RESUMO
Clinical assessment outweighs the use of paraclinical investigations in the diagnosis of acute appendicitis. Few studies have addressed the predictive value of white blood cells [WBCs] and C-reactive protein [CRP] at different cut-off values in appendicitis. Our purpose was to determine the predictive value of WBC count, CRP, ESR and neutrophil to lymphocyte ratio in pediatric appendicitis. WBC count, CRP, ESR and neutrophil to lymphocyte ratio were measured prospectively in 307 patients presenting with lower abdominal pain who underwent surgical exploration; the results were correlated with each patient's outcome. Gold standard for diagnosing appendicitis was based on histopathologic evaluation. Patients [189 boys, 118 girls] were 1-14 years old [mean 7.9 +/- 2.9 years]. Overall WBC count had the highest sensitivity in the prediction of diagnosis of appendicitis [86.8%], whereas sensitivity of CRP was 76%. ESR and neutrophil to lymphocyte ratio revealed a modest sensitivity. Combining the diagnostic tests increased the sensitivity significantly. Sensitivity increased to 96.1% when CRP and WBC count were used together while it was 99.1% when the combination of all diagnostic tests were used. This result may have important clinical and economic implications. We suggest that patients experiencing lower abdominal pain, with normal WBC count and CRP values, are unlikely to have acute appendicitis and can be safely observed for a longer time