ObjectiveTo determine whether cate-cholamine and cortisol secretory responses to surgery contribute to postoperative complications.DesignProspective, randomized, case series.SettingA university hospital operating suite and surgical intensive care unit.PatientsSixty patients undergoing lower extremity vascular surgery.InterventionsPatients were randomized to receive either epidural anesthesia/epidural opiate analgesia (regional anesthesia) or general anesthesia/intravenous patient-controlled analgesia (general anesthesia).Measurements and Main ResultsAnesthesia was managed according to a prospectively designed protocol. Hemodynamic parameters and plasma catecholamine concentrations were determined at specific intraoperative and postoperative time points. Intraoperative and postoperative urine samples were collected and analyzed for free cortisol concentrations. Outcomes evaluated were cardiac (nonfatal myocardial infarction and cardiac death) and surgical (graft occlusion). Mean arterial pressure during emergence from anesthesia and in the early postoperative period correlated positively with plasma norepinephrine concentration (p less than .01). In addition, plasma catecholamine concentrations were higher in patients with postoperative hypertension. Plasma norepinephrine concentrations at the time of emergence from anesthesia and postoperatively were also higher in patients requiring repeat surgery for graft revision, thrombectomy, or amputation (p less than .05). Multivariate analysis indicated that the norepinephrine concentration at the time of emergence, but not type of anesthesia, correlated with reoperation for graft occlusion, suggesting that the previously reported beneficial effect of regional anesthesia may be due to modulation of the stress response. Myocardial infarction or cardiac death occurred in three patients. These patients had markedly increased catecholamine concentrations.ConclusionsThe catecholamine response to lower extremity vascular surgery contributes to the development of postoperative hypertension and may also be important in the development of thrombotic complications.(Crit Care Med 1995; 23:1954-1961)