Original Article

Assessment of Depth of Anesthesia During Cardiopulmonary Bypass

Department of Anesthesiology, Mount Sinai School of Medicine, New York, New York

^* Direct communications to: George Silvay, M.D., The Mount Sinai Medical Center, Dept. of Anesthesiology, Box 1010, One G.L. Levy Place, New York, NY 10029-6574.

Abstract

Despite recent advances in the anesthetic management of patients undergoing open heart surgery (OHS), little is known concerning depth of anesthesia in the presence of variable surgical stimuli. The present study was designed to evaluate anesthetic depth during hypothermic cardiopulmonary bypass (CPB) utilizing continuous monitoring of lower esophageal contractility (LEC). Tertiary esophageal contractions are stress related, and their presence during cardiopulmonary bypass may indicate inadequate depth of anesthesia. The responses to inappropriate depth of anesthesia may correlate with increased postoperative morbidity or awareness. The present study was designed to evaluate the depth of anesthesia during hypothermic cardiopulmonary bypass and compare lower esophageal contractility (LEC) with other parameters available to assess depth of anesthesia: mean arterial pressure/perfusion flow/temperature and electroencephalogram (EEG) and somatosensory evoked potential (SEP) measurements.