An investigation has been launched after 10 seriously ill patients in Northern Ireland receiving dialysis treatment suffered unexpected complications.

Dialysis units — which help patients filter blood and can be used during kidney failure — across the province have been affected.

The cause of the problem, which involves the breakdown of red blood cells, has not been established. Units at Daisy Hill, Belfast City, Tyrone County and Antrim Area were included.

A spokesman for the four health trusts said: “Dialysis units across Northern Ireland are participating in a full and thorough investigation of all of these cases and in the interim staff are vigilant to the possibility of further cases and to the need for early identification and treatment.”

The patients affected have recovered and all receiving dialysis have been contacted and advised of symptoms to look out for.

The illness is called haemolysis and can cause abdominal or chest pain, vomiting, shivering or flushing and rising blood pressure.

It involves the release of haemoglobin into the surrounding fluid of the blood, plasma.

The health trusts spokesman added: “Haemolysis is an uncommon but recognised complication of dialysis.

“It can occur in clusters and while there are possible causes, an underlying cause isn’t identified in around 50% of incidents.”

Reasons vary and take detailed investigation. Haemolysis may relate to how blood is collected.