Fiser RT et al: RBC transfusion in pediatric patients supported with extracorporeal membrane oxygenation: Is there an impact on tissue oxygenation?
Pediatr Crit Care Med 2014;15:806-13.
The authors analyzed data from a retrospective observational study of pediatric patients supported with extracorporeal membrane oxygenation (ECMO) in pediatric, cardiovascular and neonatal ICUs of a tertiary care children’s hospital. Study objectives were to examine: 1) RBC transfusion practices in pediatric patients supported by ECMO, and 2) the relationship between RBC transfusion and changes in mixed venous oxygen saturation (SVO2) and cerebral regional tissue oxygenation (as measured by near-infrared spectroscopy (NIRS). SVO2 and NIRS were obtained for the 2 hours before and 2 hours following each RBC transfusion with mean values analyzed and compared. RBC transfusions were given at the discretion of the attending physician with no specific transfusion threshold utilized.
Forty-five patients were supported with ECMO; 20 for cardiac indications (15 surgical, 5 nonsurgical) and 25 for non-cardiac indications (respiratory failure, septic shock, and extracorporeal CPR). 617 transfusions were administered (median 9 per patient, range 1-57). Median RBC exposure was 10.9 (range 3-43) individual donor units. Median transfusion trigger threshold was Hct 36% with the median Hct maintained during ECMO 37%. Median (IQR) volume of phlebotomy blood loss was 75 mL/kg (33,149 mL/kg).
Most transfusions resulted in no significant change in either SVO2 or cerebral NIRS. Only 5% (31/617) of transfusions resulted in an increase in SVO2 of > 5%, and only 9% (53/617) resulted in an increase of NIRS > 5.
This study demonstrates that pediatric patients supported by ECMO have large volume phlebotomy losses and receive large RBC transfusion volume for treatment of mild anemia. In the majority of cases, RBC transfusion did not significantly alter global tissue oxygenation. Most transfusions were administered when the patients did not appear to be oxygen delivery dependent.
It appears that even in this fragile population, RBC transfusions should be reserved for clinical indications.
Jill M Cholette MD
Associate Professor of Pediatrics
Medical Director Pediatric Cardiac Care Center
University of Rochester, Golisano Children’s Hospital