In premature infants there is no decrease in 24-hour posttransfusion allogeneic red blood cell recovery after 42 days...

Critically ill preterm very-low-birthweight (VLBW) neonates (birthweight ≤ 1.5 kg) frequently develop anemia that is treated with red blood cell (RBC) transfusions. Although RBCs transfused to adults demonstrate progressive decreases in posttransfusion 24-hour RBC recovery (PTR₂₄ ) during storage-to a mean of approximately 85% of the Food and Drug Administration-allowed 42-day storage-limited data in infants indicate no decrease in PTR₂₄ with storage.

We hypothesized that PTR₂₄ of allogeneic RBCs transfused to anemic VLBW newborns: 1) will be greater than PTR₂₄ of autologous RBCs transfused into healthy adults and 2) will not decrease with increasing storage duration. RBCs were stored at 4°C for not more than 42 days in AS-3 or AS-5. PTR₂₄ was determined in 46 VLBW neonates using biotin-labeled RBCs and in 76 healthy adults using ⁵¹ Cr-labeled RBCs. Linear mixed-model analysis was used to estimate slopes and intercepts of PTR₂₄ versus duration of RBC storage.

For VLBW newborns, the estimated slope of PTR₂₄ versus storage did not decrease with the duration of storage (p = 0.18) while for adults it did (p < 0.0001). These estimated slopes differed significantly in adults compared to newborns (p = 0.04). At the allowed 42-day storage limit, projected mean neonatal PTR₂₄ was 95.9%; for adults, it was 83.8% (p = 0.0002).

These data provide evidence that storage duration of allogeneic RBCs intended for neonates can be increased without affecting PTR₂₄ . This conclusion supports the practice of transfusing RBCs stored up to 42 days for small-volume neonatal transfusions to limit donor exposure.