Children and neonates are physiologically distinct from adults, and there is frequently an “evidence gap” we cross when we apply practices that are known to be effective in the adult world to our younger patients. Children have unique medical needs that frequently aren’t well studied, especially when it comes to a field such as transfusion medicine, which is still in need of more well designed studies and evidence for all patient groups. The NIH/NHLBI has wisely recognized this need in their 2015 State of the Science in Transfusion Medicine symposium by specifically identifying the urgent need for more studies in pediatric and neonatal populations in order to generate robust transfusion guidelines for these patients1. Beyond this, an April 2016 meeting of representatives from NHLBI, DHHS/OAHS and FDA entitled Scientific Priorities in Pediatric Transfusion Medicine, identified many areas of need and questions to be answered among six distinct pediatric areas, which will serve as a focus for research efforts over the next 5-10 years2. Hopefully, the work generated from these recommendations will bring needed evidence to the practice of pediatric transfusion medicine.
In the meantime, what can we do, using available evidence and best practices, to optimize the treatment of these important patient populations? One issue that has been emphasized is the need to minimize iatrogenic blood loss, which disproportionately affects these patients due to their smaller size. This can be accomplished through utilizing smaller volume pediatric blood collection tubes, and through coordinated efforts among clinicians, nurses, phlebotomists and the laboratory to batch orders for lab tests in ways that achieve maximum efficiency and minimize the frequency and volume of blood collections. Additionally, promoting the appropriate use of add-on testing can minimize iatrogenic losses and achieve desired results when applied responsibly.
Blood-sparing surgical techniques have shown promise in reducing both RBC and plasma utilization, as well as decreasing estimated blood loss, in pediatric populations3. Additionally, interest in patient blood management protocols that utilize viscoelastic testing platforms, shows promise for reducing intraoperative transfusions for pediatric patients. A recent study that incorporated a ROTEM-assisted transfusion strategy for pediatric craniosynostosis surgery demonstrated significant decreases in transfusion requirements4.
The use of antifibrinolytic therapeutics has been well documented to reduce transfusion requirements and improve survival in adult surgical and trauma cases, and is beginning to be utilized with more frequency in pediatrics. Tranexamic acid (TXA) currently is most commonly utilized in the context of congenital heart surgery5, and although evidence for its utility in pediatric trauma is limited, there is one relatively recent study in a combat setting in Afghanistan that suggests decreased mortality among patients treated with TXA6. More studies of this promising therapy are necessary to clarify its role in the pediatric setting.
Just as there has been intense interest in the safety and feasibility of adopting restrictive transfusion strategies for adults, so too is there an emerging body of literature examining these practices in specific pediatric populations. Beginning with a 2007 NEJM publication, (Transfusion Requirements in Pediatric Intensive Care Units, TRIPICU), it was shown that a 7 g/dl RBC transfusion threshold resulted in decreased transfusion requirements with no increase in adverse outcomes for critically ill children7. Since that publication, various subgroup analyses and other studies have demonstrated similar findings of safety with regard to restrictive, as opposed to liberal, transfusion strategies in pediatric patients. Of note, a 2013 randomized controlled trial in patients with non-cyanotic congenital heart defects showed that a restrictive RBC transfusion strategy (8 g/dl threshold) was not only safe, but also led to shorter hospital stays and cost savings8.
Finally, it is important to keep in mind that, if transfusion is required, we should not be transfusing more than is necessary to achieve the clinical goal. At volumes above 20 ml/kg, RBC transfusion can be complicated by citrate toxicity, hypothermia, hyperkalemia and volume overload. A 10 ml/kg RBC dose can result in a 2 g/dl increase in hemoglobin, which may be greater than the patient needs! Determine what the patient’s needs are, and choose the dose appropriately.
- Transfusion. 2015 Sep;55(9):2282-90.
- Paediatr Anaesth. 2014 Jul;24(7):774-80.
- J Neurosurg Pediatr. 2015 Jul 31:1-8.
- J Emerg Med. 2016 Jun;50(6):868-874.e1.
- J Trauma Acute Care Surg. 2014 Dec;77(6):852-8.
- N Engl J Med. 2007 Apr 19;356(16):1609-19.
- Intensive Care Med. 2013 Nov;39(11):2011-9.