The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Changes in autonomic response of the cerebral circulation after normothermic extracorporeal circulation.
Patients who undergo cardiopulmonary bypass frequently have neuropsychologic dysfunction. This study was undertaken to determine whether altered cerebral perfusion and vascular responses may in part lead to these neuropsychologic changes. Pigs were placed on normothermic cardiopulmonary bypass for 2 hours. ⋯ In vitro relaxation responses to sodium nitroprusside and forskolin (an adenylate cyclase activator) were similar in all experimental groups, suggesting that second-messenger mechanisms remain intact after normothermic cardiopulmonary bypass. In conclusion, basal cerebrovascular resistance and internal carotid artery blood flow are maintained if the systemic circulation and pressure are supported with fluid administration after cardiopulmonary bypass. Agonist-induced vasodilation of cerebral microvessels to cholinergic and beta-adrenoceptor stimulation are selectively impaired after normothermic cardiopulmonary bypass, whereas second-messenger mechanisms remain intact.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Unifocalization for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.
To extend the indications for corrective operation in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries, surgical procedures were done to unify the blood sources for pulmonary perfusion. Since December 1985, 50 patients have undergone unifocalization at ages from 2 months to 26 years with a mean of 6 +/- 7 years. In total, 84 staged unifocalization procedures and 5 other palliative procedures were done in 49 patients. ⋯ One patient (4%) died shortly after intracardiac repair because of thrombosis within the pulmonary arteries. Postoperative catheterization showed that pulmonary vascular resistance was correlated significantly with the number of pulmonary vascular segments functioning rather than with the condition of the central pulmonary arteries. We conclude that surgical unifocalization is a feasible procedure before subsequent intracardiac repair, even in patients with critically hypoplastic or absent central pulmonary arteries.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Inhaled nitric oxide improves lung allograft function after prolonged storage.
Morbidity caused by early allograft dysfunction, manifested by a progressive increase in pulmonary vascular resistance and a decrease in oxygenation, remains a serious problem in lung transplantation. Inhalation of nitric oxide, an essential homeostatic molecule, has been shown to have beneficial effects on a variety of acute lung injuries. The purpose of the present study was to investigate the effect of inhaled nitric oxide on posttransplant function of canine left lung allografts. ⋯ Systemic hemodynamics were unaffected by nitric oxide. However, an immediate decrease in pulmonary vascular resistance was noted. Group I myeloperoxidase activity was significantly lower than that in control group III (0.24 +/- 0.06 versus 0.36 +/- 0.04 units, respectively; p < 0.05).
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J. Thorac. Cardiovasc. Surg. · Jul 1996
Comparative StudyMeasurement of heparin concentration in whole blood with the Hepcon/HMS device does not agree with laboratory determination of plasma heparin concentration using a chromogenic substrate for activated factor X.
Measurement of circulating heparin concentration has been suggested to optimize anticoagulation during cardiopulmonary bypass. The Hepcon/HMS device (Medtronic HemoTec, Inc., Parker, Colo.) uses heparin/protamine titration to quantitatively determine heparin concentration. Extensive validation of this instrument is still lacking. ⋯ We conclude that heparin concentrations determined with the Hepcon/HMS instrument do not agree with laboratory determination of heparin concentration. Monitoring of heparin concentrations during bypass with the Hepcon/HMS device cannot be recommended.
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J. Thorac. Cardiovasc. Surg. · Jul 1996
Randomized Controlled Trial Clinical TrialThe routine use of fresh frozen plasma in operations with cardiopulmonary bypass is not justified.
The negative influence of cardiopulmonary bypass on hemostasis has been documented. Although abnormalities in platelet function are reported as the major cause of postoperative blood loss related to this hemostasis defect, fresh frozen plasma is often used in operations with cardiopulmonary bypass because it is thought to contribute to the reduction of postoperative bleeding complications. This study was designed to evaluate the effect of the administration of fresh frozen plasma after cardiopulmonary bypass on blood loss, transfusion requirements, and a number of coagulation parameters. ⋯ The routine use of fresh frozen plasma in operations with cardiopulmonary bypass cannot be recommended.