Efficacy of different doses of atracurium on intubating conditions of burned patients

Background
Burned patients exhibit resistant response to nondepolarizing muscle relaxants. This study was designed to investigate the efficacy of high dose atracurium (3 and 4 times ED95) with and without application of the priming principle on the intubating conditions and the onset times in burned patients.
Methods
ASA physical status I and II patients undergoing burn related surgery, were randomly allocated into one of four groups of 20 patients each. Group I received 1 ml placebo followed 3 min later by atracurium 0.75 mg/kg, group II received atracurium 0.04 mg/kg as the priming dose followed 3 min later by atracurium 0.71 mg/kg, group III received 1 ml placebo followed 3 min later by atracurium 1 mg/kg and group IV received atracurium 0.04 mg/kg as the priming dose followed 3 min later by atracurium 0.96 mg/kg. Datex relaxograph was used at the adductor pollicis to monitor and record the twitch response to the train of four (TOF) stimulation.
Results
The conditions for intubation improved significantly with increasing the dose of atracurium, as we seen, when comparing patients in group IV and group I. Onset times were significantly delayed in groups I and II compared with groups III and IV.
Conclusion
Combinations of 4 times ED95 of atracurium together with the application of the priming principle are required to overcome the resistance and produce satisfactory intubating conditions in burned patients.