Evaluating Concordance Between Complete Blood Count and Point-of-Care Tests in Pediatric Extracorporeal Membrane Oxygenation

The accuracy of point-of-care (POC) hemoglobin (Hgb) and hematocrit (Hct) testing in pediatric patients on extracorporeal membrane oxygenation (ECMO) is unknown. Point-of-care testing uses less blood volume and could decrease iatrogenic anemia. However, inaccurate results could lead to repeat testing or increased risk of red blood cell (RBC) transfusions. We performed a single-center, retrospective study to quantify agreement between laboratory and POC tests for Hgb and Hct in pediatric ECMO. Patients were included if laboratory and POC values were recorded within 5 minutes of each other. Discordance was defined as discrepancy of >0.5 g/dl (Hgb) or >1.5% (Hct). Exclusion criteria included >18 years of age, cannulated at outside hospital, or ECMO support <24 hours. One hundred thirty-six patients with an average age of 2 months were included. Fifty-one percent were female. Sixty-six percent were supported with VA ECMO. Two hundred seventy-nine values compared laboratory with inline and 59 compared laboratory with blood gas analyzer. Forty-one percent of values were discordant, with the majority of discordant POC value less than the lab value. Our findings suggest that using POC values could increase RBC transfusions, though further study is needed to determine the effects of POC tests on transfusion burden and to evaluate factors predictive of discordance.