The haematological hazards of autotransfusion.

Fourteen heparinized dogs were autotransfused from 1-5 to 6 times calculated blood volume. Five animals retransfused 12 litres from an intraperitoneal bleed had marked decreases in all cellular elements, haematuria and a large (82 percent) drop in fibrinogen. All these animals died within 12 hours and post-mortem examination revealed evidence of disseminated intravascular coagulopathy. The dogs in which a smaller volume (3-6 litres) was recycled showed similar, but less devastating, changes. Haematocrit and platelet count dropped by a half and fibrinogen by 20 per cent. A leucocytosis of about 30 000/mm3 occurred within 24 hours. Autotransfusion of salvaged blood which was not allowed extravascular tissue contact significantly lessened these adverse effects. We conclude that the risk of cellular destruction and defibrination in large volume intra-operative autotransfusion is significant and must be weighed against its potential benefits in each case, and that red cell and platelet damage results primarily from extravascular tissue contact and is therefore unavoidable.