SPUTUM INDUCTION: METHODS AND SAFETY.

The aim of sputum induction is to collect an adeguate sample of lower airway secretions in patients who are not able to produce sputum spontaneously. Sputum induction requires a high degree of patient cooperation and is best conducted in a quiet, secluded area to minimize embarrassment for the patient. Adeguate facilities and equipment are needed. Infection control procedures for the protection of personnel and patients must be carried out according to the local anti-infection policy, which sometimes includes purpose-built chambers.
The technique of sputum induction has been standardized to enable comparison between researchers and to ensure adequate reproducibility of the technique. Frequent repetition of sputum induction can itself lead to airway inflammation, resulting in a change in cell populations obtained by subsequent inductions. Thus, repeating induction 8-24 h after an initial induction can cause an increase in neutrophils, and it is possible that mediator levels also change. For this reason., an interval of 2 days between inductions is recommended.