Photo by Elise Amendola
ORLANDO, FL—The storage duration of red blood cells (RBCs) doesn’t affect transfusion outcomes in children with lactic acidosis due to severe anemia, according to a new study.
Investigators found no significant differences in lactate levels, 30-day recovery, survival, or adverse events between children who received RBCs stored for 25 to 35 days and children who received RBCs stored for 1 to 10 days.
These results were published in JAMA and presented at the 2015 ASH Annual Meeting as abstract 769.
Christine Cserti-Gazdewich, MD, of University Health Network in Toronto, Canada, provided insights on the data during a press conference at ASH.
A concern of the investigators, according to Dr Cserti-Gazdewich, was that previous studies on blood storage were conducted in “high-income countries in high-technology care settings with blood inventory wealth, and findings may not be generalizable to the other half of the world.”
She pointed out that, in less developed countries, the shortfall in blood availability compared to the need is up to 3-fold.
So the investigators examined whether longer-stored red blood cells actually deliver oxygen in a manner not worse than shorter-stored or fresh blood and examined it at the extremes of storage duration in the context of a very high-dose need.
The team evaluated 290 children (aged 6 months to 60 months) with elevated blood lactate levels due to severe anemia who presented at a university-affiliated national referral hospital in Kampala, Uganda.
The children were randomized to receive RBC units stored for 25 to 35 days (longer-storage group, n=145) or RBCs stored for 1 to 10 days (shorter-storage group, n=145).
All units were leukoreduced prior to storage. All patients received 10 mL/kg of RBCs during hours 0 through 2 and, if indicated per protocol, an additional 10 mL/kg during hours 4 through 6.
In the entire population, the mean presenting hemoglobin level was 3.7 g/dL, and the mean lactate level was 9.3 mmol/L. The median RBC unit storage duration was 8 days (range, 7-9) for the shorter-storage group and 32 days (range, 30-34) for the longer-storage group.
Results
The investigators found that RBC units maintained under standard storage conditions for 25 to 35 days were not inferior to RBC units stored for up to 10 days.
The study’s primary endpoint was the proportion of patients with a lactate level of 3 mmol/L or lower at 8 hours, using a margin of noninferiority equal to an absolute difference of 25%.
The proportion of patients meeting this endpoint was 0.61 in the longer-storage group and 0.58 in the shorter-storage group (P<0.001 for noninferiority).
Average lactate levels were not statistically different between the 2 groups at 0, 2, 4, 6, 8, or 24 hours. And there was no statistical difference in the median time to achieve a blood lactate of 3 mmol/L or lower at 4 hours (hazard ratio=0.99, P=0.92).
Cerebral tissue oxygen saturation rose significantly during transfusion, but there was no significant difference between the 2 storage groups. The median area under the curve of cerebral tissue oxygen saturation during transfusion was 679 (range, 334-1156) for the longer-storage group and 521 (range, 303-835) for the shorter-storage group (P=0.25).
There was no significant difference between the longer-storage group and the shorter-storage group in the persistence of stupor or coma 8 hours after transfusion (12.6% and 19.6%, respectively, P=0.11) or the persistence of respiratory distress at 8 hours (28.7% and 30%, respectively, P=0.79).
The median length of hospital stay was 4 days (range, 2-6) in the longer-storage group and 4 days (range, 3-7) in the shorter-storage group.
There were 8 deaths, 3 in the longer-storage group and 5 in the shorter-storage group, during the 24 hours from the start of transfusion. Four additional patients, 2 in each group, died in the hospital after the initial 24-hour observation period.
The proportion of patients who had returned to good health by 30 days was 86% of the longer-storage group and 93% of the shorter-storage group (P=0.13).
“By every single measure we explored, and we explored many, we found that long-stored blood was not inferior . . . ,” Dr Csert-Gazdewich said. “We truly found no justification to shorten the current storage duration of red cells as judged by the fundamental role to deliver oxygen.”
