Rate of Packed Red Blood Cell Transfusion in Pediatric Patients with Severe Chronic Anemia and Normal Cardiopulmonary Status: How Slow Is Truly Necessary?.
Authors: Agrawal Anurag K. , Hsu Edmund , Neumayr Lynne , Quirolo Keith C. , Flori Heidi R. 
Published: October 2019

Abstract
Abstract 3155
Poster Board III-92

Background
Standard of practice recommends slow transfusion (i.e., 5 ml per kg over 4 hours) for children with a hemoglobin level less than 5.0 g per dL secondary to severe chronic anemia (Principles and Practice of Pediatric Oncology. 4th ed. 2002:1206). Transfusion-associated circulatory overload (TACO) remains a theoretical problem but usually manifests in patients with poor underlying cardiopulmonary status and specifically in the very young (i.e., neonates) and the very elderly (ISBT Science Series 2009;4:63-71). As no evidence exists as to what rate of transfusion for children with severe chronic anemia would be unsafe, our Pediatric Intensive Care Unit (PICU) has been utilizing a more liberal transfusion practice intermittently for the last ten years.

Methods
After institutional review board approval, we reviewed all patients admitted to the PICU over the last ten years with a hemoglobin less than 5.0 g per dL. Patients transfused an average of less than 5 ml per kg over 4 hours were excluded. The remaining patients transfused greater than 5 ml per kg over 4 hours had a more extensive chart review and those patients diagnosed by ICD9 code with acute blood loss were further excluded. For the remaining patients who met the criteria for severe chronic anemia and received greater than 5 ml per kg averaged over 4 hours, we documented vitals including heart rate, respiratory rate, systolic and diastolic blood pressure, oxygen saturation and inputs/outputs as well as diuretic usage and chest radiograph findings to analyze for signs of TACO. We further compared these patients to a control group that received slow transfusions. Statistical analysis was done using one- and two-sample t-tests.

Results
17 patients with a median age of 2.2 years (range 4 mos-12 yrs) received transfusions which met our inclusion and exclusion criteria, with a median transfusion rate of 10 ml/kg/4 hrs (range 6.8-49.6). No patient had an adverse event or changes in their vitals consistent with TACO. Heart rate dropped significantly although not statistically more than the randomly assigned control population (one-sample t-test, t=3.277, p=0.002, two-sample t-test, t=0.68, p=0.25). No patient in either group had a new oxygen requirement or worsening of their chest radiograph. Diuretics and oxygen supplementation were used in both groups empirically only.

Discussion
TACO appears to be a theoretical risk in the normal pediatric population; therefore, slow transfusion is likely an unwarranted anecdotal practice for children with severe chronic anemia. Both the study patients and control group had a statistically significant drop in heart rate with transfusion, emphasizing the safety of any rate of transfusion in our population. Rate of transfusion must be based on multiple factors including convenience, timeliness of procedures and of transport to an appropriate care facility, risk of alloimmunization, wastage of blood, stress for the family and need for PICU monitoring. Jayabose et al. reported similar results in 1993 (Am J Pediatr Hematol/Oncol 1993;15:324-7), but institutional practice has not changed. Although with a small preliminary sample size, we report a similar retrospective safety profile emphasizing the lack of risk for more liberal transfusion rates in pediatric patients with severe chronic anemia.

Disclosures
No relevant conflicts of interest to declare.