Fresh blood failed to improve outcomes in infants who received transfusions
Infants with low birth weight who received transfused blood that had been stored for 7 days or less had similar adverse outcome rates as those who received blood that had been stored for the standard duration, according to study results.
Dean Fergusson, PhD, program director of clinical epidemiology at Ottawa Hospital Research Institute and associate professor of at the University of Ottawa, and colleagues suggested that transfusing older red blood cells may be linked to adverse outcomes, including higher rates of organ dysfunction, nosocomial infection and length of hospital stay.
“Before now, most of the literature on the subject suggested that fresh red blood cells are better,” Fergusson said in a press release. “However, the effect of fresher blood on clinical outcomes had never been examined using a randomized clinical trial in human patients, which is considered the gold standard in medical science.”
Fergusson and colleagues aimed to determine whether red blood cells that had been stored for 7 days or less were linked to decreased incidence of these outcomes than usual standards of storage.
The double blind, randomized controlled trial included 377 premature infants with birth weights less than 1,250 grams. Eligible participants had been admitted to six tertiary care units in Canada between May 2006 and June 2011 and required at least one transfusion.
The study included 188 infants randomly assigned to receive transfusion of red blood cells stored 7 days or less group. Researchers assigned the other 189 infants to standard care. They received transfusions that met criteria for standard blood bank practice.
The primary endpoint was a composite of major neonatal comorbidities, including necrotizing enterocolitis, retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage and death. The secondary endpoint was rate of nosocomial infection. Researchers measured outcomes up to 90 days after randomization.
The mean duration of stored blood was 5.1 days (standard deviation, 2) in the study group and 14.6 days (standard deviation, 8.3) in the standard group.
The primary endpoint occurred in 99 (52.7%) infants in the fresh blood group and 100 (52.9%) in the standard blood bank practice group (RR=1.00; 95% CI, 0.82-1.21).
Clinically suspected infections occurred in 77.7% of infants in the fresh blood group and 77.2% of infants in the standard group (RR=1.01; 95% CI, 0.9-1.12).
The rate of positive cultures was 67.5% in the fresh blood group and 64% in the standard group (RR=1.06; 95% CI, 0.91-1.22).
“Over the years, the number of retrospective studies showing possible harm from older blood has created pressure to change the management of the blood supply to provide fresher transfusion products,” Dana Devine, PhD, vice president for medical, scientific and research affairs of Canadian Blood Services, a not-for-profit organization that manages the blood and blood products supply for Canadians, said in a press release.
This is a huge undertaking that would require many more donations than we currently have and greatly increase the cost of operating the blood system,” Devine said. “To have this particular human clinical trial saying otherwise is important because it is the first such study using the highest level of evidence, the randomized controlled trial, and it was done in a very vulnerable patient population.”