[Comparison of the clinical effects of vecuronium and pancuronium bromide in general surgery]

50 patients selected at random were given vecuronium (group A) or pancuronium bromide (group B) at an initial dose of 0.05 mg X kg-1, followed by repeat injections of 0.0125 mg X kg-1. 34 other patients, separated in two groups: group C (vecuronium) and group D (pancuronium), received stronger doses of both drugs: 0.07 mg X kg-1 initially, followed by 0.022 mg X kg-1 repeat injections. The four groups were anaesthetized according to the same protocol; the patients underwent gastrointestinal and gynaecological surgery, lasting 122 +/- 50 min. The results showed that the time of onset and the duration of action of vecuronium were shorter, and that increasing the dose did not increase significantly the duration of action of these repeat doses: time of onset: 104 +/- 42 s (group A), 205 +/- 36 s (group B), 96 +/- 23 s (group C), 255 +/- 36 s (group D); duration of action: 19 +/- 6 min (group A), 36 +/- 6 min (group B), 24 +/- 7 min (group C), 43 +/- 13 min (group D); mean time between doses: 26 +/- 10 min (group A), 55 +/- 5 min (group B), 33 +/- 7 min (group C), 49 +/- 3 min (group D). The degree of muscle relaxation was always satisfactory in the four groups. Decurarization appeared to be particularly sudden with vecuronium. Neither an abnormally prolonged duration of action, nor any haemodynamic effect, nor any signs of histamine release were seen.