The latest figures from the INMO reveal numbers waiting at the Midlands Regional Hospitals.
The Irish Nurses' and Midwives' Organisation says the first full week of 2020 has been the worst-ever for overcrowding.
144 people have been left waiting on trolleys across midlands hospitals this week.
Latest figures from the INMO show Mullingar hospital was the worst-affected, with 73 people waiting for beds.
That's more than double at the regional hospitals in Tullamore and Portlaoise combined - with 49 and 22, respectively, waiting on trolleys there.
Nationally, 3,143 patients were without beds this week, with Monday and Tuesday both hitting a record high of 760.