Blood crossmatching for burn surgery: potential for reduced wastage using a modified dye formula

Estimating the perioperative crossmatch requirement (CMR) of burn patients is difficult, as losses are variable and hard to predict. Accuracy is important, however, as over-provision risks wasting blood. Blood ordering tariffs have increased efficiency and reduced blood wastage in other branches of surgery. Dye has published a tariff for burn patients in the form of a formula, relating CMR to weight and percentage total body surface area (TBSA) excised. This study examines the efficiency of blood ordering and use among 72 burn patients and compares outcomes with the predictions of Dye's and a modified Dye's formula, for the same patients. All patients were crossmatched, but only 34 patients were transfused. The crossmatch:transfusion ratio was 2.1, with 52% of crossmatched blood being unused. Dye's formula would have reduced the total volume crossmatched for the same patients by 13%. The crossmatch:transfusion ratio would be 1.8, with 44% of cross-matched blood remaining unused. A modified form of Dye's formula was designed to reduce the high rate of blood non-use. This would reduce the total volume crossmatched by 40% and the rate of blood non-use to 20%. The crossmatch:transfusion ratio would be 1.24.