Simplified postoperative nausea and vomiting impact scale for audit and post-discharge review.

Abstract

Postoperative nausea and vomiting (PONV) is common but many episodes may be trivial or transient. The aim of the study was to develop a simple-to-use measure of the intensity and clinical impact of PONV. We re-analysed data from a study enrolling 163 patients recovering from surgery and anaesthesia that had experienced or were at increased risk of developing PONV. A range of measures of PONV characteristics and quality of recovery were collected. We devised a simplified nausea-vomiting impact scale based on patients' assessment of the impact of their nausea on their postoperative recovery and the number of times they experienced vomiting. We then undertook further tests of construct and discriminant validity, and reliability and responsiveness, of the impact scale using psychometric methodology. Around one in five patients with PONV had features that could classify them as having clinically important PONV. We found that patients with clinically important PONV had a much poorer quality of recovery (P<0.0005), needed more antiemetic administrations for treatment (P<0.0005), and were more likely to have consequences and complications of PONV (all P<0.01), when compared with those with lesser degrees of PONV. A change in clinically important PONV status can be reliably detected with the PONV impact scale. We have devised and validated a simplified PONV impact scale that can be used to identify those with clinically important PONV. The avoidance of clinically important PONV could be used as a quality indicator or outcome measure after surgery.