Singapore General Hospital Experience on Ethnicity and the Incidence of Postoperative Nausea and Vomiting after Elective Orthopaedic Surgeries

Introduction. We explored how ethnicity affects the risk of postoperative nausea and vomiting (PONV) and established the correlation of suggested risk factors of PONV in the multiethnic population of Singapore. Methods. 785 patients who underwent orthopaedic surgery were recruited. These comprised 619 Chinese (78.9%), 76 Malay (9.7%), 68 Indian (8.7%), and 22 other (2.8%) cases. The presence of possible risk factors of PONV and nausea and/or vomiting within 24 h after surgery was studied. Univariate and multivariate logistic regression analyses were performed. Results. The incidence of PONV was 33.2% (261 patients). There was no statistically significant difference of PONV incidence between Chinese, Malay, and Indian cases (34.6% versus 34.2% versus 29.4%, p=0.695 ). Indian females younger than 50 years were found to have a higher incidence of vomiting ( p=0.02 ). The significant risk factors for this population include females, use of nitrous oxide, and a history of PONV. Conclusion. In the groups studied, ethnicity is not a significant risk factor for PONV except for young Indian females who have a higher risk of postoperative vomiting. We suggest the selective usage of antiemetic for young Indian females as prophylaxis and avoiding nitrous oxide use in high-risk patients.