The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Jun 1994
Comparative StudyComparison of saphenous vein graft relaxation between Plasma-Lyte solution and normal saline solution.
Venospasm of saphenous vein grafts may damage endothelial cells and compromise early and late graft performance. Hence it is desirable to identify and use storage solutions that minimize vascular spasm during vein preparation. In view of this, we initiated isometric tension-recording studies in isolated canine and human saphenous vein to evaluate the acute, vasoactive effects of two storage solutions, Plasma-Lyte solution and normal saline solution. ⋯ Finally, we tested the vasoactive effect of Plasma-Lyte solution on human saphenous vein obtained by discard from coronary bypass operations. Plasma-Lyte solution at 37 degrees C effectively dilated norepinephrine-activated human saphenous vein, inducing complete relaxation within 20 minutes. On this basis, we recommend the use of Plasma-Lyte solution as a venodilating storage solution during coronary bypass operations to optimize vein graft relaxation before implantation.
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J. Thorac. Cardiovasc. Surg. · Jun 1994
Inhibition of the fetal stress response improves cardiac output and gas exchange after fetal cardiac bypass.
Cardiac bypass in late-gestation fetal lambs causes severe placental vasoconstriction, which leads to fetal death from hypoxemia and respiratory acidosis. This response can be blocked by the administration of indomethacin; however, a fatal metabolic acidosis then gradually develops in the fetus. Because the fetus is known to mount an intensive catecholamine response to stress, and because the fetal myocardium is particularly sensitive to increased afterload, we hypothesized that elevated afterload as a result of fetal stress contributes to diminished cardiac output after bypass. ⋯ When spinal anesthesia and indomethacin are both given, hemodynamics also approach normal after bypass, and gas exchange is further improved. These data suggest that the inhibition of the stress response by spinal anesthesia improves the hemodynamic status of the fetus during operation and, in combination with indomethacin, allows maintenance of near-normal placental function after fetal cardiac bypass. Similar responses may also be possible in human fetuses with use of a high-dose narcotic technique.
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J. Thorac. Cardiovasc. Surg. · Jun 1994
Acute renal failure in the patient undergoing cardiac operation. Prevalence, mortality rate, and main risk factors.
A total of 775 consecutive patients who survived the first 24 hours after cardiac operation were prospectively studied to assess the prevalence, mortality rate, and main risk factors for development of new acute renal failure. Normal renal function before operation (serum creatinine level less than 1.5 mg/dl) was registered in 734 (94.7%) patients. Of these, 111 (15.1%) showed a postoperative renal complication including 84 (11.4%) classified as renal dysfunction (serum creatinine level between 1.5 and 2.5 mg/dl) and 27 (3.7%) as acute renal failure (serum creatinine level higher than 2.5 mg/dl). ⋯ The 41 patients (5.3%) with preoperative renal failure showed a significantly higher morbidity and mortality rate than those without renal complications before operation. We conclude that in patients undergoing cardiac operation without preexisting renal dysfunction the likelihood of severe renal complications is reasonably low, but the associated mortality remains high. A prominent role in the development of postoperative acute renal failure must be recognized for preoperative, intraoperative, and postoperative hemodynamic factors, whereas cardiopulmonary bypass seems to be of lesser importance in this respect.