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.