Malignant pleural effusions

may have already occurred, thus providing a rich environment for growth of P. aeruginosa. Nevertheless, the lack of improvement in lung function measures, despite aggressive treatment and apparent eradiation of P. aeruginosa, is concerning. This finding emphasizes the importance of employing preventative therapy before the development of airway inflammation and infection. Driven by detailed work performed in laboratories such as that described in this issue of the Journal, infant lung function testing has now entered a new stage and can be considered a clinical outcome measure, similar to spirometry in the older child. The raised-volume technique has been standardized (12), published reference values are available (14), procedural risks are acceptable, and studies have clearly demonstrated that this technique is suitable to discriminate lung disease from health (3–5). Results from a recently completed trial performed in infants with CF in the United States are encouraging as they demonstrate the feasibility of studying infant lung function in a multicenter setting when strict quality assurance and training is implemented (15). The tremendous progress in this area of measuring infant physiology will naturally lead to intervention studies using these parameters as outcome measures. Over the next decade, we expect that techniques such as infant and preschool lung function testing will not only improve our understanding of the once ‘‘silent’’ and mysterious young CF lung but will also help us to develop stronger evidence for potential early intervention strategies in this vulnerable age group (16).