Waiting times at Katoomba hospital's emergency department blew out in the first quarter of this year, with more than 30 per cent of patients waiting more than four hours for treatment.
This was a significant rise on the same period last year when just 22 per cent of patients were kept waiting and 78 per cent were treated on time.
Figures at Nepean were worse with 59 per cent getting timely treatment but it was an improvement of 11 percentage points on the previous year.
The report for the January-March 2022 quarter covered the peak of the Omicron COVID-19 outbreak.
Chief executive of Nepean Blue Mountains Local Health District, Kay Hyman, said the dedication and commitment of staff to delivering the best care had been nothing short of exceptional.
"I'm incredibly proud of how staff have risen to the challenges presented by COVID-19. We're quickly adapting to new and more complex ways of working and continuing to ensure training is available to those who need it," Mrs Hyman said.
"At our hospitals we put in place a variety of measures to help with increased COVID-19 activity, including rearranging the ED floor space at Nepean Hospital and opening additional dedicated COVID-19 wards to keep our patients and staff safe."
But Blue Mountains MP, Trish Doyle, said the figures painted a "dire picture" of waiting times with too many patients not seen within four hours.
"The fact that at our region's biggest hospital [Nepean], a majority of emergency department patients were not seen within the timeframe that this Liberal and Nationals Government has set to measure its own performance is frankly unforgiveable."
Ms Doyle said her office regularly hears from people who have been kept waiting, sometimes all day or night, until they are seen by a doctor in EDs.
"One young man who contacted me had to wait over 12 hours to have appendicitis treated. I've had calls from people in tears because their elderly parents have been left out in the corridor on trolleys because there aren't enough beds. I've had staff write to me to tell me they feel overworked, underpaid, and under-appreciated."
Non-urgent elective surgery waiting times also blew out, with patients at Nepean now waiting a year (363 days) for their procedures and those at Blue Mountains waiting 135 days.
But Mrs Hyman pointed out that non-urgent elective surgery requiring an overnight stay had been suspended on January 10 in NSW public hospitals because of Omicron. Procedures resumed in a staged manner from February 7.
She said after the resumption, the number of elective surgeries performed each week gradually increased and NBMLHD is working hard to ensure patients are treated as soon as possible.
She said that any patients who felt their condition had deteriorated while waiting were encouraged to contact their treating doctor for a clinical review.
Ms Doyle said: "The fabulous staff of the Nepean-Blue Mountains Local Health District have been under enormous pressure, particularly over the past two years. They deserve a government that will work to make sure hospitals are properly equipped so that they can deliver for patients. The NSW Liberals and Nationals have had 11 long years to be that government and have proven themselves utterly incapable."
