Blood transfusion is associated with prolonged duration of mechanical ventilation in infants undergoing reparative cardiac surgery

Effects of a comprehensive blood-sparing approach using body weight-adjusted miniaturized cardiopulmonary bypass circuits on transfusion requirements in pediatric cardiac surgery

OBJECTIVES

Transfusion-free pediatric cardiac surgery remains a challenge, mainly owing to the mismatch between the cardiopulmonary bypass (CPB) priming volume and the infants' blood volume. Within a comprehensive blood-sparing approach, we developed body weight-adjusted miniaturized CPB circuits with priming volumes of 95, 110, and 200 mL for, respectively, infants weighing less than 3 kg, 3 to 5 kg and 5 to 16 kg. We analyzed the effects of this approach on transfusion requirements and risk factors predisposing for blood transfusion.

METHODS

A total of 288 children with body weights between 1.7 and 15.9 kg were included and divided into 3 groups: No transfusion, postoperative transfusion only, and intraoperative and postoperative transfusion. Groups were compared by analysis of variance or analysis of variance on ranks. Risk factors predisposing for transfusion were identified by multivariate logistic regression.

RESULTS

Of the infants, 24.7% required no transfusion, 23.6% received postoperative transfusion only and 51.7% received intraoperative and postoperative transfusion. Groups differed by age, body weight, and size and by duration of surgery, CPB, and aortic crossclamp (P<.00001). Body weight (P<.00001), CPB duration (P<.00001), and persisting cyanosis (P=.03) were predictors of intraoperative and postoperative transfusion, whereas body weight (P=.00095), reoperations (P=.0051), and cyanotic heart defects (P=.035) were associated with postoperative transfusion only.

CONCLUSIONS

Our blood-sparing approach allows for transfusion-free surgery in a substantial number of infants. The strongest predictors of transfusion requirement, body weight and complexity of surgery as reflected by CPB duration, are not amenable to further improvements. Better preservation of the coagulatory system might allow for reduction of postoperative transfusion requirements.

Differential effects of aprotinin and tranexamic acid on outcomes and cytokine profiles in neonates undergoing cardiac surgery

OBJECTIVE

Factors contributing to postoperative complications include blood loss and a heightened inflammatory response. The objective of this study was to test the hypothesis that aprotinin would decrease perioperative blood product use, reduce biomarkers of inflammation, and result in improved clinical outcome parameters in neonates undergoing cardiac operations.

METHODS

This was a secondary retrospective analysis of a clinical trial whereby neonates undergoing cardiac surgery received either aprotinin (n = 34; before May 2008) or tranexamic acid (n = 42; after May 2008). Perioperative blood product use, clinical course, and measurements of cytokines were compared.

RESULTS

Use of perioperative red blood cells, cryoprecipitate, and platelets was reduced in neonates receiving aprotinin compared with tranexamic acid (P < .05). Recombinant activated factor VII use (2/34 [6%] vs 18/42 [43%]; P < .001), delayed sternal closure (12/34 [35%] vs 26/42 [62%]; P = .02), and inotropic requirements at 24 and 36 hours (P < .05) were also reduced in the aprotinin group. Median duration of mechanical ventilation was reduced compared with tranexamic acid: 2.9 days (interquartile range: 1.7-5.1 days) versus 4.2 days (2.9-5.2 days), P = .04. Production of tumor necrosis factor and interleukin-2 activation were attenuated in the aprotinin group at 24 hours postoperatively. No differential effects on renal function were seen between agents.

CONCLUSIONS

Aprotinin, compared with tranexamic acid, was associated with reduced perioperative blood product use, improved early indices of postoperative recovery, and attenuated indices of cytokine activation, without early adverse effects. These findings suggest that aprotinin may have unique effects in the context of neonatal cardiac surgery and challenge contentions that antifibrinolytics are equivalent with respect to early postoperative outcomes.

Emerging Role for Use of Liposomes in the Biopreservation of Red Blood Cells

SUMMARY: Biopreservation is the process of maintaining the integrity and functionality of cells held outside the native environment for extended storage times. The development of red blood cell (RBC) biopreservation techniques that maintain in vitro RBC viability and function represents the foundation of modern blood banking. The biopreservation of RBCs for clinical use can be categorized based on the techniques used to achieve biologic stability, including hypothermic storage and cryopreservation. This review will examine the emerging role of liposomes in the RBC biopreservation, including the incorporation of liposomes into RBC membranes as an effective approach for minimizing RBC hypothermic storage membrane lesion and use of liposomes as a permeabilization strategy for the intracellular accumulation of novel intracellular cryoprotectants. Integration of current biopreservation research with blood banking practices offers enormous potential for future improvements of safety and efficacy of RBC transfusion.