The Journal of thoracic and cardiovascular surgery
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Talc was used intrapleurally for the creation of pleural adhesions in 360 patients. The indications for use were malignant pleural effusion in 169 patients, benign effusions in 41, recurrent pneumothorax in 122, empyema in 19, and chylothorax in 9. Of 336 patients available for follow-up, excellent results (complete pleurodesis) were achieved in 284 patients (84.5%), fair results in 28 (8.3%), and poor results (no adhesions) in 24 (7.2%). ⋯ Talc is the most effective and least expensive agent for creation of pleural adhesions. Its use is simple and easily tolerated by the patients. Because of the carcinogenic effect of asbestos, purified talc that is free of asbestos fibers must be used.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Influence of hydrogen ion concentration versus carbon dioxide tension on pulmonary vascular resistance after cardiac operation.
Disturbances of respiratory acid-base status are common in patients supported with mechanical ventilation of the lungs after cardiac operations. This study was conducted with two protocols. The purpose was to determine whether respiratory acid-base status influences pulmonary vascular resistance in adults after cardiac operations and whether the influence is mediated by hydrogen ion concentration or carbon dioxide tension. ⋯ The results of the second protocol showed that changes in pulmonary vascular resistance index were parallel to changes in hydrogen ion concentration as arterial carbon dioxide tension was held constant (p < 0.05). These data demonstrate that respiratory acid-base status is an important determinant of pulmonary vascular resistance in the adult after cardiac operations. Furthermore, these data suggest the effect is mediated by hydrogen ion concentration, not carbon dioxide tension.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Comparative StudyComplement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits.
The degree of complement activation during cardiopulmonary bypass is considered a valuable parameter of biocompatibility of the extracorporeal circuit. In an in vitro setting with a heart-lung machine primed with fresh whole blood and saline solution, the C3 activation products C3b, iC3b, and C3c and the terminal complement complex were measured in double-antibody enzyme immunosorbent assays. No differences were found between seven sets treated with Duraflo II heparin coating and seven uncoated sets after 2 hours of circulation. ⋯ In a supplementary series, the sterilization process did not influence the results. Although Duraflo II heparin coating is considered highly effective in preventing coagulation, it did not prevent complement activation in the present in vitro study. We hypothesize that the mode by which the heparin molecule is bound to the surface may be essential to obtain effects on both coagulation and complement system.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Increased plasma levels of endothelin-1 after cardiopulmonary bypass in patients with pulmonary hypertension and congenital heart disease.
The plasma level of the potent vasoconstrictor endothelin-1 was measured in children who underwent cardiac operations. Forty-five patients were divided into two groups, those with a high pulmonary blood flow (HF group; n = 23) and those with a normal or low flow (NF group; n = 22). Seven blood samples were taken: immediately before cardiopulmonary bypass, immediately after removing the aortic cross-clamps, immediately after discontinuing bypass, and at 20 minutes and 3, 6, and 24 hours after termination of bypass. ⋯ In addition, a significant positive correlation was obtained between endothelin-1 3 hours after bypass and the maximum pulmonary/systemic arterial pressure ratio during the first 12 hours after operation (r = 0.86, p < 0.05). These results suggest that cardiopulmonary bypass is associated with an immediate postoperative increase in circulating endothelin and that patients who had a high pulmonary blood flow before the operation are particularly vulnerable, bypass having a more injurious effect on a lung with preexisting endothelial dysfunction. A high level of circulating endothelin may predispose to pulmonary vascular lability and pulmonary hypertensive crises in the postoperative period.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Altered pulmonary microvascular reactivity after total cardiopulmonary bypass.
Pulmonary vascular resistance is frequently elevated after cardiac operations in which cardiopulmonary bypass is used. In our study of the possible contribution of altered pulmonary microvascular reactivity to this condition, sheep were heparinized, cannulated via the aorta and right atrium, and placed on total cardiopulmonary bypass. After 90 minutes of total cardiopulmonary bypass and pulmonary arterial occlusion, the sheep were removed from cardiopulmonary bypass, and their lungs were perfused normally for 60 minutes. ⋯ Endothelium-independent responses to sodium nitroprusside and U46619 and dilation responses to adenosine were not altered after cardiopulmonary bypass. Extracorporeal circulation with continued pulmonary arterial perfusion (right heart bypass group) had no effect on microvascular responses. In conclusion, total cardiopulmonary bypass with associated reduced pulmonary perfusion causes significant alterations of endothelium-dependent pulmonary microvascular responses because of the increased release of a constrictor prostanoid substance and possibly because of reduced release of endothelium-derived relaxing factor.