One size will never fit all: the future of research in pediatric transfusion medicine

Postoperative Interventions in Pediatric Digital Replantation: A Tertiary Referral Center Case Review

PURPOSE

Although a few case series have been published describing the excellent outcomes of replantation and revascularization operations in children, there has been limited study of the hospital course that these patients experience and the number of potentially harmful interventions and treatments that occur. The purpose of this study was to detail the results of various postoperative interventions, including anticoagulation, transfusion, leeching, sedation, and additional anesthetic exposures.

METHODS

Twenty-nine patients aged less than 18 years had 34 digital revascularizations or replantations performed between January 2000 and May 2020. The details of each patient's presentation, surgery, and postoperative care were analyzed.

RESULTS

Nine of 29 children underwent repeat anesthetics, including 6 revision amputations. No demographic, surgical, or postoperative variables consistently preceded revision amputation or additional anesthetic procedures. Only 5 patients had >1 hemoglobin (Hb) measurement. Two patients received blood transfusions; the average drop in Hb was 3.5 g/dL from before surgery to the lowest after surgery. Four patients underwent leech therapy. Only patients receiving leech therapy required postoperative transfusions. Anticoagulation regimens were prescribed on the basis of demographic and surgical factors, although no medication or regimen seemed to affect outcomes.

CONCLUSIONS

Although the experience of digital replantation is essentially the same in pediatric patients as adults, there may be different ramifications for children. Specifically, postoperative management of pediatric digital replantation or revascularization can involve multiple interventions that carry their risks. Parents should be counseled about the risks of anticoagulants, transfusions, and repeat anesthetics, and clinicians should monitor Hb closely when using leech therapy.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The Ratio of Intraoperative Red Blood Cell Transfusion to Blood Loss Associated with Early Postoperative Complications in Pediatric Liver Transplantation Patients

Introduction

Liver transplantation (LT) is an operation purposed to save the lives of children with acute or chronic liver diseases, hepatic tumors, and some genetic and metabolic diseases. However, patients who underwent LT have a significant risk of intraoperative blood loss and red blood cell (RBC) transfusion, especially in pediatric patients.

Methods

In this study, 569 pediatric patients (<18 years old) who underwent LT at a tertiary university hospital between 2013 and 2020 were included. Multiple logistic regression was used to analyze the association between the ratio of intraoperative RBC transfusion to blood loss (IRTBL) and the complications after LT in pediatric patients. IRTBL was divided into quartiles in the adjusted model. Odds ratios, 95% confidence intervals, and p values for trends were calculated. Restricted cubic spline (RCS) regression was used to evaluate the nonlinear association between IRTBL and complications.

Results

Compared with the lowest level and the highest level of IRTBL, Q2 and Q3 quartiles of IRTBL showed significantly positive association with early complications. A significantly nonlinear association was observed between the IRTBL and early complications in the RCS model with the multiple adjustments of potential covariates (P overall<0.01, P nonlinear<0.01). However, no significant association was observed between late complications and IRTBL.

Conclusion

In this study, we found there was a nonlinear relationship between the ratio of IRTBL and early postoperative complications in pediatric LT patients, which provides a theoretical basis for RBC transfusion in pediatric LT patients.

Therapeutic plasma exchange practices in immune thrombocytopenia related hospitalizations: Results from a nationally representative sample

Per the American Society for Apheresis, therapeutic plasma exchange (TPE) is a Category III indication in the management of immune thrombocytopenia (ITP). This nationally representative study evaluates TPE utilization in hospitalized adults with a primary admission diagnosis of ITP. Hospitalizations with ITP as the primary admitting diagnosis were analyzed from the 2010 to 2014 National Inpatient Sample, the largest all-payer inpatient database in the United States. Univariate and multivariable logistic regressions were used to determine clinical outcomes in ITP patients undergoing TPE. Sampling weights were applied to generate nationally representative estimates. From 2010 to 2014, there were a total of 56,149 admissions with a primary admitting diagnosis of ITP, of which 0.66% admissions (n = 372) also coded TPE. Most subjects undergoing TPE were the highest disease severity class: major (34.6%) and extreme severity (31.0%), by all-patients refined diagnoses-related groups severity of illness subclass. After multivariable analysis, underlying severity of illness remained the most significant predictor of TPE (P < .001). ITP admissions with TPE had a high rate of comorbidities (50%) and significantly longer mean length of hospital stay than those without (P < .001). TPE was reported in ~0.6% of hospitalizations with ITP as the primary diagnosis in this nationally representative sample from 2010 to 2014. TPE was performed in patients with the highest severity of underlying illness, and higher rates of comorbidities.

Multinational Analysis of Children Transfused With Pathogen Inactivated Platelets

BACKGROUND

Pathogen inactivated (PI) platelets are a technological advancement in blood safety; however, the pediatric experience is not well characterized. We studied pediatric patients who received transfusions of PI platelets across several centers and countries to determine if transfusion reaction rates differed when compared with conventional platelets.

METHODS

This is a retrospective multisite study conducted during 2 time periods. The study period started at the time each site began using PI platelets on a widespread basis, and the control period was a similar timespan before PI introduction. Suspected acute transfusion reactions were compared.

RESULTS

The study included 3839 pediatric patients who were 0 to 18 years of age who received >7930 platelet transfusions, in total, across 4 centers in 3 countries between 2013 and 2019. The age distribution of patients in the study and control period was not significantly different (P = .190). There was not a difference in the percentage of patients who had any type of transfusion reaction between the time periods (1.0% and 1.1%, P = .803). There were fewer patients with mild allergic reactions in the study period compared with the control period (0.2% and 0.7% of patients with reactions, respectively, P = .018).

CONCLUSIONS

Pediatric patients have the same rate of acutely suspected transfusion reactions when receiving PI or conventional platelet transfusions. Subgroup analysis found fewer mild allergic reactions in the study period, which was contemporaneous to the addition of using platelet additive solution more broadly. Future studies of PI platelets should include children to better assess transfusion efficacy and hemostatic outcomes.

A Single-Center Description of Pediatric Transfusion Reactions and Preventable Patient Harm

BACKGROUND AND OBJECTIVES

In previous studies, researchers highlight that children have higher rates of transfusion reactions than adults. However, little is known about the pediatric populations that experience reactions, and there are no reports that consider appropriateness of pediatric transfusions in relation to preventable harm. With this study, we aim to describe pediatric transfusion reactions occurring at an academic institution and to quantify transfusion reactions that resulted from inappropriate transfusion indications, thereby identifying an area of potentially preventable patient harm (PPH).

METHODS

This is a case series of acute transfusion reactions in pediatric patients at a single institution from January 2018 to December 2019. We reviewed patient data, clinical documentation, and transfusion reaction reports to determine the appropriateness of transfusions and calculate PPH.

RESULTS

A total 155 acute transfusion reactions occurred in 106 pediatric patients, amounting to a total reaction rate of 544 of 100 000 transfusions. In 65% of reactions, the indication for transfusion was appropriate by institutional standards; 23% had questionable indication; and 12% were not indicated. The rate of potential PPH from inappropriate transfusions was 67 of 100 000 transfusions.

CONCLUSIONS

Transfusion reactions that occur during inappropriately ordered blood transfusions represent PPH. Efforts should be made to develop transfusion guidelines, standardize practice, and educate physicians to prevent transfusion-related harm.

Potential Consequences of the Red Blood Cell Storage Lesion on Cardiac Electrophysiology

Background The red blood cell (RBC) storage lesion is a series of morphological, functional, and metabolic changes that RBCs undergo following collection, processing, and refrigerated storage for clinical use. Since the biochemical attributes of the RBC unit shifts with time, transfusion of older blood products may contribute to cardiac complications, including hyperkalemia and cardiac arrest. We measured the direct effect of storage age on cardiac electrophysiology and compared it with hyperkalemia, a prominent biomarker of storage lesion severity. Methods and Results Donor RBCs were processed using standard blood-banking techniques. The supernatant was collected from RBC units, 7 to 50 days after donor collection, for evaluation using Langendorff-heart preparations (rat) or human induced pluripotent stem cell-derived cardiomyocytes. Cardiac parameters remained stable following exposure to "fresh" supernatant from red blood cell units (day 7: 5.8±0.2 mM K+), but older blood products (day 40: 9.3±0.3 mM K+) caused bradycardia (baseline: 279±5 versus day 40: 216±18 beats per minute), delayed sinus node recovery (baseline: 243±8 versus day 40: 354±23 ms), and increased the effective refractory period of the atrioventricular node (baseline: 77±2 versus day 40: 93±7 ms) and ventricle (baseline: 50±3 versus day 40: 98±10 ms) in perfused hearts. Beating rate was also slowed in human induced pluripotent stem cell-derived cardiomyocytes after exposure to older supernatant from red blood cell units (-75±9%, day 40 versus control). Similar effects on automaticity and electrical conduction were observed with hyperkalemia (10-12 mM K+). Conclusions This is the first study to demonstrate that "older" blood products directly impact cardiac electrophysiology, using experimental models. These effects are likely caused by biochemical alterations in the supernatant from red blood cell units that occur over time, including, but not limited to hyperkalemia. Patients receiving large volume and/or rapid transfusions may be sensitive to these effects.

Transfusion in children with acute respiratory distress syndrome

Transfusion is a frequent treatment in pediatric patients with acute respiratory distress syndrome (PARDS) although evidence to support transfusion decision-making is lacking. The purpose of this review is to review the current state of knowledge on the issue of transfusion in children with PARDS and to detail the possible beneficial effects and potential deleterious impacts of transfusion in this patient population. Based on the current literature and recent guidelines, a restrictive red blood cell (RBC) transfusion strategy (avoidance of transfusion when the haemoglobin level is above 7 g/dL) is indicated in stable patients without severe PARDS, as these were excluded from the large trials. In children with severe PARDS, further research is needed to determine if factors other than the haemoglobin level might guide RBC transfusion decision-making by better characterizing the presence of low oxygen delivery (DO₂). Additionally, appropriate indications for prophylactic transfusion of hemostatic products (plasma or platelets) in children with PARDS are lacking.

Recommendations on RBC Transfusion in General Critically Ill Children Based on Hemoglobin and/or Physiologic Thresholds From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the consensus recommendations and supporting literature for RBC transfusions in general critically ill children from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based recommendations and research priorities regarding RBC transfusions in critically ill children. The subgroup on RBC transfusion in general critically ill children included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 30, 2017, using a combination of keywords to define concepts of RBC transfusion and critically ill children. Recommendation consensus was obtained using the Research and Development/UCLA Appropriateness Method. The results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Three adjudicators reviewed 4,399 abstracts; 71 papers were read, and 17 were retained. Three papers were added manually. The general Transfusion and Anemia Expertise Initiative subgroup developed, and all Transfusion and Anemia Expertise Initiative members voted on two good practice statements, six recommendations, and 11 research questions; in all instances, agreement was reached (> 80%). The good practice statements suggest a framework for RBC transfusion in PICU patients. The good practice statements and recommendations focus on hemoglobin as a threshold and/or target. The research questions focus on hemoglobin and physiologic thresholds for RBC transfusion, alternatives, and risk/benefit ratio of transfusion.

CONCLUSIONS

Transfusion and Anemia Expertise Initiative developed pediatric-specific good practice statements and recommendations regarding RBC transfusion management in the general PICU population, as well as recommendations to guide future research priorities. Clinical recommendations emphasized relevant hemoglobin thresholds, and research recommendations emphasized a need for further understanding of physiologic thresholds, alternatives to RBC transfusion, and hemoglobin thresholds in populations with limited pediatric literature.

The age of blood in pediatric intensive care units (ABC PICU): study protocol for a randomized controlled trial

Background

The “Age of Blood in Children in Pediatric Intensive Care Unit” (ABC PICU) study is a randomized controlled trial (RCT) that aims to determine if red blood cell (RBC) unit storage age affects outcomes in critically ill children. While RBCs can be stored for up to 42 days in additive solutions, their efficacy and safety after long-term storage have been challenged. Preclinical and clinical observational evidence suggests loss of efficacy and lack of safety of older RBC units, especially in more vulnerable populations such as critically ill children. Because there is a belief that shorter storage will improve outcomes, some physicians and institutions systematically transfuse fresh RBCs to children. Conversely, the standard practice of blood banks is to deliver the oldest available RBC unit (first-in, first-out policy) in order to decrease wastage.

Methods/design

The ABC PICU study, is a double-blind superiority trial comparing the development of “New or Progressive Multiple Organ Dysfunction Syndrome” (NPMODS) in 1538 critically ill children randomized to either transfusion with RBCs stored for ≤ 7 days or to standard-issue RBCs (oldest in inventory). Patients are being recruited from 52 centers in the US, Canada, France, Italy, and Israel.

Discussion

The ABC PICU study should have significant implications for blood procurement services. A relative risk reduction of 33% is postulated in the short-storage arm. If a difference is found, this will indicate that fresher RBCs do improve outcomes in the pediatric intensive care unit population and would justify that use in critically ill children.

If no difference is found, this will reassure clinicians and transfusion medicine specialists regarding the safety of the current system of allocating the oldest RBC unit in inventory and will discourage clinicians from preferentially requesting fresher blood for critically ill children.

Trial registration

ClinicalTrials.gov, ID: NCT01977547. Registered on 6 November 2013.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2809-y) contains supplementary material, which is available to authorized users.

Recent advances in transfusions in neonates/infants

Transfusions of red blood cells (RBCs), platelets, and plasma are critical therapies for infants and neonates (particularly preterm neonates) in the neonatal intensive care unit, who are the most frequently transfused subpopulation across all ages. Although traditionally a significant gap has existed between the blood utilization and the evidence base essential to adequately guide transfusion practices in infants and neonates, pediatric transfusion medicine is evolving from infancy and gradually coming of age. It is entering an exciting era with recognition as an independent discipline, a new and evolving high-quality evidence base for transfusion practices, novel technologies and therapeutics, and national/international collaborative research, educational, and clinical efforts. Triggers and thresholds for red cell transfusion are accumulating evidence with current phase III clinical trials. Ongoing trials and studies of platelet and plasma transfusions in neonates are anticipated to provide high-quality evidence in years to come. This article aims to summarize the most current evidence-based practices regarding blood component therapy in neonates. Data on the use of specific components (RBCs, plasma, and platelets) are provided. We attempt to define thresholds for anemia, thrombocytopenia, and abnormal coagulation profile in neonates to highlight the difficulties in having a specific cutoff value in neonates and preterm infants. Indications for transfusion of specific products, transfusion thresholds, and current practices and guidelines are provided, and possible adverse outcomes and complications are discussed. Finally, the critical research knowledge gaps in these practices as well as ongoing and future research areas are discussed. In an era of personalized medicine, neonatal transfusion decisions guided by a strong evidence base must be the overarching goal, and this underlies all of the strategic initiatives in pediatric and neonatal transfusion research highlighted in this article.

Research Opportunities to Improve Neonatal Red Blood Cell Transfusion

Red blood cell (RBC) transfusion is a common and lifesaving therapy for anemic neonates and infants, particularly among those born prematurely or undergoing surgery. However, evidence-based indications for when to administer RBCs and adverse effects of RBC transfusion on important outcomes including necrotizing enterocolitis, survival, and long-term neurodevelopmental impairment remain uncertain. In addition, blood-banking practices for preterm and term neonates and infants have been largely developed using studies from older children and adults. Use of and refinements in emerging technologies and advances in biomarker discovery and neonatal-specific RBC transfusion databases may allow clinicians to better define and tailor RBC transfusion needs and practices to individual neonates. Decreasing the need for RBC transfusion and developing neonatal-specific approaches in the preparation of donor RBCs have potential for reducing resource utilization and cost, improving outcomes, and assuring blood safety. Finally, large donor-recipient-linked cohort studies can provide data to better understand the balance of the risks and benefits of RBC transfusion in neonates. These studies may also guide the translation of new research into best practices that can rapidly be integrated into routine care. This review highlights key opportunities in transfusion medicine and neonatology for improving the preparation and transfusion of RBCs into neonates and infants. We focus on timely, currently addressable knowledge gaps that can increase the safety and efficacy of preterm and term neonatal and infant RBC transfusion practices.

Neonatal Transfusion Medicine: Five Major Unanswered Research Questions for the Twenty-First Century

Blood component transfusions are important to the care of preterm neonates; however, their use in clinical practice often is not based on high levels of evidence. Five major questions for neonates are discussed: (1) What is the optimal red blood cell (RBC) transfusion threshold? (2) What is the optimal platelet transfusion threshold? (3) Does the storage age of an RBC unit affect outcomes? (4) Does RBC transfusion contribute to the pathogenesis of necrotizing enterocolitis? and (5) Which new practices should be used to prevent transfusion-transmitted infections? Although definitive answers to these questions do not exist, future research should help answer them.