Monitoring of neuromuscular block after administration of vecuronium in patients with diabetes mellitus.

BACKGROUND We studied the supramaximal current for ulnar nerve stimulation during electromyographic monitoring of onset and recovery of neuromuscular block using a neuromuscular transmission module (M-NMT Module, Datex-Ohmeda) in patients with Type 2 diabetes undergoing anaesthesia with nitrous oxide, oxygen, isoflurane and fentanyl. METHODS Thirty-six diabetic patients were randomly assigned to a post-tetanic count (PTC) group (n=17) or train-of-four (TOF) group (n=19). In addition, 30 non-diabetic patients were divided into control PTC (n=15) and TOF groups (n=15). RESULTS In the diabetic patients (diabetes PTC and diabetes TOF groups), the mean supramaximal stimulating current was significantly higher than in the non-diabetic patients (control PTC and TOF groups) (50.5 (SD 14.1) vs 33.4 (6.1) mA, P<0.01). Onset of neuromuscular block (time to disappearance of T1) after vecuronium 0.1 mg kg(-1) in the diabetic patients did not differ significantly from that in the non-diabetic patients (276 (77) vs 244 (44) s, P=0.055). Time to return of PTC1 did not differ significantly between the diabetes and control PTC groups (21.0 (12.1) vs 15.7 (5.0) min, P=0.126). Times to return of T1 and T4 in the diabetes TOF group were significantly longer than in the control TOF group (T1: 37.5 (15.2) vs 25.7 (7.6) min, P=0.01; T4: 61.4 (23.7) vs 43.5 (11.4) min, P=0.01). During recovery, PTC and T4/T1 in the diabetes PTC and TOF groups were similar to those in the control PTC and TOF groups, respectively. T1/T0 in the diabetes TOF group was significantly less than in the control TOF group, 80-120 min after vecuronium (P<0.05). CONCLUSIONS In diabetic patients, supramaximal current is higher than in non-diabetic patients. After vecuronium, onset of neuromuscular block and recovery of PTC or T4/T1 are not altered, but time to return of T1 or T4, and recovery of T1/T0 are delayed in diabetic patients.