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.

RESULTS

The sample included 148 patients with a mean age of 40 ± 16.5 years, 66 (44.6%) of whom were male. The incidence of PONV was 31 (20.9%) at 0 to 2 hours, 7 (4.7%) at 2 to 6 hours, and 0 (0%) at 6 to 24 hours. POP VAS scores were significantly higher in the PONV group than in the non-PONV group at 2 hours. The mean VAS score at 2 hours was 40.5 ± 29.2 (PONV group) versus 29.8 ± 23.7 (non-PONV group) (P = .03); the VAS score at 6 hours was 41.0 ± 29.4 (PONV group) compared with 25.4 ± 26.4 (non-PONV group) (P = .13).

CONCLUSION

Our present study revealed that PONV is associated with increased POP in patients undergoing minor OMS under general anesthesia.