Clinical characteristics and cytokine changes in children with pneumonia requiring mechanical ventilation

Objective: To assess clinical characteristics and cytokine levels in children with severe pneumonia who required ventilatory support. Methods: In this prospective, descriptive, cross-sectional study, blood and endotracheal fluid samples were obtained from patients with severe pneumonia, aged <5 years, within 24 h following intubation. Blood samples were also obtained from age-matched healthy controls. Cytokine levels were investigated using flow cytometry-assisted immunoassay. Results: Forty-five patients with severe pneumonia requiring mechanical ventilation (aged 10 +/- 5 months) and 35 healthy age-matched controls were included. Patients with severe pneumonia had significantly increased serum interleukin (IL)-6, IL-8, and granulocyte/macrophage colony-stimulating factor concentrations compared with controls (80.84 pg/ml versus 2.06 pg/ml, 90.03 pg/ml versus 6.62 pg/ml, and 115.58 pg/ml versus 11.47 pg/ml, respectively). In the severe pneumonia group, serum IL-10 levels were significantly higher in patients aged <6 months versus those aged 6-12 months. Age-group differences in serum cytokine levels did not correspond to age-group differences in endotracheal-fluid cytokine levels. Serum IL-6 levels were significantly higher in patients who subsequently died versus those who survived (267.12 pg/ml versus 20.75 pg/ml, respectively). Conclusion: High IL-6 concentrations were associated with mortality in patients <5 years of age with severe pneumonia requiring mechanical ventilation.