Clinical features and inflammatory markers in pediatric pneumonia: a prospective study

In this prospective, observational study on previously healthy children <18 years, we aimed to study the diagnostic ability of clinical features and inflammatory markers to (i) predict pathologic chest radiography in suspected pneumonia and (ii) differentiate etiology in radiological proven pneumonia. In 394 cases of suspected pneumonia, 265 (67%) had radiographs consistent with pneumonia; 34/265 had proof of bacterial etiology. Of the cases, 86.5% had received pneumococcal conjugate vaccine. In suspected pneumonia, positive chest radiography was significantly associated with increasing C-reactive protein (CRP) values, higher age, and SpO₂ ≤92% in multivariate logistic regression, OR 1.06 (95% CI 1.03 to 1.09), OR 1.09 (95% CI 1.00 to1.18), and OR 2.71 (95% CI 1.42 to 5.18), respectively. In proven pneumonia, bacterial pneumonia was significantly differentiated from viral/atypical pneumonia by increasing CRP values and SpO₂ >92% in multivariate logistic regression, OR 1.09 (95% CI 1.05 to 1.14) and OR 0.23 (95% CI 0.06 to 0.82), respectively. Combining high CRP values (>80 mg/L) and elevated white blood cell (WBC) count provided specificity >85%, positive likelihood ratios >3, but sensitivity <46% for both radiographic proven and bacterial pneumonia.

Conclusion: With relatively high specificity and likelihood ratio CRP, WBC count and hypoxemia may be beneficial in ruling in a positive chest radiograph in suspected pneumonia and bacterial etiology in proven pneumonia, but with low sensitivity, the clinical utility is limited.