The Journal of thoracic and cardiovascular surgery
-
J. Thorac. Cardiovasc. Surg. · Oct 1995
Studies of hypoxemic/reoxygenation injury: without aortic clamping. II. Evidence for reoxygenation damage.
This study tested the hypothesis that the developing heart is susceptible to oxygen-mediated damage after reintroduction of molecular oxygen and that this "unintended" reoxygenation injury causes lipid peroxidation and functional depression that may contribute to perioperative cardiac dysfunction. Among 49 Duroc-Yorkshire piglets (2 to 3 weeks old, 3 to 5 kg) 15 control studies were done without hypoxemia to test the effects of the surgical preparation (n = 10) and 60 minutes of cardiopulmonary bypass (n = 5). Twenty-nine piglets underwent up to 2 hours of ventilator hypoxemia (with inspired oxygen fraction reduced to 6% to 7%) to lower arterial oxygen tension to approximately 25 mm Hg. ⋯ Comparable biochemical and functional changes occurred in piglets undergoing ventilator hypoxemia and/or cardiopulmonary bypass hypoxemia and reoxygenation on cardiopulmonary bypass. We conclude that hypoxemia increases vulnerability to reoxygenation damage by reducing antioxidant reserve capacity and that reoxygenation by either ventilator or cardiopulmonary bypass produces oxidant damage with resultant functional depression that is not a result of cardiopulmonary bypass. These findings suggest that initiation of cardiopulmonary bypass in cyanotic immature subjects causes an unintended reoxygenation injury, which may increase vulnerability to subsequent ischemia during surgical repair.
-
J. Thorac. Cardiovasc. Surg. · Oct 1995
Randomized Controlled Trial Clinical TrialRecombinant aprotinin in coronary artery bypass graft operations.
To evaluate the role of recombinant bovine aprotinin in reducing blood loss in coronary artery bypass graft surgery. ⋯ We conclude that, at the dosages given, recombinant bovine aprotinin decreases surgical blood loss and transfusion requirements in patients undergoing coronary artery bypass grafting, but its use requires appropriate monitoring of heparin use during bypass. Whether higher dosages of aprotinin increase the risk of graft thrombosis must be further assessed with a larger patient sample.
-
J. Thorac. Cardiovasc. Surg. · Oct 1995
Randomized Controlled Trial Multicenter Study Clinical TrialAcadesine: a new drug that may improve myocardial protection in coronary artery bypass grafting. Results of the first international multicenter study. Multinational Acadesine Study Group.
The effect of acadesine, an adenosine-regulating agent, on the incidence of myocardial infarction, all adverse cardiovascular outcomes (myocardial infarction, cardiac death, left ventricular dysfunction, life-threatening arrhythmia, or cerebrovascular accident) and mortality was assessed in 821 patients undergoing coronary artery bypass grafting. Patients were prospectively stratified to a high-risk group (age > 70 years, unstable angina, previous coronary bypass, unsuccessful angioplasty, or ejection fraction < 30%) or a non-high-risk group. They were randomized in a double-blind manner to placebo (n = 418) or acadesine (n = 403) by intravenous infusion over 7 hours (0.1 mg/kg per minute) and in the cardioplegic solution (placebo or acadesine; 5 micrograms/ml). ⋯ However, acadesine reduced the incidence of cardiac related events that contributed to deaths occurring during the first 3 postoperative days so that the incidence of death in this period was lower (placebo, 1.9%; acadesine, 0.2%; p = 0.038). No adverse events were related to acadesine treatment. Although overall there were no statistically significant between-group differences for the primary study end points, a secondary analysis in a prospectively defined high-risk subgroup suggests that acadesine may be beneficial in some patients.
-
J. Thorac. Cardiovasc. Surg. · Oct 1995
Randomized Controlled Trial Comparative Study Clinical TrialAprotinin versus desmopressin for patients undergoing operations with cardiopulmonary bypass. A double-blind placebo-controlled study.
Aprotinin reduces blood loss in operations done with cardiopulmonary bypass, whereas the use of desmopressin remains controversial. We compared aprotinin, desmopressin, and placebo in a double-blind, randomized trial to evaluate bleeding and transfusion requirements. ⋯ Aprotinin administration reduces blood loss and transfusion requirements in cardiopulmonary bypass. This benefit may be explained by a lower activation of fibrinolysis.
-
J. Thorac. Cardiovasc. Surg. · Oct 1995
Studies of hypoxemic/reoxygenation injury with aortic clamping: XI. Cardiac advantages of normoxemic versus hyperoxemic management during qardiopulmonary bypass.
The conventional way to start cardiopulmonary bypass is to prime the cardiopulmonary bypass circuit with hyperoxemic blood (oxygen tension about 400 mm Hg) and deliver cardioplegic solutions at similar oxygen tension levels. This study tests the hypothesis that an initial normoxemic oxygen tension strategy to decrease the oxygen tension-dependent rate of oxygen free radical production will, in concert with normoxemic blood cardioplegia, limit reoxygenation damage and make subsequent hyperoxemia (oxygen tension about 400 mm Hg) safer. Thirty-five immature (3 to 5 kg, 2 to 3 week old) piglets underwent 60 minutes of cardiopulmonary bypass. ⋯ In contrast, abrupt and gradual reoxygenation without blood cardioplegia produced significant lipid peroxidation (84% increase in conjungated dienes), lowered antioxidant reserve capacity 68% +/- 5%, 44% +/- 8%, respectively, and decreased functional recovery 75% +/- 6% (p < 0.05), 66% +/- 4% (p < 0.05). Similar impairment followed abrupt reoxygenation before blood cardioplegic myocardial management, because conjungated diene production increased 13-fold, antioxidant reserve capacity fell 40%, and contractility recovered only 21% +/- 2% (p < 0.05). Conversely, normoxemic induction of cardiopulmonary bypass and blood cardioplegic myocardial management reduced conjungated diene production 73%, avoided impairment of antioxidant reserve capacity, and resulted in 58% +/- 11% recovery of contractile function.(ABSTRACT TRUNCATED AT 400 WORDS)