To assess the usefulness of 6-min walk test for determining autonomic dysfunction in diabetic patients compared with non-diabetic patients during preoperative evaluation: A prospective observational controlled study.

Abstract

Background: The incidence of perioperative cardiovascular morbidity and mortality in diabetic patients is due to impaired cardiovascular response to exercise caused by impairment in peripheral blood flow and oxygen diffusion to the exercising muscle. Preoperative bedside testing by 6-min walk for autonomic dysfunction in diabetic patients might reduce haemodynamic instability and cardiovascular complications.

Methods and materials: Sixty patients with American Society of Anaesthesiologists grade 1 classification and 60 diabetic patients (total of 120) of age 30-60 years, of either sex, undergoing elective surgery under general anaesthesia were recruited. A 6-min walk test, breath-holding time and five clinical bedside tests for autonomic dysfunction were performed. Based on that, patients were classified into non-diabetic patients (group C), diabetic patients without autonomic dysfunction (group D) and diabetic patients with autonomic dysfunction (group A).

Results: The incidence of autonomic dysfunction was 31.7%. Among all the parameters, breath-holding time, steps and distance covered by 6-min walk test was significantly less in group A. The incidence of intraoperative tachycardia and hypotension was significantly higher (78.9% and 57.9%, respectively) in group A.

Conclusion: The 6-min walk test can be used as one of the preliminary tests for detection of cardiac autonomic neuropathy in diabetes since it had association with distance covered and intraoperative haemodynamic disturbances.