Elevated hemolysis susceptibility of neonatal blood investigated in-vitro

Hemolysis is a relevant complication and is responsible for morbidity and mortality of neonatal ECMO therapy. For novel therapies like artificial placenta, hemolysis could also lead to complications or therapy failure, especially since the aimed patients are born at the border of viability. Standardized in-vitro blood testing using animal blood is commonly used to assess the hemolytic potential of newly developed systems during design and development. However, neonatal human blood is different compared to animal blood. Neonatal blood has for example higher erythrocyte volume, less overall viscosity and higher erythrocyte elasticity. This study investigates whether the porcine blood analogue used in the standardized protocols can also be used to assess hemolysis in neonatal blood. The human neonatal blood was harvested from the placentas and umbilical cords of neonates born by cesarean section. Porcine blood was taken from the local abattoir. Both processes followed preliminary defined standardized protocols. NIH was calculated based on determined free plasma hemoglobin. There was a significant (p<0.05) higher normalized index for hemolysis in the human neonatal blood group (NIH 0.165 g 100 L ^-1 (SD 0.082)) compared to the porcine group (NIH 0.101 g 100L ^-1 (SD 0.038)). In contrast, the static reference showed the opposite with neonatal blood hemolysis (NIH 0.025 g 100 L ^-1 (SD 0.018)) being lower compared to porcine blood (NIH 0.055 g 100L ^-1 (SD 0.038)). In standardized in-vitro hemolysis testing, porcine blood might not be a suitable analogue for human neonatal blood since a significant underestimation of hemolysis for neonatal blood was shown.