Some 39 beds are closing at the Royal Adelaide Hospital (RAH) at a time when its emergency department is already under significant pressure, the doctors' union has said.

Staff were today told wards S7 and Q3B would close in the next few months as part of the Government's Transforming Health overhaul.

Central Adelaide Local Health Network chief executive officer Julia Squire said the beds were effectively being transferred to private aged care provider Southern Cross Care under an agreement.

She said elderly patients who had completed their medical treatment often remained in the RAH while awaiting placement in an aged care facility.

"There are additional risks associated with staying in a hospital if you don't need to be so we've invested in suitable alternative care packages for those patients with Southern Cross," Ms Squire said.

But Bernadette Mulholland from the Salaried Medical Officers Association (SMOA) questioned whether any beds should close while significant demand on the hospital's services remained.

"We are incredibly concerned, given the environment and that it's currently the winter season, what the closure of 39 beds will mean to emergency departments and surgery generally," she said.

The patients will be transferred to the Southern Cross' Lourdes Valley Care Centre, Myrtle Bank, but SA Health has not yet said how much it would pay the private provider for the service.

Ms Squire said she was confident the RAH had enough beds without S7 and Q3B.

"I'm absolutely sure, with the flow and the careful planning that our clinical teams have put into place for this, that we'll be able to flow patients through the hospital as they need to be," she said.

SA Health said affected staff members would be shifted to other areas of the hospital.

The closures are happening despite ramping — attending to patients in ambulances parked outside hospital — regularly being necessary to overcome bed shortages in Adelaide's emergency departments.

Frustrations escalating over Transforming Health

SMOA has lodged a dispute with the Industrial Relations Commission of SA over another key part of the plan.

The Transforming Health manifesto was released in March last year. ( ABC News: Nick Harmsen )

Ms Mulholland said the union was unhappy with a lack of consultation over the planned movement of staff involved in specialties such as vascular surgery and orthopaedics.

They are to be moved from the Royal Adelaide and Queen Elizabeth hospitals to the Lyell McEwin and Modbury hospitals.

"What does that mean for the services that remain behind in the Royal Adelaide and Queen Elizabeth Hospital and what does that mean for workloads?" Ms Mulholland said.

"What does that mean for patients, clinical trials?

"We're extremely frustrated. We're reaching a point where the relationship between the two parties is breaking down considerably and we have no trust in what they are telling us," she said.

Opposition health spokesman Stephen Wade said staff were fast losing confidence in Transforming Health.

"SA Health has been saying from day one that it's vital for a health reform project to have the health professionals coming with them," he said.

"This is clearly a situation where the whole project is losing the confidence of the very people who are engaged to provide care in our hospitals.

SA Health acting chief executive officer Vickie Kaminski told a parliamentary committee the agency was listening to concerns but staff could see the benefit of the changes being made.

"Categorically all of them said we need, not surprisingly, we need more information, we need it on the ground, we need it all the time and we need to know we're being heard," she said.

"So I think that was good for us to hear."