Canadian Journal of Anesthesia, Vol 33, 453-457, Copyright © 1986 by Canadian Anesthesiologists' Society

The Optimal Priming Dose for Atracurium

¹ Department of Anaesthesiology and the Biostatistics Unit, Department of Community Medicine, King Faisal University

Address correspondence to: Dr. Mohamed Naguib, Department of Anaesthesiology, King Faisal University, King Fahd Hospital, P.O. Box 2208, Al-Khobar 31952, Saudi Arabia.

To determine the optimal priming dose for administration in divided doses, atracurium was given to 77 patients either in a single dose of 0.5 mg·kg^-1 or in an initial dose of 0.04, 0.05, 0.06, 0.07, 0.08 or 0.09 mg·kg^-1, followed three minutes later by the remainder of the 0.5 mg·kg^-1 dose. Patients were anaesthetized throughout the study. When atracurium was given as a single bolus of 0.5 mg·kg^-1, the mean time to complete neuromuscular block was 141.5 seconds. Administration in divided doses accelerated the onset time (p < 0.01), that is the time from the intubating dose to the complete suppression of train-of-four (TOF) response. The TOF ratio decreased slightly but statistically significantly following the priming doses. When the priming dose was 0.05 mg·kg^-1, the mean onset time was 70.9 seconds and priming with larger doses did not add any further advantage. It is concluded that 0.05 mg·kg^-1 appears to be the optimal priming dose for the administration of atracurium in divided doses. When 0.05 mg·kg^-1 is given three minutes before the intubating dose, tracheal intubation can be accomplished in less than 90 seconds.

Key Words: INDUCTION: anaesthesia • INTUBATION: endotracheal • NEUROMUSCULAR RELAXANTS: atracurium