Pulmonary function testing in children with cardiac disease.

These cases illustrate the clinical importance of pulmonary function testing in children. The first case demonstrated a significant restrictive defect in a child with pulmonic stenosis and scoliosis. Although this child had no respiratory symptoms, it was important to document the degree of functional impairment to plan for her postoperative course. The second case demonstrated the way in which pulmonary function tests can lead to a specific diagnosis and provide important information about response to therapy. This patient had distressing symptoms which limited her ability to participate in sports. Her chest x-ray revealed no significant abnormality and she had no auscultatory finding. Pulmonary function tests defined both the nature and severity of her problems and provided objective information about her response to therapy. In the third case, one might have anticipated decreases in flow rates and lung volumes because of neuromuscular weakness. That was not evident on testing and the patient had an uneventful postoperative recovery. Pulmonary function testing provides invaluable information about the nature and severity of functional impairment in children with known or suspected pulmonary disease. New equipment and individuals specifically trained to work with children now permit the evaluation of even young children. Pulmonary function testing can expand our knowledge of disease processes and improve our therapeutic strategies.