THE INFUSION REQUIREMENTS AND RECOVERY CHARACTERISTICS OF CISATRACURIUM OR ATRACURIUM IN INTENSIVE-CARE PATIENTS

Objective: To investigate the infusion requirements and recovery chara cteristics of cisatracurium compared with atracurium when both are adm inistered by prolonged continuous infusion. Design: A prospective, ran domised, single-blind study. Settings. The Intensive Care Unit of the Manchester Royal Infirmary. Patients. 20 patients requiring a continuo us infusion of a neuromuscular blocking agent to facilitate mechanical ventilation. 12 patients received cisatracurium and 8 received atracu rium. Interventions. Cisatracurium or atracurium was administered by c ontinuous infusion for a minimum of 24 h. The level of neuromuscular b lockade was measured by recording the train-of-four responses using ac celeromyography, the aim being to maintain 1-2 twitch responses of the adductor pollicis. At the end of the infusion period, the train-of-fo ur was recorded until the ratio was greater than 0.7. Measurements and Results: The mean infusion rate of cisatracurium was 0.23 mg kg(-1) h (-1), compared to 0.62 mg kg(-1) h(-1). No time-related increase in in fusion requirements was seen for either drug. The mean recovery time t o a train-of-four ratio greater than 0.7 was the same (46 min). There was no correlation between recovery time and age, duration of infusion or mean infusion rate. Conclusions. Cisatracurium provides a satisfac tory level of neuromuscular blockade in adult ICU patients at approxim ately one-third the infusion rate of atracurium and with a similar rec overy time.