Association of intraocular pressure and postoperative nausea and vomiting after microvascular decompression - a prospective cohort study

BACKGROUND: Postoperative nausea and vomiting is common in patients receiving microvascular decompression. In the current study, we examined whether postoperative nausea and vomiting is associated with reduced intraocular pressure (IOP) after microvascular decompression, a measure that reflects intracranial pressure. METHODS: This is a prospective cohort study. Adult patients scheduled for microvascular decompression surgery for hemifacial spasm between January 2020 and August 2020 were eligible. IOP was measured immediately before anesthesia induction and 30 min after patients regained complete consciousness using non-contact tonometry. IOP reduction was defined by at least 1 mmHg decrease vs. preoperative baseline. The primary outcome was vomiting on postoperative day 1. RESULTS: A total of 103 subjects were enrolled. IOP was reduced in 56 (54.4%) subjects. A significantly greater proportion of patients with IOP reduction had vomiting on postoperative day 1 (51.8% (29/56) vs. 23.4% (11/47) in those without IOP reduction; p = 0.003). In the multivariate regression analysis, vomiting on postoperative day 1 was associated with female sex [odds ratio = 7.87, 95% CI: 2.35–26.32, p = 0.001] and IOP reduction [odds ratio = 2.93, 95% CI: 1.13–7.58, p = 0.027]. CONCLUSIONS: In patients undergoing microvascular decompression surgery, postoperative IOP reduction is associated with postoperative vomiting. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000029083. Registered 13 January 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12871-022-01665-x.