Background/purpose: Diagnosis of acute appendicitis in children remains challenging, and the role of blood tests in the decision-making process is still unclear. We prospectively evaluated if routine inflammatory markers could contribute to exclude the presence of acute appendicitis in children.
Methods: Preoperative white blood cell count (WBCC) and C-reactive protein (CRP) were prospectively tested in children undergoing surgery for suspected appendicitis. Surgery was indicated on the basis of clinical findings and/or ultrasound scan, but WBCC and CRP values were ignored during the decision-making process. Sensitivity of individual markers and their combinations were assessed.
Results: One hundred children (55 males) with a mean age of 9.34 years (SD, 3.54 years) had pathologically confirmed diagnosis of appendicitis. A perforated appendix was found in 23% of cases. Elevated WBCC alone had a sensitivity of 0.6 (confidence interval [CI], 0.506-0.694). Sensitivity of elevated CRP alone was 0.86 (CI, 0.926-0.793). Elevation of either WBCC or CRP or both had a sensitivity of 0.98 (CI, 1.0-0.953).
Conclusions: White blood cell count or CRP values alone do not appear to provide any useful additional information to the surgeon. However, the sensitivity of the 2 combined tests is extremely high, and normal values of both WBCC and CRP are very unlikely in pathologically confirmed appendicitis.