Is it acceptable to administer hypersaline nebulizers to induce sputum in a patient with active Tuberculosis (TB)?

From the Guidelines

No, it is not recommended to give an active TB patient hypersaline nebulizers to induce sputum in routine clinical settings. This procedure creates aerosolized particles that can significantly increase the risk of TB transmission to healthcare workers and other patients. According to the American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America guidelines 1, when the lung is the site of disease, three sputum specimens should be obtained, and sputum induction with hypertonic saline may be necessary to obtain specimens, but this should be done under appropriate infection control measures.

Instead, spontaneously produced sputum samples should be collected whenever possible. If sputum induction is absolutely necessary for diagnosis, it should only be performed in specialized negative pressure rooms with appropriate airborne infection isolation precautions, as recommended by the Centers for Disease Control and Prevention 1. Healthcare workers should wear N95 respirators or higher-level respiratory protection. Alternative methods for TB diagnosis should be considered first, such as early morning sputum collection, gastric aspirates (especially in children), or more advanced diagnostic techniques like GeneXpert MTB/RIF testing on various specimen types.

The primary concern is that hypersaline nebulization causes patients to produce deep coughs, creating infectious aerosols containing viable TB bacilli that can remain suspended in the air for extended periods and potentially infect others, making this procedure a significant infection control risk in TB management. The guidelines emphasize the importance of preventing the transmission of Mycobacterium tuberculosis in healthcare facilities, and cough-inducing procedures should be performed with caution and under appropriate infection control measures 1.

Some key points to consider when dealing with active TB patients include:

• Collecting spontaneously produced sputum samples whenever possible
• Using alternative methods for TB diagnosis, such as early morning sputum collection or gastric aspirates
• Performing sputum induction with hypertonic saline only under appropriate infection control measures and in specialized negative pressure rooms
• Ensuring healthcare workers wear N95 respirators or higher-level respiratory protection when performing cough-inducing procedures
• Prioritizing infection control measures to prevent the transmission of TB in healthcare facilities, as recommended by the Centers for Disease Control and Prevention 1 and the American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America guidelines 1.

From the Research

Sputum Induction for Active TB Patients

• The use of hypersaline nebulizers to induce sputum in active TB patients has been studied in several research papers 2, 3, 4.
• A study published in 2022 found that hypertonic saline sputum induction improves the quality of collected samples and may increase the rate of MTB detection in sputum using microscopic, bacteriological, and molecular genetic methods for diagnosing TB 2.
• Another study from 2015 compared the diagnostic yield and safety of sputum induction with nebulized racemic salbutamol versus hypertonic saline in smear-negative pulmonary tuberculosis, and found that racemic salbutamol solution could increase the TB diagnostic yield similarly to 3% NaCl, but with less adverse effects 3.
• A 2014 study found that sputum induction with hypertonic saline improves sputum specimen adequacy and may be useful for same-day bacteriological diagnosis with microscopic examination and PCR 4.

Safety and Efficacy

• The studies suggest that hypersaline nebulizers are a safe and effective method for inducing sputum in active TB patients, with minimal adverse effects 2, 3, 4.
• However, it is essential to note that the risk of transmission of M tuberculosis remains a concern, and proper ventilation and personal protective devices should be used when performing sputum induction 5.
• Airway clearance techniques, such as chest wall percussion, vibration, and huffing, do not appear to have a significant effect on the sputum induction procedure 6.

Clinical Practice

• The use of hypersaline nebulizers for sputum induction in active TB patients may be a useful tool in clinical practice, particularly in middle- and low-income countries with limited resources 2.
• The studies suggest that sputum induction with hypertonic saline can improve the quality of collected samples and increase the rate of MTB detection, which can aid in the diagnosis and treatment of TB 2, 4.