Sputum specimen collection

Definition

Sputum specimen collection is a procedure designed to collect expectorated secretions from a patient's respiratory tract.

Purpose

Sputum is collected to be used as a laboratory specimen for the isolation of organisms that might be causing abnormalities of the respiratory tract.

Precautions

This procedure should not be performed if the patient is unable to take several deep breaths or cough deeply from the lungs .

KEY TERMS

Expectorate —To cough up excessive secretions from the respiratory tract.

Haemoptysis —The presence of blood in the sputum.

Hypertonic saline —Saline that has a higher osmotic pressure than normal saline.

Inhalation —A medicinal substance for inhaling.

Mucoid —Resembling the thick liquid secreted by the mucous glands.

Mucopurulent sputum —Sputum containing mucus and pus.

Pulmonary embolism —A clot in the lungs.

Description

When secretions from the respiratory tract are expectorated, the secretions are called sputum. A sputum culture is a sample of expectorated sputum.

Induced sputum is a procedure to assist patients who have difficulty expectorating sputum. The patient inhales nebulized saline to loosen the sputum. To collect an induced sputum sample, the patient's mouth should be rinsed thoroughly with water to reduce the amount of oral bacteria that are normally present from contaminating the sputum. The patient then inhales 20–30 ml of hypertonic saline from an ultrasonic nebuliser. The sputum is loosened and collected in a sterile sputum container.

The patient should be supervised during the collection of the sputum to ensure the expectorated product has come from the lungs rather than saliva from the oral cavity. The sample is best taken first thing in the morning when the production of sputum is greatest.

To collect an expectorated sputum sample, the patient should gargle and rinse out the mouth with water to reduce the amount of oral bacteria that are normally present from contaminating the sputum. The patient must take a deep breath and cough into a sterile sputum container.

For a suspected common bacteria, one sputum sample may be required. If the suspected infection is more complex, a sputum sample may be required on three to five successive mornings.

Preparation

If there is any difficulty in expectorating, the physician may suggest the use of an inhalation, an expectorant, or physiotherapy to aid in producing sputum for collection. The sputum should be transferred to the laboratory within two hours for analysis.

Results

Sputum is mucoidal in appearance, resembling the thick liquid secreted by the mucous glands. It can be clear, white, or greenish in color, even blood stained. Blood in the sputum is called haemoptysis and may be a pink froth, mucus with a streak of blood, or an obvious clot, red in color representing fresh blood or brownish representing old blood. Haemoptysis may indicate that there has been some trauma to the respiratory tract, or that there is an infection present such as tuberculosis or even carcinoma. If it is determined that the blood is not from a simple cut to the mouth or a nosebleed, it is considered a serious condition and should be treated immediately. The sputum may also be frothy, indicating that the patient's pulmonary blood pressure is raised. Mucopurulent sputum contains mucus and pus and indicates an infection, such as an abscess , is present.

There may be an unpleasant odor associated with sputum.

Health care team roles

The procedure must be fully explained to the patient. The nurse should note if the patient has any difficulty with expectoration, and report it to the physician.

Resources

BOOKS

Nettina, Sandra. Lippincott Manual of Nursing Practice, 7th ed. Philadelphia: Lippincott, 2001, p.197.

OTHER

"Cytology Exam of Sputum." <http://www.healthcentral.com>.

"Routine Sputum Culture." <http://www.thriveonline.oxygen.com/medical/library/article/003723.html>.

"Signs and Symptoms of Respiratory Disease." WebMD.com. <http://www.webMD.com>.

Margarte A. Stockley, R.G.N.