Carboxyhemoglobin Elevation, a Marker for Hemolysis, Is Common in Veno-venous Extracorporeal Membrane Oxygenation

Giani et al. found low levels of carboxyhemoglobin (COHb) in a cohort of patients supported on veno-venous extracorporeal membrane oxygenation (VV ECMO) at their center. It is noteworthy that even on ECMO support, COHb values were below average levels found in general intensive care unit population (1.3–1.9%) without extracorporeal support. Moreover, in observational studies of VV ECMO, severe hemolysis occurs between 10% and 23%. Thus, as a surrogate for hemolysis, one would expect COHb levels to be higher during VV ECMO support. Hence, we speculate if their experience is generalizable.

Thus, we believe that COHb elevation is a prevalent phenomenon in patients supported on VV ECMO. Causes include but are not limited to excessive negative pressure and high-blood flow.