The Infusion Requirements and Recovery Characteristics of Cisatracurium or Atracurium in Intensive Care Patients

Objective: To investigate the infusion requirements and recovery characteristics of cisatracurium compared with atracurium when both are administered by prolonged continuous infusion.

Design: A prospective, randomised, single-blind study.

Settings: The Intensive Care Unit of the Manchester Royal Infirmary.

Patients: 20 patients requiring a continuous infusion of a neuromuscular blocking agent to facilitate mechanical ventilation. 12 patients received cisatracurium and 8 received atracurium.

Interventions: Cisatracurium or atracurium was administered by continuous infusion for a minimum of 24 h. The level of neuromuscular blockade was measured by recording the train-of-four responses using acceleromyography, the aim being to maintain 1-2 twitch responses of the adductor pollicis. At the end of the infusion period, the train-of-four 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 infusion requirements was seen for either drug. The mean recovery time to 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 satisfactory level of neuromuscular blockade in adult ICU patients at approximately one-third the infusion rate of atracurium and with a similar recovery time.