Post-tetanic burst count and train-of-four during recovery from vecuronium-induced intense neuromuscular block under different types of anaesthesia.

Recovery of neuromuscular blockade after vecuronium 0.2 mg kg-1 was measured by post-tetanic burst count (PTBC) and train-of-four (TOF) in 120 adult patients anaesthetized by one of four techniques: neuroleptanaesthesia or one minimum alveolar concentration of isoflurane, enflurane, or sevoflurane. Onset of recovery was taken when there was reflex movement in response to carinal stimulation. The time course of recovery measured by burst count was similar for all four types of anaesthesia. Recovery of each of the twitches of the TOF was significantly shorter under neuroleptanaesthesia than under isoflurane, enflurane, or sevoflurane anaesthesia [times to return of T1 were 41.4 +/- 5.4, 51.5 +/- 10.6, 52.2 +/- 10.0, or 55.3 +/- 11.2 min (mean +/- SD). P < 0.05]. The burst count at the onset of reflex movement was less under neuroleptanaesthesia than under isoflurane, enflurane, or sevoflurane anaesthesia (16.3 +/- 4.8, 26.7 +/- 6.7, 27.7 +/- 6.8, 28.0 +/- 8.4, P < 0.05). The ratio of first twitch to control twitch at the onset of reflex movement was the same for all four types of anaesthesia.