Blood Transfusions After Pediatric Cardiac Operations: A North American Multicenter Prospective Study

Safety of bloodless open-heart surgery on cardiopulmonary bypass in selected children: A single center experience with minimal invasive extracorporeal circulation

INTRODUCTION

Bloodless cardiac surgery refers to open-heart surgery without blood or blood products. The cardiopulmonary bypass (CPB) circuits are primed with crystalloid solely, and there is no intraoperative blood transfusion.

METHODS

Our program considers bloodless congenital cardiac surgery with a minimal invasive extracorporeal circulation (MiECC) system for patients above 10 kg of weight. We performed a single-center retrospective cohort study of all consecutive patients undergoing bloodless cardiac surgery for congenital heart defects between January 2016 and December 2018.

RESULTS

A total of 164 patients were reviewed (86 male and 78 female) at a median age of 9.6 years (interquartile range (IQR), 4.5-15), a weight of 32 kg (IQR, 16-55), preoperative hemoglobin 13.7 g/dl (IQR, 12.6-14.9), and preoperative hematocrit of 40.4% (IQR, 37.2-44.3). Median CPB time was 81.5 min (IQR, 58-125), and median hematocrit coming off CPB was 26% (IQR, 23-29.7). The congenital heart surgery risk (STAT) category was distributed in STAT 1 for 70, STAT 2 for 80, STAT 3 for 9, and STAT 4 for 5 patients. Most patients (95%) were extubated in the operating room with a low complication rate during the hospital stay (14.6%). Only 6 (4%) patients needed a blood transfusion during the postoperative period, with a higher incidence of complications during the hospital course (p < 0.001).

CONCLUSIONS

Bloodless congenital heart surgery with MiECC system is safe in low-surgical-risk patients. Our patients had a low rate of complications and short hospital stays.

Evidence for the cardiodepressive effects of the plasticizer di-2-ethylhexyl phthalate

Di-2-ethylhexyl phthalate (DEHP) is commonly used in the manufacturing of plastic materials, including intravenous bags, blood storage bags, and medical-grade tubing. DEHP can leach from plastic medical products, which can result in inadvertent patient exposure. DEHP concentrations were measured in red blood cell units stored between 7 and 42 days (17-119 μg/ml). Using these concentrations as a guide, Langendorff-perfused rat heart preparations were acutely exposed to DEHP. Sinus activity remained stable with lower doses of DEHP (25-50 μg/ml), but sinus rate declined by 43% and sinus node recovery time (SNRT) prolonged by 56.5% following 30-min exposure to 100 μg/ml DEHP. DEHP exposure also exerted a negative dromotropic response, as indicated by a 69.4% longer PR interval, 108.5% longer Wenckebach cycle length (WBCL), and increased incidence of atrioventricular (AV) uncoupling (60-min exposure). Pretreatment with doxycycline partially rescued the effects of DEHP on sinus activity, but did not ameliorate the effects on AV conduction. DEHP exposure also prolonged the ventricular action potential and effective refractory period, but had no measurable effect on intracellular calcium transient duration. Follow-up studies using human-induced pluripotent stem cell-derived cardiomyocytes confirmed that DEHP slows electrical conduction in a time (15 min-3 h) and dose-dependent manner (10-100 μg/ml). Previous studies have suggested that phthalate toxicity is specifically attributed to metabolites of DEHP, including mono-2-ethylhexylphthalate. This study demonstrates that DEHP exposure also contributes to cardiac dysfunction in a dose- and time-dependent manner. Future work is warranted to investigate the impact of DEHP (and its metabolites) on human health, with special consideration for clinical procedures that employ plastic materials.

Effect of Red Blood Cell Transfusion on Regional Tissue Oxygenation in Pediatric Cardiac Surgery Patients

BACKGROUND

Red blood cell (RBC) transfusions are used frequently in pediatric patients admitted to the intensive care unit (ICU) after cardiac surgery. To improve data-driven transfusion decision-making in the ICU, we conducted a retrospective analysis to assess the effect of RBC transfusion on cerebral and somatic regional oxygenation (rSO2).

METHODS

We evaluated post- versus pre-RBC transfusion cerebral rSO2 and somatic rSO2 in all consecutive pediatric patients (age >28 days to <18 years) who underwent biventricular cardiac surgery at a single center between July 2016 and April 2020.

RESULTS

The final data set included 263 RBC postoperative transfusion events in 75 patients who underwent 83 surgeries. The median pretransfusion hemoglobin was 10.6 g/dL (25th-75th percentile, 9.3-11.6). The median pretransfusion cerebral and somatic rSO2 were 63% (54-71) and 69% (55-80), which increased by a median of 3 percentage points (-2 to 6) and 2 percentage points (-3 to 6), respectively, after transfusion. After adjusting for pretransfusion hemoglobin, change in hemoglobin posttransfusion versus pretransfusion, and potential confounders (age, sex, and STAT surgical mortality risk score), the posttransfusion versus pretransfusion change in cerebral or somatic rSO2 was not statistically significant. Pretransfusion cerebral rSO2 (crSO2) was ≤50%, a previously described threshold for increased risk for unfavorable neurological outcome, for 22 of 138 (16%) transfusion events with complete pre- and post-crSO2 data. Sixteen of these 22 (73%) transfusions resulted in a posttransfusion crSO2 >50%. When restricting analysis to the first (index) transfusion after arrival to the ICU from the operating room (administered at a median of 1.15 postoperative days [25th-75th percentile, 0.84-1.93]), between-patient pretransfusion hemoglobin was not associated with pretransfusion crSO2 but within-patient posttransfusion versus pretransfusion hemoglobin difference was significantly associated with posttransfusion versus pretransfusion crSO2 difference (mean posttransfusion versus pretransfusion crSO2 difference, 2.54; 95% confidence interval, 0.50-4.48).

CONCLUSIONS

In this study, neither cerebral nor somatic rSO2 increased significantly post- versus pre-RBC transfusion in pediatric cardiac surgery patients admitted to the ICU after biventricular repairs. However, almost three-quarters of transfusions administered when pretransfusion crSO2 was below the critical threshold of 50% resulted in a posttransfusion crSO2 >50%. In addition, the significant within-patient change in crSO2 in relation to the change in posttransfusion versus pretransfusion hemoglobin in the immediate postoperative period suggests that a personalized approach to transfusion following within-patient trends of crSO2 rather than absolute between-patient values may be an important focus for future research.

Impact of Phlebotomy Volume Knowledge on Provider Laboratory Ordering and Transfusion Practices in the Pediatric Cardiac ICU

OBJECTIVES

Phlebotomy can account for significant blood loss in post-surgical pediatric cardiac patients. We investigated the effectiveness of a phlebotomy volume display in the electronic medical record (EMR) to decrease laboratory sampling and blood transfusions. Cost analysis was performed.

DESIGN

This is a prospective interrupted time series quality improvement study. Cross-sectional surveys were administered to medical personnel pre- and post-intervention.

SETTING

The study was conducted in a 19-bed cardiac ICU (CICU) at a Children's hospital.

PATIENTS

One hundred nine post-surgical pediatric cardiac patients weighing 10 kg or less with an ICU stay of 30 days or less were included.

INTERVENTIONS

We implemented a phlebotomy volume display in the intake and output section of the EMR along with a calculated maximal phlebotomy volume display based on 3% of patient total blood volume as a reference.

MEASUREMENTS AND MAIN RESULTS

Providers poorly estimated phlebotomy volume regardless of role, practice setting, or years in practice. Only 12% of providers reported the availability of laboratory sampling volume. After implementation of the phlebotomy display, there was a reduction in mean laboratories drawn per patient per day from 9.5 to 2.5 ( p = 0.005) and single electrolytes draw per patient over the CICU stay from 6.1 to 1.6 ( p = 0.016). After implementation of the reference display, mean phlebotomy volume per patient over the CICU stay decreased from 30.9 to 14.4 mL ( p = 0.038). Blood transfusion volume did not decrease. CICU length of stay, intubation time, number of reintubations, and infections rates did not increase. Nearly all CICU personnel supported the use of the display. The financial cost of laboratory studies per patient has a downward trend and decreased for hemoglobin studies and electrolytes per patient after the intervention.

CONCLUSIONS

Providers may not readily have access to phlebotomy volume requirements for laboratories, and most estimate phlebotomy volumes inaccurately. A well-designed phlebotomy display in the EMR can reduce laboratory sampling and associated costs in the pediatric CICU without an increase in adverse patient outcomes.

Risk of Inappropriately Timed Live Vaccination After Pediatric Cardiovascular Surgery

OBJECTIVE

The American Academy of Pediatrics (AAP), Advisory Committee on Immunization Practices (ACIP), and Centers for Disease Control and Prevention (CDC) recommend delaying live vaccinations up to 11 months after transfusions of certain blood products due to the risk of immunoglobulins decreasing immunization efficacy. Because vaccination schedules recommend live immunizations at 12 months, infants aged 5 to 12 months who undergo cardiac surgery requiring blood products are potentially at risk for improper vaccination. The objective of this study was to identify the risk of inappropriately timed live vaccination in pediatric patients after cardiovascular surgery.

METHODS

This single-center, retrospective chart review included 345 patients 5 to 12 months of age who underwent cardiovascular surgery between January 1, 2010, and December 31, 2016. Included patients received packed red blood cells (PRBCs) and/or platelets during the surgical admission and a live vaccine within the first 18 months of life. The primary endpoint was the incidence of live vaccine administration within 7 months of receiving PRBCs and/or platelets.

RESULTS

Of the 345 included patients, 67% (n = 230) were inappropriately vaccinated after receiving platelets and/or PRBCs during cardiac surgery.

CONCLUSIONS

Infants who undergo cardiac surgery between the ages of 5 and 12 months are at risk for inappropriate live vaccination timing. A clinically significant percentage of pediatric patients who received blood products during a cardiac surgical admission later received live vaccines at times that were inconsistent with AAP, ACIP, and CDC recommendations. Future interventions aimed at educating providers and patients may be warranted.

Risk Assessment of Red Cell Transfusion in Congenital Heart Disease

Background  The storage time of packed red blood cells (pRBC) is an indicator of change in the product's pH, potassium, and lactate levels. Blood–gas analysis is a readily available bedside tool on every intensive care ward to measure these factors prior to application, thus facilitating a calculated decision on a transfusion's quantity and duration.

Our first goal is to assess the impact of storage time on pH, potassium, and lactate levels in pRBC. The influence of those parameters in the transfused children will then be evaluated.

Methods  In this retrospective study, we conducted blood–gas analyses of pRBC units before they were administered over 4 hours to neonates, infants, and children in our pediatric cardiac intensive care ward. All patients underwent regular blood–gas analyses themselves, before and after transfusion.

Results  We observed a highly significant correlation between the storage time of pRBC units and a drop in pH, as well as an increase in potassium and lactate of stored red cells ( p < 0.0001). Median age of recipients with a complete blood–gas dataset was 0.1 (interquartile range [IQR] = 0.0–0.7) years; median pRBC storage duration was 6 (IQR = 5–8) days. Further analyses showed no statistically significant effect on children's blood gases within 4 hours after transfusion, even after stratifying for pRBC storage time ≤7 days and >7 days.

Conclusion  Stored red blood cells show a rapid decrease in pH and increase in potassium and lactate. Slow transfusion of these units had no adverse effects on the recipients' pH, potassium, and lactate levels.

A Surgeon's Perspective on Blood Conservation Practice in Pediatric Cardiac Surgery

Blood conservation practice in pediatric cardiac surgery has not been consistently adopted as quality improvement in many centers despite known risks associated with allogeneic blood products, shortage of donors, and costs. There are many blood conservation strategies available which collectively minimize exposure to allogeneic transfusion by maximizing the use of autologous red cells. These strategies are safe, reproducible, and have been implemented in clinical practice collectively with great efficacy for all patient ages and complexity levels. Institutional commitment to a set guideline will improve their blood conservation practice and quality outcome. The purpose of this article is to provide early career and practicing congenital cardiac surgeons with practical information concerning blood conservation strategies which can be considered for implementation in any pediatric cardiac surgery program, and which may be of particular value in resource-limited programs.

Incidence of and risk factors for perioperative blood transfusion in infants undergoing index pediatric surgery procedures

BACKGROUND

There is a paucity of data on the frequency of transfusion during pediatric surgery index cases and guidelines for pretransfusion testing, defined as type and screen and crossmatch testing, prior to operation are not standardized. This study aimed to determine the incidence of perioperative blood transfusions during index neonatal operations and identify risk factors associated with perioperative blood transfusion to determine which patients benefit from pretransfusion testing.

METHODS

A retrospective review of infants who underwent index neonatal cases between 2013 and 2019 was performed. Data were collected for patients who underwent operations for Hirschsprung's disease, esophageal atresia/tracheoesophageal fistula (EA/TEF), biliary atresia, anorectal malformation, omphalocele, gastroschisis, duodenal atresia, congenital diaphragmatic hernia (non-ECMO) or pulmonary lobectomy. Infants under 6 months were included except in the case of lobectomy where infants up to 12 months were included.

RESULTS

Analysis was performed on 420 patients. Twenty-five (6.0%) patients received perioperative blood transfusion. Patients who received perioperative transfusion most commonly underwent EA/TEF repair. Patients who received perioperative transfusion had higher rates of structural heart disease (52.0% vs 17.7%, p<0.001), preoperative transfusion (48.0% vs 8.9%, p<0.001), and prematurity (52.0% vs 25.6%, p = 0.005). Presence of all three risk factors resulted in a 48% probability of requiring perioperative transfusion.

CONCLUSIONS

Blood transfusion during the perioperative period of neonatal index operations is rare. Factors associated with increased risk of perioperative transfusion include prematurity, structural heart disease, and history of previous blood transfusion.

LEVEL OF EVIDENCE

III.

Evaluating the Impact of Cardiopulmonary Bypass Priming Fluids on Bleeding After Pediatric Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

Cardiopulmonary bypass (CPB) predisposes young children to coagulopathy. The authors evaluated possible effects of CPB priming fluids on perioperative bleeding in pediatric cardiac surgery.

DESIGN

Meta-analysis and systematic review of previously published studies.

SETTING

Each study was conducted in a surgical center or intensive care unit.

PARTICIPANTS

Studies investigating patients <18 years without underlying hematologic disorders were included.

INTERVENTIONS

The authors evaluated randomized controlled trials (RCTs) published between 1980 and 2020 on MEDLINE, EMBASE, PubMed, and CENTRAL databases. The primary outcome was postoperative bleeding; secondary endpoints included blood product transfusion, mortality, and safety.

MEASUREMENTS AND MAIN RESULTS

Twenty eligible RCTs were analyzed, with a total of 1,550 patients and a median of 66 patients per study (range 20-200). The most frequently assessed intervention was adding fresh frozen plasma (FFP) to the prime (8/20), followed by albumin (5/20), artificial colloids (5/20), and blood-based priming solutions (3/20). Ten studies with 771 patients evaluated blood loss at 24 hours in mL/kg and were included in a meta-analysis. Most of them investigated the addition of FFP to the priming fluid (7/10). No significant difference was found between intervention and control groups, with a mean difference of -0.13 (-2.61 to 2.34), p = 0.92, I² = 69%. Further study endpoints were described but their reporting was too heterogeneous to be quantitatively analyzed.

CONCLUSIONS

This systematic review of current evidence did not show an effect of different CPB priming solutions on 24-hour blood loss. The analysis was limited by heterogeneity within the dataset regarding population, type of intervention, dosing, and the chosen comparator, compromising any conclusions.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Anemia after Pediatric Congenital Heart Surgery

The postoperative course of infants following congenital heart surgery is associated with significant blood loss and anemia. Optimal transfusion thresholds for cardiac surgery patients while in pediatric intensive care unit (PICU) remain a subject of debate. The goal of this study is to describe the epidemiology of anemia and the transfusion practices during the PICU stay of infants undergoing congenital heart surgery. A retrospective cohort study was performed in a PICU of a tertiary university-affiliated center. Infants undergoing surgery for congenital heart disease (CDH) before 6 weeks of age between February 2013 and June 2019 and who were subsequently admitted to the PICU were included. We identified 119 eligible patients. Mean age at surgery was 11 ± 7 days. Most common cardiac diagnoses were d-Transposition of the Great Arteries (55%), coarctation of the aorta (12.6%), and tetralogy of Fallot (11.8%). Mean hemoglobin level was 14.3 g/dL prior to surgery versus 12.1 g/dL at the PICU admission. Hemoglobin prior to surgery was systematically higher than hemoglobin at the PICU entry, except in infants with Hypoplastic Left Heart Syndrome. The average hemoglobin at PICU discharge was 11.7 ± 1.9 g/dL. Thirty-three (27.7%) patients were anemic at PICU discharge. Fifty-eight percent of patients received at least one red blood cell (RBC) transfusion during PICU stay. This study is the first to describe the epidemiology of anemia at PICU discharge in infants following cardiac surgery. Blood management of this distinctive and vulnerable population requires further investigation as anemia is a known risk factor for adverse neurodevelopment delays in otherwise healthy young children.

Postoperative Hematocrit and Adverse Outcomes in Pediatric Cardiac Surgery Patients: A Cross-Sectional Study From the Society of Thoracic Surgeons and Congenital Cardiac Anesthesia Society Database Collaboration

BACKGROUND

We sought to examine potential associations between pediatric postcardiac surgical hematocrit values and postoperative complications or mortality.

METHODS

A retrospective, cross-sectional study from the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) and Congenital Cardiac Anesthesia Society Database Module (2014-2019) was completed. Multivariable logistic regression models, adjusting for covariates in the STS-CHSD mortality risk model, were used to assess the relationship between postoperative hematocrit and the primary outcomes of operative mortality or any major complication. Hematocrit was assessed as a continuous variable using linear splines to account for nonlinear relationships with outcomes. Operations after which the oxygen saturation is typically observed to be <92% were classified as cyanotic and ≥92% as acyanotic.

RESULTS

In total, 27,462 index operations were included, with 4909 (17.9%) being cyanotic and 22,553 (82.1%) acyanotic. For cyanotic patients, each 5% incremental increase in hematocrit over 42% was associated with a 1.31-fold (95% confidence interval [CI], 1.10-1.55; P = .003) increase in the odds of operative mortality and a 1.22-fold (95% CI, 1.10-1.36; P < .001) increase in the odds of a major complication. For acyanotic patients, each 5% incremental increase in hematocrit >38% was associated with a 1.45-fold (95% CI, 1.28-1.65; P < .001) increase in the odds of operative mortality and a 1.21-fold (95% CI, 1.14-1.29; P < .001) increase in the odds of a major complication.

CONCLUSIONS

High hematocrit on arrival to the intensive care unit (ICU) is associated with increased operative mortality and major complications in pediatric patients following cardiac surgery.

Transfusion-Associated Hyperkalemic Cardiac Arrest in Neonatal, Infant, and Pediatric Patients

Red blood cell (RBC) transfusions are a life-saving intervention, with nearly 14 million RBC units transfused in the United States each year. However, the safety and efficacy of this procedure can be influenced by variations in the collection, processing, and administration of RBCs. Procedures or manipulations that increase potassium (K⁺) levels in stored blood products can also predispose patients to hyperkalemia and transfusion-associated hyperkalemic cardiac arrest (TAHCA). In this mini review, we aimed to provide a brief overview of blood storage, the red cell storage lesion, and variables that increase extracellular [K⁺]. We also summarize cases of TAHCA and identify potential mitigation strategies. Hyperkalemia and cardiac arrhythmias can occur in pediatric patients when RBCs are transfused quickly, delivered directly to the heart without time for electrolyte equilibration, or accumulate extracellular K⁺ due to storage time or irradiation. Advances in blood banking have improved the availability and quality of RBCs, yet, some patient populations are sensitive to transfusion-associated hyperkalemia. Future research studies should further investigate potential mitigation strategies to reduce the risk of TAHCA, which may include using fresh RBCs, reducing storage time after irradiation, transfusing at slower rates, implementing manipulations that wash or remove excess extracellular K⁺, and implementing restrictive transfusion strategies.

Transfusion Strategies for Pediatric Cardiac Surgery: A Meta-Analysis and Trial Sequential Analysis

This study aimed to compare the effects of restrictive and liberal red blood cell (RBC) transfusion strategies on pediatric patients undergoing cardiac surgery, including cyanotic and non-cyanotic children. A literature search of the MEDLINE, EMBASE, PubMed, and the Cochrane Library database was conducted. Meta-analyses were carried out comparing restrictive and liberal transfusion strategies. Subgroup analyses were performed based on the basis of cyanotic status. Five randomized controlled trials with a total of 497 children were included. There was no significant difference in the risk of in-hospital mortality between the two transfusion strategies (risk ratio 1.21; 95% confidence interval 0.49 to 2.99; P = 0.68). The trial sequential analysis suggested that the current meta-analysis had an absence of evidence for in-hospital mortality, and the data were insufficient. Moreover, no significant differences existed between groups in terms of risk of infection, blood loss, duration of mechanical ventilation, pediatric intensive care unit (PICU) stay duration, or hospital stay duration. Cyanotic children treated with a liberal transfusion strategy had a shorter ventilator duration, but the transfusion strategy did not affect in-hospital mortality, infection, hospital stay, or PICU stay duration. On the basis of the available data, our analysis indicates that a liberal transfusion strategy did not lead to a better outcomes, but the data are extremely sparse, which highlights the need for clearer transfusion guidelines specific to this specific population.Trial registration number CRD42018102283.

Preoperative Hemoglobin Level, Oxygen Saturation and Postoperative Outcomes in Children With Cyanotic Congenital Heart Disease: A Propensity-Score Matching Analysis

BACKGROUND

The optimal preoperative hemoglobin (Hb) level is difficult to define in children with cyanotic congenital heart disease (CHD) due to hypoxemia-induced secondary erythrocytosis. This retrospective study integrated preoperative Hb and pulse oxygen saturation (SpO₂) using the product of Hb × SpO₂ to predict postoperative outcomes in children with cyanotic CHD.

PATIENTS AND METHODS

Children aged <18 years undergoing cardiac surgery with cyanotic CHD were included. The cutoff value of Hb × SpO₂ was the age-adjusted lower limit of normal Hb (aaHb) in healthy children. The main outcomes were in-hospital death and the composite outcome of severe postoperative events. Multivariate logistic regression analysis and propensity score matching analysis were used to adjust for important confounders.

RESULTS

The presence of preoperative Hb × SpO₂ < aaHb was observed in 21.6% of cyanotic children (n = 777). Children with Hb × SpO₂ < aaHb had higher in-hospital mortality (12.5% vs. 4.6%, P < 0.001) and composite outcome incidence (69.6% vs. 32.3%, P < 0.001) than those with Hb × SpO₂ ≥ aaHb. After propensity score matching, 141 pairs of children were successfully matched. Multivariate analysis showed that preoperative Hb × SpO₂ < aaHb was significantly associated with the composite outcome in the entire population (odds ratio = 4.092, 95% confidence interval = 2.748-6.095, P < 0.001) and the matched cohorts (odds ratio = 2.277, 95% confidence interval = 1.366-3.795, P = 0.002).

CONCLUSION

Our results suggest that a preoperative Hb × SpO₂ value below the lower limit of normal hemoglobin is a prognostic factor in cyanotic children undergoing cardiac surgery and is a potential criterion to evaluate preoperative anemia in this population.

Outcomes of cardiac surgery in Jehovah's Witness patients: A review

Objective:

To review current literature evidence on outcomes of cardiac surgery in Jehovah’s Witness patients.

Methods:

A comprehensive electronic literature search was done from 2010 to 20th August 2020 identifying articles that discussed optimisation/outcomes of cardiac surgery in Jehovah’s Witness either as a solo cohort or as comparative to non-Jehovah’s Witnesses. No limit was placed on place of publication and the evidence has been summarised in a narrative manner within the manuscript.

Results:

The outcomes of cardiac surgery in Jehovah’s Witness patients has been described, and also compared, to non-Witness patients within a number of case reports, case series and comparative cohort studies. Many of these studies note no significant differences between outcomes of the two groups for a number of variables, including mortality. Pre-, intra and post-operative optimisation of the patients by a multidisciplinary team is important to achieve good outcomes.

Conclusion:

The use of a bloodless protocol for Jehovah’s Witnesses does not appear to significantly impact upon clinical outcomes when compared to non-Witness patients, and it has even been suggested that a bloodless approach could provide advantages to all patients undergoing cardiac surgery. Larger cohorts and research across multiple centres into the long term outcomes of these patients is required.

Intermediate monocytes exhibit higher levels of TLR2, TLR4 and CD64 early after congenital heart surgery

INTRODUCTION

Congenital heart surgery with cardiopulmonary bypass (CPB) initiates an immune response which frequently leads to organ dysfunction and a systemic inflammatory response. Complications associated with exacerbated immune responses may severely impact the postoperative recovery. The objective was to describe the characteristics of monocyte subpopulations and neutrophils at the level of pattern recognition receptors (PRR) and the cytokine response after CPB in infants.

METHODS

An observational cohort study was conducted between June 2016 and June 2017 of infants < 2 years of age, electively admitted for surgical correction of acyanotic congenital heart defects using CPB. Fourteen blood samples were collected sequentially and processed immediately during and up to 48 h following cardiac surgery for each patient. Flow cytometry analysis comprised monocytic and granulocytic surface expression of CD14, CD16, CD64, TLR2, TLR4 and Dectin-1 (CLEC7A). Monocyte subpopulations were further defined as classical (CD14⁺⁺/CD16^-), intermediate (CD14⁺⁺/CD16⁺) and nonclassical (CD14⁺/CD16⁺⁺) monocytes. Plasma concentrations of 14 cytokines, including G-CSF, GM-CSF, IL-1β, IL-1RA, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, TNF-α, IFN-γ, MIP-1β (CCL4) and TGF-β1, were measured using multiplex immunoassay for seven points in time.

RESULTS

Samples from 21 infants (median age 7.4 months) were analyzed by flow cytometry and from 11 infants, cytokine concentrations were measured. Classical and intermediate monocytes showed first receptor upregulation with an increase in CD64 expression four hours post CPB. CD64-expression on intermediate monocytes almost tripled 48 h post CPB (p < 0.0001). TLR4 was only increased on intermediate monocytes, occurring 12 h post CPB (p = 0.0406) along with elevated TLR2 levels (p = 0.0002). TLR4 expression on intermediate monocytes correlated with vasoactive-inotropic score (r_s = 0.642, p = 0.0017), duration of ventilation (r_s = 0.485, p = 0.0259), highest serum creatinine (r_s = 0.547, p = 0.0102), postsurgical transfusion (total volume per kg bodyweight) (r_s = 0.469, p = 0.0321) and lowest mean arterial pressure (r_s = -0.530, p = 0.0135). Concentrations of IL-10, MIP-1β, IL-8, G-CSF and IL-6 increased one hour post CPB. Methylprednisolone administration in six patients had no significant influence on the studied surface receptors but led to lower IL-8 and higher IL-10 plasma concentrations.

CONCLUSIONS

Congenital heart surgery with CPB induces a systemic inflammatory process including cytokine response and changes in PRR expression. Intermediate monocytes feature specific inflammatory characteristics in the 48 h after pediatric CPB and TLR4 correlates with poorer clinical course, which might provide a potential diagnostic or even therapeutic target.

Red Blood Cell Transfusion After Stage I Palliation Is Associated With Worse Clinical Outcomes

Background Packed red blood cell transfusion may improve oxygen content in single-ventricle neonates, but its effect on clinical outcomes after Stage 1 palliation is unknown. Methods and Results Retrospective multicenter analysis of packed red blood cell transfusion exposures in neonates after Stage 1 palliation, excluding those with intraoperative mortality or need for extracorporeal membrane oxygenation. Transfusion practice variability was assessed, and multivariable regression used to identify transfusion risk factors. After propensity score adjustment for severity of illness, clinical outcomes were compared between transfused and nontransfused subjects. Of 396 subjects, 323 (82%) received 930 postoperative red blood cell transfusions. Packed red blood cell volume (median 9-42 mL/kg [P<0.0001]), donor exposures (1-2 [P<0.0001]), transfusion number (1-3 [P<0.0001]), and pretransfusion hemoglobin (12.1-13 g/dL, P=0.0049) varied between sites. Cyanosis (P=0.02), chest tube output (P=0.0003), and delayed sternal closure (P=0.0033) increased transfusion risk. Transfusion was associated with prolonged mechanical ventilation (6 [interquartile range 4, 12] versus 3 [1, 5] days, P=0.02) and intensive care unit stay (19 [12, 33] versus 9 [6, 19] days, P=0.016). When stratified by number of transfusions (0, 1, or >1), duration of mechanical ventilation (3 [1, 5] versus 4 [3, 6] versus 9 [5, 16] days [P<0.0001]) and intensive care unit stay (9 [6, 19] versus 13 [8, 25] versus 21 [13, 38] days [P<0.0001]) increased for those transfused more than once. Most subjects who died were transfused, though the association with mortality was not significant. Conclusions Packed red blood cell transfusion after Stage 1 palliation is common, and transfusion practice is variable. Transfusion is a significant predictor of longer intensive care unit stay and mechanical ventilation. Further studies to define evidence-based transfusion thresholds are warranted.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

Red blood cell transfusion threshold after pediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Restrictive red blood cell transfusion strategy is implemented to minimize risk following allogeneic blood transfusion in adult cardiac surgery. However, it is still unclear if it can be applied to pediatric cardiac patients. The purpose of this systematic review and meta-analysis was to determine the effect of postoperative restrictive transfusion thresholds on clinical outcomes based on up-to-date results of randomized controlled trials (RCTs) and observational studies in pediatric cardiac surgery.

METHOD

We searched for RCTs and observational studies in the following databases: the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and ClinicalTrials.gov from their inception to October 26, 2017. We also searched reference lists of published guidelines, reviews, and relevant articles, as well as conference proceedings. No language restrictions were applied and no observational study met the inclusion criteria.

RESULTS

Four RCTs on cardiac surgery involving 454 patients were included. There were no differences in the pooled fixed effects of intensive care unit (ICU) stay between the liberal and restrictive transfusion thresholds (standardized mean difference SMD, 0.007; 95% confidence interval CI, -0.18-0.19; P = .94). There were also no differences in the length of hospital stay (SMD, -0.062; 95% CI, -0.28-0.15; P = .57), ventilation duration (SMD, -0.015; 95% CI, -0.25-0.22; P = .90), mean arterial lactate level (SMD, 0.071; 95% CI, -0.22-0.36; P = .63), and mortality (risk ratio, 0.49; 95% CI, 0.13-1.94; P = .31). There was no inter-trial heterogeneity for any pooled analysis. Publication bias was tested using Egger, Begg, or the trim-and-fill test, and the results indicated no significant publication bias.

CONCLUSION

Evidence from RCTs in pediatric cardiac surgery, though limited, showed non-inferiority of restrictive thresholds over liberal thresholds in length of ICU stay and other outcomes following red blood cell transfusion. Further high-quality RCTs are necessary to confirm the findings.

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.

Recommendations on RBC Transfusion in Infants and Children With Acquired and Congenital Heart Disease From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with acquired and congenital heart disease developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of 38 international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

Experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations and research priorities for RBC transfusions in critically ill children. The cardiac disease subgroup included three experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA appropriateness method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Twenty-one recommendations were developed and reached agreement. For children with myocardial dysfunction and/or pulmonary hypertension, there is no evidence that transfusion greater than hemoglobin of 10 g/dL is beneficial. For children with uncorrected heart disease, we recommended maintaining hemoglobin greater than 7-9.0 g/dL depending upon their cardiopulmonary reserve. For stable children undergoing biventricular repairs, we recommend not transfusing if the hemoglobin is greater than 7.0 g/dL. For infants undergoing staged palliative procedures with stable hemodynamics, we recommend avoiding transfusions solely based upon hemoglobin, if hemoglobin is greater than 9.0 g/dL. We recommend intraoperative and postoperative blood conservation measures. There are insufficient data supporting shorter storage duration RBCs. The risks and benefits of RBC transfusions in children with cardiac disease requires further study.

CONCLUSIONS

We present RBC transfusion management recommendations for the critically ill child with cardiac disease. Clinical recommendations emphasize relevant hemoglobin thresholds, and research recommendations emphasize need for further understanding of physiologic and hemoglobin thresholds and alternatives to RBC transfusion in subpopulations lacking pediatric literature.

Influence of factor XIII activity on post-operative transfusion in congenital cardiac surgery-A retrospective analysis

Objectives

Coagulation factor XIII (FXIII) plays a key role in fibrin clot stabilization—an essential process for wound healing following cardiothoracic surgery. However, FXIII deficiency as a risk for post-operative bleeding in pediatric cardiac surgery involving cardiopulmonary bypass (CPB) for congenital heart disease (CHD) is controversially discussed. Thus, as primary outcome measures, we analyzed the association of pre-operative FXIII activity and post-operative chest tube drainage (CTD) loss with transfusion requirements post-operatively. Secondary outcomes included the influence of cyanosis and sex on transfusion.

Methods

Our retrospective analysis (2009–2010) encompassed a single center series of 76 cardio-surgical cases with CPB (0–17 years, mean age 5.61 years) that were post-operatively admitted to our pediatric intensive care unit (PICU). The observational period was 48 hours after cardiac surgery. Blood cell counts and coagulation status, including FXIII activity were routinely performed pre- and post-operatively. The administered amount of blood products and volume expanders was recorded electronically, along with the amount of CTD loss. Uni- and multivariate logistic regression analysis was performed to calculate the associations (odds ratios) of variables with post-operative transfusion needs.

Results

FXIII activities remained stable following CPB surgery. There was no association of pre- and post-operative FXIII activities and transfusion of blood products or volume expanders in the first 48 hours after surgery. Similarly, FXIII showed no association with CTD loss. Cyanosis and female sex were associated with transfusion rates.

Conclusions

Although essentially involved in wound healing and clotting after surgery, FXIII activity does not serve as a valid predictor of post-operative transfusion need.

Indications for red cell transfusions in pediatric patients

Red cell transfusions are amongst the most common therapeutic procedures in seriously ill children, particularly in the inpatient setting. This is despite the fact that there is no evidence base for most clinical settings, with the exception of patients with hemoglobinopathies, particularly thalassemia and sickle cell anemia. Obviously exsanguinating hemorrhage and life threatening anemia are urgent indications for which no other therapeutic approach is currently available. Most transfusions are, however, given prophylactically to prevent the complications of hypoxia or hemodynamic stability, based upon expert opinion and a faith in the oxygen carrying capacity and beneficial hemodynamic properties of transfused red cells. The question confronting current day pediatric practice is to what extent transfused red cells prevent adverse events, other than in thalassemia and sickle cell anemia, as opposed to causing them. Do transfusions of red cells prevent organ failure, stroke, etc. or not? There is epidemiologic evidence in the adult randomized trial literature that liberal red cell transfusion likely causes more such adverse events than it prevents. The relevance of such studies to children, particularly neonates, is uncertain. Randomized trials in critically ill neonates have yielded little to no evidence that liberal red cell transfusion is beneficial, but the data are not definitive. In critically ill older children the data suggest there is no benefit to liberal red cell transfusion, but the indications for red cell transfusion are uncertain. Most practitioners would agree that combining laboratory data such hemoglobin/hematocrit with clinical indications for transfusions (evidence of end organ hypoxia such as tachycardia, shortness of breath, etc.) is the only viable strategy at present, until more definitive randomized trial data are available.

Hemoglobin Levels Across the Pediatric Critical Care Spectrum: A Point Prevalence Study

OBJECTIVES

To determine the prevailing hemoglobin levels in PICU patients, and any potential correlates.

DESIGN

Post hoc analysis of prospective multicenter observational data.

SETTINGS

Fifty-nine PICUs in seven countries.

PATIENTS

PICU patients on four specific days in 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients' hemoglobin and other clinical and institutional data. Two thousand three hundred eighty-nine patients with median age of 1.9 years (interquartile range, 0.3-9.8 yr), weight 11.5 kg (interquartile range, 5.4-29.6 kg), and preceding PICU stay of 4.0 days (interquartile range, 1.0-13.0 d). Their median hemoglobin was 11.0 g/dL (interquartile range, 9.6-12.5 g/dL). The prevalence of transfusion in the 24 hours preceding data collection was 14.2%. Neonates had the highest hemoglobin at 13.1 g/dL (interquartile range, 11.2-15.0 g/dL) compared with other age groups (p < 0.001). The percentage of 31.3 of the patients had hemoglobin of greater than or equal to 12 g/dL, and 1.1% had hemoglobin of less than 7 g/dL. Blacks had lower median hemoglobin (10.5; interquartile range, 9.3-12.1 g/dL) compared with whites (median, 11.1; interquartile range, 9.0-12.6; p < 0.001). Patients in Spain and Portugal had the highest median hemoglobin (11.4; interquartile range, 10.0-12.6) compared with other regions outside of the United States (p < 0.001), and the highest proportion (31.3%) of transfused patients compared with all regions (p < 0.001). Patients in cardiac PICUs had higher median hemoglobin than those in mixed PICUs or noncardiac PICUs (12.3, 11.0, and 10.6 g/dL, respectively; p < 0.001). Cyanotic heart disease patients had the highest median hemoglobin (12.6 g/dL; interquartile range, 11.1-14.5). Multivariable regression analysis within diagnosis groups revealed that hemoglobin levels were significantly associated with the geographic location and history of complex cardiac disease in most of the models. In children with cancer, none of the variables tested correlated with patients' hemoglobin levels.

CONCLUSIONS

Patients' hemoglobin levels correlated with demographics like age, race, geographic location, and cardiac disease, but none found in cancer patients. Future investigations should account for the effects of these variables.

Plasma levels of alarmin HNPs 1-3 associate with lung dysfunction after cardiac surgery in children

Background

Early onset of lung injury is considerable common after cardiac surgery and is associated with increasing in morbidity and mortality, but current clinical predictors for the occurrence of this complication always have limited positive warning value. This study aimed to evaluate whether elevated plasma levels of human neutrophil peptides (HNPs) 1–3 herald impaired lung function in infants and young children after cardiac surgery necessitating cardiopulmonary bypass (CPB).

Methods

Consecutive children younger than 3 years old who underwent cardiac surgery were prospectively enrolled. Plasma concentrations of HNPs 1–3 and inflammatory cytokines were measured before, and immediately after CPB, as well as at 1 h, 12 h, and 24 h after CPB.

Results

Thirty patients were enrolled, 18 (60%) of whom were infants. Plasma levels of HNPs 1–3 and the pro-inflammatory cytokine interleukin-6 (IL-6) significantly increased immediately after CPB (P < 0.001), while IL-8 increased 1 h after the CPB operation (P = 0.002). The anti-inflammatory cytokine IL-10 levels were also significantly elevated immediately after CPB compared with the baseline (P < 0.001). The stepwise multiple linear regression analysis showed that the plasma HNPs 1–3 levels immediately after CPB was independent correlated with the declined lung function, as reflected by the PaO₂/FiO₂ ratio on the first 2 days after operation (for the first day: OR, −1.067, 95% CI, −0.548 to −1.574; P < 0.001; for the second day: OR, −0.667, 95% CI, −0.183 to −1.148; P = 0.009) and prolonged mechanical ventilation time (OR, 0.039, 95% CI, 0.005 to 0.056; P = 0.011). Plasma levels of HNPs 1–3 and IL-10 returned to the baseline values, while IL-6 and IL-8 levels remained significantly higher than baseline 24 h after CPB (P ≤ 0.01).

Conclusions

Elevated HNPs 1–3 levels immediately after CPB correlate with impaired lung function, and HNPs 1–3 could serve as a quantifiable early alarmin biomarker for onset of lung injury in infants and young children undergoing cardiac surgery with CPB.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0558-4) contains supplementary material, which is available to authorized users.

Comprehensive blood conservation program in a new congenital cardiac surgical program allows bloodless surgery for the Jehovah Witness and a reduction for all patients

BACKGROUND

Cardiac surgery on Jehovah's Witnesses (JW) can be challenging, given the desire to avoid blood products. Establishment of a blood conservation program involving the pre-, intra- and post-operative stages for all patients may lead to a minimized need for blood transfusion in all patients.

METHODS

Pre-operatively, all JW patients were treated with high dose erythropoietin 500 IU/kg twice a week. JW patients were compared to matching non-JW patients from the congenital cardiac database, two per JW to serve as control. Blood use, ventilation time, bypass time, pre-operative hematocrit, first in intensive care unit (ICU) and at discharge and 24 hour chest drainage were compared. Pre-operative huddle, operating room huddle and post-operative bedside handoff were done with the congenital cardiac surgeon, perfusionist, anesthesiologist and intensive care team in all patients for goal alignment.

RESULTS

Five JW patients (mean weight 24.4 ± 25.0 Kg, range 6.3 - 60 Kg) were compared to 10 non-JW patients (weight 22.0 ± 22.8 Kg, range 6.2 - 67.8 Kg). There was no difference in bypass, cross-clamp, time to extubation (0.8 vs. 2.1 hours), peak inotrope score (2.0 vs. 2.3) or chest drainage. No JW patient received a blood product compared to 40% of non-JW. The pre-operative hematocrit (Hct) was statistically greater for the JW patients (46.1 ± 3.3% vs. 36.3 ± 4.7%, p<0.001) and both ICU and discharge Hct were higher for the JW (37 ± 1.8% vs 32.4 ± 8.0% and 41 ± 8.1% vs 34.8 ± 7.9%), but did not reach statistical significance. All patients had similar blood draws during the hospitalization (JW x 18 mL/admission vs non-JW 20 mL/admission).

CONCLUSION

The continuous application and development of blood conservation techniques across the continuum of care allowed bloodless surgery for JW and non-JW patients alike. Blood conservation is a team sport and to make significant strides requires participation and input by all care providers.

Hemoglobin Level at Stage 1 Discharge has No Impact on Inter-stage Growth and Stability in Single Ventricle Infants

Hemoglobin levels (Hgb) of infants with a single ventricle (SV) are traditionally maintained high to maximize oxygen-carrying capacity during stage 1 palliation (S1P), stage 2 palliation (S2P), and between stages (IS). A single-center observational cohort study was performed to determine if red blood cell transfusion during the convalescent phase of the S1P (late S1P transfusion) to achieve higher Hgb is associated with benefits during the IS including improved growth and decreased acute medical events. 137 infants <1 year with SV with SIP undergoing care from January 2008 to June 2015 were retrospectively evaluated. 78 (57%) infants received a late S1P transfusion. Median Hgb at S1P discharge was 15.9 g/dL (IQR 14.7-17.1) and median Hgb S2P at admission was 15.3 g/dL (IQR 14-16.3). Median daily weight gain was 22 g/day during IS (IQR 17-26) and median daily length gain was 0.09 cm (IQR 0.06-0.11). Hgb at SIP discharge was not associated with IS growth or fewer IS acute events. However, late S1P transfusions were associated with illness severity at S1P and more complicated S1P care. Our data suggest that SV infants after S1P, who are steadily recovering, do not benefit from late transfusion to raise their hemoglobin level at discharge.

Blood conservation pediatric cardiac surgery in all ages and complexity levels

AIM

To demonstrate the feasibility of blood conservation methods and practice across all ages and risk categories in congenital cardiac surgery.

METHODS

We retrospectively analyzed a collected database of 356 patients who underwent cardiac surgery using cardiopulmonary bypass (CPB) from 2010-2015. The patients were grouped into blood conservation (n = 138) and non-conservation (n = 218) groups and sub-grouped based on their ages and procedural complexity scores.

RESULTS

There were no statistical differences in gender, weight, pre-operative and pre-CPB hematocrit levels in both groups. Despite equivalent hematocrit levels during and after CPB for both groups, there was significantly less operative homologous blood utilized in blood conservation group across all ages and complexity levels.

CONCLUSION

Blood conservation surgery can be performed in congenital patients needing cardiac surgery in all age groups and complexity categories. The above findings in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products justify blood conservation in congenital cardiac surgery.

Strategies for blood conservation in pediatric cardiac surgery

Cardiac surgery accounts for the majority of blood transfusions in a hospital. Blood transfusion has been associated with complications and major adverse events after cardiac surgery. Compared to adults it is more difficult to avoid blood transfusion in children after cardiac surgery. This article takes into account the challenges and emphasizes on the various strategies that could be implemented, to conserve blood during pediatric cardiac surgery.

Blood derived products in pediatrics: New laboratory tools for optimizing potency assignment and reducing side effects

Neonates and children can develop rare bleeding disorders due to congenital/acquired coagulation Factor deficiencies, or allo-immune/autoimmune complications, or can undergo surgeries at high haemorrhagic risk. They then need specialized transfusion of blood components/products, or purified blood extracted products or recombinant proteins. Blood-derived therapies conventionally used for management of affected infants with genetic/acquired deficiencies, bleeding problems (coagulation Factor reduced or missing) or thrombotic disorders (reduced or missing anticoagulant proteins) pose some additional risks. These remedial therapies can cause tolerance when used very early in life and, sometimes needed, repeatedly. The introduction of recombinant proteins has allowed manufacturers to produce large amounts of the proteins usually present at very low concentration in blood. This has also changed the risk pattern of plasma-extracted products, especially in terms of continual reduction of viral transmission. Many efforts have been made over these past decades to reduce the risks associated with the use of all these products in terms of viral and bacterial safety, as well as immune disorders but they are not the objective of this article. Other associated side effects are the presence of undesired activities in blood products, which can produce thrombotic events or adverse reactions. The progressive introduction of blood derived products has greatly improved the prognosis and quality of life of affected patients. This concerns whole blood, but also blood cell concentrates, mainly platelets and red blood cells, plasma, while the blood extracted products are increasingly replaced by recombinant proteins. All these therapeutic products, i.e. blood extracted drugs, improve health and quality of life for hemophiliac's A or B, or patients with auto/allo-immune thrombocytopenias or with rare bleeding disorders, and those with thrombotic events occurring in childhood, which are mainly due to Protein C or Protein S deficiencies (congenital or acquired). Progress in analytical methods and biotechnology allow better control of the manufacturing processes for all blood derived or plasma extracted products and recombinant proteins, and contribute to improved manufacturing processes to minimize the occurrence of side effects. These adverse events can be due to the aging of the blood cell concentrate with release of their granule content, and generation of EVs, which can produce anaphylactic reactions and risk of thrombosis, but also to the presence of activated coagulation Factors in purified products, such as Factor Xia as recently identified in immunoglobulin concentrates. Characterization and measurement of contaminant products is of special usefulness during product preparation and for optimization of manufacturing processes for purified extracted products, but also for recombinant proteins. The pharmaceutical industry introduces these new methods for validating manufacturing processes, or for quality control assessments. The objective is first to warrant the full quality and safety of the lots produced, and assure the highest efficacy with the lowest risks when used in patients. For cell concentrates and fresh blood, storage conditions are critical and measurement of analytes such as EVs or Annexin V allows evaluation of quality of each individual transfused pouch. In addition to all the rules around viral and bacterial transmission risk, and immune tolerance, our available laboratory methods contribute to reducing the side effects of blood cell concentrates and derived plasma products, as well as those of the therapeutic recombinant proteins.

Pediatric Patient Blood Management Programs: Not Just Transfusing Little Adults

Red blood cell transfusions are a common life-saving intervention for neonates and children with anemia, but transfusion decisions, indications, and doses in neonates and children are different from those of adults. Patient blood management (PBM) programs are designed to assist clinicians with appropriately transfusing patients. Although PBM programs are well recognized and appreciated in the adult setting, they are quite far from standard of care in the pediatric patient population. Adult PBM standards cannot be uniformly applied to children, and there currently is significant variation in transfusion practices. Because transfusing unnecessarily can expose children to increased risk without benefit, it is important to design PBM programs to standardize transfusion decisions. This article assesses the key elements necessary for a successful pediatric PBM program, systematically explores various possible pediatric specific blood conservation strategies and the current available literature supporting them, and outlines the gaps in the evidence suggesting need for further/improved research. Pediatric PBM programs are critically important initiatives that not only involve a cooperative effort between pediatric surgery, anesthesia, perfusion, critical care, and transfusion medicine services but also need operational support from administration, clinical leadership, finance, and the hospital information technology personnel. These programs also expand the scope for high-quality collaborative research. A key component of pediatric PBM programs is monitoring pediatric blood utilization and assessing adherence to transfusion guidelines. Data suggest that restrictive transfusion strategies should be used for neonates and children similar to adults, but further research is needed to assess the best oxygenation requirements, hemoglobin threshold, and transfusion strategy for patients with active bleeding, hemodynamic instability, unstable cardiac disease, and cyanotic cardiac disease. Perioperative blood management strategies include minimizing blood draws, restricting transfusions, intraoperative cell salvage, acute normovolemic hemodilution, antifibrinolytic agents, and using point-of-care tests to guide transfusion decisions. However, further research is needed for the use of intravenous iron, erythropoiesis-stimulating agents, and possible use of whole blood and pathogen inactivation. There are numerous areas where newly formed collaborations could be used to investigate pediatric transfusion, and these studies would provide critical data to support vital pediatric PBM programs to optimize neonatal and pediatric care.