Efficacy of modified Alvarado score combined with ultrasound in the diagnosis of acute appendicitis: a prospective analytical study

Abstract

Background: Appendicitis is the most common surgical emergency encountered in the emergency department and diagnosis is difficult at times. Imaging and various clinical scoring are present to aid in the diagnosis. Ultrasound is an easily accessible modality and can accomplish more than a computed tomography (CT) scan at times. Modified Alvarado score (MAS) includes parameters that do not pose an extra financial burden to the patient. Combining both the imaging and clinical scoring systems, we decided to evaluate the Combined MAS for the diagnosis of acute appendicitis. Methods: This is a prospective analytical study conducted in a tertiary hospital for one and a half years. Fifty-five patients with right lower quadrant pain were enrolled, and evaluated along with an ultrasound. Modified Alvarado score and Combined MAS were obtained and the results were compared with the histopathological examination results. Results: Out of 55 clinically diagnosed cases who underwent emergency appendectomy, 27 were males and 28 were females. Of these, 50 cases had acute appendicitis as per histopathological examination. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the MAS was 42%, 100%, 100%, 20.8%, 47.27% respectively. The sensitivity, specificity, PPV, NPV and accuracy of the USG were 84%, 40%, 93.3%, 20%, and 80% respectively. Combining both the scores, the Combined MAS had the sensitivity, specificity, PPV, NPV, and accuracy of 98.18%, 0%, 90.7%, 0%, and 89.09% respectively. Conclusion: As the combination of USG has raised the sensitivity and diagnostic accuracy of the MAS, it can be an alternative to CT/MRI imaging for the diagnosis of acute appendicitis in resource-limited settings. This score requires further studies to validate with a larger sample size.