Transfusion practice in patients receiving VV ECMO (PROTECMO): a prospective, multicentre, observational study.

Area of Science:

• Critical Care Medicine
• Hematology
• Respiratory Medicine

Background:

• Venovenous extracorporeal membrane oxygenation (VV ECMO) often involves higher packed red blood cell (PRBC) transfusion thresholds compared to other critically ill patients.
• Existing guidelines lack specific recommendations for PRBC transfusion in VV ECMO patients.

Purpose of the Study:

• To describe current hemoglobin values, transfusion rates, and thresholds for PRBC transfusion in patients undergoing VV ECMO.
• To investigate the association between hemoglobin levels, PRBC transfusion, and mortality in VV ECMO patients.

Main Methods:

• A multicenter, prospective cohort study (PROTECMO) involving 41 ECMO centers across multiple continents.
• Inclusion of consecutive adult patients with acute respiratory distress syndrome (ARDS) receiving VV ECMO.
• Monitoring of daily hemoglobin, pre-transfusion hemoglobin, and transfusion rates, with analysis stratified by region and center volume.

Main Results:

• 604 patients were enrolled; mean hemoglobin at cannulation was 10.9 g/dL. Over 7944 ECMO days, mean hemoglobin was 9.1 g/dL.
• PRBCs were transfused on 31% of ECMO days; 83% of patients received at least one unit. Mean pre-transfusion hemoglobin was 8.1 g/dL.
• Hemoglobin < 7 g/dL was associated with higher ICU mortality (HR 2.99). PRBC transfusion reduced mortality only when hemoglobin was < 7 g/dL (HR 0.15).

Conclusions:

• No universal PRBC transfusion threshold exists for VV ECMO patients.
• PRBC transfusion is associated with reduced mortality in VV ECMO solely when initiated at hemoglobin concentrations below 7 g/dL.