Close to half the critically ill patients who should be treated within 10 minutes faced delays at Wollongong Hospital's emergency department in the first three months of 2019.
The latest Bureau of Health Information Quarterly Report reveals that only 56 per cent of patients who were triaged as 'emergency' cases started their treatment within the recommended timeframe at the hospital from January to March.
'Emergency' or T2 patients - the second-highest triage category - are those who have an "imminently life-threatening condition" such as severe chest pains, severe fractures or difficulty breathing.
The recent BHI report showed that some of these patients faced waits of 27 minutes at Wollongong's ED earlier this year, nearly three times the recommended timeframe.
Meantime more than 30 per cent of "urgent" or T3 cases did not start treatment within the recommended 30-minute timeframe at the hospital according to the figures.
Some patients in this category - who may be suffering severe illness, major fractures or bleeding heavily from cuts - waited up to one hour and 17 minutes for treatment.
BHI senior director Hilary Rowell said an increase in presentations at Wollongong's ED had led to some declines in performance.
"The figures show that across all triage categories, seven in 10 patients (72.8 per cent) started treatment on time at Wollongong Hospital," she said.
"However in the emergency category there were 13.5 per cent more patients during the quarter, so we saw that flip back in performance with just 56 per cent of patients starting treatment on time.
"While that's below the state average of 63.1 per cent for that category, it's a similar performance to other principal referral hospitals."
Like many hospitals across the state, Wollongong Hospital's ED saw a rise in presentations in the first quarter of 2019. There were than 18,256 presentations - up five per cent on the same period last year.
Ms Rowell said the percentage of patients leaving Wollongong's ED within the state's four-hour benchmark declined quite markedly this year.
"Fifty-seven per cent of patients left the ED within four hours from January to March - a drop of 15 percentage points on the same quarter in 2018," she said.
"The NSW average was 70.6 per cent of patients leaving within four hours; for other principal referral hospitals it was 60.3 per cent."
Presentations to EDs across the Illawarra Shoalhaven Local Health District rose to 43,444 from January to March. That's a six per cent rise - or 2506 presentations more - than the previous year.
ISLHD executive director clinical operations Margaret Martin said the district's EDs had a number of initiatives in place to improve the delivery and timeliness of care.
"At Wollongong Hospital, the ED continues to review its systems and models of care and develop new initiatives," she said.
"Such as the introduction of specialised staff who are trained to start clinically initiated tasks for a patient under supervision of a nurse or medical officer, and who will help with movement of patients through the department."
Ms Martin said while there had been "some challenges" with the demands for emergency surgery at Wollongong Hospital, the elective surgery performance had improved since January.
"Wollongong Hospital performed almost all (99.8 per cent) of its 548 urgent elective surgeries on time," she said.
District-wide, 99.9 per cent of the 755 urgent surgeries were completed on time, and 89.5 per cent of the 921 semi-urgent surgeries.
At the end of the quarter 5970 patients remained on the district's elective surgery waiting list - 2599 of those were awaiting elective procedures at Wollongong Hospital.