Sputum induction in children.

Abstract

Sputum induction has been used to study asthma in children since the first description of the technique in 1992 1. Since then, >20 reports (five reviews) have appeared in the literature describing sputum induction in children with airways disease. In general, sputum induction in children of >6 yrs is safe and has a satisfactory success rate. Approximately 500 children have been studied by sputum induction. The diagnoses of the studied children include stable asthma (n=308), acute asthma (n=18) and healthy control subjects (n=185). Studies have included children aged 5–18 yrs, with a mean age of 11.2 yrs. Most studies have included children of >6 yrs. Studies of children with asthma have included subjects across the spectrum of severity. The following issues regarding sputum induction in children are reviewed in the present article: 1) protocols used in children; 2) safety of induction; 3) management of airway obstruction during sputum induction; 4) sputum processing; 5) normal values in children; 6) findings in asthmatic children; 7) effect of treatment on induced sputum parameters; and 8) clinical applications. A wide variety of sputum induction protocols have been reported successful in children (table 1⇓). There is great variation as to the brands of nebuliser used. All of the studies have used ultrasonic nebulisers, but these were either high­ or low­output devices. Hypertonic saline has been used either at 4.5% (in four studies) or by increasing concentrations from 3 to 4 and then …