Validation of the postoperative nausea and vomiting intensity score in gynaecological patients

The Postoperative Nausea and Vomiting (PONV) Intensity Scale was developed to distinguish trivial from clinically important PONV perioperatively and has been validated in a general surgical population. This study aimed to assess the scale in gynaecological surgery patients. Seventy-three patients undergoing gynaecological surgery were included. Interviews occurred at four and 24 hours postoperatively. Measurements included the PONV Intensity Scale, nausea and pain visual analogue scale, antiemetic use and complications related to PONT. Ten patients (14%) had a clinically significant PONV Intensity Scale score, 42 (58%) reported nausea and 15 (21%) reported vomiting during the study. At 24 hours, 80% of patients with a clinically significant score at four hours had received antiemetics vs 18% of those without a clinically significant score (P = 0.001). Of patients with a clinically significant score at 24 hours, 71% had suffered a complication vs 11% of those without a clinically significant score (P < 0.0001). The median nausea visual analogue scale scores at four hours were 69 mm (interquartile range 69 to 76 mm) in patients with a clinically significant score vs 0 mm (0 to 9 mm) in patients without a clinically significant score (mean difference 56 mm, 95% confidence interval 41 to 72 mm, P < 0.0001). The PONV Intensity Scale is a valid, responsive and practically useful instrument in distinguishing trivial from clinically significant PON. The rate of clinically important PONV is considerably lower than the rate of any PONV symptoms perioperatively.