Overcrowding in a Dublin emergency department was critical today with 46 patients waiting on trolleys and chairs for admission, it was claimed.
The Irish Nurses Organisation (INO) said the situation was so bad at Beaumont Hospital that emergency ambulances were detained at the department for more than two hours.
The hospital said it was aware of extra pressure on the service and trying to address it.
"Once again patients and staff in the A&E department of Beaumont Hospital find themselves enduring disgraceful conditions as a result of overcrowding," said Edward Mathews, INO Industrial Relations Officer.
"Horror stories are being told to us about a 90-year-old on a chair for 24 hours.
"It is at full capacity and has been at full capacity for a number of days now. Staff are totally exasperated and patients are in deplorable conditions.
"It is a very serious situation."
Beaumont Hospital said it, alongside public representatives, has continuously lobbied the Government for more services in the community for patients in need of long term beds.
A spokesman said although the issue of long stay patients has been a fundamental problem for a number of years, it wasn't greater today than at any other time.