PICU Transfusion Study: Harmful Effects of Red Blood Cell Transfusions

Harmful Effects of Red Blood Cell Transfusions Are Mediated by Iron: Pediatric ICU Aim

The investigators hypothesize that the storage-damaged red cells are responsible for some of the adverse effects of transfusion. In this observational study, the investigators will measure various laboratory parameters both before and after transfusion in a pediatric intensive care unit to determine at what duration of storage is there laboratory evidence of refrigerator storage damage.

The investigators hypothesize that increasing storage time of packed red blood cells (PRBCs) transfused will be associated with increasing non-transferrin-bound iron (NTBI), pro-inflammatory cytokine concentrations, and enhanced microbial growth in vitro in pediatric patients.

Transfusions of red blood cells (RBCs) stored for longer durations are associated with adverse effects in hospitalized patients. During storage, RBCs undergo cumulative changes that reduce their survival in vivo, and have been associated with impairment in oxygen transport and adverse outcomes. Transfusion of older RBCs results in increased NTBI levels in healthy adults, and elevated NTBI levels have been associated with increased morbidity and mortality in hospitalized patients. Transfusion of PRBCs has also been associated with up-regulation of inflammatory cytokines. Pediatric patients are exposed to PRBC transfusions; however, this patient population has not been previously studied for these outcomes.

According to current practice guidelines, PRBCs are stored in the blood bank up to 42 days prior to transfusion. In this study, blood sample will be collected from pediatric ICU patients prior to every PRBC transfusion and again 2-6 hours post-transfusion to determine iron parameters, inflammatory marker concentrations, and growth of microbial pathogens in vitro.

The investigators hopes to further the understanding of the effects of blood storage on outcome in children, thereby making transfusion safer and more effective.

Inclusion Criteria:

• Less than 21 years of age;
• Greater than 5kg weight;
• Parents or legal guardian have signed informed consent;
• Will be receiving transfusion of packed, leukoreduced RBCs stored in an additive saline (AS) solution (standard practice).

Exclusion Criteria:

• Patients have undergone transfusion of platelets or fresh frozen plasma 4 hours before or will receive these products after transfusion of the RBC unit;
• Transfusion of RBC from more than one donor at the test transfusion event.