A Prospective Study on the Diagnostic Value of Hyperbilirubinemia as a Predictive Factor for Appendicular Perforation in Acute Appendicitis

INTRODUCTION: The most common emergency encountered in surgical practice is acute appendicitis. The diagnosis of any form of appendicular pathology is clinical, clinical & clinical. However even in experts hands there is possibility of missing the diagnosis as well as overt diagnosis. The currently available blood tests and radiological imaging can aid in diagnosis but not very specific and not pertinent to the pathology involved. Recent studies have shown that elevated bilirubin levels are associated with acute appendicitis & appendicular perforation. These studies emphasized that hyperbilirubinemia can be used as a marker for both acute appendicitis and appendicular perforation. Most of the studies conducted were retrospective on a large scale, few were prospective and were conducted on a small scale. Taking the challenge to conduct a prospective study on this subject on a large scale basis & eliminating the bias, a step ahead to see whether the elevated bilirubin levels have a predictive potential for appendicular perforation thereby differentiating between the acute appendicitis and perforation seems fairly possible, to predict the preoperative diagnosis to precision thereby proper planning could be made and reducing the morbidity involved motivated me to conduct and complete this study. AIMS & OBJECTIVES: 1. To evaluate whether elevated bilirubin level has a predictive potential for the diagnosis of appendicular perforation. 2. The diagnosis of appendicular perforation should no longer be a diagnostic dilemma by availing the bilirubin level which would complement the clinical assessment. 3. To predict the preoperative diagnosis to precision thereby proper planning in management could be done and thence reducing the morbidity. MATERIALS AND METHODS: Study Design: Prospective study. Study Population: 378 patients. Study Period: January 2012 - November 2012. Patients admitted with features of acute appendicitis or appendicular perforation in emergency surgical ward in RGGGH. The criteria for selection of cases based on clinical history, physical finding, radiological and haematological & biochemical investigations. Inclusion Criteria: 1. All patients diagnosed as acute appendicitis or appendicular perforation clinically on admission. 2. For both these groups, only patients with histopathological report suggestive of appendicitis would be included. Exclusion Criteria: All patients with positive HBs Ag / cholelithiasis / cancer on hepatobiliary systems. All patients documented to have a past history of Liver disease, Jaundice, Chronic alcoholism, Hemolytic disease, Congenital or acquired biliary disease, H/O drug intake causing cholestasis. RESULTS: Sensitivity = 89.6 %. Specificity = 71.4 %. Positive Predictive Value, PPV = 27 %. Negative Predictive Value, NPV= 96.9 %. It is more prudent to set the bilirubin level cut-off at 1.3 mg% (as explained in the previous graph) so as to exclude the patients with appendicitis having elevated bilirubin levels because most of them fall in this category i.e, below 1.3 mg%. SENSITIVITY= 79% (in combining with clinical assessment = 97 %) because they are complementary to each other. SPECIFICITY = 89 %, PPV = 93 %, NPV = 96 %. Mean bilirubin level & ALP were 1.63 110 ( perforation), 0.97 86 (non-perforated cases). Statistically significant with ‘p’ < 0.001. In majority of the cases, direct bilirubin is much more elevated compared to the indirect bilirubin. Even in patients with normal total bilirubin, direct moiety is elevated ( i.e, > 15 % of the total bilirubin). This supports the postulated physiological bile flow obstruction. CONCLUSION: The inclusion of hyperbilirubinemia as a standard criterion in the interpretation of appendicular perforation should be considered strongly along with the clinical assessment. • Bilirubin level _ 1.3 mg % indicates clearly that there is a high likelihood of appendicular perforation. • Hyperbilirubinemia as a predictive tool is easy to interpret, feasible and cost-effective.