There are ways to protect staff and patients

The pandemic saw many GPs shelve their spirometers because of concerns around the aerosolisation of COVID-19 in their practices.

With the pandemic now more endemic, spirometers can be used again. Dr Andrew Scroop, a Respiratory Physician at the St Andrews Medical Centre, says patients with indications of asthma or COPD should be tested at least once.

“Even prior to COVID, spirometry was significantly under-utilised by practices. It is common for patients with respiratory symptoms to be sent to me and they’ve had x-rays and blood tests done, but they’ve never had spirometry or lung function tests done,” Dr Scroop says.

“Where you suspect someone has asthma because they’ve had symptoms from childhood, for example, or you suspect COPD for someone who’s an ex-smoker or had industrial exposure, you can use spirometry to confirm or refute your diagnosis. It’s a valuable test.”

To help practices recommence testing while COVID-19 lingers, the Australian and New Zealand Society of Respiratory Science (ANZSRS) released guidelines in August detailing measures to take to protect the safety of staff and patients.

One recommendation is to have a dedicated room for testing, similar to the one Dr Scroop uses at his practice.

“No one else goes in our lung function testing room except the person performing and doing the tests. The surfaces are cleaned between patients and we screen people beforehand for acute or recent onset of new respiratory symptoms,” he says.

“We use inline filters for the spirometers, which are available off the shelf for a small charge per filter and are single use.

“And we have an air purifier in the room with a HEPA filter, the kind you can get from Harvey Norman or The Good Guys, that adds an extra level of protection.”

If a dedicated space is not possible at a practice, Dr Scroop says there are plenty of labs GPs can refer a patient to for testing. The lab will provide a report and an interpretation of results, and the out-of-pocket expense for the patient is generally lower than the amount for a chest X-ray (CXR).

Interpreting spirometry results can be an intimidating task. If you are not used to looking at the shape of the flow volume loop, Dr Scroop says to start with the FEV1/FVC ratio.

“If the ratio is 0.7 or less with a low FEV1 but normal FVC, you have an airflow obstruction. Above 0.7 is normal or could be a restriction,” he says.

“You then look at the absolute FEV1 and FVC numbers. If the FEV1 is under 80% with a normal FVC, that is an obstruction. If both are reduced but with a normal ratio, then that is a restriction.”

The RACGP published a detailed article on spirometry testing and interpreting results in 2011 that Dr Scroop says is still relevant but contains no reference to infection control or COVID-19.

Hear Dr Andrew Scroop talk more about spirometry in the upcoming Healthed webcast on Tuesday 8 November 2022. Register here to attend.