Association of Intraoperative Hypotension with Postoperative Nausea and Vomiting in Laparoscopic Gastrointestinal Surgery: A Secondary Analysis of a Randomized Trial.

Background: Few studies have examined the association between intraoperative hypotension and postoperative nausea and vomiting (PONV), and no definitive conclusions have been established. This study investigated the association between intraoperative hypotension and PONV in patients undergoing laparoscopic gastrointestinal surgery.

Methods: This secondary analysis of a randomized trial included adult patients at high risk for PONV undergoing laparoscopic gastrointestinal surgery. Intraoperative hypotension was quantified as a time-weighted average mean arterial pressure (TWA-MAP) less than 65 mmHg. Primary and secondary outcomes were PONV within 0 to 24 h and 25 to 120 h after surgery, respectively. The authors assessed the association between intraoperative hypotension and outcomes using restricted cubic splines and multiple logistic regression models, adjusting for potential confounders. Sensitivity analyses were conducted using various mean arterial pressure thresholds (70, 60, 55 mmHg) and metrics (area under the curve [AUC], duration) with similar models.

Results: In total, 1,093 patients were included (median age, 56 yr; 1,054 [96.4%] women). The medians [interquartile ranges] of TWA-MAP less than 65 mmHg, AUC, and duration of mean arterial pressure less than 65 mmHg were 0.03 [0.00, 0.14] mmHg, 6.33 [0.17, 30.17] mmHg · min, and 1.83 [0.17, 7.00] min, respectively. The overall incidence of PONV within 0 to 24 h and 25 to 120 h after surgery was 40.4% and 42.9%, respectively. No exposure-response relationship was found between TWA-MAP less than 65 mmHg and either the primary or secondary outcome. Compared with the first tertile of TWA-MAP less than 65 mmHg, patients in the second and third tertiles did not have a higher risk of primary outcome (adjusted odds ratio, 0.92 [95% CI, 0.67 to 1.24; P = 0.569] and 0.95 [95% CI, 0.70 to 1.30; P = 0.755], respectively) or secondary outcome (adjusted odds ratio, 1.05 [95% CI, 0.77 to 1.42; P = 0.772] and 0.86 [95% CI, 0.63 to 1.18; P = 0.360], respectively). Intraoperative hypotension was not associated with PONV in any sensitivity analyses.

Conclusions: Intraoperative hypotension was not associated with PONV in patients at high risk of PONV who underwent laparoscopic gastrointestinal surgery.