Do we have different transfusion practices in COVID-19 and non-COVID-19 patients?

Hemoglobin (Hb)-based transfusion triggers are the most commonly used transfusion triggers in clinical practice at present, despite of having many drawbacks. In daily clinical practice, the traditional 10/30 rule (Hb 10 g/dL - hematocrit 30%) has been the most commonly used trigger for blood transfusions. The physiological rationale for this approach is that both Hb and hematocrit are key determinants of arterial oxygen delivery (DO₂) and thus the lower limit of oxygen transport and adequate tissue oxygenation. Transfusions with allogeneic red blood cells (RBCs) can be avoided in most patients with Hb thresholds above 7 g/dL with stable hemodynamics. Although physiological transfusion triggers appear to be the most suitable for blood transfusion yet due to the lack of sufficient clinical trials their significance has not been proved. Venous oxygen saturation (SvO₂), central venous oxygen saturation, arterial lactate, and near-infrared spectroscopy, when combined together seem to be most useful in avoiding premature blood transfusion. However, large clinical trials are needed to prove their suitability. Blood centers faced a huge challenge in devising a preparedness strategy to withstand COVID-19 outbreak globally. A drastic fall in the red cell inventory was observed as compared to pre-COVID-19 time period due to disproportionate decrease in blood collection and demand. A restrictive transfusion strategy was also applied in hospitals using a threshold for transfusion based on a drop in the Hb level below 7 g/dl in patients with stable hemodynamics. In patients having anemia with acute coronary syndromes, the RBCs transfusion threshold is when Hb levels fall below 8 g/dl and hematocrit below 24%. There was an increase in the demand of convalescent plasma in the initial phase of the pandemic as its benefits were overestimated. The efficacy and safety of convalescent plasma are questionable. Implementation of the most recent evidence-supported transfusion guidelines and eliminating unnecessary transfusions are considered the main goals of patient blood management programs during COVID-19 pandemic.