Accuracy in Diagnosis of Acute Appendicitis by Comparing Serum C - reactive protein Measurements and Modified Alvarado Score

Abstract

Acute appendicitis is perhaps the most common surgically correctable cause ofacute abdominal pain and its diagnosis remains difficult in many instances. Some ofthe signs and symptoms can be subtle to both the clinician and the patient and may notbe present in all the instances. Arriving at the correct diagnosis and decreasing therate of negative appendicectomy is essential. However a delay in diagnosis may allowprogression to perforation and significantly increase the morbidity and mortality.This study was a prospective study and comprised 60 patients admitted with suspected acute appendicitis and planned for Appendicectomy. The patients selected were older than 15 years, of either sex. The preoperative modified Alvarado score (MAS) was determined and C-reactive protein levels (CRP) were estimated. The results of the MAS and preoperative CRP levels were compared with the histopathology of the removed appendix.Among all the patients studied, 6, 29 and 25 patients had preoperative MAS of <5, 5-6, and 7-9 respectively. 42 patients had CRP level raised. 41 patients were histopathologically positive for appendicitis. 55% and 88% of patients with a MAS of 5-6 and 7-9 had appendicitis on histopathology respectively. We found 82.9% sensitivity and 57.9% specificity of CRP for the diagnosis of acute appendicitis. When combined with CRP, the sensitivity and specificity of MAS in patients with score of 5-6 was raised significantly from 55% to 75% and 45% to 61.5%. CRP was raised in all patients with MAS score of 7-9.Our study concluded that MAS in combination with the CRP levels is very helpful in the diagnosis of acute appendicitis especially in patients with modified Alvarado scores in the middle range, who are categorized as "equivocal" for appendicitis by the Alvarado score.