The Journal of thoracic and cardiovascular surgery
-
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.
-
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.
-
J. Thorac. Cardiovasc. Surg. · May 1994
Randomized Controlled Trial Comparative Study Clinical Trial Retracted PublicationInfluence of aprotinin on the thrombomodulin/protein C system in pediatric cardiac operations.
Thirty consecutive children scheduled for pediatric cardiac operation with cardiopulmonary bypass were included in the study. Before the operation, the patients were randomly divided into two groups: with aprotinin (n = 15, 30,000 U/kg after induction of anesthesia, 30,000 U/kg added to the prime of the cardiopulmonary bypass or without aprotinin (n = 15). Thrombomodulin, (free) protein S, protein C, and thrombin/antithrombin III complex were measured from arterial blood samples taken after induction of anesthesia (at baseline, before aprotinin) and before, during, and after cardiopulmonary bypass until the first postoperative day. ⋯ Blood loss and the need for homologous blood and blood products did not differ significantly between the two groups. We concluded that administration of aprotinin resulted in reduced thrombomodulin plasma levels in pediatric patients undergoing cardiac operation without altering protein C/protein S plasma concentration. The exact role of aprotinin in endothelium-derived coagulation should be further studied.
-
J. Thorac. Cardiovasc. Surg. · May 1994
Comparative StudyReduction of homologous blood requirements by blood-pooling at the onset of cardiopulmonary bypass.
This study was done to investigate whether an intraoperative autologous blood donation (pooling) at the onset of cardiopulmonary bypass can reduce homologous blood requirements during and after operations for myocardial revascularization. Ninety patients were assigned equally to two groups. In group C, serving as the control group, cardiopulmonary bypass was done with a membrane lung primed with 1500 ml of Ringer's solution. ⋯ Remarkably, 44% of patients in group P did not require any homologous blood products compared with 16% in group C. In conclusion, modern oxygenators, which provide sufficient oxygen transport capacity, make it feasible to decrease the hematocrit to 20% by "pooling" blood at the beginning of cardiopulmonary bypass and replacing it with saline solution. This procedure led to a highly significant saving of homologous blood.
-
J. Thorac. Cardiovasc. Surg. · May 1994
Comparative StudyComparative experimental study between retrograde cerebral perfusion and circulatory arrest.
To evaluate the efficacy of retrograde cerebral perfusion in protecting the brain, we comparatively studied retrograde cerebral perfusion and total circulatory arrest in 18 hypothermic (20 degrees C) mongrel dogs (retrograde cerebral perfusion, n = 10; total circulatory arrest, n = 8). Retrograde cerebral perfusion was performed, maintaining an external jugular venous pressure of 25 mm Hg for 60 minutes. Retrograde cerebral perfusion provided half the cerebral blood flow and a third of the oxygen that was supplied during hypothermic cardiopulmonary bypass, which had a flow rate of 100 ml/min per kilogram. ⋯ These changes were smaller than those seen in total circulatory arrest. Tissue concentrations of adenosine triphosphate in the brain remained relatively high during retrograde cerebral perfusion but decreased rapidly during total circulatory arrest (0.49 +/- 0.16 versus 0.21 +/- 0.05 mmol/gm, p < 0.01, just before resuming cardiopulmonary bypass). Retrograde cerebral perfusion cannot maintain aerobic metabolism but may reduce ischemic damage of the brain and may safely extend the cerebral circulation interruption time.