Longer RBC storage duration is associated with increased postoperative infections in pediatric cardiac surgery

Abstract

Objectives: Infants and children undergoing open heart surgery routinely require multiple RBC transfusions. Children receiving greater numbers of RBC transfusions have increased postoperative complications and mortality. Longer RBC storage age is also associated with increased morbidity and mortality in critically ill children. Whether the association of increased transfusions and worse outcomes can be ameliorated by use of fresh RBCs in pediatric cardiac surgery for congenital heart disease is unknown.

Interventions: One hundred and twenty-eight consecutively transfused children undergoing repair or palliation of congenital heart disease with cardiopulmonary bypass who were participating in a randomized trial of washed versus standard RBC transfusions were evaluated for an association of RBC storage age and clinical outcomes. To avoid confounding with dose of transfusions and timing of infection versus timing of transfusion, a subgroup analysis of patients only transfused 1-2 units on the day of surgery was performed.

Measurements and main results: Mortality was low (4.9%) with no association between RBC storage duration and survival. The postoperative infection rate was significantly higher in children receiving the oldest blood (25-38 d) compared with those receiving the freshest RBCs (7-15 d) (34% vs 7%; p = 0.004). Subgroup analysis of subjects receiving only 1-2 RBC transfusions on the day of surgery (n = 74) also demonstrates a greater prevalence of infections in subjects receiving the oldest RBC units (0/33 [0%] with 7- to 15-day storage; 1/21 [5%] with 16- to 24-day storage; and 4/20 [20%] with 25- to 38-day storage; p = 0.01). In multivariate analysis, RBC storage age and corticosteroid administration were the only predictors of postoperative infection. Washing the oldest RBCs (> 27 d) was associated with a higher infection rate and increased morbidity compared with unwashed RBCs.

Discussion: Longer RBC storage duration was associated with increased postoperative nosocomial infections. This association may be secondary in part, to the large doses of stored RBCs transfused, from single-donor units. Washing the oldest RBCs was associated with increased morbidity, possibly from increased destruction of older, more fragile erythrocytes incurred by washing procedures. Additional studies examining the effect of RBC storage age on postoperative infection rate in pediatric cardiac surgery are warranted.

Figure 1

Figure 1a and 1b. The proportion of patients, with post-operative infection according to red blood cell storage age of the oldest unit received. The population was divided into tertiles, determined by the the oldest unit received (Figure 1a). Similar results were found employing quartiles (data not shown), with infection rates progressively increasing from 3% (oldest unit 7–14 days in storage) to 33% (oldest unit 28–38 days in storage). Figures 1a includes all transfused patients in the original study (n=128). Figure 1b is restricted to patients receiving only 1–2 transfusions which were given only on the day of surgery (n=74).

Figure 1

Figure 1a and 1b. The proportion of patients, with post-operative infection according to red blood cell storage age of the oldest unit received. The population was divided into tertiles, determined by the the oldest unit received (Figure 1a). Similar results were found employing quartiles (data not shown), with infection rates progressively increasing from 3% (oldest unit 7–14 days in storage) to 33% (oldest unit 28–38 days in storage). Figures 1a includes all transfused patients in the original study (n=128). Figure 1b is restricted to patients receiving only 1–2 transfusions which were given only on the day of surgery (n=74).