The effects of antagonizing residual neuromuscular blockade by neostigmine and glycopyrrolate on nausea and vomiting after ambulatory surgery.

UNLABELLED: The effects of neostigmine on the incidence of postoperative nausea and vomiting (PONV) are controversial. In this study, we evaluated the effects of neostigmine and glycopyrrolate on the incidence of PONV and the need for antiemetics in patients undergoing ambulatory surgery. One hundred healthy patients undergoing outpatient surgical procedures were included in the study. A standardized anesthetic technique was used for all patients. Patients were randomized to receive either mivacurium (n = 50) or rocuronium (n = 50) to achieve muscle paralysis. Bolus doses of mivacurium 2-4 mg or rocuronium 5-10 mg were administered to maintain one or two twitches of the train-of-four stimulation of the ulnar nerve at the wrist. After surgery, residual neuromuscular blockade was reversed with neostigmine 2.5 mg i.v. and glycopyrrolate 0.5 mg i.v. only if clinically deemed necessary (i.e., fade on train-of-four stimulation, inadequate tidal volume, reduced hand grip, or inability to maintain head lift). The incidence of PONV and the need for antiemetics were recorded in the post-anesthesia care unit (PACU), in the phase II unit, and 24 h after surgery. We compared patients who received neostigmine (n = 40) for reversal of residual neuromuscular blockade with those who did not (n = 60). More patients receiving rocuronium required reversal drugs than those receiving mivacurium (68% vs 10%). There were no differences in the incidence of nausea (18% vs 15%), vomiting (8% vs 12%), and the need for antiemetics (13% in both the groups) in the PACU between patients who received neostigmine and those who did not. In addition, the duration of PACU stay and the time to home-readiness were also similar between the groups. We conclude that, compared with rocuronium, the use of mivacurium decreases the need for reversal drugs. In addition, reversal of residual neuromuscular blockade with neostigmine does not increase the incidence of PONV or the need for antiemetic medications in patients undergoing ambulatory surgery. IMPLICATIONS: In this study, we showed that the incidence of postoperative nausea and vomiting and the need for antiemetics do not increase with the use of neostigmine and glycopyrrolate for reversal of residual muscle paralysis.