Transfusion of frozen thawed blood stored at -20 degrees C to -25 degrees C

To determine the clinical efficacy of transfusion of frozen-thawed (FT) red cells using a 5-bag system for freezing (at -20 degrees C to -25 degrees C), storage and reconstitution.

A prospective, controlled, non-randomised clinical trial was undertaken with two groups of orthopaedic surgical patients. Nine patients received FT homologous blood and a control group of 10 patients received homologous blood stored in liquid form at 4 degrees C. Five transfusion-dependent patients with medical conditions were also studied.

Thirty-three FT units were transfused without incident to 14 patients. In addition to clinical assessment, haematological and biochemical parameters were monitored after transfusion. There were no clinical side effects and laboratory data were consistent with those after recent surgery or for pre-existing medical conditions and subsequent blood transfusion. On the practical side certain technical difficulties were encountered which improved with experience.

One of the major advantages of the system is the 35-day shelf-life at 4 degrees C after reconstitution. This system has potential for pre-deposit autologous collection, especially where large volume replacement may be required.