Use of blood transfusions by helicopter emergency medical services: is it safe?

All injured patients given prehospital blood transfusions by flight nurses of the 'Lifeflight' Helicopter Emergency Medical Service (HEMS) programme based at Emanuel Hospital, Portland, Oregon, USA, between 1985 and 1991 were included in the study. Of the 112 patients, there were no documented adverse reactions directly related to the administration of O-negative packed red cells, although one patient suffered transient shortness of breath. It is a safe and practical prehospital procedure. Further studies are required to assess the advantages over other fluids.