Laboratory aid and ultrasonography in the diagnosis of appendicitis in children.

Forty-seven consecutive patients with clinically suspected acute appendicitis were studied at this hospital from June, 1994 to March, 1995. All the patients had received a complete study protocol including: detailed history and physical examination; complete blood cell count with differential count; erythrocyte sedimentation rate; C-reactive protein and sonographic examination. The male to female ratio is 29: 18. The age range is from 4 to 14 years. Thirty patients received laparotomy and 27 were diagnosed as appendicitis by histologic findings including 6 cases of perforated appendicitis. The remaining 3 patients had no evidence of appendicitis histologically. The other 17 patients were observed clinically. In these, the abdominal pain resolved spontaneously, or it was proved due to other diseases. The sensitivity and specificity of these laboratory examinations are: leukocytosis (> 10,000/mm3): 85. 2%, 65%; leukocytosis with a shift-to-the-left (neutrophil > 75%): 81.5%, 70%; elevated ESR (> 20 mm/hr): 40.7%, 85%; elevated CRP (> 0.9 mg/dl): 70.4%, 65%; (> 5 mg/dl); 51.9%, 95%; sonography: 85.2%, 100%. There were 4 false-negative and no false-positive ultrasonographic results in our study. Five of the 6 case of perforated appendicitis had elevated CRP levels of more than 8 mg/dl. In conclusion, detailed history taking and physical examination are still the most reliable tools for diagnosis. For the doubtful cases, sonography can provide excellent specificity and good sensitivity for differential diagnosis. The classical tools of leukocytosis and shift-to-the-left can only provide a screening property but not for diagnosis. CRP was not a good predictor in our study, but it can be a useful parameter when perforated appendicitis is suspected.