Influence of standardized orders on postoperative nausea and vomiting after gynecologic surgery

The risk of postoperative nausea and vomiting (PONV) after gynecologic surgery remains high, despite effective prophylactic medications. Thus, the objectives of this study were to determine whether standardized orders for the prophylaxis and treatment of PONV in gynecologic surgery patients (1) reduce PONV occurrence, (2) reduce total costs, and (3) influence the choice of medications used for PONV prophylaxis and treatment.

A retrospective design was employed in which a random sample of 200 patients was selected from each of the two 6-month phases before (pre) and after (post) the implementation of standardized orders for PONV prophylaxis and treatment. The primary outcome was the occurrence of any PONV episode. Logistic regression was used to adjust for potential confounding factors. All costs were in 1999 Canadian dollars (Canadian dollar = US$0.673 in 1999).

Characteristics were similar except for surgical and anesthesia length between phases. The proportion of patients who received PONV prophylaxis increased from 31% (pre) to 47% (post; p = 0.002). There was a reduction in the risk of a PONV event in the post-phase (odds ratio [OR] 0.67, 95% CI 0.67 to 0.97; p = 0.04). The risk of PONV was significantly reduced with the administration of prophylactic medications (OR 0.46, 95% CI 0.46 to 0.67; p = 0.001). There was a reduction in the mean number of PONV episodes in the post-phase (1.47 events) versus the pre-phase (1.81 events; p = 0.02). A reduction in mean PONV management costs was observed in the post-phase ($8.31, SD +/- 8.50) compared with the pre-phase ($10.23, SD +/- 8.25; p = 0.02). For mean prophylactic costs, these were significantly higher in the postimplementation phase compared with the preimplementation phase ($1.64, SD +/- 3.36 vs. $0.91, SD +/- 2.43; p = 0.013). For mean total PONV costs (prophylaxis plus management costs), there was a nonsignificant reduction in the postimplementation phase compared with the preimplementation phase ($9.95, SD +/- 9.20 vs. $11.15, SD +/- 8.51, respectively; p = 0.18). Univariate sensitivity analyses revealed that the economic results were sensitive to several parameters.

The implementation of preprinted order forms for PONV prophylaxis and treatment appears to be an effective and economically attractive strategy.