The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Mar 1981
Complement activation and neutropenia occurring during cardiopulmonary bypass.
Complement activation and pulmonary leukostasis with neutropenia occur in hemodialysis and filtration leukapheresis, with attendant pulmonary dysfunction. Wondering whether similar phenomena might attend cardiopulmonary bypass (CPB), we studied 34 patients undergoing coronary artery bypass operations. As in the other extracorporeal circulation systems, neutropenia (mean 44.7% +/- 4.3% SEM of prebypass PMN count) occurred during the first half hour of bypass and then a rebound neutrophilia followed. ⋯ Nonetheless, polymorphonuclear neutrophils (PMNs) harvested late in bypass showed low adherence to nylon and selective chemotactic and aggregative insensitivity to C5a--functional aberrations which are seen after exposure to activated complement. Furthermore, smaller infusions of activated complement into animals produced neutropenia than were required to achieve a detectable [C5a] in the plasma. We conclude that neutropenia during CPB probably results from complement activation below the threshold of detection; complement-stimulated PMNs deserve study as possible mediators of tissue injury occurring during CPB.
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J. Thorac. Cardiovasc. Surg. · Mar 1981
Comparative StudyObjective evaluation of the efficacy of various venous cannulas.
Six venous cannulas (USCI No. 32, USCI No. 40, USCI No. 44, Sarns No. 40, Sarns two-stage cavoatrial, and Ferguson Argyle No. 40) were tested for efficiency of venous flow during cardiopulmonary bypass, with and without aortic cross-clamping. Each cannula was tested six times in dog models (twice in each of three dogs) and the data were averaged. The tip of the cavoatrial Sarns catheter was positioned as recommended. ⋯ Aortic cross-clamping eliminated coronary sinus flow and decreased right ventricular vent flow. Therefore, a single atrial cannula is more efficient in draining blood from the right side of the heart than are two caval or a cavoatrial cannula. This advantage is negated by aortic cross-clamping.
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J. Thorac. Cardiovasc. Surg. · Mar 1981
Management of postoperative heparin rebound following cardiopulmonary bypass.
Postoperative heparin rebound was investigated in 50 adult patients undergoing cardiopulmonary bypass with the use of the Hepcon heparin analyzer. Prior to bypass each patient received 2 mg/kg of heparin. During bypass, the activated clotting time (ACT) was utilized to assess the need for additional heparin to maintain the value between 300 and 400 seconds. ⋯ Three patients (6%) did not require any blood transfusions. The use of the Hepcon unit has produced a safe and expedient method of analyzing and neutralizing active circulating heparin in patients following cardiopulmonary bypass. It is a useful adjunct in blood conservation because it reduces excessive postoperative blood loss associated with heparin rebound.