Which children could benefit from additional diagnostic tools in case of suspected appendicitis?

Background: New diagnostic tools such as ultrasound scan, computed tomography (CT) scan, and diagnostic laparoscopy, have become available for children with suspected appendicitis but should be reserved for equivocal cases. The aim of this study was to develop a scoring system to identify this subgroup of children. Methods: Patients from 2 different periods (period 1, 99 consecutive children [group 1] and period 2, 62 consecutive children [group 2] with suspected appendicitis) were prospectively evaluated. Variables predicting appendicitis were obtained from group 1. By means of a regression analysis, a scoring system was created and applied to the patients of group 2. Missed appendicitis and negative appendectomy rates obtained by clinical practice were compared with the results that would have been accomplished based on the scoring system. Thereafter, the scoring system was externally validated in a group of children presented at another hospital (group 3, n = 114). Results: The variables, leukocyte count greater than or equal to 10.10(9)/L (2 points); rebound tenderness (2 points); and temperature greater than or equal to 38degreesC (1 point) correlated significantly with appendicitis. The scoring system was used to categorize patients into 3 groups: appendicitis unlikely, doubtful appendicitis, and suspected appendicitis. The specificity and sensitivity of the scoring system were, respectively, 85% and 89%. Applying the scoring system would lead to comparable negative appendectomy rates of 8% versus 6% using clinical judgement and a comparable number of performed laparoscopies (26% v 31%). However, it could lead to a lower missed appendicitis rate (1% v 6%) and a lower perforation rate (0% v 11%). External validation showed comparable performed laparoscopies (32%) and missed appendicitis (2%) rates but a higher negative appendectomy rate (19%), probably owing to a lower percentage of appendicitis in hospital (2, 47%) compared with hospital (1, 71%). Conclusions: Children can be observed if leukocyte count is less than 10.10(9)/L and rebound tenderness is absent; a diagnostic laparoscopy should be performed if one of these is present, and if both are present one could perform an appendectomy.