Response to double-burst appears before response to train-of-four stimulation during recovery from non-depolarizing neuromuscular blockade.

Background: Double-burst stimulation (DBS) it a relatively new nerve stimulation mode introduced for improved manual detection of residual neuromuscular blockade. Previous studies have shown that DBS3,3 50/50 (3 stimuli at 50 Hz followed 0.75 seconds later by 3 stimuli at 50 Hz) can detect deeper degrees of neuromuscular blockade than train-of-four (TOF) stimulation.

Aim: The aim of the present study was to examine if DBS3,3 80/40 (3 stimuli at 80 Hz followed 0.750 s later by 3 stimuli at 40 Hz) can detect even deeper degrees of neuromuscular blockade than DBS3,3 50/50 and to determine the time lapse from reappearance of response to each of the two DBS modes until reappearance of response to the TOF mode of nerve stimulation.

Methods: The study comprised 20 women undergoing gynaecological surgery and anaesthetised with fentanyl, thiopentone, halothane, and nitrous oxide. Neuromuscular transmission was monitored by using mechanomyography and stimulation of the ulnar nerve. Atracurium was used for neuromuscular blockade.

Results: Elapsed time from reappearance of response to DBS3,3 80/40 and DBS3,3 50/50 to reappearance of response to TOF stimulation was 459 +/- 196 (mean +/- SD) and 360 +/- 150 seconds, respectively, (P < 0.05).

Conclusions: DBS3,3 80/40 is capable of detecting deeper degrees of blockade than DBS3,3 50/50, which again is capable of detecting deeper degrees of blockade than TOF.