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

The effects of neostigmine on the incidence of postoperative nausea and vom iting (PONV) are controversial. Ln this study, we evaluated the effects of neostigmine and glycopyrrolate on the incidence of PONV and the need for an tiemetics in patients undergoing ambulatory surgery. One hundred healthy pa tients undergoing outpatient surgical procedures were included in the study . A standardized anesthetic technique was used for all patients. Patients w ere randomized to receive either mivacurium (n = 50) or rocuronium (n = 50) to achieve muscle paralysis. Bolus doses of mivacurium 2-4 mg or rocuroniu m 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 IV and glycopyr rolate 0.5 mg IV only if clinically deemed necessary (i.e., fade on train-o f-four stimulation, inadequate tidal volume, reduced hand grip, or inabilit y to maintain head lift). The incidence of PONV and the need for antiemetic s were recorded in the postanesthesia care unit (PACU), in the phase II uni t, and 24 h after surgery. We compared patients who received neostigmine (n = 40) for reversal of residual neuromuscular blockade with those who did n ot (n = 60). More patients receiving rocuronium required reversal drugs tha n 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 a ntiemetics (13% in both the groups) in the PACU between patients who receiv ed neostigmine and those who did not. Ln addition, the duration of PACU sta y and the time to home-readiness were also similar between the groups. We c onclude that, compared with rocuronium, the use of mivacurium decreases the need for reversal drugs. In addition, reversal of residual neuromuscular b lockade with neostigmine does not increase the incidence of PONV or the nee d for antiemetic medications in patients undergoing ambulatory surgery. Imp lications: In this study, we showed that the incidence of postoperative nau sea and vomiting and the need for antiemetics do not increase with the use of neostigmine and glycopyrrolate for reversal of residual muscle paralysis .