Mivacurium as an alternative to succinylcholine during outpatient laparoscopy

Abstract Study Objectives: To compare (1) the adequacy of conditions for tracheal intubation; (2) the onset, depth, clinically effective duration, and recovery profile; and (3) adverse effects associated with mivacurium as an alternative to succinylcholine during general (endotracheal) anesthesia for outpatient laparoscopy. Design: A randomized, controlled clinical trial. Setting: Barnes Hospital Outpatient Surgery Center. Patients: Sixty healthy consenting ASA physical status I or II adult female outpatients. Interventions: Following a standardized thiopental sodium-alfentanil induction, patients were randomly assigned to one of three groups: Group I - alfentanil-nitrous oxide (N 2 O)-succinylcholine; Group II - alfentanil-N O-mivacurium; Group III — enflurane-N 2 O-mivacurium. Measurements and Main Results: Neuromuscular blockade was measured by electromyography of the stimulated adductor pollicis muscle contraction. Tracheal intubation was attempted after achieving 70% or greater blockade and was graded on a fourpoint scale. Onset and recovery were more rapid with succinylcholine than with mivacurium. The clinically effective duration of action of mivacurium was not significantly different in the enflurane-N 2 O group compared with the alfentanil-N O group. Side effects with mivacurium included flushing and occasional wheezing. Conclusions: Mivacurium 0.15 mglkg given intravenously provided good to excellent conditions for tracheal intubation in 2 to 3 minutes. This dose provided a clinically effective duration of action of 20 to 25 minutes, and the residual blockade was readily reversible with neostigmine. Mivacurium did not, however, offer any apparent advantage over succinylcholine in this outpatient population.