Neostigmine 50 μg kg−1 with glycopyrrolate increases postoperative nausea in women after laparoscopic gynaecological surgery

Abstract
Neostigmine, used for reversal of neuromuscular block, has been implicated in the development of postoperative nausea and vomiting (PONV). The use of mivacurium, which does not require neostigmine reversal due to its metabolism by plasma cholinesterase, has made it possible to study the effect of neostigmine on PONV in a randomised, double-blind, placebo-controlled manner. Ninety healthy women scheduled for laparoscopic gynaecological surgery were randomly allocated to two groups in a double-blind manner. One group was given neostigmine (50 microg kg(-1)) and glycopyrrolate (10 microg kg(-1)) (group NG), the other NaCl i.v. as placebo (group P) at the end of surgery when all the patients were spontaneously reversed to at least 75% of full muscle power. The risk of PONV was reduced by using low doses of opioids and ondansetron prophylaxis. All the patients were monitored and assessed for 24 h with regard to pain, nausea, vomiting and overall satisfaction. There was a statistically significant difference (P=0.03) in the occurrence of nausea during the first 6 h postoperatively between NG group (30%) and P group (11%), resulting in the more extensive use of antiemetic drugs in the NG group (28%) than in P group (7%) (P=0.01) in this period. There was no difference between the groups in the frequency of vomiting; seven nauseated patients had vomiting, four in group NG, three in group P. Total number of patients with PONV during the observation period of 24 h, usage of antiemetic rescue medication and overall patient satisfaction did not differ significantly between the groups. The results suggest that antagonism of neuromuscular block with a high dose of neostigmine increases postoperative nausea and the use of antiemetic drugs during the first 6 h after administration.