Thousands of elderly South Australians will avoid unnecessary trips to hospital following the expansion of a virtual health service trial.

Following a successful test run, SA's Virtual Care Service is being rolled out at more than 150 residential care facilities, which are home to more than 11,000 residents.

The program will also help reduce demand on the state's under fire ambulance service and emergency departments, Health Minister Chris Picton said.

The trial, undertaken at 11 Eldercare aged care homes, found about 80 per cent of patients treated by the service could receive care within the home, avoiding the need for hospital and an unnecessary triple-zero call.

The service provides direct access to specialist medical, nursing and paramedic clinicians.

Facilities can instead organise video link consultations to assess, monitor and determine care options, which can often be provided in-house.

Approximately 35 SA aged care residents are taken to metropolitan emergency departments each day.

Due to their age and sometimes complex needs, they are often end up admitted to hospital unnecessarily.

"This rollout ... will make a big difference to older South Australians and ensures vulnerable patients can receive the care they need outside of hospital," Mr Picton said on Sunday.

"It will deliver better care for more residents and their families in a comfortable and familiar setting, freeing up emergency resources across the health system."

The service is expected to receive approximately 18 referrals per day - calls that would otherwise have resulted in an ambulance call out.

It is estimated every aged care resident who avoids a trip to the ED frees up at least six hours there and two hours for the state's ambulance service.

SA's most serious emergency cases increased more than six per cent in September compared to the same time a year ago.

There was also a 2.3 per cent jump in these cases compared to August.