ABSTRACT
OBJECTIVE: To compare the clinical conditions for intubation and neuromuscular parameters after a high dose of mivacurium (0.25 mg/kg; 3 x SD95) administered in 30 s to those obtained after use of the usual dose of succinylcholine (1 mg/kg). PATIENTS AND METHODS: Eighty-two patients, 37 in the succinylcholine group and 45 in the mivacurium group, were studied. Intubating conditions were assessed on a scale of 3 to 12 points analyzing ease of laryngoscopy, relaxation of vocal cords and presence of cough 60 seconds after administration of the drug. Neuromuscular parameters were acceleration of the thumb induced by supramaximal train-of-four stimulation of the cubital nerve. Heart rate and non-invasive mean blood pressure were recorded throughout surgery. Cutaneous flush was looked for after administration of the relaxant. RESULTS: Time to onset of effect (159 s versus 82 s) and times to recovery after mivacurium were significantly longer than with succinylcholine. Mivacurium afforded excellent/good conditions for intubation in 95.6% of cases, with a neuromuscular blockade at intubation of 52.68%. No significant hemodynamic changes or side effects were observed. CONCLUSIONS: Given the moderate conditions of intubation achieved at 60 s, mivacurium can not be recommended as a relaxant in situations that require a rapid induction sequence. In elective surgery, 0.25 mg/kg of mivacurium can, however, be considered an alternative to succinylcholine.
