Introduction: Regular over-ordering of cross-matched blood is expensive and can result in a shortage of available blood. In order to minimize the impact on an already over-stretched transfusion service, the ratio of blood ordered to that actually transfused should be as efficient as possible. We aimed to audit the efficiency of our blood ordering for free flap cases against a gold standard cross-match:transfusion ratio of 1.5:1 and compare requirements for different types of flap.
Methods: Relevant database records were retrospectively reviewed for 346 consecutive patients who underwent head and neck free flap surgery in our unit.
Results: 41 composite, 293 soft tissue and 12 multiple flaps were included in the study. The average number of cross-matched units ordered pre-operatively per case was 4.5, of which an average of 1.9 were transfused, giving a C:T ratio of 2.3:1. The average number of units transfused for composite flaps was 2.8 with a transfusion ratio of 1.7:1, compared to an average of 1.8 units with a C:T ratio of 2.5:1 for soft tissue flaps. The overall transfusion rate was 56.5%; 85.4% for composite flaps compared to 51.9% for soft tissue flaps.
Conclusion: Improvement is required in the efficiency of blood ordering overall in order to minimize wastage. Composite flaps are more likely to require transfusion of the ordered blood than soft tissue flaps, resulting in a more efficient C:T ratio. With the advent of faster electronic cross-matching allowing additional blood provision at short notice, we recommend ordering fewer cross-matched units pre-operatively, particularly for soft tissue flaps.