate,institution of cardiac massage. If the chest is open this can be done very quickly and efficiently. Occasionally the heart can be successfully massaged through the diaphragm but usually it is done more effectively if the chest is open. Cardiac massage should be continued; in one of our cases the heart resumed beating after twenty minutes and the patient made an uneventful recovery.