ABSTRACT
In seven patients (M/F: 4:3) rocuronium 0.6 mg kg-1 was given after the induction of anaesthesia with propofol, and during maintenance with N2O/O2, halothane 0.5% and alfentanil 60-90 micrograms kg-1 h-1. Intubation conditions were scored at 60 s and lag time, onset time, maximal block achieved, recovery to 25% of T1, and Recovery Index, were measured using a Relaxograph. Blood samples were taken over a 300 min period and analysed for rocuronium. Intubating conditions at 60 s were excellent in all patients. Mean clearance was 5.2 ml kg-1 min-1, the terminal half-life was 69 min and distribution volume at steady state was 0.22 litre kg-1. Cumulative urinary excretion was around 18% within 24 h.
Subject(s)
Androstanols/pharmacokinetics , Neuromuscular Nondepolarizing Agents/pharmacokinetics , Adult , Androstanols/pharmacology , Anesthesia , Electromyography , Female , Humans , Intubation, Intratracheal , Male , Neuromuscular Junction/drug effects , Neuromuscular Junction/physiology , Rocuronium , Synaptic Transmission/drug effects , Time FactorsABSTRACT
OBJECTIVES: To compare intubation conditions and neuromuscular parameters, patency time, maximum level of block, time and clinical duration of effect for rocuronium bromide 0.6 mg/kg (ORG 9426) versus equally potent doses of vecuronium and atracurium under similar experimental conditions. PATIENTS AND METHODS: Sixty patients were divided into three groups of twenty. Intubation conditions were scored on a scale of 3-12 points based on relaxation of the vocal cords, presence of cough and ease of laryngoscopy after 60 or 90 sec. Neuromuscular parameters were obtained by integrated electromyography of the thenar and hypothenar muscle structure, evoked by supramaximal stimuli of the cubital nerve in train of four (2 Hz in 2 sec). The shape of the electrocardiographic curve, heart rate and mean arterial pressure measured non-invasively were recorded throughout the surgical procedure. RESULTS: Means of onset times and times of effect for rocuronium (33 and 135 sec) were significantly lower than those obtained with vecuronium and atracurium. Clinical duration, free of hemodynamic changes, was similar in the three groups. Rocuronium produces excellent intubation conditions 60 sec after administration, although at this point peripheral muscle block was only partial. Rocuronium may be superior to other neuromuscular blockers available today as a result of the speed with which it affords excellent intubation conditions.
