Modified Alvarado Score Versus Ultrasound Examination in Acute Appendicitis

Abstract

BACKGROUND Appendicitis, one of the most common causes of acute surgical abdomen, presents with a myriad of symptoms and signs resulting in a potential for delay in diagnosis or misdiagnosis. As a result, timely diagnosis is of paramount importance to avoid potential complications. However, appendicectomy based on mere clinical suspicion results in an increased incidence of negative appendicectomies. In this context, modified Alvarado score and ultrasound examination can aid in confirming suspected acute appendicitis. We conducted this study to find out the diagnostic accuracy of ultrasound examination and modified Alvarado scoring system. MATERIALS AND METHODS This prospective study of 150 patients was conducted in department of General Surgery, Govt. Medical College, Kottayam. Study involves application of modified Alvarado scoring system and performing ultrasound scan inside Kottayam Medical College Hospital in all cases. Modified Alvarado Score (MAS) is obtained by proper history taking, clinical examination and laboratory values. Following emergency appendicectomy of all cases the specimen was sent for histopathological diagnosis. RESULTS This study included 150 consecutive patients diagnosed with acute appendicitis undergoing emergency appendicectomy. There were 96 (64%) male patients and 54 (36%) female patients. As per the modified Alvarado scoring, 125 (83.3%) of the patients were diagnosed to have acute appendicitis. However, only 104 (69.3%) of the patients were diagnosed as acute appendicitis by sonological findings. This study showed rebound tenderness as the most common MAS factor, it was present in 147 cases (98%). It was followed by 'Migratory pain' which was present in 129 cases (86%). The area under the curve for the ROC for total modified Alvarado scoring was 0.77 (CI 0.62-0.92) figure-3. The sensitivity of USG was 73.4% whereas that of Modified Alvarado score was 86.3%. Specificity of USG was 81.8% and that of Modified Alvarado score was 54.5%. Positive predictive value was 98.1% and 96% respectively. The negative predictive value was 19.6% and 24% for USG and Alvarado scores. CONCLUSION From the present study, it can be concluded that modified Alvarado score is a better diagnostic tool than ultrasonography alone. However, neither modified Alvarado score nor ultrasonography is an absolute tool in reducing negative laparotomy. Both when used together have reduced negative appendicectomy rate by a large number.