Applied physiology: Lung function tests in children

Summary 

Recent developments in the techniques available to measure lung function in children have greatly improved our understanding of lung development in both health and disease. In everyday clinical practice, lung function tests can provide objective information about the severity and progression of disease and the response to treatment. Although spirometry remains the most useful and widely used test, newer techniques, such as specific airways resistance and resistance measured by the interrupter technique, allow children who are too young to co-operate with spirometry to be tested. This is of great importance as it is increasingly recognized that many chronic respiratory illnesses in older children and adults have their origins in early life. This paper will describe the basic physiology of some standard tests and some of the newer tests that are increasing our understanding of lung disease in children.

Keywords: Lung function tests, Spirometry, Plethysmography, Flow–volume curves, Helium dilution, Rint, Airways resistance, Airways hyper-responsiveness, Bronchial challenge, Airways obstruction