MIVACURIUM IN CONTINUOUS-INFUSION FOR SHO RT PROCEDURES - DELAYS OF ONSET AND RECOVERY FROM NEUROMUSCULAR BLOCKADE

Objective: To assess the delays of onset and spontaneous recovery from neuromuscular block produced by univacurium administered by continuou s infusion for short procedure requiring a deep relaxation. Study desi gn :Prospective open non comparative study. Patients: Twenty-nine clas s ASA I and II adults undergoing a stomatological procedure of short d uration were included in the study. Method :General anaesthesia was ob tained with a continuous infusion of propofol, supplemented with alfen tanil and N2O-O-2 mixture. Neuromuscular blockade, assessed with elect romyography of the adductor pollicis muscle, was obtained with mivacur ium (150 mu g . kg(-1)). After restoration of 5% of neuromuscular tran smission, mivacurium was administered by continuous infusion in order to maintain a blockade between 91 and 99%. Results : The delay for dec reasing twitch height by 95% was 2.9 +/- 1.0 min. The mean dose for ma intenance of blockade was 10.9 +/- 1.5 mu g . kg(-1). min(-1). The del ay of spontaneous recovery from blockade was 10.2 min, 16.6 min and 21 .3 min for obtaining 25, 75 and 95% twitchs respectively. The delay fo r the twitch increase hom 25 to 75% was 6.6 min. Discussion : Mivacuri um in continuous infusion provides rapidly a deep and stable neuromusc ular blockade followed by a rapid spontaneous restoration of neuromusc ular transmission in patients with normal pseudocholinesterases.