In pain and vomiting, an Adelaide man's 000 call should have resulted in an ambulance picking him up in no more than 60 minutes.

But on December 27, after a 10-hour wait, with ambulances backed up at hospitals across the city, the 54-year-old died an agonising death with no help in sight.

That night, a Code White was declared for emergency departments across Adelaide, meaning all treatment rooms were being used.

Unable to unload their passengers, ambulances were stuck "ramped" outside hospitals instead of being available for the community, leading to long delays in ambulance responses.

A video posted by the Ambulance Employees Association to X, formerly Twitter, shows at least 10 vehicles waiting outside the Royal Adelaide Hospital on the night.

"This tragic death is a stark reminder that when ambulances are ramped at hospitals, patients waiting for help in the community are left without care for unacceptably and dangerously long periods of time," AEA industrial officer Josh Karpowicz said.

"Ramping takes ambulances off-road and puts patients at risk of deterioration in an environment where there is no one available to help them."

SA Ambulance Service chief executive Rob Elliott said very high triple zero demand and significant ramping on the night of the man's death meant ambulances had to prioritise more urgent calls.

The man was initially listed as a priority five, which the union says should have resulted in a pick up within 60 minutes. But after 10 hours his condition deteriorated and a subsequent triple zero call resulted in him being bumped up to a priority one.

Mr Elliott said ambulance crews responded four minutes after the priority was lifted.

Three calls were made between the patient and dispatchers on the night, he said.

Performance on the night against procedures for calling back patients experiencing ambulance delays will be assessed as part of a review into the incident.

Ambulance ramping was a key issue that helped propel Labor to power at the 2022 state election.

The Malinauskas government has ploughed millions of dollars into expanding hospital capacity in a bid to fix the crisis, yet ramping has increased by almost a third under its stewardship.

In December, 3595 hours of ambulance availability were lost to ramping across Adelaide.

Claims ambulances patients were being fast-tracked into emergency rooms over waiting room patients to reduce ramping statistics prompted the government to launch a clinical review in December.

But the union says high ramping levels and the man's tragic death demonstrate that this is not the case and patients in the community are being put at risk because of delayed transfers of care.

Opposition health spokeswoman Ashton Hurn said despite Premier Peter Malinauskas' promises to fix ramping, the issue was worse under his watch.