Neonatal and pediatric respiratory diagnostics.

Evaluating respiratory function in children, especially infants and preschoolers, is difficult because of lack of patient cooperation with and understanding of lung function testing. Because of recent advances in diagnostic tools, investigators are now able to assess normal lung physiology, the presence or absence of airway disease, and therapeutic interventions in this young age group. Recent advances in infant lung function testing, preschool spirometry, forced oscillation methods, and the interrupter respiratory resistance technique are discussed. Exhaled nitric oxide and carbon monoxide measurements in children are also reviewed. The technical aspects, advantages, disadvantages, and clinical applications of these tools are summarized. These remarkable advances have yet to be applied in multicenter trials with young children. Adhering to standards will be critical for future multicenter trials to assess the clinical utility of these potential outcome measures.