Timing of reversal with respect to three nerve stimulator end-points from cisatracurium-induced neuromuscular block

After elective ear surgery with cisatracurium neuromuscular blockade, 48 adults were randomly assigned to receive neostigmine: (a) at appearance of the fourth twitch of a 'train-of-four'; (b) at loss of fade to train-of-four; or (c) at loss of fade to double-burst stimulation, all monitored using a TOF-Watch SX® on one arm. For each of these conditions, the recovery from train-of-four (TOF) ratio was measured in parallel objectively using a TOF-Watch SX placed on the contralateral arm. The median (IQR [range]) time from administration of reversal to a train-of-four ratio ≥ 0.9 was 11 (9-15.5 [2-28]) min, 8 (4-13.5 [1-25]) min and 7 (4-10 [2-15]) min in the three groups, respectively. This recovery time was significantly shorter when reversal was given at loss of fade to double-burst stimulation (c), than when given at the appearance of the fourth twitch (a), p = 0.046. However, the total time to extubation may be unaffected as it takes longer for fade to be lost after double-burst stimulation than for four twitches subjectively to appear.