The number of patients on trolleys at hospitals across the country today has risen to 617.
Cork University Hospital is the worst affected, with 55 people awaiting a bed, according to the INMO.
That's followed by 51 at University Hospital Limerick and 48 at South Tipperary General Hospital.
In this region, there are 41 patients waiting for a bed at both Sligo and Galway University Hospitals.
13 patients are on trolleys at Portiuncla in Ballinasloe, and 9 at Mayo University Hospital.
Meanwhile the INMO says the risk of further industrial action by nurses has not been eliminated.
The union yesterday objected strongly at the Labour Court to controversial management proposals for a new contract, which included major changes to existing shift patterns and the right to redeploy nursing staff by up to 40km during shifts.
Speaking after the hearing, INMO general secretary Phil Ni Sheaghdha said if industrial action was reinstated, it would be because of the employers' insistence on imposing what she called a "punitive" contract.
She claimed the proposed shift changes and redeployment were not necessary, and would worsen recruitment and retention difficulties.