Staff had problems getting a resuscitation trolley to patients at a major emergency department because of overcrowding, a regulator has revealed.
Trolleys at the Royal Victoria Hospital were packed close together and the area was crowded with patients on chairs as well as relatives, it was found.
The former Chief Medical Officer of England, Sir Liam Donaldson, is to advise Northern Ireland's Health Minister on improvements to the service after the serious concerns were highlighted.
A regulator's report said: "Limited access space for staff, lack of cubicles and high footfall has resulted in patients being nursed on trolleys and chairs throughout the emergency department.
"Patients are placed beside the central work station and ambulance triage, in front of the resuscitation area, in the side corridor at X-ray, and in the back corridor along the short stay unit."
Following a Major Incident at the Royal A&E earlier this year Health Minister Edwin Poots asked the Regulation and Quality Improvement Authority (RQIA) to carry out an urgent inspection of the emergency department and acute medical unit at the Royal.
The inspectors found that "the effective operation of critical departments, in particular the emergency department, was being put at risk by the need to care for patients, who should have been transferred to other more appropriate environments and care teams.
"Staff in affected departments were working hard to maintain patient safety," it added, "but were finding this stressful and difficult to maintain for a prolonged period."
Mr Poots said he wanted to take action to correct what went wrong and announced the appointment of Sir Liam to advise him on improvements across the health service.