RBC Transfusion in Pediatric Patients Supported With Extracorporeal Membrane Oxygenation

Abstract

Patients supported with extracorporeal membrane oxygenation were exposed to large RBC transfusion volumes for treatment of mild anemia resulting from blood loss, particularly phlebotomy. In the majority of events, RBC transfusion did not significantly alter global tissue oxygenation, as assessed by changes in SvO2 and cerebral near-infrared spectroscopy. Most transfusions were administered at a time at which the patient did not appear to be oxygen delivery dependent according to global measures of tissue oxygenation.

Outcomes Using a Conservative Versus Liberal Red Blood Cell Transfusion Strategy in Infants Requiring Cardiac Operation

“…Although need for improved oxygen delivery is often the rationale for transfusion, stored allogeneic RBC transfusions do not reliably increase oxygen delivery. We found similar estimated avO 2 diff values before and after transfusion consistent with other works demonstrating no change in avO 2 diff [18] or oxygen delivery/consumption after RBC transfusion [19,20]. Our results suggest infants with congenital heart disease had stable oxygen extraction without evidence of tissue hypoxia despite relative anemia.…”

Comparison of transfusion thresholds during neonatal extracorporeal membrane oxygenation

“…Despite efforts in the ECMO community to limit unique blood donor exposures, reduce phlebotomy, and standardize anticoagulation practice, evidence to support reflexive RBC transfusion is limited . At least one retrospective study showed no correlation between RBC transfusion and improved tissue oxygenation or increase in SvO 2 . In an attempt to reduce unnecessary RBC transfusions, we reduced our reflexive transfusion threshold Hct value for neonates receiving ECMO support from 40% to 35% and report no difference in complication rates or adverse patient outcomes.…”

Evidence for a more restrictive hematocrit trigger for neonates with respiratory failure requiring ECMO

“…Current practice of RBC transfusions in children and neonates supported by ECMO is not well known, and only a handful of retrospective, observational studies have quantified transfusion support at single institutions . RBC support varies tremendously, as reflected in the analysis from Sawyer and coworkers, which indicates that neonates received a median of between 10.4 and 13.3 mL/kg RBCs daily; however, other institutions have reported as much as a median of 52 mL/kg RBCs daily in cardiac neonatal and pediatric patients and 39 mL/kg RBCs daily in noncardiac neonatal patients .…”

“…For 617 RBC transfusions prescribed for a median Hct trigger threshold of 36%, most RBC transfusions (73%) were administered at a time when the pretransfusion SvO 2 was greater than 70%, and most RBC transfusions did not result in a statistically or clinically significant change in either SVO 2 (95%) or NIRS (91%), suggesting that most transfusions were administered when the patient was not oxygen delivery–dependent. The authors concluded that the vast majority of RBC transfusions did not impact global tissue oxygen delivery …”

“…Children supported with ECMO are necessarily exposed to anticoagulation therapy, most commonly unfractionated heparin, to maintain the patency of the circuit and reduce thrombotic complications. Median blood loss through phlebotomy reportedly has been as high as 75 mL/kg per ECMO run . Although Sawyer and his colleagues do not specifically address their protocol for monitoring anticoagulation therapy, again, there is a paucity of evidence to guide anticoagulation management in patients on ECMO, leading to a variety of laboratory tests among centers, often in combination and without institutional expertise to guide optimal management.…”