The bloody mess of red blood cell transfusion

Abstract

Red blood cell (RBC) transfusion might be life-saving in settings with acute blood loss, especially uncontrolled haemorrhagic shock. However, there appears to be a catch-22 situation reflected by the facts that preoperative anaemia represents an independent risk factor for postoperative morbidity and mortality, and that RBC transfusion might also contribute to adverse clinical outcomes. This dilemma is further complicated by the difficulty to define the "best" transfusion trigger and strategy. Since one size does obviously not fit all, a personalised approach is merited. Attempts should thus be made to critically reflect on the pros and cons of RBC transfusion in each individual patient. Patient blood management concepts including preoperative, intraoperative and postoperative optimisation strategies involving the intensive care unit are warranted and are likely to provide benefits for the patients and the healthcare system. In this context, it is important to consider that "simply" increasing the haemoglobin content, and in proportion oxygen delivery, may not necessarily contribute to a better outcome but potentially the contrary in the long term. The difficulty lies in identification of the patients who might eventually profit from RBC transfusion and to determine in whom a transfusion might be withheld without inducing harm. More robust clinical data providing long-term outcome data are needed to better understand in which patients RBC transfusion might be life-saving vs life-limiting.

Fig. 1

Prevalence of anaemia. Prevalence of anaemia worldwide and in patients at high risk. Figure based on [6]

Fig. 2

Risk of death for liberal vs restrictive transfusion in critically ill patients. Relative risk of death for patients with a liberal transfusion regime compared to a restrictive transfusion regime (23.3% vs 17.7%, RR 1.25) [23] (Hébert 1999). Relative risk of death for patients with a liberal transfusion regimen (higher Hb threshold, 45%) compared to a restrictive infusion strategy (lower Hb threshold, 43%) (RR 1.05) [25] (Holst 2014). Hazard ratio for 30-day survival 0.89 [24] (Vincent 2008). HR hazard ratio, RR relative risk. Figure based on [–25]

Fig. 3

Effect sizes of recent patient blood management programmes. Recent publications on the effects of multimodal PBM programmes have demonstrated substantial reductions in the number of patients receiving RBC transfusions in an RCT and in the number of transfusions utilised at a hospital. Based on [39] (Kopanidis 2016) and [40] (Mehra 2015)