The quiet revolution in blood transfusion therapy Blood transfusions are now a central part of modem medical and surgical therapy. Blood can be collected, stored and administered with relative safety thanks to the development of anticoagulants, blood storage techniques and compatibility testing. These discoveries were made prior to or during World War II, so that in the early years after the war the banking of blood became a reality and transfusion services were established. In 1947 the Canadian Red Cross developed a national blood transfusion service based on the principles of voluntary donations, free blood and a national comprehensive program. The record of the blood transfusion service has been one of remarkable success, whereby all our needs for blood have been met by the donations of our fellow citizens. In the past 15 years a gradual but important change has occurred in transfusion therapy and blood banking. This resulted from the development of the plastic bag, which replaced the faithful bottle into which blood had always been collected: a "bag of blood" replaced a "bottle of blood". Plastic bags made it possible to separate blood into its components within a completely closed system. Erythrocytes could be packed by centrifugation, and the supernatant plasma and platelets could be removed aseptically into another bag within a closed system. In turn, platelets could be collected by centrifugation, and the supernatant plasma could be expressed into a third bag, leaving only the pellet of platelet concentrate. The plasma could be frozen for later use or it could be fractionated by low-temperature freezing and thawing, which would leave a cold-precipitable protein - cryoprecipitate - that contained antihemophilic globulin (factor VIII) and fibrinogen. The remaining plasma could be expressed into a fourth bag, again within a closed system. Thus, one bag of blood could yield a unit each of packed erythrocytes, platelet concentrate, cryoprecipitate and plasma. The plasma, in turn, could be used

as such or could be fractionated into gamma globulin or albumin, for example. Blood component therapy has appeared gradually on the medical scene, but, when compared with the early use of whole blood for all the needs for "blood", it can be seen as a revolutionary change. In this issue of the Journal (starting on page 33) Drs. Blajchman, Shepherd and Perrault outline the various components of blood used in therapy and provide a detailed guide for their use. We have moved into the era of blood component therapy, and the necessary technology is now available to us. We must, however, learn to treat patients with the specific components they require. Anemic patients should receive erythrocytes, thrombocytopenic patients platelets and so forth. Therapy with whole blood is wasteful and unnecessary. Is therapy with whole blood ever necessary? Should all blood be separated into components and no whole blood be made available? A modern transfusion service should aim to use every component of a unit of blood as effectively as possible. However, some argue that whole blood must be available for the treatment of shock and surgical bleeding.1 Since packed erythrocytes, electrolyte solutions, albumin and fresh frozen plasma are readily available, it seems reasonable and not difficult to use them as necessary so that these needs can be met within a highly developed component program. In this way we will be using these human gifts in the most efficient and knowledgeable manner known to us. A. ZIPURSKY, MD

Professor and chairman Department of pediatrics McMaster University Hamilton, Ont.

Reference 1. SCHMIDT PJ: Red cells for transfusion (E). N Engi J Med

The Canadian Medical Association/l'Association medicale canadienne 1867 Alta Vista Dr., Ottawa, Ont. KIG 3Y6; (613) 731-9331 President/pr6sident: D.L. WI son, MD, FRCPLC] Secretary generai/secr6taire g6n6rai: R.G. Wilson, MD Director of communications/directeur des communications: D.A. Geekie, BPHE, CPH

CMA Journal/Journal de l'AMC Scientific editor/r6dacteur scientifique: N.J.B. Wiggin, MD, MSc, PhD News and features editor/r.dacteur des nouveiles et reportages: J. Garner Asociate scientific editor/r6dacteur scientifique associ6: PP. Morgan, MD, DPH, DEpid Senior assistant editor/r6dactrice adjointe en chef: A. Bolster, BA Assistant editors/r6dactrices adjointes: L.D. MacDougaii, J. Whitney, BSc Quebec reporter/journaiiste pour ies affaires du Quebec: D. Robiiiard, PhD Contributing editors/coiiaborateurs: CL. Jarrett, PhD, MD; D.T. Wigie, MD, PhD, MPH; D. Woods Business manager/directeur g6n6rai: C.K. Goodman Saies manager/chef du service des ventes: N. Hutton Production manager/chef du service de is production: R.M. Sinnott

14 CMA JOURNAL/JULY 7, 1979/VOL 121

The Canadian Medical Association Journal is published twice a month by the Canadian Medical Association, P0 Box 8650, Ottawa, Ont. KiG 0GB and is printed by Harpeil's Press Cooperative, Gardenvale, P0 HOA iBO. Subscription rstes and information for contributors of manuscripts are published in the first issue of each volume. All reproduction rights are reserved.

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