Performance of imaging studies in patients with suspected appendicitis after stratification with adult appendicitis score.

BACKGROUND: Diagnostic scoring is used to stratify patients with suspected appendicitis into three groups: high, intermediate, and low probability of appendicitis. The stratification can be used for selective imaging to avoid the harms of radiation without compromising diagnostic accuracy. The aim was to study how stratification by Adult Appendicitis Score affects diagnostic performance of imaging studies. METHODS: Analysis of 822 patients who underwent diagnostic imaging for suspected appendicitis was made. Adult Appendicitis Score was used to stratify patients into groups of high, intermediate, and low probability of appendicitis. Diagnostic performance of computed tomography (CT) and ultrasound (US) was compared between these patient groups. RESULTS: After scoring, pre-test probability of appendicitis ranged from 9-16% in low probability group to 75-79% in high probability group in patients who underwent US or CT. Post-test probability of appendicitis after positive CT was 99, 91, and 75% in high probability, intermediate probability and low probability groups, respectively, p < 0.001. After positive US the respective probabilities were 95, 91 and 42%, p < 0.001. CONCLUSION: Diagnostic imaging has limited value in patients with low probability of appendicitis according to Adult Appendicitis Score.

High admission C-reactive protein level and longer in-hospital delay to surgery are associated with increased risk of complicated appendicitis.

PURPOSE: Debate on the effect of in-hospital delay on the risk of perforation in appendicitis persists, and the results from previous studies are controversial. The aims of this study were to present the effect of in-hospital delay on the risk of perforation in appendicitis and to assess the utility of C-reactive protein (CRP) measurement in detecting the patients with complicated appendicitis. METHODS: Prospectively collected data of 389 adult patients who underwent surgery for acute appendicitis were analyzed in order to find the most accurate method for recognizing the pre-hospital perforations. The effect of in-hospital delay on the further risk of perforation in patients with not yet perforated acute appendicitis was then analyzed. RESULTS: Out of 389 patients with appendicitis, 91 patients (23.4 %) had complicated appendicitis, 23 with abscess, and 68 with free perforation. Admission CRP level of 99 mg/l or higher was 90.3 % specific for complicated appendicitis. In patients with admission CRP less than 99 mg/l, the incidence of perforation doubled from 9.5 to 18.9 % when the in-hospital delay increased from less than 6 h to more than 12 h. CONCLUSIONS: Complicated appendicitis can be identified with a high CRP level on admission. Delaying surgery can increase the risk of perforation.

A new adult appendicitis score improves diagnostic accuracy of acute appendicitis--a prospective study.

BACKGROUND: The aim of the study was to construct a new scoring system for more accurate diagnostics of acute appendicitis. Applying the new score into clinical practice could reduce the need of potentially harmful diagnostic imaging. METHODS: This prospective study enrolled 829 adults presenting with clinical suspicion of appendicitis, including 392 (47%) patients with appendicitis. The collected data included clinical findings and symptoms together with laboratory tests (white cell count, neutrophil count and C-reactive protein), and the timing of the onset of symptoms. The score was constructed by logistic regression analysis using multiple imputations for missing values. Performance of the constructed score in patients with complete data (n = 725) was compared with Alvarado score and Appendicitis inflammatory response score. RESULTS: 343 (47%) of patients with complete data had appendicitis. 199 (58%) patients with appendicitis had score value at least 16 and were classified as high probability group with 93% specificity.Patients with score below 11 were classified as low probability of appendicitis. Only 4% of patients with appendicitis had a score below 11, and none of them had complicated appendicitis. In contrast, 207 (54%) of non-appendicitis patients had score below 11. There were no cases with complicated appendicitis in the low probability group. The area under ROC curve was significantly larger with the new score 0.882 (95% CI 0.858-0.906) compared with AUC of Alvarado score 0.790 (0.758-0.823) and Appendicitis inflammatory response score 0.810 (0.779-0.840). CONCLUSIONS: The new diagnostic score is fast and accurate in categorizing patients with suspected appendicitis, and roughly halves the need of diagnostic imaging.