Pharmacodynamics of rocuronium 0.3 mg kg(-1) in adult patients with and without renal failure.

BACKGROUND AND AIM: The neuromuscular effects of a bolus dose of rocuronium 0.6 mg kg(-1) under propofol anaesthesia in renal failure patients are prolonged compared to healthy patients. The present study aims to describe the neuromuscular effects of 0.3 mg kg(-1) rocuronium under propofol anaesthesia in patients with renal failure and to compare these effects with healthy control patients.

METHODS: With institutional approval and informed consent, 18 healthy patients and 18 patients with renal failure took part in this prospective open label study. The renal failure patients were undergoing either renal transplantation or insertion of a shunt. Rocuronium 0.3 mg kg(-1) was given intravenously after induction of anaesthesia with propofol 1-2 mg kg(-1) and fentanyl 2 microg kg(-1). Propofol 6-12 mg kg(-1) h(-1) was used for maintenance of anaesthesia. Four acceleromyographic responses of the thumb after supramaximal stimulation of the ulnar nerve using surface electrodes at 2 Hz every 15 s were measured and recorded. The onset time, the time to recovery of the first twitch to 25% recovery and the time to a train-of-four ratio of 0.7 were all recorded. Wilcoxon rank sum testing was used to compare the pharmacodynamics and to see if medication, gender or electrolytes influenced the duration of the block. P < 0.05 was significant.

RESULTS: No statistical differences were seen in the neuromuscular blocking effects of rocuronium between the two groups but there was a significant difference (P < 0.00001) in the variability of the total duration of the block.

CONCLUSIONS: Rocuronium 0.3 mg kg(-1) is suitable for use in patients with renal failure when endotracheal intubation and neuromuscular block for a short period of time are needed. Tracheal intubation is facilitated within 4 min and the block can be antagonized within 20 min.