Hospitals in Limerick and Cork were the most overcrowded in Ireland on Wednesday morning with 175 patients waiting for beds, according to the Irish Nurses and Midwives Organisation (INMO).
University Hospital Limerick had 93 patients waiting for a bed, while Cork University Hospital had 82 patients waiting on trolleys.
Nationally, the union said there were 441 patients waiting for beds in emergency departments, while 152 were waiting in wards elsewhere in hospitals.
According to the Health Service Executive's own figures, 465 people were waiting on trolleys across HSE-run hospitals on Wednesday morning.
There were 70 patients waiting more than 24 hours, according to the HSE's daily urgent and emergency care report.
The HSE counts patients waiting on a hospital trolley or extra bed placed in an inappropriate space in a hospital ward.
In addition to those in wards, the INMO also counts patients placed on corridors or chairs elsewhere in hospitals while waiting for admission to a bed.
