A study has found a way to ventilate two lungs at the same time amid the spread of COVID-19, but researchers warn the practice carries some risk.

Australian researchers have found a way to help two people breathe from one ventilator as coronavirus sparks a global machine shortage.

The researchers have successfully tested ventilator splitting in a simulated setting, a study published on Tuesday reveals.

Ventilator splitting is when two or more patients are connected to one ventilator and both are exposed to the same circuit dynamics.

The ventilators help push oxygen into patients whose lungs are failing.

While the researchers from Monash University, The Alfred and The Royal Women's Hospital in Melbourne do not condone ventilator splitting, it could be done in extreme emergencies such as COVID-19.

Coronavirus can lead to severe respiratory failure and viral inflammation of lung tissue which can kill.

"Patients with COVID-19 may develop progressive viral pneumonitis leading to severe respiratory failure," study lead Alexander Clarke said.

"While ventilator splitting has, at face value, validity in addressing ventilator shortages, we agree that on sober reflection, it is a solution that needs to be weighed up carefully as it may cause more harm than good."

The process is challenged as ventilation needs differ between patients and cross-infection from inter-patient gas exchange, a lack of monitoring for individual flow and pressure, and irregularly pressurised air supply can kill.

Hospitals across the globe are experiencing ventilator shortages amid COVID-19, with the USA's Food and Drug Administration recently passing emergency use authorisation for the splitting of ventilators.

The study researchers warn the findings need to be interpreted and applied with caution.

"We are hopeful of one day being able to get great surety with this approach to ventilator splitting so we can help save lives in dire cases of emergency," Monash University's Shaun Gregory said.

Until there are further trials, researchers warn against wider use.

The study has been published in the international journal Anaesthesia.