Serum bilirubin as a predictor of complications of acute appendicitis in adults

Abstract

Introduction: Acute appendicitis is a very common cause of acute abdomen and the diagnosis is essentially clinical. A decision to operate based on clinical suspicion alone can result in removal of a normal appendix; whereas, if left untreated, appendicitis can result in necrosis and perforation. Therefore, improving the diagnostic accuracy of appendicitis is a need of the hour. This study was conducted to evaluate hyperbilirubinaemia in acute appendicitis to find out its predictive value in complications like perforation. Materials and Methods: This prospective study for diagnostic test evaluation was conducted amongst the inpatients in the Department of General Surgery, KIMSHEALTH Trivandrum, during the period from August 2019 to August 2020. A total number of 100 patients who were admitted with the clinical diagnosis of acute appendicitis were studied, and serum bilirubin and liver function tests were carried out in all of them. Results: Total bilirubin levels when compared with histopathological diagnosis by unpaired samples t-test, the t-value = 0.763, P = 0.447 > 0.05 which shows no statistically significant difference between total bilirubin levels in uncomplicated and complicated acute appendicitis based on histopathological diagnosis. Sensitivity is 81.8%; specificity is 29.2%; positive predictive value (PPV) is 12.5%; negative predictive value (NPV) is 92.9%. Conclusion: Elevated total serum bilirubin levels have a fairly high sensitivity and NPV in predicting complications of acute appendicitis, but the specificity and PPV are quite low, and hence, hyperbilirubinaemia could be used as an aid in diagnosing complicated acute appendicitis along with the clinical findings and ultrasonography findings, but it is not reliable as a standalone diagnostic test. If the total serum bilirubin levels are low, an alternate diagnosis could be suspected, and the chances of complicated appendicitis are quite low, but elevated serum bilirubin values alone cannot confirm the presence of complications. Therefore, our study could not find any correlation between the absolute levels of elevation of total bilirubin values and the presence or absence of complications in acute appendicitis.