A COMPARISON OF CISATRACURIUM(51W89) AND ATRACURIUM BY INFUSION IN CRITICALLY-ILL PATIENTS

Objective: To evaluate and compare the safety and efficacy of cisatrac urium (51W89) and atracurium administered by continuous infusion to cr itically ill patients requiring neuromuscular blocking agents to facil itate mechanical ventilation, Design: Open, randomized, multicenter st udy of patients receiving cisatracurium or atracurium infusion to faci litate mechanical ventilation, Setting: Five university teaching hospi tal intensive care units in the United Kingdom, Patients: Sixty-one ad ult patients requiring neuromuscular blocking agents to facilitate mec hanical ventilation. Interventions: Bolus doses followed by continuous infusions of cisatracurium or atracurium were administered, Onset, ma intenance, and recovery of neuromuscular blockade were measured, using transcutaneous ulnar nerve stimulation and an accelerometer. Measurem ents and Main Results: Forty patients received cisatracurium (mean dur ation 48.1 +/- 4.2 [SEM] hrs), and 21 patients received atracurium (me an duration 46.1 +/- 5.8 hrs), The infusion rate for patients receivin g cisatracurium was 3.1 +/- 0.2 mu g/kg/min, and for patients receivin g atracurium 10.4 +/- 0.9 mu g/kg/min. There were no significant diffe rences in mean times to 70% recovery of Train-of-Four ratio (cisatracu rium 60 mins, atracurium 57 mins), although there was considerable int erpatient variation (20 to 175 mins with cisatracurium vs. 35 to 85 mi ns with atracurium). One patient who received cisatracurium exhibited intermittent bronchospasm during and after the study period. Conclusio ns: Cisatracurium, an isomer of atracurium, appears to be a suitable a gent for providing muscle relaxation in critically ill patients.