A total of 69 cases of patients receiving incorrect blood components during transfusions were identified in 2001, according to a report published yesterday.
Errors of this type, while rare in Irish hospitals, were responsible for nearly half the cases in which patients suffered an adverse reaction to a transfusion, the report said.
Many of the mistakes had the potential to cause permanent injury or to be life-threatening, although most patients showed no ill-effects and no deaths were attributed to the transfusions concerned.
The Irish Blood Transfusion Service said the report demonstrated that transfusion therapy was a "relatively safe" procedure.
It could not say "completely safe" because there was no such thing as a risk-free transfusion, the board pointed out.
The figures for adverse reactions are contained in the annual report for 2001 of the National Haemovigilance Office (NHO).
Launching the report in Dublin, the acting chief executive of the IBTS, Mr Andy Kelly, said it showed "the majority of transfusions" were given "within extremely high standards of care".
Responding to a suggestion that this was not entirely reassuring, he said everyone had to be aware that transfusions were not "zero risk".
"We have never said they were and the general public should be aware of that. But that does not mean that they are not safe," he said.
In its report, the NHO said serious adverse reactions to transfusions were rare in Irish hospitals. During 2001, more than 163,000 units red cells, platelets, fresh frozen plasma (FFP) and cryoprecipitate were issued, with adverse events being reported in only 144 cases. Of these, 69 were the result of an incorrect blood component being transfused.
Dr Emer Lawlor, the director of the NHO, said this was "very much in line with international findings". The report had sought to establish the root causes of such error and had made a number of recommendations, particularly dealing with hospital information systems, aimed at reducing the incidence of human error.
Of the 69 cases of error identified in the report, 37 had the potential to cause permanent injury or to be life-threatening. In the most serious six cases, patients received blood components of the wrong ABO group, Dr Lawlor said.
In only three of these, however, were there symptoms of an adverse reaction because blood of the wrong group could sometimes, "by chance", be compatible.
"Very fortunately," she said, there had been no deaths among those three cases, but there had been a risk of this happening.
The annual report is the third such study conducted by the NHO and was based on figures supplied by 77 per cent of hospitals.