Doctors at the five major Dublin hospitals have expressed "grave clinical concern" about patients whose treatments have been deferred due to the strike.
While these patients did not strictly meet emergency criteria, they suffered from conditions such as suspected cancers, which if not diagnosed and treated rapidly, could deteriorate greatly with serious consequences, the joint statement from Tallaght, Beaumont, the Mater, St James's and St Vincent's said.
Many hospitals around the State reported increasing casualty admissions, but said the staff had coped reasonably well.
The public had taken the advice not to go to hospital unless it was an absolute emergency, said the Irish Medical Organisation.
But its GP spokesman, Dr Cormac McNamara, said this may have resulted in a 40 per cent increase in the workload for GPs. He said some doctors with many elderly patients were under severe pressure.
Yesterday the Irish Nurses' Organisation (INO) rejected the claim that nurses were responsible for any shortcomings in emergency cover. In a statement it said hospital managers had thought it appropriate "to leave their hospitals devoid of management for long periods of time, particularly at night".
The position of the National Cancer Referral Centre at St Luke's Hospital, Rathgar, Dublin, was the subject of a dispute between the INO and the chief executive officer of the hospital, Mr Nicolas C. Jermyn.
The INO statement said there was only one doctor on duty for 33 patients and no management presence at St Luke's on Saturday night. A spokesman for Mr Jermyn rejected this and said management and doctors were working on a 24-hour basis.
The INO said the cover around the State was not inadequate, but on bank holiday weekends hospitals operated with a reduction or absence of management and administrative staff. "Consultants are also traditionally in very short supply," it added.
This was rejected by Mr Finbarr Fitzpatrick, spokesman for the Irish Hospital Consultants' Association (IHCA), who said many consultants had cancelled holiday plans and made themselves available on a 24-hour basis to deal with the workload.
Mr Fitzpatrick said one of the problems some IHCA members were experiencing was disagreement with strike committees in some of the hospitals. "Some consultants have had their classification of some patients as emergency cases challenged by the strike committees," the IHCA spokesman.
He declined to name hospitals where this had happened, but said it had caused a lot of friction as "one strike committee in the morning takes one view and another one coming on in the afternoon has another".
The Fine Gael health spokesman, Mr Alan Shatter, said a Sunday Independent poll, reflecting large support for the nurses showed the "PR and advertising campaign" of the Minister for Health, Mr Cowen, had "not washed with the ordinary people".
He said Mr Cowen had displayed hypocrisy by asking for children to be exempt from the nurses' strike action. Such a statement was "staggering in light of Mr Cowen's abysmal track record on child waiting lists".