Correlation of white cell count and CRP in acute appendicitis in paediatric patients

Background: Ten per cent of children who present with abdominal pain at an emergency department are diagnosed with acute appendicitis. The diagnosis of which relies on clinical acumen, but addition of tests such as measurement of the white cell count (WCC) and C-reactive protein (CRP) are needed to decrease the morbidity associated with inappropriate surgical management. This study evaluates the sensitivity, specificity and accuracy of the WCC and CRP separately and when used in combination and evaluates whether an increased WCC and CRP are associated with complicated appendicitis. Methods: A retrospective record review of all paediatric patients who underwent appendicectomy between June 2010 and December 2016 was conducted. Demographic data, the WCC, CRP and histology results were reviewed. Results: 763 records were reviewed. The sensitivity and specificity of the WCC were 69.6% and 43.1% respectively and of the CRP were 95.4% and 24.5% respectively. The sensitivity was higher when both the CRP and WCC were elevated (97.47%). A normal WCC and CRP had a specificity of 98%, with an odds ratio of 8.69 of a patient not having appendicitis. There was a borderline significance between the WCC and the presence of acute appendicitis (p = 0.0494). The CRP was significant in patient with acute appendicitis (p < 0.0001). The WCC and CRP between uninflamed appendix specimens, uncomplicated appendicitis and complicated appendicitis was significant. Conclusion: Both increasing CRP and WCC correlates with an increased likelihood of the presence of complicated appendicitis. The chance of a patient having appendicitis with both normal WCC and CRP is low.