Opposition parties have called on on the Minister for Health, Ms Harney, to act immediately to the deferral of cardiac operations on children at Our Lady's Hospital in Crumlin. Ms Harney appealed to parties not to play politics with the situation.
The State's largest children's hospital was forced to send two children, scheduled for heart surgery, home on Monday because of a shortage of intensive care nurses.
The hospital said it deeply regretted the decision and said the children's operations were less-urgent and were deferred in order to carry out two emergency operations.
Last year, two-year-old Róisin Ruddle died after being sent home from the hospital when her heart surgery was cancelled. A shortage of intensive care staff was also blamed for this cancellation.
"It is over a year since the tragic death of Róisin Ruddle but the problem is still unresolved and a report on case has still not been produced," said the Labour Party's health spokeswoman, Ms Liz McManus.
"There is a chronic staffing situation in the intensive care unit at Our Lady's Hospital in Crumlin which is reducing the bed capacity of the unit to care for sick children."
Ms McManus added: "Yesterday in the Dáil, Minister Harney made claims about the high level of nurses available now in the Irish health system. Today we see the grim reality. In fact, there are over 700 nursing vacancies at present and this is particularly acute in the Dublin region."
"Paediatric nursing is a very difficult job and there are issues around pay and working conditions which need to be addressed. There is a case for a weighting system in Dublin in particular due to the high cost of living and housing in the capital city."
Fine Gael's health spokeswoman, Ms Olivia Mitchell, said the Government must be called to account on what measures they have taken in the last 12 months to overcome the shortage of specialist nurse shortages for which Roisin Ruddle paid with her life.
"It simply isn't good enough that no lessons were learnt, and no actions taken since Baby Ruddle's tragic death," she said.
"Not only do Crumlin hospital still find themselves in the intolerable situation of having to send acutely-ill, at-risk children home untreated but there is no indication that there is any prospect of a change in that situation."
"Minister Harney must make every effort to ensure that sufficient medical personnel areavailable to run the health service. After all there is no point reforming the service unless there are enough doctors and nurses to operate it. What has happened at Crumlin Hospital cannot be allowed to happen again," she added.
Ms Harney told the Dáil she would discuss the situation in Crumlin with health authorities later today.
"This is a sad and serious situation," she said, "it has arisen before, we want to ensure that it doesn't arise again and that's why it is important that we get the nurses that we require."