K E Griffith1, G P Joshi, P F Whitman, S A Garg. 1. Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center at Dallas 75235-9068, USA.
Abstract
STUDY OBJECTIVE: To investigate the effects of priming rocuronium on the time course of neuromuscular blockade. DESIGN: Prospective, controlled, randomized clinical study. SETTING:University teaching hospital. PATIENTS: 42 ASA physical status I and II patients undergoing peripheral surgery with general anesthesia. INTERVENTIONS: Following a standardized propofol-fentanyl induction, patients in Group 1 (n = 21) received a priming dose of rocuronium 0.06 mg/kg followed two minutes later by an intubating dose of rocuronium 0.54 mg/kg. Patients in Group 2 (n = 21) received a saline placebo injection followed two minutes later by rocuronium 0.6 mg/kg. Anesthesia was maintained with isoflurane and nitrous oxide 60% in oxygen. MEASUREMENTS AND MAIN RESULTS:Neuromuscular function was assessed at the wrist using mechanomyography with a single-twitch mode of stimulation at a frequency of 1 Hz until tracheal intubation and at 0.1 Hz thereafter. The times from injection of the intubating dose of rocuronium until 95% suppression of the twitch tension (onset time), recovery of twitch tension to 25% of control (clinical duration of action), and the time from 25% to 75% spontaneous recovery of twitch tension (recovery index) were recorded. The trachea was intubated at 95% depression of the twitch tension and the intubating conditions were graded using a 3-point scale. The onset times with priming rocuronium (34 +/- 6 s) were significantly shorter (p < 0.01) than those without priming (59 +/- 14 s). The intubation conditions were similar in the two groups; however, the intubating times with priming were significantly shorter. The clinical duration of action and the recovery index did not differ significantly between the two groups. CONCLUSIONS: Priming rocuronium decreased the onset times and thus, the intubating times without increasing the clinical duration of action or recovery index.
RCT Entities:
STUDY OBJECTIVE: To investigate the effects of priming rocuronium on the time course of neuromuscular blockade. DESIGN: Prospective, controlled, randomized clinical study. SETTING: University teaching hospital. PATIENTS: 42 ASA physical status I and II patients undergoing peripheral surgery with general anesthesia. INTERVENTIONS: Following a standardized propofol-fentanyl induction, patients in Group 1 (n = 21) received a priming dose of rocuronium 0.06 mg/kg followed two minutes later by an intubating dose of rocuronium 0.54 mg/kg. Patients in Group 2 (n = 21) received a saline placebo injection followed two minutes later by rocuronium 0.6 mg/kg. Anesthesia was maintained with isoflurane and nitrous oxide 60% in oxygen. MEASUREMENTS AND MAIN RESULTS: Neuromuscular function was assessed at the wrist using mechanomyography with a single-twitch mode of stimulation at a frequency of 1 Hz until tracheal intubation and at 0.1 Hz thereafter. The times from injection of the intubating dose of rocuronium until 95% suppression of the twitch tension (onset time), recovery of twitch tension to 25% of control (clinical duration of action), and the time from 25% to 75% spontaneous recovery of twitch tension (recovery index) were recorded. The trachea was intubated at 95% depression of the twitch tension and the intubating conditions were graded using a 3-point scale. The onset times with priming rocuronium (34 +/- 6 s) were significantly shorter (p < 0.01) than those without priming (59 +/- 14 s). The intubation conditions were similar in the two groups; however, the intubating times with priming were significantly shorter. The clinical duration of action and the recovery index did not differ significantly between the two groups. CONCLUSIONS: Priming rocuronium decreased the onset times and thus, the intubating times without increasing the clinical duration of action or recovery index.