Modified alvarado score and ultrasonography in the diagnosis of acute appendicitis at Moi Teaching and Referral hospital, Eldoret, Kenya

Abstract

Background: Acute appendicitis is a common surgical emergency. Its diagnosis can be challenging. Scoring systems that make use of clinical and laboratory findings, like the Alvarado score, have been developed to improve on the diagnosis of acute appendicitis. Ultrasonography is used as an adjunct in the diagnosis. Correlation between the clinical and ultrasound diagnosis with histopathology has been done in various places globally, however, there is no data in our locality. Objective: To assess accuracy of Alvarado score and Ultrasonography in comparison to histopathology in the diagnosis of acute appendicitis at Moi Teaching and Referral Hospital (MTRH). Method: Hospital-based descriptive cross-sectional study at MTRH. Consecutive sampling was done between January 2015 and June 2016. Patients who were clinically diagnosed to have acute appendicitis and subsequently underwent appendectomy were included. Questionnaires were used to collect data, which included symptoms and signs at presentation and the ultrasound findings, obtained from the case notes. Alvarado scoring was done for all patients. Histopathology reports were sought from the pathology laboratory and finally the results were analysed. Result: A total of 85 patients were studied. Male to female ratio was 1.3:1. Age ranged from 6 to 64 years. Mean duration of onset of symptoms to presentation was 4.56 days (range of <1 – 21 days). Commonest signs and symptoms were right lower quadrant tenderness, right lower quadrant pain and nausea/vomiting in 90.6% (n=77), 84.7% (n=72) and 78.8% (n=67) patients respectively. Sensitivity and specificity of the ultrasound were 70.5% and 30% respectively. Majority, (81.2%, n=69) had Alvarado score of ≥ 4, of which, 90.6% (n=58) had appendicitis. In the 0 - 3 Alvarado score group, majority (62.5%, n=10) had no appendicitis. The sensitivity and specificity of Alvarado score from ≥ 4 was 90.6% and 47.6% respectively. The overall negative appendectomy rate was 24.7%. Conclusion: Alvarado score is an accurate tool in the diagnosis of acute appendicitis. Ultrasonography is not as accurate as Alvarado score and cannot be relied upon on its own to make a diagnosis of acute appendicitis. Recommendation: Application of Alvarado score should be made the standard operating procedure in diagnosing acute appendicitis at MTRH. Ultrasound should not be heavily relied upon in diagnosis of acute appendicitis.