How safe is transfusion of uncross-matched group-specific blood?

Uncross-matched blood either group specific or Group O is advocated in patients with exsanguinating haemorrhage when cross-matched blood cannot be made available rapidly. The risk of using uncross-matched blood is not known clearly. The purpose of this study is to attempt to quantify the risk of major transfusion reactions resulting from the use of uncross-matched group specific blood.

The cross-matching record of Patan hospital for the period of two years was analysed looking at the number of units that had major or minor incompatibility among all the cross-matching done during this period.

A total of 6027 units were cross-matched in two years. Only one unit of blood was found to have both major and minor incompatibility. All other units of blood taken out from the freeze for the purpose of cross-matching matched the patients blood. This puts the risk of having major transfusion reaction from incompatible blood when using uncross-matched group-specific blood at 1 in 6000.

Using uncross-matched group specific blood in patients with severe haemorrhage, when delay in transfusion can put life at risk, is justifiable and needs to be encouraged.