10,018 patients were left without a bed in Irish hospitals in September, according to the Irish Nurses and Midwives Organisation (INMO).
INMO said at least 200 children in hospital did not have a bed as over 10,000 patients are treated on a trolly or chair.
The most overcrowded hospital in Ireland in September was University Hospital Limerick, with 2,174 patients going without beds.
The Limerick hospital was followed Cork University Hospital (1,024 patients), Sligo University Hospital (775 patients), St. James’ Hospital (532 patients) and University Hospital Galway (516 patients).
INMO General Secretary Phil Ní Sheaghdha said September is a “reliable indicator of how the winter is going to look for healthcare staff”.
“The situation that our members are predicting based on these figures as was the case in August, indicates a huge red flag,” she said.
“Our members are very worried for themselves and the people in their care. Without real action the State is basically just asking staff and patients to lower their expectations for their health service.
“We need risk reduction measures to be introduced now - not when it is too late and an inevitable adverse incident occurs.”
Children in hospital
Ms Ní Sheaghda said INMO was particularly concerned about the children not accessing hospital beds.
“Knowing what we do about how trolley waits negatively affect patient outcomes, and how rapidly children can decline when they are sick, the risks that children are being exposed to in our hospital are too high,” she said.
“Following our engagements with the HSE at the most recent Emergency Department Taskforce meeting, we don’t believe that the HSE are willing at this point to put the necessary measures in place.
“There needs to be a serious mindset shift if we are to see improvements.”