UNDERSTANDING SPUTUM INDUCTION

Sputum induction is a straightforward and non-invasive procedure designed for patients who struggle to produce sputum naturally. The patient inhales a nebulized hypertonic saline solution(i.e hyperconcentrated normal saline), which helps to liquefy the secretions in the airways. 

This process facilitates coughing, making it easier to expel respiratory secretions. If successful, sputum induction often eliminates the need for a more invasive procedure like bronchoscopy.

When undergoing sputum induction, patients often start coughing, which can release infectious droplets into the air.

 To prevent the spread of these droplets, it's essential to follow strict airborne respiratory precautions during the procedure.

Here are several conditions where sputum induction might be considered:

1. Suspected Bacterial Pneumonia: When bacterial infection is suspected in the lungs.

2. Suspected Pneumocystis Pneumonia: Often seen in immunocompromised patients.

3 . Suspected Mycobacterium Tuberculosis: For diagnosing tuberculosis.

4 . Questionable Chest X-ray: When the X-ray results are unclear and further analysis is needed.

5 . Suspected Lung Cancer: To gather more information if lung cancer is suspected

CONTRA-INDICATIONS

1. Hyperactive airways

Hypertonic saline used in sputum induction can cause the airways to constrict, making it unsuitable for people with conditions like asthma or COPD. This procedure should be done only after administering salbutamol and under medical supervision.

2. Severe coughing caused by the procedure can be harmful to some patients, so it should be avoided in individuals who could be negatively impacted by intense coughing. This includes patients with:

-Haemoptysis of unknown origin

-Acute respiratory distress

-Unstable cardiovascular status, such as arrhythmias or angina

-Thoracic, abdominal, or cerebral aneurysms

-Hypoxia (SaO2 less than 90% on room air)

-Lung function impairment (FEV1 less than 1.0 liter)

-Pneumothorax

-Pulmonary emboli

-Fractured ribs or other chest trauma.

-Recent eye surgery

3. Patients who are unable to follow instructions.

PRECAUTIONS BEFORE THE PROCEDURE

A. Infection control.

For infection control, sputum induction should be performed in a single room equipped with a ventilation system designed to completely exhaust air to the external environment.
This ensures that air from the room does not recirculate back into the building.

The room should remain closed during the procedure to maintain a controlled environment, minimizing the risk of airborne contaminants spreading.

B. Staff preparation

• Maintain a documented record of your tuberculin skin test (TST) or Interferon gamma release immunoassay (IGRA) status.
• Wear the recommended TB respiratory protection (P2 mask) and disposable gloves when handling sputum specimens.
• Assess the patient for any contraindications before proceeding.
• Clearly explain the procedure to the patient, including potential side effects such as coughing, dry mouth, chest tightness, nausea, and excess salivation.

EQUIPMENT

• 3% Saline (15cc vial)Small Volume Nebulizer
• Specimen cup
• N95 or P2 mask
• Lab requisition
• Specimen bag

A nebulizer

PHYSICIAN'S ORDER

There must be an order in the patient's medical record for sputum induction that includes:

• Date and time of induction (e.g., every morning for 3 days is preferred).
• If the doctor needs induction to start at the time the order was written (e.g., to start at noon).
• Specified medications or methods; if not specified, use 3% hypertonic saline.
• Type of tests ordered on the specimen.

PROCEDURE FOR SPUTUM INDUCTION 

1. Assemble and check all necessary equipment before bringing the patient into the area.
2. Fill the nebulizer chamber with water between the "min fill line" and "max fill line".
3. Place the nebulizer cup into the nebulizing chamber, ensuring the convex base is in the water.
4. Load 20ml of the 3% hypertonic saline solution and inject it into the nebulizer cup.
5. Connect the assembly to the nebulizer machine.
6. Instruct the patient to thoroughly clean their mouth by brushing with a toothbrush if it hasn’t been done since their last meal, or by forcefully rinsing and repeatedly gargling with tap water until the returned fluid is free from debris.
7. Seat the patient comfortably in an upright position in the designated room.
8. Reiterate the procedure and the possible side effects to the patient.

Patient Instructions:

• Instruct the patient to inhale and exhale through the mouthpiece only.
• Saliva should be expectorated into the emesis bowl, while sputum should be coughed up into the sterile jar.

Staff Safety Measures:

• Explain the necessity for the staff to wear a TB respiratory protective device (P2/N95 mask) and put it on.
• Ensure all doors and windows are shut to prevent air contamination.

Procedure Steps:

• Place the mouthpiece into the patient's mouth, emphasizing the importance of mouth breathing.
• Allow the patient to inhale the hypertonic mist for approximately 5 minutes.
• Instruct the patient to take several deep breaths from the nebulizer.
• If spontaneous coughing does not occur, ask the patient to attempt a forced cough.
• The staff may use gentle chest physiotherapy, such as vibration and percussion, to help produce sputum.

Monitoring and Safety:

• Observe the patient closely throughout the procedure, watching for any signs of respiratory distress.

When to Stop:

The procedure should be stopped

• If the patient has produced 1-2 ml of sputum for each specimen.
• 15 minutes of nebulization have passed.
• if the patient experiences dyspnoea, chest tightness, wheezing, lightheadedness, or nausea.

Post-Procedure:

• Place the patient's identification sticker on the specimen container; write on the sticker the time and date of the procedure.
• Assess the patient's condition post-procedure, and take appropriate action if required.
• Remove the nebulizer chamber and metal shield from the machine. Rinse and dry both with water and a paper towel.
• Wipe over the nebulizer machine with methylated spirits.
• Dispatch the specimen to the Pathology Department.