Artificial oxygen carriers might be one possible solution for the RBC supply/demand dilemma. Since hemoglobin-based oxygen carriers have been shown to be associated with significant adverse effects limiting their use in daily clinical practice, perfluorocarbon-based oxygen carriers are the most promising agents nowadays. Cabrales and Briceño report that a perfluorocarbon-based oxygen carrier is able to maintain perfusion and oxygenation during extreme anemia. However, this study has one severe limitation: perfluorocarbon-based oxygen carriers are only effective if the inspiratory oxygen concentration is increased. It has been demonstrated convincingly that hyperoxic ventilation per se improves oxygen transport, tissue oxygenation and outcomes of extreme acute anemia. The protocol presented by Cabrales and Briceno fails to separate these two effects, which complicates the discussion of the results observed.
– Jens Meier