We have found the article published by Nanwani Nanwani et al.1 on blood donation from brain-dead (BD) patients to be very interesting. It has opened a valuable debate on the clinical circumstances and ethical principles which should be revised in order to view this option as feasible. In our opinion, we must not obviate the close relationship between the progression of severe brain damage and the generation of hypermetabolic reactions and immune-mediated processes throughout the body. Brain death is the greatest stress factor to which organs, tissue and cells are exposed before possible donation, due to the generation of hemodynamic, ventilatory, endocrine and inflammatory modifications, mediated by an important neuromodulated inflammatory response.2

If in addition BD is reached secondary to severe traumatic brain injury, for example, we know that the elevated secretion of cytokines produces an increase in the concentration of brain tissue factor. This in turn activates the complement system, which in combination with important catecholamine release, contributes to perpetuating the coagulopathic state. Such rapid release of large amounts of tissue factor following severe traumatic brain injury also induces thrombin formation. Likewise, the systemic proinflammatory state is responsible for the activation of fibrinogen and IL-6, which together with complement activation would explain the hypercoagulability state that predominates in the first 24 h after trauma. On the other hand, platelet inhibition and consumption, together with the excessive activation of fibrinolysis, would account for the increased risk of bleeding in later stages after trauma.3

Taking into account that several studies have shown high plasma IL-6 concentrations in donors to be significantly associated with reduced recipient survival at 6 months after hospital discharge,4 to what extent are we able to affirm that blood from BD patients will not be affected by this metabolic and immune cascade that is activated in patients with severe brain injury? From our perspective, current scientific knowledge does not allow us to be sure of the absence of immune-modulating effects in the recipients.

In turn, once BD has been established, it is common practice to administer amines, antibiotics and several different drugs to maintain donor clinical stability - and this undoubtedly could affect the theoretical quality of the blood components.2

We also must remember that during the organ harvesting and preservation process, vascular infusions are performed involving specially prepared fluids which seek to maintain homeostasis. These solutions contain additives (osmotic agents, electrolytes, colloids, metabolic inhibitors, metabolites, antioxidants and even drugs), and can have an impact on the presence of coagulation factors.5 In this way, if blood extraction as suggested by the authors is performed during or after harvesting of the rest of body organs, we likewise would not be able to discard potential clinically significant alterations of the extracted blood components.

Coinciding with the authors on the importance of finding new resources and seeking solutions to the more than likely shortage of blood products which we may face, we believe that if this practice is finally implanted, it must be done so with extreme caution. Although the ethical debate is important, we feel that attention should focus on demonstrating the viability of using such blood products and clarifying the doubts regarding possible adverse effects.