Reversal of neuromuscular blockade with neostigmine has no effect on the incidence or severity of postoperative nausea and vomiting

We performed this randomized, double-blind, placebo-controlled study to determine whether reversal of neuromuscular block with neostigmine increases the incidence and severity of postoperative nausea and vomiting (PONV). We studied 162 women undergoing abdominal hysterectomy and randomly allocated them into two groups. In Group A, neuromuscular block produced with mivacurium was antagonized with neostigmine 2.0 mg and glycopyrrolate 0.4 mg intravenously, whereas Group B received no drugs to facilitate antagonism of blockade. The incidence and severity of PONV was assessed up to 27 h after the operation. There was no difference in PONV between the groups (in Group A 35% had nausea and 33% vomited; in Group B 28% nauseated and 40% vomited) or in the amount of antiemetics given. We had a 75% chance to find a 30% difference in PONV. We conclude that the administration of neostigmine and glycopyrrolate at the end of anesthesia to reverse neuromuscular block does not increase the incidence or severity of PONV. Implications: Neostigmine may increase postoperative nausea and vomiting. In this study, omission of reversal of neuromuscular block with neostigmine failed to decrease the incidence or severity of postoperative nausea and vomiting.