Preoperative Autonomic Function Abnormalities in Patients with Diabetes Mellitus and Patients with Hypertension

BACKGROUND: This study was done to assess whether or not autonomic function abnormalities identified patients with diabetes mellitus as being at risk for postoperative cardiac arrest or death. STUDY DESIGN: We prospectively studied 74 patients with diabetes mellitus and 118 patients with hypertension without diabetes mellitus undergoing elective noncardiac operation. The study was done at an academic medical center between 1982 and 1985. Patients were evaluated preoperatively, monitored intraoperatively by an independent observer and had daily follow-up evaluation for seven days postoperatively, according to a standard surveillance protocol. Outcomes were judged by assessors unaware of the preoperative status and intraoperative course. Patients were interviewed at three and five years postoperatively. RESULTS: Patients with diabetes mellitus with two or more abnormal autonomic function test results did not experience more intraoperative hypotension, nor did they require more intraoperative pressor agents than patients with diabetes mellitus with one or no abnormalities. Seven percent of the patients with diabetes mellitus experienced postoperative cardiorespiratory arrest or death. All of these patients had more than two abnormal autonomic function test results as well as a previous history of either myocardial infarction or cardiomegaly. CONCLUSIONS: While this study obviously requires confirmation in a larger population, the data are sufficiently strong to warrant close postoperative monitoring of all patients with diabetes mellitus who have two or more autonomic abnormalities.