Applied physiology: lung function testing in children

Abstract 

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 (sRaw) and Rint (resistance measured by the interrupter technique) now 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.

In this paper we describe the basic physiology of some standard tests and some of the newer tests which are increasing our understanding of lung disease.

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