Blood transfusion requirements in bimaxillary osteotomies.

The over-ordering of cross-matched blood to cover operations can result in blood shortages and is costly; it can never be free of risk. Current published guidelines recommend cross-matching 2 units of blood for bimaxillary orthognathic procedures with an additional 2 units if combined with a genioplasty. We reviewed the records of 115 consecutive cases of simultaneous bimaxillary osteotomies at Morriston Hospital over a 5-year period (January 1996 to December 2000). Ordering and use of blood were investigated and the cost analysed. Blood loss was minimised using a strategy of controlled moderate hypotension and meticulous haemostasis. Nine patients were given transfusions of blood but five of these were deemed inappropriate. No predisposing factors for transfusion were identified. We recommend that the tariff for ordering blood for bimaxillary osteotomies should be revised to a "group and save" with antibody screen, providing that a 30-min indirect antibody cross-match is available.