Dexmedetomidine reduces rocuronium dose requirement in sevoflurane anaesthesia

SummaryBackgroundWe evaluated the effect of dexmedetomidine infusion on rocuronium dose requirement, haemodynamic parameters, and the recovery of neuromuscular blockade during sevoflurane anaesthesia in patients.MaterialThis randomized study was conducted on 40 ASA I–II patients. Neuromuscular block was measured by stimulation of the ulnar nerve and acceleromyograph of adductor pollicis muscle. After tracheal intubation; patients received either 1.0 μ/kg over 10 min followed by a maintenance 0.2 μg/kg/h of dexmedetomidine (Group D)(n=20) or the same volume saline infusion (Group C)(n=20). After this, 0.6 mg/kg rocuronium was given to all patients. The incremental doses of rocuronium (0.15 mg/kg) were repeated to maintain muscle relaxation at the level of with T1 just positive or maximum up to 10% of its control. The variables recorded were times to recovery of T1 to 25%, 75%, and 90% of control and total dose of rocuronium used during surgery. Heart rate, and mean arterial pressure were recorded. The extubation criteria were adequate recovery of neuromuscular function as judged by TOF ratio >0.95.ResultsThere were significant decreases in heart rate, and mean arterial pressure in group D 15 min after intubation. The times to T1 of 25% was also significantly longer in the dexmedetomidine group (54±13 vs 35±6.7 min, respectively, p=0.001). There were no significant variables in recovery time between groups (T1 25–75%, 14.5±6.8 vs 12±5 min, respectively, p=0.193). The time required to a 90%T1 recovery was significantly longer in the dexmedetomidine group (86±29.2 vs 58±15.3 min, respectively, p=0.005). The total dose requirement of rocuronium was significantly lower in the dexmedetomidine group (61.5±4.65 vs 74±5.21 mg respectively, p=0.001).ConclusionWe concluded that dexmedetomidine infusion reduced rocuronium dose requirement, decreased hemodynamic parameters during sevoflurane anaesthesia.