The Influence of Intraoperative Hypotension on the incidence of Postoperative Nausea and Vomiting

Abstract

Background and objectives: Postoperative Nausea and Vomiting (PONV) and Intraoperative Hypotension (IOH) are very frequent adverse events from anesthesia. IOH may trigger emesis as interferes with function of the vestibular apparatus and blood circulation to the brainstem. The present study has been designed to determine the association between the degree and duration of IOH and the incidence of PONV. Methods: We conducted a single-center, observational, prospective study in Portuguese-speaking adults admitted to non-cardiac surgery of intermediate or high risk according to ESC/ESA Guidelines on non-cardiac surgery between March 2020 and October 2020. Data was extracted from patient´s records in three different moments: pre-operative, intraoperative, and the immediate post-operative. Two different definitions of IOH were considered: mean arterial pressure (MAP) less than 65 mmHg for at least 15 min or clinically important hypotension with systolic blood pressure (SBP) less than 90 mmHg requiring intervention. Results: A total of 45 patients were enrolled: 57,8% women, mean age of 60,7 years. 66,7% were submitted to general anesthesia, 55.5% patients had two or more risk factors for PONV, and 46,7% of cases used two drugs from different classes as PONV prophylaxis. During intraoperative period, 68,9% of patients had at least one episode of IOH considering both definitions used. The median lowest SBP was 77mmHg. Of these patients 48,9% needed vasopressors during surgery. In the postoperative period 15,6% individuals presented with PONV. Conclusions: It was found no association between IOH episodes and the incidence of PONV. IOH definitions shown a moderate correlation.