Factors associated with postoperative nausea and vomiting at Mulago hospital

Abstract

INTRODUCTION: Postoperative nausea and vomiting (PONV) are among the most common complications following surgery and despite modern anesthetic and surgical technique the incidence remains at 20% to 30%. Although some clinicians regard PONV as a mild medical problem, it can cause delayed hospital discharge, decreased patient satisfaction and increased use of hospital resources. Many studies have been done worldwide on incidence and risk factors, but no such studies have been done in Uganda. OBJECTIVE: To establish the prevalence and factors associated with postoperative nausea and vomiting among in-patients at mulago hospital complex. STUDY SITE: Main surgical wards at mulago hospital complex STUDY DESIGN: This was a cross-sectional study. A total of 182 patients aged 10 years and above were enrolled between November 2006 and march 2007. The patients had undergone both general anesthesia and surgery and had fasted 6 hours prior to surgery. Patients who had medical and surgical conditions that could lead to nausea and vomiting were excluded. Also patients on chemotherapy and anti-emetic drugs were not included in the study. Patients were interviewed. 24 hours after the operation. PONV was defined as at least one episode of nausea and/ or vomiting within the first 24 hours after surgery. DATA ANALYSIS: Data were collected using a questionnaire and entered into EPI-DATA Program, then transported to SPSS for analysis. First, univariate analysis was done to determine the association between the outcome (PONV) and the possible pre-operative, intra-operative and post-operative factors. Then Pearson Chi-square was used to determine the significance of the association between outcome (PONV) and those possible risk factors. Lastly, multivariative analysis was performed using a logistic model to determine predictors of PONV. RESULTS: 182 consecutive in-patients were enrolled for the study. 53% of the patients were male and 47% were female. The prevalence of PONV was 40.7% within 24 hours after surgery. Factors that were significantly ( p value<0.05) associated with PONV following univariate analysis included; age group 20 to 30 years, female gender, history of PONV, intra-operative use of pethidine, type of operation (orthopedic surgery). And postoperative use of pethidine. Independent predictors of PONV include; age group of 20 to 30 years, history of PONV, and the type of operation. CONCLUSIONS: Predictors of PONV within 24 hours include, age group of 20 to 30 years, history of PONV and the type of operation (orthopedic surgery). RECOMMENDATIONS: Patients who have an increased likelihood of having PONV should be put on anti-emetic prophylaxis. Also a study with a large sample size should be carried out to capture most of the possible risk factors.