Validation of the translation and cross-cultural adaptation into Spanish of the Postoperative Nausea and Vomiting Intensity Scale

Introduction: Postoperative nausea and vomiting (PONV) is a common problem in patients undergoing surgical procedures, generating patient dissatisfaction and increasing hospital costs. The Postoperative Nausea and Vomiting Intensity Scale identifies clinically significant cases; however, it has not been validated in Spanish. Objective: To carry out a cross-cultural adaptation of the PONV Intensity Scale into Spanish and validate it for use in the postoperative period of patients undergoing elective non-cardiac and non-intracranial surgery. Materials and methods: Cross-sectional validation study of a diagnostic test. The NVPO Intensity Scale was culturally adapted to Spanish and administered to 393 adult hospitalized patients at 6 postoperative hours. The data were compared with the Apfel Scale and nausea measured on a visual analogue scale (VAS). Internal consistency and inter-observer concordance were calculated. Results: 59.8% of patients presented NVPO, of which 14.5% were clinically significant. An acceptable internal consistency was obtained for the NVPO Intensity Scale (Cronbach's alpha 0.7) and a high inter-observer correlation (Kappa 0.9, 95% CI 0.86-0.92), statistically significant, for the overall scale. The correlation with VAS was high (Rho Spearman 0.9). The mean VAS and Apfel scale score was significantly higher in patients with clinically significant PONV. Conclusions: The PONV Intensity Scale adapted to Spanish is a valid and reliable instrument for monitoring and evaluating postoperative nausea and vomiting.