Clinical use of vecuronium (ORG NC 45) in balanced anesthesia. Comparison with pancuronium

In 2 groups of 25 patients 0.1 mg/kg vecuronium (Org NC 45) or pancuronium, according to a randomised basis, was injected during balanced anesthesia (thiopental, fentanyl, dehydrobenzperidol and N2O). Intubation conditions 120 seconds after injection were satisfactory. After intubation, a heart rate increase was present with pancuronium (p less than 0.01), but not with vecuronium (difference: p less than 0.05); heartrate decreased 15 and 30 minutes after injection of vecuronium (p less than 0.01). The clinical duration of action of vecuronium was 32.7 +/- 2.4 min (Mean +/- SEM) and of pancuronium 73.5 +/- 4.8 min (p less than 0.01). Successive maintenance doses of 0.025 mg/kg of vecuronium had a duration of action of 23.1 +/- 1.7, 26.8 +/- 2.1, 27.6 +/- 4.0 and 24.0 +/- 2.8 min (diff. NS), showing no cumulative activity. The duration of action of identical doses of pancuronium were 56.9 +/- 3.1, 52.1 +/- 7.2 and 61.3 +/- 17.6 min (diff. NS), values nearly +/- 220% above those of vecuronium (p less than 0.01). Reversion of neuromuscular blockade after vecuronium with small amounts of neostigmine was clinically adequate.