Lung function testing and the use of respiratory therapies such as nebulisers should be stopped in all but medically essential cases because of the risk of COVID19 transmission, the Thoracic Society of Australia and New Zealand (TSANZ) has advised.

There is potential for spread of airborne droplets from an infected person undergoing lung function testing including spirometry, even if they are asymptomatic, the TSANZ has advised health professionals.

Since the respiratory plume of exhaled virus can persist for several hours and on surfaces for several days, the organisation says it is prudent to suspend spirometry testing unless it is deemed clinically essential.

In a statement signed by TSANZ President Bruce Thompson, the organisation notes that many lung function laboratories have already closed temporarily or are limiting testing only to essential tests, while others are not measuring lung volumes with body plethysmography.

It advises that most spirometry testing – including for occupational respiratory surveillance – should be postponed, as should fit testing, except in rare circumstances “as determined by a respiratory physician”.

Portable individual patient dedicated spirometers can be used to monitor serial changes in lung function within the patient’s own home. If deemed essential, lung function testing should be done with staff PPE protection.

The TSANZ also advises that respiratory therapies, including nebulisation, high flow oxygen, non-invasive ventilation (NIV) and cough assist devices have the potential to produce aerosols that pose a significant risk of transmission of viral infection to staff and patients.

“While these therapies offer significant benefits to some patients, there are often viable alternative approaches to management that have less risk of transmitting viral infection.

The overall risk can be mitigated by restricting the use of these high-risk therapies and using personal protective equipment (PPE),” it states.

“TSANZ and the Australian and New Zealand Society of Respiratory Science (ANZSRS) thus recommend the use of spacers rather than nebulisers wherever possible due to the potential for droplet spread. “

The TSANZ and ANZSRS suggest that members should check for guidance from their state and federal health departments. The link to the Australian Department of Health is: www.health.gov.au and the link to the Ministry of health in NZ is