Trial results suggest African children with uncomplicated, severe anemia may not require immediate blood transfusion, and the volume of transfusion may only matter in the context of fever.
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The TRACT trial showed no significant differences in 28-day mortality or other clinical outcomes between children who received immediate transfusions and those who did not.
Similarly, there was no significant difference in 28-day mortality among children who received transfusions of 20 mL/kg and those who received transfusions of 30 mL/kg. There was evidence to suggest a higher transfusion volume may benefit children without fevers, but this was an exploratory endpoint. The findings were published in the New England Journal of Medicine.
These results suggest “there is no credible reason to transfuse immediately or to transfuse a higher volume of blood, at least in pediatric populations in regions such as these two sub-Saharan countries [Uganda and Malawi],” Julie R. Ingelfinger, MD, of Massachusetts General Hospital in Boston, wrote in an accompanying editorial, also published in the New England Journal of Medicine (2019;381:475-6).
“The possible effect of higher volume transfusion in patients with fever may trigger additional and potentially useful studies,” she added.
Immediate transfusion
One goal of the TRACT trial was to determine if blood transfusion is the best treatment for children with severe anemia. With this in mind, Kathryn Maitland, MD, PhD, of Imperial College London and colleagues evaluated 1,565 Ugandan and Malawian children with uncomplicated, severe anemia. The patients’ median age was 26 months, and 984 (62.9%) had malaria.
The children were randomized to immediate transfusion (n = 778) or no immediate transfusion (n = 787). Children who did not have an immediate transfusion (control group) could receive a transfusion if they exhibited new signs of clinical severity or had their hemoglobin decrease to below 4 g/dL.
All children in the immediate-transfusion group received a transfusion, as did 386 (49.0%) in the control group. The median time to transfusion was 1.3 hours in the immediate group and 24.9 hours in the control group. The mean total blood volume transfused per child was 314 plus or minus 228 mL and 142 plus or minus 224, respectively. The follow-up period was 180 days, and 4.5% of patients (n = 71) were lost to follow-up.
The researchers found no significant difference between the treatment groups with regard to mortality, other clinical outcomes, or the cost of care.
The 28-day mortality rate was 0.9% in the immediate-transfusion group and 1.7% in the control group (hazard ratio, 0.54; 95% confidence interval, 0.22-1.36; P = .19). The 180-day mortality was 4.5% and 6.0%, respectively (HR, 0.75; 95% CI, 0.48-1.15).
Transfusion volume
To assess the effects of transfusion volume, Dr. Maitland and colleagues evaluated 3,196 Ugandan and Malawian children with severe anemia. The median age of the children was 37 months, and 2,050 (64.1%) had malaria.
The children received a transfusion of 30 mL/kg (n = 1,592) or 20 mL/kg (n = 1,596) at a median of 1.2 hours after randomization. Some children – 197 in the 30-mL/kg group and 300 in the 20-mL/kg group – received additional transfusions. The mean volume of total blood transfused per child was 475 plus or minus 385 mL, and 353 plus or minus 348 mL, respectively.
Overall, there was no significant between-group difference with regard to mortality. The 28-day mortality rate was 3.4% in the 30 mL/kg group and 4.5% in the 20 mL/kg group (HR = 0.76; 95% CI, 0.54 to 1.08; P = .12).
However, the 28-day mortality rate did differ according to the presence of fever at screening. The mortality rate was lower in the 30 mL/kg group for children without fevers (HR = 0.43; 95% CI, 0.27 to 0.69) but higher in the 30 mL/kg group for febrile children (HR = 1.91; 95% CI, 1.04 to 3.49).
For other outcomes, including readmissions and serious adverse events, the researchers found no significant between-group differences.
This trial was supported by a grant from the United Kingdom Medical Research Council through a concordat with the Department for International Development. One researcher has a Wellcome Senior Research Fellowship, and another is a National Institute for Health Research Senior Investigator. Dr. Ingelfinger is a deputy editor at the New England Journal of Medicine. No other relevant conflicts of interest were reported.