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Pericardial fluid and hemolysis
Ann Thorac Surg
CORRESPONDENCE
1!393;56593-7
In the search for an alternative conduit suitable for use in the aortocoronary position, several other bovine and porcine arteries with differing characteristics are currently being evaluated. Nevertheless, so long as the tanning procedure leaves behind what is histologically little more than a collagen tube, then marked thrombogenicity seems likely to remain a problem.
lan M . Mitchell, FRCS Paul G. Martin, BSc Nigel R. Saunders, FRCS R. Unnikrishnan Nair, FRCS Department of Cardiac Surgery Killingbeck Hospital York Rd Leeds LS14 6UQ England
Pericardial Fluid and Hemolysis To the Editor: Doctor Ford and associates [ l ] addressed the issue of hemolysis of blood after it falls into the pericardium during a heart operation. Previous authors [2, 31 had pointed out that blood in the pericardium was more rapidly hemolyzed than it was while being subjected to suction and pumping in the pump oxygenator. Doctor Ford and associates [l] dismissed these as indirect observations. Instead they mixed an unstated volume of pericardial fluid with 15 mL of arterial blood and found no significant amount of hemolysis. In addition, Yz g of tissue of pericardium, fat, muscle, or vein was incubated with blood and tested for hemolysis. Again the pericardium did not cause significant hemolysis whereas muscle and fat did. Ford and associates thought this was important as one could therefore safely return pericardial blood to the patient, and they stated that cardiopulmonary bypass might be a more important cause of hemolysis. Morris and colleagues’ [2] original observations are difficult to dismiss. In 22 patients having open heart operations (either congenital or valve operations), the pericardial blood was kept separate from the pump blood. There was a marked difference in the serum free hemoglobin level in the pump blood (mean, 39 mg/dL) as compared with the blood in the pericardial sac (mean, 256 mg/dL). Morris and colleagues also tested their hypothesis in 8 patients who had open heart operations without cardiopulmonary bypass (repair of atrial septa1 defect by Gross well technique). In these patients the mean intracardiac serum free hemoglobin value was 42 mg/dL, whereas the serum free hemoglobin level of pericardial blood ranged from 335 to 1,140 mg/dL. Aware of Dr Morris and colleagues’ work, we attempted to repeat it. In 6 patients in whom the blood spilled into the pericardium was not returned to the patient, the serum free hemoglobin level of the pericardial blood averaged 485 mg/dL, whereas the pump blood averaged 15mg/dL. Before we made the direct measurements, we were as convinced as Dr Ford and associates that cardiopulmonary bypass might play a more prominent role than the pericardium in hemolysis. We cannot readily explain why Ford and associates’ findings were different from those of Morris and colleagues or our own, although we might suggest the methods used by Morris and colleagues and by ourselves more closely simulate the clinical situation than those of Ford and associates. We do, however, agree with Ford and associates that it is probably safe to return blood from the pericardium to the patient. Thurer and associates [4] found that in the postoperative period, even though the shed mediastinal blood had a mean serum free
595
hemoglobin level of 315 mg/dL, there were no ill effects that could be attributed to its use.
Harry Siderys, M D Department of Medical Research Methodist Hospital of lndiana 1701 N Senate Blvd PO Box 1367 Indianapolis, IN 46206
References 1. Ford EG, Picone AL, Baisden CE. Role of autologous tissue factors in hemolysis during cardiopulmonary bypass operations. Ann Thorac Surg 1993;55:41&2. 2. Morris KN, Kinross FM, Stirling GR. Hemolysis of blood in the pericardium: the major source of plasma hemoglobin during total body perfusion. J Thorac Cardiovasc Surg 1965; 49:150-8. 3. Siderys H, Herod GT, Halbrook H, et al. A comparison of membrane and bubble oxygenation as used in cardiopulmonary bypass in patients. The importance of pericardial blood as a source of hemolysis. J Thorac Cardiovasc Surg 1975;69: 708-1 1. 4. Thurer RL, Lytle BW, Cosgrove DM, et al. Autotransfusion following cardiac operations: a randomized, prospective study. Ann Thorac Surg 1979;2750&7.
Thoracic Esophageal Perforations To the Editor: I write this letter as a protest to a myth propagated by many surgeons who write from academic centers. Doctor Ohri and associates have written an article entitled “Primary Repair of Iatrogenic Thoracic Esophageal Perforation and Boerhaave’s Syndrome” [l]. This is a competently presented 10-patient study of the therapy of esophageal perforation. The principles of diagnosis and surgical care are clearly espoused, as well as the life-threatening nature of the condition. I take great issue, however, with the last half of the last paragraph of the article, and particularly the last two sentences, which state, “However, the use of the latter technique or indeed the management of this lethal condition is not for the occasional esophageal surgeon. We would recommend referral of patients with esophageal perforations to centers with experience in the management of this condition.” There are many board certified, extensively trained thoracic surgeons in community hospitals who are attuned to the diagnosis of this problem and perfectly capable of as good surgical management of a perforated esophagus as any “center.” Many community hospitals are finely tuned to give excellent intraoperative and postoperative care, including intensive care, of cardiopulmonary instability, metabolic difficulties, and septic complications. The innuendo in the article using the words “occasional esophageal surgeon” and “referral . . . to centers with experience in the management of this condition” is just what our plaintiffs’ barristers feed upon. It will not be surprising if conscientious and skilled thoracic surgeons in the next several years are faced with this article promulgated by the plaintiffs’ attorney in substantiating that the physician in question should have referred a case, when in reality the care rendered may well have been exemplary. One cannot help but wonder if statements such as this at the end of articles in the literature are not more self-serving than a
CORRESPONDENCE
1!393;56593-7
In the search for an alternative conduit suitable for use in the aortocoronary position, several other bovine and porcine arteries with differing characteristics are currently being evaluated. Nevertheless, so long as the tanning procedure leaves behind what is histologically little more than a collagen tube, then marked thrombogenicity seems likely to remain a problem.
lan M . Mitchell, FRCS Paul G. Martin, BSc Nigel R. Saunders, FRCS R. Unnikrishnan Nair, FRCS Department of Cardiac Surgery Killingbeck Hospital York Rd Leeds LS14 6UQ England
Pericardial Fluid and Hemolysis To the Editor: Doctor Ford and associates [ l ] addressed the issue of hemolysis of blood after it falls into the pericardium during a heart operation. Previous authors [2, 31 had pointed out that blood in the pericardium was more rapidly hemolyzed than it was while being subjected to suction and pumping in the pump oxygenator. Doctor Ford and associates [l] dismissed these as indirect observations. Instead they mixed an unstated volume of pericardial fluid with 15 mL of arterial blood and found no significant amount of hemolysis. In addition, Yz g of tissue of pericardium, fat, muscle, or vein was incubated with blood and tested for hemolysis. Again the pericardium did not cause significant hemolysis whereas muscle and fat did. Ford and associates thought this was important as one could therefore safely return pericardial blood to the patient, and they stated that cardiopulmonary bypass might be a more important cause of hemolysis. Morris and colleagues’ [2] original observations are difficult to dismiss. In 22 patients having open heart operations (either congenital or valve operations), the pericardial blood was kept separate from the pump blood. There was a marked difference in the serum free hemoglobin level in the pump blood (mean, 39 mg/dL) as compared with the blood in the pericardial sac (mean, 256 mg/dL). Morris and colleagues also tested their hypothesis in 8 patients who had open heart operations without cardiopulmonary bypass (repair of atrial septa1 defect by Gross well technique). In these patients the mean intracardiac serum free hemoglobin value was 42 mg/dL, whereas the serum free hemoglobin level of pericardial blood ranged from 335 to 1,140 mg/dL. Aware of Dr Morris and colleagues’ work, we attempted to repeat it. In 6 patients in whom the blood spilled into the pericardium was not returned to the patient, the serum free hemoglobin level of the pericardial blood averaged 485 mg/dL, whereas the pump blood averaged 15mg/dL. Before we made the direct measurements, we were as convinced as Dr Ford and associates that cardiopulmonary bypass might play a more prominent role than the pericardium in hemolysis. We cannot readily explain why Ford and associates’ findings were different from those of Morris and colleagues or our own, although we might suggest the methods used by Morris and colleagues and by ourselves more closely simulate the clinical situation than those of Ford and associates. We do, however, agree with Ford and associates that it is probably safe to return blood from the pericardium to the patient. Thurer and associates [4] found that in the postoperative period, even though the shed mediastinal blood had a mean serum free
595
hemoglobin level of 315 mg/dL, there were no ill effects that could be attributed to its use.
Harry Siderys, M D Department of Medical Research Methodist Hospital of lndiana 1701 N Senate Blvd PO Box 1367 Indianapolis, IN 46206
References 1. Ford EG, Picone AL, Baisden CE. Role of autologous tissue factors in hemolysis during cardiopulmonary bypass operations. Ann Thorac Surg 1993;55:41&2. 2. Morris KN, Kinross FM, Stirling GR. Hemolysis of blood in the pericardium: the major source of plasma hemoglobin during total body perfusion. J Thorac Cardiovasc Surg 1965; 49:150-8. 3. Siderys H, Herod GT, Halbrook H, et al. A comparison of membrane and bubble oxygenation as used in cardiopulmonary bypass in patients. The importance of pericardial blood as a source of hemolysis. J Thorac Cardiovasc Surg 1975;69: 708-1 1. 4. Thurer RL, Lytle BW, Cosgrove DM, et al. Autotransfusion following cardiac operations: a randomized, prospective study. Ann Thorac Surg 1979;2750&7.
Thoracic Esophageal Perforations To the Editor: I write this letter as a protest to a myth propagated by many surgeons who write from academic centers. Doctor Ohri and associates have written an article entitled “Primary Repair of Iatrogenic Thoracic Esophageal Perforation and Boerhaave’s Syndrome” [l]. This is a competently presented 10-patient study of the therapy of esophageal perforation. The principles of diagnosis and surgical care are clearly espoused, as well as the life-threatening nature of the condition. I take great issue, however, with the last half of the last paragraph of the article, and particularly the last two sentences, which state, “However, the use of the latter technique or indeed the management of this lethal condition is not for the occasional esophageal surgeon. We would recommend referral of patients with esophageal perforations to centers with experience in the management of this condition.” There are many board certified, extensively trained thoracic surgeons in community hospitals who are attuned to the diagnosis of this problem and perfectly capable of as good surgical management of a perforated esophagus as any “center.” Many community hospitals are finely tuned to give excellent intraoperative and postoperative care, including intensive care, of cardiopulmonary instability, metabolic difficulties, and septic complications. The innuendo in the article using the words “occasional esophageal surgeon” and “referral . . . to centers with experience in the management of this condition” is just what our plaintiffs’ barristers feed upon. It will not be surprising if conscientious and skilled thoracic surgeons in the next several years are faced with this article promulgated by the plaintiffs’ attorney in substantiating that the physician in question should have referred a case, when in reality the care rendered may well have been exemplary. One cannot help but wonder if statements such as this at the end of articles in the literature are not more self-serving than a