Hospitals cannot always share the heavy patient load
Why do hospitals that are bursting with patients on trolleys not divert some of the pressure to other emergency departments that are not as busy?
Although this does happen -and it should be easier now that hospitals are part of different groups - the reality is that it is often the exception rather than the rule. A hospital that is swamped can request another to offer "protection" for some hours.
This would see patients in ambulances following 999 calls taken to less busy emergency departments.
But the request needs to be accepted by the other hospital and the National Ambulance Service (NAS).
If other hospitals, plus the NAS, agree, then there might be ambulance "protection" to ease a bottleneck, particularly in Dublin.
However, the request can be turned down if the receiving hospital feels with good reason that it cannot cope.
There is no protocol to transfer patients from one emergency department to another.
Even when ambulances are diverted, it does not stop the patient influx. This is because ambulance patients account for only around one in five people who come to emergency departments, with others making their own way.
In a hospital like Beaumont in Dublin, most patients come to A&E directly.
It has a large elderly population in its catchment area. Around one in three of the over-65s in surrounding suburbs live on their own. Even if it was possible to transfer these patients, it would be upsetting for them to be far from friends and family.
Beaumont Hospital was under such pressure yesterday, as it asked patients not to attend and go instead to their GP or private facility if possible.
However, north Dublin GP Dr Ray Walley said this practice was "putting patients' health in danger".
"This is especially affecting elderly frail patients. The 'emergency situation' of emergency departments is the national norm now and is a continuing national disgrace," Dr Walley said.
"I have one patient with a serious neurosurgical problem awaiting elective surgery. Her admission is deferred. Her mother reported that a medic on the team told her the only way she was to get her operation done in the future was to present to the emergency department.
"She was told next to no elective neurosurgical work is being done in Beaumont for months. Beaumont is the national neurosurgical centre, which makes this of more concern.
"I had an elderly sick patient who is too scared to go to Beaumont. She refused referral despite being very sick. I have told her that, despite the wait, it is the safest place to go and that she is putting her health in peril."
Dr Walley, who is president of the Irish Medical Organisation, said patients and families had said to him "that the Taoiseach has convened an emergency meeting of all resources for floods".
"But the ongoing emergency of overcrowding in hospitals... has become the norm [and]... receives little attention. Have we become inured to suffering?"