St George Hospital's intensive care unit has been barred from training junior doctors amid protracted allegations of bullying and dysfunction among senior staff.

It is the third damning case of a major Sydney hospital unit banned from supervising trainees over concerns for their welfare.

St George Hospital. John Veage

The College of Intensive Care Medicine (CICM) withdrew accreditation from the South East Sydney hospital this week, following an inspection of its ICU and multiple bullying complaints.

Once the current CICM trainees finish their contract periods, the ICU will need to find ways to cover shifts vacated by the trainees, such as relying on unaccredited junior doctors, anaesthesia registrars, and locum specialists.

If the shifts can't be covered, the hospital may need to close some of its 40 ICU beds, which would have knock-on effects for other units treating patients in critical condition, including the cardiothoracic, neurosurgery, trauma and general surgery.

CICM president Dr Raymond Raper declined to discuss what triggered St George's loss of accreditation, saying the process was conducted in confidence.

“Taking accreditation is the last resort," Dr Raper said. "It’s not done lightly and it’s only done when things get pretty dire.

“The fact that there are two [ICUs] in Sydney [that have lost accreditation] at the moment is extraordinary.”

CICM has also stripped Westmead Hospital of its intensive care trainees in response to reports of bullying and harassment.

In November, the Herald revealed the College of Surgeons banned RPA’s cardiothoracic surgery department from training its registrars in 2019 over similar allegations. The college recently re-inspected the department and is deliberating whether to allow its trainees to return next year.

St George's ICU will likely have no accredited CICM trainees by the end of 2019, once all current trainees had finished their six-month or 12-month contracts.

“We think it would be worse for them if we suddenly took away their training," Dr Raper said.

“It’s a terrible situation for St George … we feel terribly for them. [But] we have to look at the welfare of our trainees and our fellows.”

The hospital must apply for reinspection and prove they have addressed the college's concerns.

St George's general manager Leisa Rathborne confirmed the loss of accreditation "due to cultural issues within the unit". "The ICU remains fully operational and appropriately staffed", and patients "will continue to receive the highest quality care", the statement read.

Ms Rathborne said hospital management was working with ICU staff and the college to resolve the matter.

An external investigation into the bullying allegations is expected to conclude within weeks.

CICM trainees account for roughly one-third of all trainees in ICUs nationwide, and up to half in major hospitals.

Dr Raper said the college took harassment very seriously.

“We think there may well be something about intensive care that makes it particularly problematic and we are looking at what we can do about it,” he said.

NSW Health Minister Brad Hazzard said the rash of training accreditation losses was "very disturbing".

"Fortunately the same service from first class specialists will still be delivered to patients, but losing the capacity to teach new specialists just shouldn't happen," he said.

Mr Hazzard said colleges needed to be far more proactive to head off an entrenched culture among some senior specialists. The Minister plans to invite specialist colleges to a forum later this year to discuss whether they were taking pre-emptive action.

“Is it just reactive? I fear all too often it might be,” he said.

The 2018 Junior Medical Officer Survey found less than half of respondents (43 per cent) agreed their hospital had a culture that effectively dealt with discrimination, bullying and sexual harassment. That fell to 37 per cent at South East Sydney Local Health District, which includes St George Hospital.

In February, NSW Health announced a $1 million package aimed at improving the health and wellbeing of junior medical officers (JMOs), including a SESLHD program aimed at teaching supervisors techniques to help trainees in distress.

Westmead ICU’s new director Dr Dani Goh said the hospital had undertaken extensive reform over the past six months, including hiring new staff, engaging a wellbeing expert, rostering dedicated education and training time, and cultural transformation “to make sure our staff are well supported and work in a respectful environment”.

“We hope to present results of our efforts in the intensive care unit to the College for Intensive Care Medicine in 2020,” Dr Goh said in a statement.