Patients scheduled for vascular surgery are considered at risk for perioperative cardiac complications. Choice of anesthetic in such patients is guided by a desire not to adversely affect myocardial function. On the basis of data from laboratory studies, thoracic epidural anesthesia (TEA) has been advocated to prevent myocardial ischemia. The aim of this study was to assess whether TEA combined with general anesthesia has any effect on segmental wall motion (SWM) monitored by transesophageal echocardiography in these patients. Patients received alfentanil, midazolam, vecuronium, and 50% N2O in oxygen, and ventilation was controlled after orotra-cheal intubation; 12.5 mL of 2% lidocaine HCl was injected through an epidural catheter placed at T6–7 or T7–8. Hemodynamic measurements and transesophageal echocardiographic recordings were obtained before and 10, 20, 30, 40, and 60 min after lidocaine injection. Segmental wall motion was graded a posteriori by two independent experts on a predetermined scale (from 1 = normal to 5 = dyskinesia). A decrease ≥2 grades was considered an SWM abnormality indicative of ischemia. Thoracic epidural anesthesia induced a decrease in systemic arterial blood pressure, heart rate, and cardiac index. The SWM score decreased slightly from 1.34 ± 0.68 to 1.27 ± 0.64 (mean ± SD) (at 10 and 20 min, respectively) (P < 0.05). Patients were a posteriori analyzed according to whether they had documented coronary artery disease or not. The SWM score before TEA was significantly higher in patients with documented coronary artery disease (1.51 ± 0.88 vs 1.17 ± 0.51, respectively; P < 0.05) and did not change significantly after TEA. A small but statistical decrease in the SWM score was documented in the other patients (1.08 ± 0.27 at 40 min). Ephedrine was injected intravenously in two patients because of systemic hypotension >30%. In these two patients, ephedrine induced reversible SWM abnormalities that may be related to ischemia. Thoracic epidural anesthesia combined with general anesthesia did not worsen or improve SWM in patients at risk for myocardial ischemia; however, correction of hypotension with ephedrine may induce ischemia in these patients.
Address correspondence to Dr. Bonnet, Service d'Anesthésie Réanimation, Hôpital Henri Mondor, 51 Avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
© 1992 International Anesthesia Research Society