Postoperative nausea and vomiting following inpatient surgeries in a teaching hospital: a retrospective database analysis.

OBJECTIVE: To report the incidence of postoperative nausea and vomiting (PONV), to describe the use of anti-emetics both for the prophylaxis and treatment of PONV, and to assess resource utilization and duration of post-anesthesia care unit (PACU) stay. RESEARCH DESIGN AND METHODS: We retrieved data from the Duke Anesthesia Peri-operative database. We included adult patients, who underwent inpatient surgery under general anesthesia with inhaled agents between January 2004 and February 2005, and had two or more risk factors for PONV documented preoperatively (female, previous history of PONV or motion sickness, non-smoker or use of postoperative opioid). Data on the use of prophylactic anti-emetics, the incidence of PONV, nausea scores, pain scores, and the use of rescue anti-emetics in PACU and in the period between PACU discharge and 24 h after surgery were recorded. Resource utilization and cost assessment was performed from the perspective of the hospital and included length and direct cost of PACU stay, as well as the acquisition costs of rescue anti-emetics in PACU. Descriptive statistics were used to summarize the demographic characteristics of patients. For group comparisons, data were analyzed with the t-test for continuous data, and the Chi-square test for categorical data. Multiple linear regression models were used to evaluate the association between PONV and PACU length of stay adjusting for confounding factors.
RESULTS: A total of 3641 patients were included in the analysis. Of those, 2869 (79%) received prophylactic anti-emetics. In the PACU, nausea and vomiting were reported in 16% and 3% of the patients, respectively. Rescue anti-emetics were given to 26% of all patients. The incidence of vomiting was significantly less in patients who received PONV prophylaxis (p = 0.03). In multiple linear regression models, the duration of PACU stay was longer by a mean of 25 min in patients who experienced PONV or received rescue anti-emetics in PACU (p < 0.0001) despite the fact that the duration of surgery was shorter by a mean of 24 min in this group of patients (p < 0.0001). Following PACU discharge, 40% of patients reported nausea, vomiting or needed rescue anti-emetics. PONV was associated with significantly increased resource utilization and costs of PACU stay (p < 0.0001). Emesis was associated with greater incremental cost (138 US dollars) than nausea (85 US dollars), mainly from the longer duration of PACU stay.
CONCLUSIONS: PONV remain a significant problem postoperatively and often persists beyond PACU discharge. The presence of PONV is associated with increased length of PACU stay and greater resource utilization and costs.