Modified Alvarado's Score incorporating C-reactive protein for Acute Appendicitis

ABSTRACT

Background: Acute appendicitis is one of the commonest surgical conditions requiring emergency appendectomy. The diagnosis is usually suspected clinically and confirmed on either ultrasound or Computed tomography. The aim of our study is to improve the diagnostic accuracy of acute appendicitis and reduce the rate of negative appendectomy. We have modified the Alvarado’s score by incorporating C- reactive protein and deleting two of its components (leukocyte shift to left and migration of pain from umbilical region to right iliac fossa). Methods: We successfully used this scoring system on a sample size of 100 patients. Out of 100 patients, diagnosis was confirmed on histopathological examination in 76 patients. Neutrophilic infiltration of the muscularis layer was considered as the diagnostic criteria for acute appendicitis. Ten patients were diagnosed only on CECT abdomen as Appendicular lump. These patients were not operated. Alternate diagnoses were made in twelve patients with MAS score of 5 or less and in two patients with MAS score of more than 6. Results: On statistical analysis, the result showed that the MAS is a very specific (85.7%) and highly sensitive (95.3%) in detecting Acute Appendicitis, taking Histopathology or CT as gold standard test. While, the positive predictive value is 97.6%, negative predictive value is only 75%. Conclusions: This means that it is difficult to rule out acute appendicitis in patients with lower scores. However, for such patients further investigations can be done to reach to a final diagnosis.