There were 342 patients on trolleys in emergency departments (EDs) and 158 were inappropriately placed on already full wards, the INMO said.
University Hospital Limerick, with 66 patients waiting, had the highest number. St Luke’s Hospital, Kilkenny, had 42, the second-highest number, and University Hospital Galway had 41.
Three children were waiting for a bed in Children’s University Hospital, Temple Street, Dublin.
Last Friday, there were 470 adults and 13 children on trolleys.
INMO general secretary Phil Ní Sheaghdha said that, as predicted, the trolley figures had increased again following the bank holiday weekend.
“Hospitals are still in crisis and we are now calling on the HSE to continue curtailment of services to ensure figures do not escalate again, this week, and to allow hospitals deal with the current high numbers,” said Ms Ní Sheaghdha.
The HSE’s TrolleyGAR counted 370 patients on trolleys in EDs yesterday, with 197 waiting over nine hours, and 73 waiting over 24 hours. The HSE only counts patients on trolleys in EDs.