Patients at the Emergency Department (ED) at Craigavon Area Hospital faced average waits of almost 19 hours on Wednesday morning.
Emergency department average waiting times released at 09:00 GMT by NI Direct showed the Royal Victoria and Ulster hospitals also experienced waits of about nine hours.
These figures followed reports of more than 40 ambulances waiting for release outside hospitals on Tuesday – with the longest wait in excess of 13 hours.
In October, a target to reduce maximum ambulance waits outside EDs from four hours to two by 1 December was announced as part of a plan to tackle winter healthcare pressures.
The Northern Ireland Ambulance Service (NIAS) said the delays were “as a result of challenges being felt across the entire HSC system and the impact of trade union action short of strike”.
As of 10:00 GMT on Wednesday NIAS had reported 64 calls waiting, with 15 of its ambulances at EDs.
On Tuesday there were 100 calls waiting for an ambulance response, with the “number of ambulances queued at EDs fluctuating hourly”.
NIAS said it recognised the impact these delays have on patients and families and “regrets the lengthy waits that some have experienced”.
“Across the health and social care system, significant work has been undertaken over recent months to reduce handover delays.
“This includes strengthened escalation arrangements, daily joint coordination between NIAS and trusts, and targeted improvements within EDs to support faster patient flow and release of ambulances.
“While these actions have contributed to some stabilisation, the system continues to operate under very high pressure,” a NIAS spokesperson said.
NIAS said it has a number of paramedics stationed in its Emergency Operations Centre who will triage calls to identify those which can perhaps be dealt with through alternatives other than ED attendance.
NIAS would ask patients, or carers, not to phone back on the 999 system and to check on the arrival of the ambulance, as this only adds to the pressure being experienced by our Control staff.
“However, if the condition of the patient has deteriorated since the initial call, you should call 999 immediately.”
