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The AJC in October 1960
The AJC in October 1960 RICHARD E. CLARK, MD The October 1960 issue of the AJC covered 155 pages, 135 of which were used for scientific articles. Twothirds of the issue (82 pages) was used for a symposium on anesthesia for cardiac surgery. One must recall that this was an emerging clinical speciality in an era of a mortality rate that was approximately 2O%.i The symposium had contributions by 14 centers then engaged in open-heart surgery. These reports came from Boston, New York, Los Angeles, Cleveland, Durham, Miami, Washington, D.C., Philadelphia and Baltimore. A major concern during this period was the myocardial depressant effects of the various anesthetic agents customarily used for other types of patients and operations. These anesthetic agents-diethyl ether, halothane, thiopental sodium and cyclopropane-were the principal agents being tested on isolated hearts, in dogs and in an uncontrolled nonrandomized way in patients. The additive effects of induction, premedication agents and relaxants also were studied. In the laboratory, it was evident that light anesthesia made little change in right ventricular stroke volume and left ventricular stroke work.2 Clinically, however, deeper planes of anesthesia were required and untoward effects were observed. A combination of ether and barbiturate and a parasympathetic antagonist caused a decrease in heart rate, an increase in stroke volume, and an increase in blood pressure and total peripheral resistance, with a mild to moderate decrease in cardiac output. Depressive effects particularly those of diethyl ether, cyclopropane and halothane were concentration-dependent. Each unit appeared to adopt special monitors for measurement of a variety of variables in cardiac surgery. Among these were a variety of signal conditioners and recorders for the measurement of the electrocardiogram, the electroencephalogram, and various pressures as well as an enormous effort for the measurement of whole blood pH, Pco~, and PO, and temperature in various locations in the body. Blood gas analyzers were in their infancy. These devices required an incredible amount of technical skill to calibrate both pH and PCO~ over a wide range. The physiologic importance of correction of values to 37°C had not been appreciated nor the fact that hypothermic animals became alkalotic.
Although rarely used today, electroencephalography occupied a major role in the measurement responsibilities of the anesthesiologist in 1960. The separation between cerebral hypoxemia and hypothermia was difficult, although it was clear in catastrophic cases that the electroencephalogram changed dramatically during the operation. An ear oximeter using infrared light was believed to be efficacious and was one of the earliest demonstrations of an effort toward noninvasive determination of the 02 content of the arterialized blood during cardiopulmonary bypass. Monitoring was achieved with devices that had been adapted from the cardiac catheterization laboratory and recorders used both heated styluses and mirrored galvanometry and light-sensitive paper. The conduct of cardiopulmonary bypass was of special interest because so many of the intraoperative and postoperative problems appeared to be associated with its use. Two general types of oxygenators were used: the screen (Gibbon) or the disc (Kay-Cross). Each required priming with large volumes of whole blood.3-7 Blood volume requirements for cardiac surgery caused enormous concern, and this led to a series of experiments and determinations by many centers of circulating blood volume by use of I-131 and chrominum-51 before, during and after cardiopulmonary bypass. The problems, in great part, could be traced to the fact that the extracorporeal circuit had a volume that was equal to or greater than the patient. Hemodilution with crystalloid prime was not thought possible with the devices in use until the laboratory work of Neptune et al demonstrated efficacy.3 These data from dogs and patients were not accepted readily by the clinical community for several years. The immediate postoperative interval was the most difficult for anesthesiologists, cardiac surgeons and intensive care unit nurses. It was quickly learned that volume-controlled ventilators were necessary and that a major characteristic of the immediate postoperative interval was an alveolar-capillary block, which was related to a phenomenon of water and protein extravasation into the pulmonary interstitium. This was later traced to the large volumes of unfiltered blood and crystaloid given in the prime and during the procedure. Although most heart-lung machines had arterial
701
702
AJC
25 YEARS
AGO
line filters, the pore size was large. The quantity and size of the solid microemboli in the stored blood and the perfusate were not appreciated. Postoperatively, low cardiac output was common. Whether or not the use of Melrose’s solution4 was responsible or the use of anoxic arrest was the cause were not answered in the symposium. Improved methods of protection of the heart were clearly needed, and either method was hazardous allowing precious few minutes for repair of complex lesions. The agent of choice for poor contractility was digitalis in the form of ovabain because of its rapid onset of action. Arrhythmia was a major problem with the early advent of closed- and open-heart surgery. Most arrhythmias were believed to be a result of inadequate oxygenation and carbon dioxide accumulation or were secondary to hypotention from blood loss or anesthetic agents. All reports emphasized that the minimal amount of anesthesia must be given and that careful attention to hyperventilation and avoidance of metabolic acidosis was mandatory. An arterial pH >7.45 was recommended regardless of temperature, and this was primarily done through hyperventilation, which was the hallmark of the management of early anesthesia. The era of open-heart surgery was just beginning. The Los Angeles group reported that anesthesia had been given over a 4-year interval to 164 patients who had undergone cardiac operation with the use of cardiopulmonary bypass and hypothermia and general anesthesia was given to 68 patients for the performance of a cardiac procedure.5 At that time, most patients (548) were anesthetized for cardiac catheterization. Of historical interest was the report from Cleveland in which 429 consecutive cardiac surgical patients had a hospital mortality rate for the Beck I operation of 6% over a 5-year interval, the last 200 patients having a 2% hospital mortality rate.6 This operation consisted of abrasion of the pericardium by mechanical means and application of trichloracetic acid and powdered asbestos. Additionally, a suture, placed from the external surface of the heart, surrounded the coronary sinus, narrowing it to approximately 3 mm. The theory was that the resulting congestion increased coronary sinus pressure, which would stimulate the development of intercoronary anastomoses within the ischemic myocardium. These operations were done through a left lateral thoracotomy without cardiopulmonary bypass and were followed by intercostal blockade with tetracaine. The remaining one-third of the reports covered a
variety of topics. One involved the problem of heart failure, which occurred in the immediate postpartum interval and was found to be related to the presence of heart disease in practically all patients. Another involved the relation between the cerebral circulation and arrhythmia, and Corday and Irving7 reported that there was an intimate relation between the two. The cerebral circulation was also studied by Wolfe,8 in Cleveland, who attempted to simulate the clinical situation of ventricular fibrillation under 2 conditions, normothermia and mild hypothermia (31’C). Even mild hypothermia provided protection against cerebral damage. An anecdotal article of historical note involved the notes by Thomas Bevel Peacock on dissecting aneurysm as he had observed it in 1843. He reported 5 cases to which he appended 14 from the published reports and attempted to develop a theory of pathogenesis and life history. A variety of case reports followed. One involved congenital tricuspid stenosis, indeed a rarity both then and now. An aneurysm of the right coronary artery was described with rupture into the right atrium, with lyear survival. Additionally, the problem of neonatal digitalis intoxication through the placenta was described in a mother requiring this compound. Wenckebath’s phenomenon associated with hyperparathyroidism and the problem of the atypical patent ductus arteriosis were reviewed. The October issue contained the abstracts from the Ballisticardiographic Research Societies. In the President’s column, the educational mission of The American College of Cardiology was emphasized. At that time, the college’s annual meeting was held jointly with the American Heart Association. The ninth interim meeting of the American College of Cardiology’s program was printed, and most prominent among these were so-called firestone conferences, which covered an enormous range of topics.
References 1. Stephen CR, Dent SJ, Sealy WC, Hall KD. Anesthetic and metabolic factors associated with combined extracorporeal circulation and hypothermia. Am J Cardiol 1960;6:737-751. 2. Etsten B, Li TH. Effects of anesthesia upon the heart. Am J Cardiol 1960;6:706-715. 3. Neptune WB, Panic0 FC, Bougas JN. Clinical use of pump oxygenator without donor blood for primary or support during extracorporeal perfusion. Circulation 1959;20:745. 4. Melrose DG, Dryer B, Bentall HH. Elective cardiac arrest. Lancet 1955:2:21-22. 5. Dillon JB, Kavan EM. Anesthesia for cardiac surgery. Am J Cardiol 1960;6:721-736. 6. Rendell-Baker L, Middleton HG. Anesthesia management for the operative treatment of coronary artery disease. Am J Cardiol 1960;6:728-736. 7. Corday E, Irving DW. Effect of cardiac arrhythmias on the cerebral circulation. Am J Cardiol 1960;6:803-808. 8. Wolfe KB. The effect of hypothermia on cerebral damage resulting from cardiac arrest. Am J Cardiol 1960;6:809-812.
Although rarely used today, electroencephalography occupied a major role in the measurement responsibilities of the anesthesiologist in 1960. The separation between cerebral hypoxemia and hypothermia was difficult, although it was clear in catastrophic cases that the electroencephalogram changed dramatically during the operation. An ear oximeter using infrared light was believed to be efficacious and was one of the earliest demonstrations of an effort toward noninvasive determination of the 02 content of the arterialized blood during cardiopulmonary bypass. Monitoring was achieved with devices that had been adapted from the cardiac catheterization laboratory and recorders used both heated styluses and mirrored galvanometry and light-sensitive paper. The conduct of cardiopulmonary bypass was of special interest because so many of the intraoperative and postoperative problems appeared to be associated with its use. Two general types of oxygenators were used: the screen (Gibbon) or the disc (Kay-Cross). Each required priming with large volumes of whole blood.3-7 Blood volume requirements for cardiac surgery caused enormous concern, and this led to a series of experiments and determinations by many centers of circulating blood volume by use of I-131 and chrominum-51 before, during and after cardiopulmonary bypass. The problems, in great part, could be traced to the fact that the extracorporeal circuit had a volume that was equal to or greater than the patient. Hemodilution with crystalloid prime was not thought possible with the devices in use until the laboratory work of Neptune et al demonstrated efficacy.3 These data from dogs and patients were not accepted readily by the clinical community for several years. The immediate postoperative interval was the most difficult for anesthesiologists, cardiac surgeons and intensive care unit nurses. It was quickly learned that volume-controlled ventilators were necessary and that a major characteristic of the immediate postoperative interval was an alveolar-capillary block, which was related to a phenomenon of water and protein extravasation into the pulmonary interstitium. This was later traced to the large volumes of unfiltered blood and crystaloid given in the prime and during the procedure. Although most heart-lung machines had arterial
701
702
AJC
25 YEARS
AGO
line filters, the pore size was large. The quantity and size of the solid microemboli in the stored blood and the perfusate were not appreciated. Postoperatively, low cardiac output was common. Whether or not the use of Melrose’s solution4 was responsible or the use of anoxic arrest was the cause were not answered in the symposium. Improved methods of protection of the heart were clearly needed, and either method was hazardous allowing precious few minutes for repair of complex lesions. The agent of choice for poor contractility was digitalis in the form of ovabain because of its rapid onset of action. Arrhythmia was a major problem with the early advent of closed- and open-heart surgery. Most arrhythmias were believed to be a result of inadequate oxygenation and carbon dioxide accumulation or were secondary to hypotention from blood loss or anesthetic agents. All reports emphasized that the minimal amount of anesthesia must be given and that careful attention to hyperventilation and avoidance of metabolic acidosis was mandatory. An arterial pH >7.45 was recommended regardless of temperature, and this was primarily done through hyperventilation, which was the hallmark of the management of early anesthesia. The era of open-heart surgery was just beginning. The Los Angeles group reported that anesthesia had been given over a 4-year interval to 164 patients who had undergone cardiac operation with the use of cardiopulmonary bypass and hypothermia and general anesthesia was given to 68 patients for the performance of a cardiac procedure.5 At that time, most patients (548) were anesthetized for cardiac catheterization. Of historical interest was the report from Cleveland in which 429 consecutive cardiac surgical patients had a hospital mortality rate for the Beck I operation of 6% over a 5-year interval, the last 200 patients having a 2% hospital mortality rate.6 This operation consisted of abrasion of the pericardium by mechanical means and application of trichloracetic acid and powdered asbestos. Additionally, a suture, placed from the external surface of the heart, surrounded the coronary sinus, narrowing it to approximately 3 mm. The theory was that the resulting congestion increased coronary sinus pressure, which would stimulate the development of intercoronary anastomoses within the ischemic myocardium. These operations were done through a left lateral thoracotomy without cardiopulmonary bypass and were followed by intercostal blockade with tetracaine. The remaining one-third of the reports covered a
variety of topics. One involved the problem of heart failure, which occurred in the immediate postpartum interval and was found to be related to the presence of heart disease in practically all patients. Another involved the relation between the cerebral circulation and arrhythmia, and Corday and Irving7 reported that there was an intimate relation between the two. The cerebral circulation was also studied by Wolfe,8 in Cleveland, who attempted to simulate the clinical situation of ventricular fibrillation under 2 conditions, normothermia and mild hypothermia (31’C). Even mild hypothermia provided protection against cerebral damage. An anecdotal article of historical note involved the notes by Thomas Bevel Peacock on dissecting aneurysm as he had observed it in 1843. He reported 5 cases to which he appended 14 from the published reports and attempted to develop a theory of pathogenesis and life history. A variety of case reports followed. One involved congenital tricuspid stenosis, indeed a rarity both then and now. An aneurysm of the right coronary artery was described with rupture into the right atrium, with lyear survival. Additionally, the problem of neonatal digitalis intoxication through the placenta was described in a mother requiring this compound. Wenckebath’s phenomenon associated with hyperparathyroidism and the problem of the atypical patent ductus arteriosis were reviewed. The October issue contained the abstracts from the Ballisticardiographic Research Societies. In the President’s column, the educational mission of The American College of Cardiology was emphasized. At that time, the college’s annual meeting was held jointly with the American Heart Association. The ninth interim meeting of the American College of Cardiology’s program was printed, and most prominent among these were so-called firestone conferences, which covered an enormous range of topics.
References 1. Stephen CR, Dent SJ, Sealy WC, Hall KD. Anesthetic and metabolic factors associated with combined extracorporeal circulation and hypothermia. Am J Cardiol 1960;6:737-751. 2. Etsten B, Li TH. Effects of anesthesia upon the heart. Am J Cardiol 1960;6:706-715. 3. Neptune WB, Panic0 FC, Bougas JN. Clinical use of pump oxygenator without donor blood for primary or support during extracorporeal perfusion. Circulation 1959;20:745. 4. Melrose DG, Dryer B, Bentall HH. Elective cardiac arrest. Lancet 1955:2:21-22. 5. Dillon JB, Kavan EM. Anesthesia for cardiac surgery. Am J Cardiol 1960;6:721-736. 6. Rendell-Baker L, Middleton HG. Anesthesia management for the operative treatment of coronary artery disease. Am J Cardiol 1960;6:728-736. 7. Corday E, Irving DW. Effect of cardiac arrhythmias on the cerebral circulation. Am J Cardiol 1960;6:803-808. 8. Wolfe KB. The effect of hypothermia on cerebral damage resulting from cardiac arrest. Am J Cardiol 1960;6:809-812.