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Laboratory: Clinical Microbiology
Test Name:
Test Code: SPT
Clinical Information:
Test Indications:
Induced sputum samples are obtained for the microbiological diagnosis of lower respiratory tract infections when patients are unable to produce an expectorated sputum sample.
Sputum is screened microscopically for quality.  This may lead to rejection and request for repeat specimen.
Saliva is unacceptable.  Make certain specimen is sputum.

Induced sputa are acceptable for fungal, Legionella spp. and mycobacterial culture requests.
Induced sputa are only acceptable for “bacterial culture-aerobic” requests for patients with cystic fibrosis or patients with bronchiectasis.

Patient Preparation Instructions:
Accurate patient identification must be made prior to sample collection.  Patient identification should be done in accordance with site policy. 
Samples and requisitions must be labeled/completed in accordance with the Shared Health Specimen Acceptance Policy.
Induced sputa should be collected as recommended by the Respiratory Therapy Departments.
1.  Using a nebulizer, have the patient inhale a large volume (approximately 25 mL) of 3% hypertonic saline.
2.  Collect the induced sputum in a sterile container.
Collection Devices:
Specimen Required: Sputum:  5-10 mL (minimum volume required depends on number of tests ordered) (Adult and Pediatric)
Do not add preservatives or additives.
Ensure induced sputum samples are labelled as "induced sputa".  The induced specimens may appear watery but will be processed the same way as expectorated sputum samples when they are labelled accurately.

Ensure samples that are being sent to a referral laboratory are packaged in accordance with Transport of Dangerous Goods recommendations for diagnostic samples.
Reference Values:
Mycobacteriology cultures are only performed at the Health Sciences Centre in Winnipeg and are processed on Weekdays (Monday to Friday).
See Also:
More Information:
Specimen Handling:
Respiratory samples should be refrigerated for storage.
Samples may be held at room temperature for less than 2 hours.
1.  Miller JM.  A Guide to Specimen Management in Clinical Microbiology. 1999.  American Society for Microbiology, Washington, DC.
2.  Leber A. Clinical Microbiology Procedures Handbook, 4th Edition. 2016. American Society for Microbiology, Washington, DC.