Residual curarization in the recovery room after vecuronium

We have investigated residual block after anaesthesia which included the us e of the neuromuscular blocking agent vecuronium but no anticholinesterase, in 568 consecutive patients on admission to the recovery room. The ulnar n erve was stimulated submaximally using TOF stimulation (30 mA). Postoperati ve residual curarization was defined as a TOF ratio <0.7. Of the 568 patien ts, 239 (42%) had a TOF <0.7 in the recovery room. These patients had recei ved a larger cumulative dose of vecuronium than patients who had full recov ery (mean 7.7 (SD 3.6) mg vs 6.2 (2.7) mg; P<0.05) and a shorter time had e lapsed since the last vecuronium dose (117 (70) min vs 131 (80) min; P<0.05 ). Of 435 patients whose trachea was extubated, 145 (33%) exhibited inadequ ate recovery from neuromuscular block Six of these had one or no response t o TOF stimulation and were reintubated. In the remaining 139 patients, neur omuscular block was successfully antagonized. Only 20 patients (3.5%) remem bered TOF stimulation when questioned 2 h later in the recovery room, and d iscomfort associated with it was assessed using a visual analogue scale bef ore discharge. We conclude that it is necessary to antagonize residual bloc k produced by vecuronium.