Clinical outcomes following institution of universal leukoreduction of blood transfusions for premature infants.
BACKGROUND
Leukocytes present in stored blood products can have a variety of biological effects, including depression of immune function, thereby increasing nosocomial infections and possibly resulting in organ failure and death. Premature infants, given their immature immune state, may be uniquely predisposed to the effects of transfused leukocytes.


OBJECTIVE
To evaluate the clinical outcomes following implementation of a universal prestorage red blood cell (RBC) leukoreduction program in premature infants admitted to neonatal intensive care units (NICUs).


METHODS
Retrospective before-and-after study conducted in 3 Canadian tertiary care NICUs from January 1998 to December 2000.


METHODS
A total of 515 premature infants weighing less than 1250 g who were admitted to the NICU, received at least 1 RBC transfusion, and survived at least 48 hours were enrolled. The intervention group consisted of infants admitted in the 18-month period following the introduction of universal leukoreduction (n = 247) and the control group consisted of infants admitted during the 18 months prior to the introduction of universal leukoreduction (n = 268).


METHODS
Primary outcomes were nosocomial bacteremia and NICU mortality, compared before and after implementation of universal leukoreduction using multivariate regression. Secondary outcomes included bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and intraventricular hemorrhage.


RESULTS
The proportion of infants who acquired bacteremia after an RBC transfusion was 79/267 (29.6%) in the nonleukoreduction period and 63/246 (25.6%) in the leukoreduction period. For NICU mortality, there were 45 deaths (16.8%) in the nonleukoreduction period and 44 deaths (17.8%) in the leukoreduction period. The adjusted odds ratio (OR) for bacteremia was 0.59 (95% confidence interval [CI], 0.34-1.01) and for mortality was 1.22 (95% CI, 0.59-2.50). The adjusted ORs for bronchopulmonary dysplasia and retinopathy of prematurity were 0.42 (95% CI, 0.25-0.70) and 0.56 (95% CI, 0.33-0.93), respectively. The adjusted ORs for necrotizing enterocolitis and grade 3 or 4 intraventricular hemorrhage were 0.39 (95% CI, 0.17-0.90) and 0.65 (95% CI, 0.35-1.19), respectively. The adjusted OR for a composite measure of any major neonatal morbidity was 0.31 (95% CI, 0.17-0.56). Crude and adjusted rates for all secondary outcomes suggest that leukoreduction was associated with improved outcomes.


CONCLUSIONS
Implementation of universal prestorage leukoreduction was not associated with significant reductions in NICU mortality or bacteremia but was associated with improvement in several clinical outcomes in premature infants requiring RBC transfusions.
Fergusson
Dean
D
Department of Epidemiology and Biostatistics, McGill University, Montreal, Quebec. dafergusson@ohri.ca
Hébert
Paul C
PC
Lee
Shoo K
SK
Walker
C Robin
CR
Barrington
Keith J
KJ
Joseph
Lawrence
L
Blajchman
Morris A
MA
Shapiro
Stan
S
D016470:Bacteremia / Q000453:epidemiology*; D001771:Blood Banks / Q000592:standards*; D002170:Canada; D002469:Cell Separation; D003428:Cross Infection / Q000453:epidemiology*; D017707:Erythrocyte Transfusion / Q000379:methods / Q000592:standards*; D005260:Female; D005374:Filtration; D017052:Hospital Mortality; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000453:epidemiology / Q000628:therapy*; D007363:Intensive Care Units, Neonatal; D007962:Leukocytes; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D012189:Retrospective Studies; D000094902:Blood Banking / Q000379:methods