Physiological determinants and the red blood cells transfusion decision-making process in non-bleeding critically ill patients: a comprehensive narrative review.

purposeThere is a willingness to move towards a more personalised medicine; however, the red blood cells' (RBC) transfusion decision-making process remains a one-size-fits-all practice in most non-bleeding critically ill patients. This narrative review describes the limitations of a transfusion decision-making process based only on haemoglobin (Hb) threshold and the potential physiological triggers of RBC transfusion with the clinical evidence investigating their implementation in routine.

resultsHb does not reflect tissue oxygenation and anaemia tolerance, and applying the same Hb threshold throughout the ICU stay neither prevents unnecessary transfusion nor insufficient transfusion. Central venous oxygen saturation (ScvO

conclusionsThere is a need for additional determinants in the RBC transfusion decision process to offset the limitations of RBC transfusion based only on Hb level in non-bleeding critically ill patients. A multimodal strategy, including comorbidities, underlying diseases, clinical signs, ECG changes, biochemical markers, and microcirculatory assessment, may optimise transfusion timing and avoid unnecessary red blood cell administration. However, further research is warranted to determine the potential benefit of integrating tissue oxygenation and microcirculatory parameters in the transfusion decision-making process.