Sputum Induction

Indication

It is widely used to assess the following:

• Airway inflammation in asthma - Curschmann's Spirals and Charcot Leyden crystals are popularly used to diagnose bronchial asthma.
• Airway inflammation in chronic obstructive pulmonary disease (COPD).
• It can be used as a complementary tool to BAL both in research and in clinical monitoring of patients with interstitial lung disease (ILD).
• The cells, recovered from spontaneous coughing can be used to study lung cancer.
• Respiratory infections
• Diagnosis of pneumocystis carinii pneumonia in patients infected with human immunodeficiency virus.
• In developing countries having high prevalence of pulmonary tuberculosis, sputum induction (SI) can increase the diagnostic yield, resulting in better categorization of patients for treatment purposes.
• Others - Cough due to gastroesophageal reflex disease (GRD) has shown increased macrophages laden with lipid in induced sputum.

Infection Control

Induction of sputum should only be conducted in a single room with a ventilation system that allows for the total exhausting of air from the room to the external environment.The minimum requirement is a single room with door closed and air exhausted to the outside of the building without recirculation. Gloves will be worn when handling specimens.Staff must ideally wear the recommended TB respiratory protection (P2 mask) while in the room and disposable gloves when handling sputum specimen(s).