@article{eac9adf964574dff9f2f22812bc3e883,
title = "Impact of red blood cell transfusion on regional cerebral oxygen saturation during pediatric ECMO",
abstract = "Background: Low cerebral regional tissue oxygenation (crSO2) is associated with unfavorable neurological outcomes in children requiring extracorporeal membrane oxygenation (ECMO) support. Red blood cell (RBC) transfusion can improve brain oxygenation and crSO2 has been proposed as a noninvasive monitoring tool that could aid in RBC transfusion decision-making. However, how crSO2 responds to RBC transfusion is largely unknown. Study Design and Methods: This was a retrospective, observational cohort study of all patients <21 years supported on ECMO at a single institution from 2011 to 2018. Transfusion events were grouped by pre-transfusion hemoglobin concentration (<10, 10- < 12, and ≥ 12 g/dL). Post- versus pre-transfusion crSO2 changes were analyzed using linear mixed-effects models. Results: The final cohort included 830 transfusion events in 111 patients. Hemoglobin increased significantly post- versus pre-RBC transfusion (estimated mean increase of 0.47 g/dL [95% CI, 0.35–0.58], p <.001), as did crSO2 (estimated mean increase of 1.82 percentage points [95% CI, 1.23–2.40], p <.001). Larger improvements in crSO2 were associated with lower pre-transfusion crSO2 values (p <.001). There was no difference in mean change in crSO2 across the three hemoglobin groups in unadjusted analysis (p =.5) or after adjusting for age, diagnostic category, and pre-transfusion rSO2 (p =.15). Pre-transfusion crSO2 was <50% for 112 of 830 (13.5%) transfusion events, with only 30 (26.8%) crSO2 measurements noted to increase ≥50% post-transfusion. Discussion: Among neonatal and pediatric patients on ECMO support, there was a statistically significant increase in crSO2 following RBC transfusion, although clinical significance needs to be investigated further. The effect was strongest among patients with lower crSO2 pre-transfusion.",
keywords = "ECMO, cerebral oximetry, cerebral tissue oxygenation, extracorporeal membrane oxygenation, pediatric, transfusion",
author = "Garcia, {Alejandro V.} and Velez, {Ana Karen} and Victoria Surma and Jager, {Leah R.} and Bembea, {Melania M.}",
note = "Funding Information: Extracorporeal Life Support Organization research grant (AVG); NIH/NINDS R01NS106292 (MMB). Funding Information: Extracorporeal Life Support Organization research grant (AVG); NIH/NINDS R01NS106292 (MMB). Extracorporeal membrane oxygenation (ECMO) is a mechanical support system for children with cardiopulmonary failure or isolated respiratory failure. More than 75,000 infants and children have been placed on ECMO internationally, and its use has increased substantially over the last decade.1 ECMO is associated with significant hematologic risks including coagulopathy, platelet dysfunction, consumption of thrombotic factors, and hemorrhagic complications.2–4 RBC transfusion on ECMO is standard practice and often driven by hemoglobin targets and need for intravascular volume expansion. Prior studies have shown that the volume of RBC transfusion administered every 3 days on ECMO support is approximately the equivalent of a child's entire circulating blood volume.5 For children on ECMO, higher RBC transfusion volumes have been shown to be independently associated with increased odds of mortality, while a lower daily hematocrit during the ECMO course was not independently associated with mortality.5,6 Many RBC transfusions are ordered for the sole purpose of maintaining a specific hemoglobin threshold to achieve adequate oxygen delivery to tissues in these critically ill patients. Extracorporeal Life Support Organization guidelines for the management of patients supported on ECMO specifically call for maintenance of a “normal” hemoglobin concentration and a hematocrit more than 40% in neonates with the aim of maximizing the delivery of oxygen.7 More recent Pediatric Critical Care Transfusion and Anemia Expertise Initiative (TAXI) recommendations, however, refrained from using a specific hemoglobin threshold for RBC transfusions for children on ECMO in the absence of high-quality evidence.8 Instead, the TAXI group recommended using physiologic metrics and biomarkers of oxygen delivery such as heart rate variability, capillary refill, lactate levels, and cytochrome oxidase redox, in addition to hemoglobin concentration, to guide RBC transfusion in children on ECMO support.8 Despite the rationale for RBC transfusion of achieving adequate oxygen delivery, there are no data on the impact of transfusions on oxygen delivery in pediatric patients supported with ECMO. Fiser et al. found that RBC transfusions used to treat mild anemia on ECMO failed to enhance tissue oxygenation as measured by mixed venous saturations and cerebral regional tissue oxygenation (rSO2).9 Near-infrared spectroscopy (NIRS)-based cerebral rSO2 is widely used in clinical practice as a marker of tissue oxygen delivery.10,11 A decrease in cerebral oximetry during ECMO was associated with worse neurologic outcomes.12,13 Tsou et al reviewed a series of pediatric ECMO patients and found that using routine monitoring of rSO2, a decline in rSO2 <50% or decline >20% from baseline was associated with worse neurofunctional outcomes at the time of discharge using the Pediatric Cerebral Performance Category scale.12 Khan et al reviewed a series of adult ECMO patients and found that rSO2 values that decline >25% from baseline or <40% were associated with acute brain injury on neuroimaging.13 Given that the time of onset of acute neurologic injury is difficult to ascertain, it remains unclear if the association between lower crSO2 and brain injury could be due to reverse causation (brain injury leading to lower crSO2) and it is also unclear if interventions such as administration of RBC transfusions improve crSO2 in children supported on ECMO. This study therefore aimed to determine whether crSO2, measured post- versus pre-RBC transfusion in infants and children on ECMO support, increased significantly following transfusion. Publisher Copyright: {\textcopyright} 2023 The Authors. Transfusion published by Wiley Periodicals LLC on behalf of AABB.",
year = "2023",
month = may,
doi = "10.1111/trf.17317",
language = "English (US)",
volume = "63",
pages = "942--951",
journal = "Transfusion",
issn = "0041-1132",
publisher = "Wiley-Blackwell",
number = "5",
}