Should there be arbitrary triggers for transfusing brain-dead potential organ donors?

Drs. Colleen Gilstad, Paul Mintz and Ira Shulman (attributions used with permission) wonder if those who have read the New England Journal of Medicine article by Wood KE et al entitled "Care of the Potential Organ Donor" (N Engl J Med 2004;351:2730-2739) share the concern that Wood and colleagues provided arbitrary laboratory-based guidelines (triggers) for when 'brain-dead' potential organ donors should be transfused, such as a hematocrit below 30% for red-cell transfusions. The authors did not provide references or data supporting arbitrary triggers. Does any colleague know of data that support arbitrary transfusion triggers for 'brain dead' organ donors? If so, please share the data or references. Questioning the need for references or data is not merely rhetorical, since there is currently debate over the use of laboratory-based transfusion triggers to save lives of patients who are NOT brain dead, much less their organs. For example, a published study concluded that a restrictive strategy of red-cell transfusion (using a trigger of 7.0 g/dL) is at least as effective as a liberal transfusion strategy (using a trigger of 10.0 g/dL) for critically ill patients, with the possible exception of patients with acute myocardial infarction and unstable angina. (Hebert PC et al, A multicenter, randomized controlled clinical trial of transfusion requirements in critical care. N Engl J Med 1999;340:409-417). Using transfusion trigger guidelines proposed by Wood and colleagues, one might find it ironic for an ICU patient who has been maintained at a hemoglobin level close to 7 g/dL to suddenly 'need' a transfusion when s\he was declared brain dead. Furthermore, in the context of avoiding transmission of infectious diseases to transplant recipients, it seems prudent to minimize transfusions for brain-dead potential organ donors, to the extent possible, since fewer transfusions generally mean less exposure to infectious agents. For example, in the evaluation of the case where an organ donor transmitted West Nile Virus to four recipients, it was determined that blood transfusion from one of 63 blood donors was the probable source of the infection (Iwamoto M et al. Transmission of West Nile Virus from an organ donor to transplant recipients. N Engl J Med, 2003;348:2196-203)

Finally, any recommendation to use CMV seronegative blood products for potential organ donors must take into consideration whether or not the potential organ donor was receiving CMV low risk blood products before being declared brain-dead. There may be no benefit to the organ recipient to switch the organ donor from 'standard' blood products to CMV seronegative blood products, if the organ donor received numerous blood product transfusions before being declared brain dead.

ADDENDA Mar 29, 2005

The following comments have been received.

1. The Director of the Clinical Laboratory and of Transfusion Medicine at a New York hospital reports that he is unaware of data supporting arbitrary transfusion triggers for brain dead organ donors. He acknowledges that the transfusion support of such organ donors presents challenges at his own institution, such as when house-staff order platelet transfusions for brain dead patients when the platelet count falls below 100,000/µl. He is of the opinion that any 'unnecessary' transfusion of an organ donor can create risk to the ultimate organ recipient, however small. He does not present data, but suggests that platelet transfusions may be pro-inflammatory and pro-thrombotic, potentially compromising the viability of the organs transplanted. Thus, he is inclined toward using the same or lower transfusion triggers for brain-dead organ donors as are used for living, critically ill patients.
   
   He concludes that in his opinion, if an organ donor has occult cardiac disease, the heart is probably not going to be used for transplant, but the other organs (except perhaps the brain) should be quite tolerant of anemia.
   
   
2. The prior discussion from 2002: Should brain-dead persons whose organs qualify for harvesting and transplantation receive red cell transfusions to improve organ survival? may also be of interest.

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