Association of diabetic autonomic neuropathy with hemodynamic instability following spinal anaesthesia in patients with type 2 diabetes mellitus: A prospective observational study

Background

Diabetic autonomic neuropathy (DAN) blunts the compensatory sympathetic and baroreflex responses that limitthe fall in blood pressure after spinal anaesthesia. We examined whether DAN, diagnosed preoperatively by cardiovascularautonomic reflex tests (CARTs), is associated with hemodynamic instability after subarachnoid block in patients with type 2diabetes mellitus (T2DM). Materials and Methods: In this prospective observational study, 50 adults with T2DM scheduledfor elective infra-umbilical surgery under spinal anaesthesia underwent the COMPASS-31 symptom questionnaire and the fiveEwing CARTs before surgery and were classified as having no, early, definite or severe DAN. Blood pressure and heart ratewere recorded at baseline and at 1, 3, 5, 10, 15, 20, 30, 45 and 60 min after intrathecal hyperbaric bupivacaine. The primaryoutcome was post-spinal hypotension (fall in systolic blood pressure [SBP] >20% from baseline); secondary outcomes weresevere hypotension (>30% fall), bradycardia (heart rate <50 beats/min), vasopressor requirement and the nadir of SBP andmean arterial pressure (MAP).