Steps to Ensure a Good Quality Sputum Sample

The Healthcare Worker (HCW) needs to carefully explain how to collect a good quality sputum specimen. He/she needs to demonstrate how to bring up sputum from the chest, what a good sputum specimen looks like, and the quantity of sputum required.  

Characteristics of a Good Sputum Sample 

• Thick (semi-solid) muco-purulent (yellowish) in consistency, coughed out deeply from the lungs
• Sufficient in amount i.e., 2 to 5 ml (or enough to cover the size of a fingernail at the bottom of the container)
• It should not be blood-stained (brownish colour) as far as possible.

Steps to Ensure Good Quality Sputum Sample

1. Explain to the patient the characteristics of sputum - that it is thick and mucoid as compared to saliva which is thin and watery.
2. The patient should preferably rinse his/her mouth to get rid of any food particles which may give false-positive results.
3. One should demonstrate to the patient by action how s/he should take deep breaths and bring up the sputum.
   1. The patient is instructed to inhale deeply (2–3 times), which will initiate the cough reflex in most patients.
   2. The sputum is retained in the mouth and spit into the pre-labelled container without spilling.
4. Some patients may not be able to expectorate with deep breathing, in which case HCW should demonstrate to them how they should place their palms on the waist, squat or sit and continue deep breathing again.
   1. Tapping or thumping of the back may encourage expectoration. (Sitting and placing hands on the waist fixes the shoulder and pelvic muscles and brings the intercostal muscles of the ribcage and diaphragm into action).
5. When a patient has only coughed up saliva or has coughed up less than 2 ml (the size of a fingernail at the bottom of the container) of sputum, the patient should be encouraged to provide a better specimen.

Resources

• RNTCP Module for Laboratory Technician, CTD, MoHFW, 2005.