MYOCARDIAL AND CIRCULATORY PERFORMANCE DURING THE ISCHEMIC PHASE OF SUPERIOR MESENTERIC-ARTERY OCCLUSION

Objective: To investigate myocardial and circulatory parameters during the acute ischemic phase of mesenteric artery occlusion. Design: A pr ospective, randomized, control trial. Subjects: Twelve, adult, mongrel dogs. Interventions: In seven dogs the superior mesenteric artery was occluded with two silk ligatures (experimental group). In five dogs t he ligatures were not tied (control group). Measurements were made dur ing 7 hours of occlusion. Main Outcome Measures: Myocardial performanc e and circulatory performance. Results: There were significant (p < 0. 05) reductions in arterial blood pressure, mean pulmonary artery press ure, diastolic pulmonary artery pressure and cardiac index in dogs exp osed to intestinal ischemia compared with the control dogs. No differe nces were identified in ventricular performance, stroke volume index o r peripheral vascular resistance index. Conclusions: Early cardiac and central circulatory changes in massive intestinal ischemia are due to intravascular hypovolemia. Sepsis and myocardial depressant factors w ere not found to be a cause of death.