A COMPARISON OF AMRINONE WITH SODIUM-NITROPRUSSIDE FOR CONTROL OF HEMODYNAMICS DURING INFRARENAL ABDOMINAL AORTIC-SURGERY

Objectives: The control of hemodynamic changes during surgical resecti on of abdominal aortic aneurysms (AAA) remains a challenge to anesthes iologists. In the past, hypertensive episodes have been treated with s odium nitroprusside (SNP). However, amrinone may provide some benefits when compared with SNP because of its positive inotropic and vasodila tory properties. Therefore, the purpose of this study was to compare a mrinone with SNP for hemodynamic control during AAA surgery. Design: T his study was a prospective, randomized investigation. Setting: This s tudy was performed at a single university hospital. Participants: This study included 20 patients undergoing AAA resection. Interventions: A fter institutional review board approval, participants were randomized to receive either SNP (group N=10) or amrinone (group A=10). Both age nts were started 10 minutes before aortic cross-clamping and discontin ued 10 minutes before unclamping. Anesthesia was induced with thiopent al or etomidate and maintained with oxygen, nitrous oxide, isoflurane, fentanyl, and vecuronium. Hemodynamic measurements included heart rat e, systolic and diastolic blood pressure, cardiac output, systolic and diastolic pulmonary artery pressure, pulmonary capillary wedge pressu re, central venous pressure, mixed venous oxygen saturation, electroca rdiogram, and ST-T wave trend analysis. Measurements and Main Results: Demographic and clinical characteristics for the two groups were simi lar. Mixed venous oxygen saturation was significantly lower (p < 0.05) in group N immediately after unclamping. There were no differences be tween groups for the other measurements studied. There were no episode s of myocardial ischemia in either group. Conclusions: This study demo nstrates that amrinone provides equivalent hemodynamic control to SNP during abdominal aortic aneurysm surgery because it allows moderate re ductions in blood pressure without affecting other hemodynamic measure ments. Further studies are needed to assess whether patients with poor preoperative left ventricular function would benefit from amrinone ma nagement during AAA resection. (C) 1995 by W.B. Saunders Company