The health worker, who did not wish to be named, said the sheer volume of sick people and lack of beds resulted in three ambulances being stationed outside the hospital, where staff provided ongoing care.
There was not enough room for ambulance staff to take patients into the hospital.
Some people had been sitting in the corridor of the ED since 9am, the health worker told the ODT about 3pm yesterday.
"There’s not enough flow-through and the result of that is that ambulances are now stuck."
It was an unusual situation.
Patients would sometimes be moved to the fracture clinic by ambulance staff when the ED was busy after hours, but this was not possible yesterday.
Ambulance staff were "just sitting in there" looking after patients, he said.
The health worker was worried people’s lives were at risk due to the situation.
If there was an incident in the community requiring an emergency response, three of a possible five ambulances would be out of action because they were waiting at the hospital.
Health New Zealand Te Whatu Ora (HNZ) confirmed ambulance staff were sometimes used by the hospital.
"When our emergency department is experiencing peak demand, we work closely with Hato Hone St John and other parts of the health system to ensure we manage the acute demand", Southern operations group director Hamish Brown said.
St John expertise might be used to oversee a small number of "lower complexity" or stable patients while "we work to create the necessary capacity in our hospital", he said.
"This is part of our usual escalation plan and demonstrates our partnership with Hato Hone St John to respond collectively to the fluctuations in demand for emergency care."
Hato Hone St John coastal Otago operations manager Doug Third said the handover of a patient from an ambulance to hospital normally took about 30 minutes.
Anything beyond this was considered "ramping".
St John and HNZ were working together on solutions for it, he said.
"While patients remain safe in the care of Hato Hone St John, we acknowledge any delay when handing over a patient to a hospital can be distressing for patients and their whānau", Mr Third said.
"We work closely with hospital staff to optimise the process of transferring the care of patients."
High levels of pressure on the ED have been a recurring issue.
