EFFECT OF DIABETES-MELLITUS ON THE CARDIOVASCULAR-RESPONSES TO INDUCTION OF ANESTHESIA AND TRACHEAL INTUBATION

We have compared cardiovascular responses to induction of anaesthesia and to tracheal intubation after propofol 2.5 mg kg-1 and pancuronium 0. 1 mg kg-1 in 10 diabetic and 10 matched, non-diabetic (control) ASA I patients. Anaesthesia was maintained with 0.8% enflurane and 50% ni trous oxide in oxygen, with assisted ventilation. The trachea was intu bated 3 min after induction of anaesthesia. All 10 diabetic patients ( but no controls) had abnormal autonomic function when tested on the da y before surgery. There was no difference between the two groups in th e preinduction cardiovascular state. Mean arterial pressure and vascul ar resistance decreased after induction in each group (P < 0.05). Hear t rate increased (P < 0.01) and cardiac index was sustained in the con trol group, but in the diabetic group heart rate did not change and ca rdiac index decreased (P < 0.0 1). There was an earlier decrease in st roke index in the diabetic group (2 min) compared with the controls (5 min). After tracheal intubation, heart rate and cardiac index in the control group and cardiac index in the diabetic group remained unchang ed. However there was a greater increase in heart rate, mean arterial pressure and vascular resistance in the diabetic group compared with t he controls after tracheal intubation (P < 0.05). The exaggerated pres sor response to tracheal intubation, in the diabetic patients, may ref lect autonomic dysfunction.