Is Postoperative Nausea and Vomiting Associated With Increased Postoperative Pain in Patients Undergoing Minor Oral and Maxillofacial Surgery Under General Anesthesia?

Background: Whether postoperative nausea and vomiting (PONV) contributes to increased postoperative pain (POP) remains unclear, although POP is reported to cause PONV. Purpose: This study aimed to determine whether PONV following minor oral and maxillofacial surgery (OMS) under general anesthesia increases POP. Study Design, Setting, Sample: The researchers implemented a retrospective cohort study. Patients who presented to Saitama Medical University Hospital between January 2021 and August 2022 and who required minor OMS under general anesthesia were identified from a review of electronic records. The inclusion criteria were patients aged between 16 and 65 years and nasal intubation via inhalational or propofol-based total intravenous general anesthesia. The exclusion criterion was patients who had diseases affecting POP or PONV. Predictor variables: The primary predictor variable was the occurrence of PONV (yes/no) at 2 hours postoperatively. Main outcome variables: The main outcome variable was POP measured on a 100 mm visual analog scale (VAS) at 2 hours postoperatively. The secondary outcome was the timing of POP, which was measured at 6 hours. Covariates: Covariates included patient-related factors (age, body mass index, American Society of Anesthesiologists Physical Status, smoking status, and history of PONV or motion sickness), anesthesia- related factors (intraoperative analgesics, intraoperative antiemetics, duration of anesthesia, and anesthesia type), and surgery-related factors (surgery type and duration of surgery). Analyses: Analyses were used for ordinal, categorical, and continuous variables. The POP VAS values were compared between each measurement time with repeated-measures analysis of variance. A P value <.05 indicated statistical significance.