Patient Blood Management for Neonates and Children Undergoing Cardiac Surgery: 2019 NATA Guidelines

Effects of Fibrinogen Concentrate Supplementation on Postoperative Bleeding in Infants Undergoing Complex Cardiac Surgery

The use of allogeneic blood products to restore hemostasis during pediatric cardiac surgery is associated with major risks. Consequently, there has been a growing interest in new patient blood management strategies, such as those based on the use of fibrinogen concentrate (FC). Accumulating evidence has shown FC supplementation to be safe and effective. Nevertheless, no guidelines are available on using FC in the pediatric setting, and few objective evaluations have been provided in clinical practice. The endpoint of this monocenter retrospective study was the hemostatic effect of additional FC in infants undergoing complex cardiac surgery with cardiopulmonary bypass to manage persistent clinically relevant bleeding. After weaning from cardiopulmonary bypass and after protamine administration, patients were transfused with conventional allogeneic products such as packed red blood cells, fresh frozen plasma (FFP), and platelets. In the case of redo surgery, according to the institutional protocol, patients also received tranexamic acid. In case of clinically persistent relevant bleeding, according to the anesthesiologist's judgment and thromboelastography, patients received FC supplementation (group with FC) or further FFP transfusions without receiving FC supplementation (group without FC). The primary endpoint was the hemostatic effects of FC. Secondary endpoints were the functional hypofibrinogenemia threshold value (expressed as maximum amplitude fibrinogen, MA-Fib) and postoperative MA-Fib, fibrinogenemia, intraoperative transfusions, and adverse events (AEs). In total, 139 patients who underwent cardiac surgery with CPB and aged less than 2 years were enrolled: 70 patients received allogeneic blood products and FC supplementation (group FC); 69 patients received allogeneic products without FC supplementation (group without FC). Patients that received FC supplementation were characterized by a significantly longer time of extracorporeal circulation (p < 0.001) and aortic cross-clamping (p < 0.001), a significantly lower minimum temperature (p = 0.011), increased use of concentrated prothrombin complex (p = 0.016) and tranexamic acid (p = 0.010), and a significantly higher amount of packed red blood cells, platelets (p < 0.001) and fresh frozen plasma (p = 0.03). Postoperative bleeding and severe bleeding were not statistically different between patients treated with FC and those not treated with FC supplementation (p = 0.786 and p = 0.695, respectively); after adjustment, a trend toward reduced bleeding can be observed with FC (p = 0.064). Overall, 88% of patients with severe bleeding had MA-Fib < 10 mm; a moderate association between severe bleeding and MA-Fib (odds ratio 1.7, 95% CI 0.5-6.5, p = 0.425) was found. Increased MA-Fib and postoperative fibrinogen were higher in the FC group (p = 0.003 and p < 0.001, respectively) than in FFP. AEs in the FC group were comparable to those observed in less complicated surgeries. Our results suggest a potential role of FC in complex surgery in maintaining postoperative bleeding at a level comparable to less complicated surgical procedures and favoring the increase in postoperative MA-Fib and fibrinogen.

Methodologic Quality and Pharmacotherapy Recommendations for Patient Blood Management Guidelines for Cardiac Surgery on Cardiopulmonary Bypass

Patient blood management (PBM) guidelines for patients undergoing cardiac surgery under cardiopulmonary bypass (CPB) have increased during the past decade, and pharmacotherapy plays an important role in PBM. In the face of the undefined consistency in the methodologic quality and pharmacotherapy recommendations across multiple guidelines, this study exclusively evaluated methodologies of the related guideline development process, and compiled medication recommendations of PBM for cardiac surgery patients. PBM guidelines for cardiac surgery under CPB were searched through some mainstream literature and guideline databases from database establishment to May 15, 2023. Nine guidelines meeting inclusion criteria were included in this study. The quality of the guidelines was evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool. "Stakeholder involvement" received the lowest mean score of 49.38% in the AGREE II scoring among the guidelines. PBM for cardiac surgery patients spans the perioperative phase. Drug therapy strategies of PBM for cardiac surgery patients involve anemia therapy, perioperative administration of antithrombotic drugs, intraoperative anticoagulation, and the use of hemostatic drugs. Unlike for adults, there is less evidence about the management of antithrombotic drugs and hemostatic drugs for pediatric cardiac surgery patients. Recombinant activated factor VII (rFVIIa) and desmopressin (DDAVP) are not recommended after pediatric cardiac surgery, whereas prothrombin complex concentrate could be considered in clinical trials. As for the controversies regarding the administration of rFVIIa and DDAVP after adult cardiac surgery by different societies, clinicians should exercise their clinical judgment based on individual patient features.

A single-center, retrospective analysis to compare measurement of fibrinogen using the TEG6 analyzer to the Clauss measurement in children undergoing heart surgery

BACKGROUND

Newer generation viscoelastic tests, TEG6s, offer point-of-care hemostatic therapy in adult patients. However, their efficacy in estimating fibrinogen levels in pediatric patients undergoing cardiac surgery is not well established.

AIMS

This study evaluates TEG6s for estimating fibrinogen levels in pediatric cardiac surgery patients and its predictive capability for post-bypass hypofibrinogenemia.

METHODS

A single-center, retrospective study on pediatric patients (under 18 years) who underwent cardiac surgery with cardiopulmonary bypass from August 2020 and November 2022. Blood samples for estimated whole blood functional fibrinogen level via TEG6s (Haemonetics Inc.) and concurrent laboratory-measured plasma fibrinogen via von Clauss assay were collected at pre- and post-cardiopulmonary bypass.

RESULTS

Paired data for TEG6s estimated functional fibrinogen levels and plasma fibrinogen were analyzed for 432 pediatric patients pre-bypass. It was observed that functional fibrinogen consistently overestimated plasma fibrinogen across all age groups with a mean difference of 138 mg/dL (95% confidence interval [CI]: 128-149 mg/dL). This positive bias in the pre-bypass data was confirmed by Bland-Altman analysis. Post-bypass, functional fibrinogen estimates were comparable to plasma fibrinogen in all patient groups with a mean difference of -6 mg/dL (95% CI: -20-8 mg/dL) except for neonates, where functional fibrinogen levels underestimated plasma fibrinogen with a mean difference of -38 mg/dL (95% CI: -64 to -12 mg/dL). The predictive accuracy of functional fibrinogen for detecting post-bypass hypofibrinogenemia (plasma fibrinogen ≤250 mg/dL) demonstrated overall fair accuracy in all patients, indicated by an area under the curve of 0.73 (95% CI: 0.65-0.80) and good accuracy among infants, with an area under the curve of 0.80 (95% CI: 0.70-0.90). Similar performance was observed in predicting critical post-bypass hypofibrinogenemia (plasma fibrinogen ≤200 mg/dL). Based on these analyses, optimal cutoffs for predicting post-bypass hypofibrinogenemia were established as a functional fibrinogen level ≤270 mg/dL and MAFF ≤15 mm.

CONCLUSION

This study demonstrates that whole blood functional fibrinogen, as estimated by TEG6s, tends to overestimate baseline plasma fibrinogen levels in pediatric age groups but aligns more accurately post-cardiopulmonary bypass, particularly in neonates and infants, suggesting its potential as a point-of-care tool in pediatric cardiac surgery. However, the variability in TEG6s performance before and after bypass highlights the need for careful interpretation of its results in clinical decision-making. Despite its contributions to understanding TEG6s in pediatric cardiac surgery, the study's design and inherent biases warrant cautious application of these findings in clinical settings.

Prophylactic Transfusion Strategies in Children Supported by Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding prophylactic transfusions in neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed use of prophylactic blood product transfusion in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Thirty-three references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for prophylactic transfusion strategies for children supported with ECMO. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. We developed two good practice statements, 4 weak recommendations, and three expert consensus statements.

CONCLUSIONS

Despite the frequency with which pediatric ECMO patients are transfused, there is insufficient evidence to formulate evidence-based prophylactic transfusion strategies.

Transfusion targets and adverse events in pediatric perioperative acute Anemia

STUDY OBJECTIVE

To evaluate the association between pretransfusion and posttransfusion hemoglobin concentrations and the outcomes of children undergoing noncardiac surgery.

DESIGN

Retrospective review of patient records. We focused on initial postoperative hemoglobin concentrations, which may provide a more useful representation of transfusion adequacy than pretransfusion hemoglobin triggers (the latter often cannot be obtained during acute surgical hemorrhage).

SETTING

Single-center, observational cohort study.

PATIENTS

We evaluated all pediatric patients undergoing noncardiac surgery who received intraoperative red blood cell transfusions from January 1, 2008, through December 31, 2018.

INTERVENTIONS

None.

MEASUREMENTS

Associations between pre- and posttransfusion hemoglobin concentrations (g/dL), hospital-free days, intensive care unit admission, postoperative mechanical ventilation, and infectious complications were evaluated with multivariable regression modeling.

MAIN RESULTS

In total, 113,713 unique noncardiac surgical procedures in pediatric patients were evaluated, and 741 procedures met inclusion criteria (median [range] age, 7 [1-14] years). Four hundred ninety-eight patients (68%) with a known preoperative hemoglobin level had anemia; of these, 14% had a preexisting diagnosis of anemia in their health record. Median (IQR) pretransfusion hemoglobin concentration was 8.1 (7.4-9.2) g/dL and median (IQR) initial postoperative hemoglobin concentration was 10.4 (9.3-11.6) g/dL. Each decrease of 1 g/dL in the initial postoperative hemoglobin concentration was associated with increased odds of transfusion within the first 24 postoperative hours (odds ratio [95% CI], 1.62 [1.37-1.93]; P < .001). No significant relationships were observed between postoperative hemoglobin concentrations and hospital-free days (P = .56), intensive care unit admission (P = .71), postoperative mechanical ventilation (P = .63), or infectious complications (P = .74).

CONCLUSIONS

In transfused patients, there was no association between postoperative hemoglobin values and clinical outcomes, except the need for subsequent transfusion. Most transfused patients presented to the operating room with anemia, which suggests a potential opportunity for perioperative optimization of health before surgery.

Encouraging results of blood conservation in neonatal open-heart surgery

OBJECTIVE

To report early outcomes of blood conservation in neonatal open-heart surgery.

METHODS

Ninety-nine patients undergoing neonatal open-heart surgery during the implementation of a blood conservation program between May 2021 and February 2023 were reviewed. Patients either received traditional blood management (blood prime, n = 43) or received blood conservation strategies (clear prime, n = 56). Baseline characteristics and outcomes were compared between groups.

RESULTS

There was no difference in body weight (median, 3.2 kg vs 3.3 kg; P = .83), age at surgery (median, 5 days vs 5 days; P = .37), distribution of The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories categories or duration of cardiopulmonary bypass. Patients in the clear prime group had higher preoperative hematocrit (median, 41% vs 38%; P < .01), shorter postoperative mechanical ventilation time (median, 48 hours vs 92 hours; P = .02) and postoperative intensive care unit length of stay (median, 6 days vs 9 days; P < .01) than patients in the blood prime group. Fourteen patients (25%) in the clear prime group, including 1 Norwood patient, were discharged without any transfusion. Among patients within the clear prime group, hospitalizations without blood exposure were associated with higher preoperative hematocrit (median, 43% vs 40%; P = .02), shorter postoperative mechanical ventilation times (median, 22 hours vs 66 hours; P = .01) and shorter postoperative hospital stays (median, 10 days vs 15 days; P = .02).

CONCLUSIONS

Bloodless surgery is possible in a significant proportion of neonates undergoing open-heart surgery, including the Norwood operation, even in the early stages of experience. Early clinical results are favorable but long-term follow-up and continued efforts are warranted to prove safety and reproducibility.

Approach to red blood cell transfusions in post-operative congenital heart disease surgery patients: when to stop?

BACKGROUND

The best transfusion approach for CHD surgery is controversial. Studies suggest two strategies: liberal (haemoglobin ≤ 9.5 g/dL) and restrictive (waiting for transfusion until haemoglobin ≤ 7.0 g/dL if the patient is stable). Here we compare liberal and restrictive transfusion in post-operative CHD patients in a cardiac intensive care unit.

METHODS

Retrospective analysis was conducted on CHD patients who received liberal transfusion (2019-2021, n=53) and restrictive transfusion (2021-2022, n=43).

RESULTS

The two groups were similar in terms of age, gender, Paediatric Risk of Mortality-3 score, Paediatric Logistic Organ Dysfunction-2 score, Risk Adjustment for Congenital Heart Surgery-1 score, cardiopulmonary bypass time, vasoactive inotropic score, total fluid balance, mechanical ventilation duration, length of cardiac intensive care unit stay, and mortality. The liberal transfusion group had a higher pre-operative haemoglobin level than the restrictive group (p < 0.05), with no differences in pre-operative anaemia. Regarding the minimum and maximum post-operative haemoglobin levels during a cardiac intensive care unit stay, the liberal group had higher haemoglobin levels in both cases (p<0.01 and p=0.019, respectively). The number of red blood cell transfusions received by the liberal group was higher than that of the restrictive group (p < 0.001). There were no differences between the two groups regarding lactate levels at the time of and after red blood cell transfusion. The incidence of bleeding, re-operation, acute kidney injury, dialysis, sepsis, and systemic inflammatory response syndrome was similar.

CONCLUSIONS

Restrictive transfusion may be preferable over liberal transfusion. Achieving similar outcomes with restrictive transfusions may provide promising evidence for future studies.

Retrospective Comparison of Recombinant Activated Factor VII Versus 4-Factor Prothrombin Complex Concentrate in Cardiac Surgical Patients

OBJECTIVES

To compare the incidences of postoperative thrombotic complications, transfusion of blood products, and chest tube output in congenital cardiac surgical patients who received either recombinant activated factor VII (rFVIIa) or 4-factor prothrombin complex concentrate (4F-PCC).

DESIGN

We performed a retrospective study.

SETTING

Patients who underwent surgery at a tertiary academic hospital.

PARTICIPANTS

Pediatric patients who underwent cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data were obtained from the Society of Thoracic Surgeons and the Pediatric Cardiac Critical Care Consortium databases, as well as from manual chart review. Adjusted p values were obtained from multivariate regression using age (days), surgeon (number), cardiopulmonary bypass time (minutes), and need for deep hypothermic circulatory arrest (yes/no). A total of 55 patients were included in the 4F-PCC group, and 89 in the rFVIIa group. The median dose of rFVIIa was 77 mcg/kg (46-88), and the median dose of 4F-PCC was 31 IU/kg (24-43). The incidences of thrombotic complications were 8% in the 4F-PCC group and 30% in the rFVIIa group (adjusted p = 0.023). No difference was reported between the groups regarding chest tube output on days 1 and 2 or transfusion of blood products. Using a sensitivity analysis with propensity matching, the incidence of thrombosis was 10% in the 4F-PCC group (n = 38), and 31% in the rFVIIa group (n = 39) (p = 0.036). No difference was reported in terms of bleeding or transfusion.

CONCLUSIONS

This retrospective study suggested that the administration of rFVIIa was associated with a higher risk of thrombotic complications when compared to 4F-PCC, without benefits in terms of bleeding and transfusions.

Blood Product Transfusions for Children in the Perioperative Period and for Critically Ill Children

BACKGROUND

Approximately 1% to 2% of all hospitalized children receive a transfusion of blood products, in Germany as in other countries. High-quality scientific evidence on transfusions in children is scarce. The available evidence is discussed in this review.

METHODS

This review is based on publications on blood product transfusions in children that were retrieved by a literature search, including clinical studies, international guideline recommendations, the recommendations of the German cross-sectional guideline, and results of other recent, relevant publications.

RESULTS

A restrictive transfusion strategy is recommended for all children, including those who are critically ill. Randomized controlled trials have shown that a restrictive strategy for erythrocyte concentrate transfusion in the intensive care unit is safe for children, including neonates. No robust data are available to enable the definition of a suitable threshold for the intraoperative administration of red blood cell concentrates in children undergoing extracardiac surgery. On the basis of studies from pediatric intensive care units, transfusions for hemodynamically stable children with a hemoglobin concentration of more than 7 g/dL are recommended only in exceptional cases. Therapeutic plasma is not recommended as volume replacement, except in massive transfusion. Platelet concentrate transfusions are indicated in case of active hemorrhage, and only rarely for prophylaxis.

CONCLUSION

There is a broad lack of evidence from randomized controlled trials concerning the indications for transfusions in children. A restrictive transfusion strategy, which has been found safe in the intensive-care setting, is favored by the guidelines in the perioperative setting as well. Further studies are needed to evaluate transfusion triggers and indications for all types of blood products, especially therapeutic plasma. Until more evidence is available, physicians should be aware of what the current evidence supports, and blood products should be given restrictively, and not prophylactically.

Long-Term Safety Analysis of a Fibrinogen Concentrate (RiaSTAP®/Haemocomplettan® P)

Fibrinogen concentrate treatment is recommended for acute bleeding episodes in adult and pediatric patients with congenital and acquired fibrinogen deficiency. Previous studies have reported a low risk of thromboembolic events (TEEs) with fibrinogen concentrate use; however, the post-treatment TEE risk remains a concern. A retrospective evaluation of RiaSTAP®/Haemocomplettan® P (CSL Behring, Marburg, Germany) post-marketing data was performed (January 1986-June 2022), complemented by a literature review of published studies. Approximately 7.45 million grams of fibrinogen concentrate was administered during the review period. Adverse drug reactions (ADRs) were reported in 337 patients, and 81 (24.0%) of these patients experienced possible TEEs, including 14/81 (17.3%) who experienced fatal outcomes. Risk factors and the administration of other coagulation products existed in most cases, providing alternative explanations. The literature review identified 52 high-ranking studies with fibrinogen concentrate across various clinical areas, including 26 randomized controlled trials. Overall, a higher number of comparative studies showed lower rates of ADRs and/or TEEs in the fibrinogen group versus the comparison group(s) compared with those that reported higher rates or no differences between groups. Post-marketing data and clinical studies demonstrate a low rate of ADRs, including TEEs, with fibrinogen concentrate treatment. These findings suggest a favorable safety profile of fibrinogen concentrate, placing it among the first-line treatments effective for managing intraoperative hemostatic bleeding.

Patient Blood Management in Neonates

Patient blood management (PBM) is an evidence-based care package to improve patient outcomes by optimizing a patient's blood, minimizing blood loss, and the effective management and, when appropriate, the tolerance of anemia. It is relatively well-developed in adult medicine and remains in its infancy in neonatology. This review explores why evidence-based guidelines are insufficient, discusses the variations in neonatal transfusion practice and why this matters, and provides the key updates in neonatal transfusion practice. The authors give examples of a successful neonatal PBM program and single-center projects.

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.

Effect of hemoglobin and oxygen saturation on adverse outcomes in children with tetralogy of fallot: a retrospective observational study

BACKGROUND

Tetralogy of Fallot (TOF) is a common cyanotic congenital heart malformation that carries a high risk of right-to-left shunting. Anemia is characterized by decreased hemoglobin (Hb) levels that can affect tissue oxygen delivery and impact postoperative recovery in patients. Chronic hypoxia caused by right-to-left shunting of TOF could lead to compensatory increases in Hb to maintain systemic oxygen balance. This study aims to investigate whether preoperative Hb and blood oxygen saturation (SpO2) can predict adverse outcomes in children undergoing corrective surgery for TOF.

METHODS

This retrospective study included patients under 18 years of age who underwent corrective surgery for TOF at Fuwai Hospital between January 2016 and December 2018. Adverse outcomes, including in-hospital death, extracorporeal membrane oxygenation implantation, ICU stay > 30 days, and severe complications, were considered as the primary outcome. Univariable and multivariable logistic analyses were performed to identify independent risk factors for adverse outcomes. Propensity score-matched (PSM) analysis was also conducted to minimize the confounding factors.

RESULTS

A total of 596 children were included in the study, of which 64 (10.7%) experienced adverse outcomes. Hb*SpO2 < aaHb was identified as an independent risk factor for adverse outcomes (OR = 2.241, 95% CI = 1.276-3.934, P = 0.005) after univariable and multivariable logistic analyses. PSM analysis further confirmed the association between Hb*SpO2 < aaHb and adverse outcomes. Patients with Hb*SpO2 < aaHb had a significantly higher incidence of postoperative adverse outcomes, longer time of mechanical ventilation, and hospital stay, as well as higher in-hospital costs.

CONCLUSIONS

Hb*SpO2 < aaHb is significantly associated with adverse outcomes in children undergoing corrective surgery for TOF. Clinicians can use this parameter to early identify high-risk children and optimize their postoperative management.

Diagnostic Agreement Between TEG5000 and TEG6S in the Assessment of Hemostasis in Pediatric Cardiac Surgery: A Prospective Non-inferiority Study

Thromboelastography (TEG) is a point-of-care test (POCT) used to analyze the hemostatic properties of whole blood. TEG® 5000and TEG® 6s (Haemonetics Corp, USA) measure the same parameters describing clot viscoelasticity using different methodologies. The purpose of this study was to evaluate agreement between TEG5000 and TEG6s measurements. We analyzed prospectively collected tests resulting from paired blood samples in cardiac surgery pediatric patients at one hour (T0) and 24 h (T1) postoperatively. Each citrated sample was utilized for TEG® 5000 and TEG ®6s. Six specific TEG parameters were analyzed and compared: R kaolin time (RK), R kaolin heparinase (RKH) time, K kaolin time (KK), K kaolin heparinase time KH (KKH), Maximum Amplitude kaolin (MAK), Maximal Amplitude Kaolin Heparinase (MAKH). We enrolled 30 patients. Median (interquartile range) patients' age was 206 (20-597) days. All surgical patients underwent correction except 5 who were palliated. At T0, RK and RKH showed an average (standard deviation) % bias of 15.8 (31) and 16.1 (28), respectively, with similar results at T1. A % bias of -6 (23) and - 6 [15] in MAK was found at T0 and T1, respectively. Similarly, MAKH % bias was 1.5 (22) and 7.6 (29) at T0 and T1, respectively. At both timepoints, low % biases (< ± 6%) were demonstrated in KK and KKH. All parameters showed improved coagulation from T0 to T1, but without significant interaction between type of device and time. Analysis of the entire pool of 60 paired samples showed no agreement in diagnostic performance (within the range vs. outside the range) in 12 (20%), 5 (9.8%), 1 (1.7%), 4 (7.8%), 9 (15%), and 5 (9.8%) cases for RK, RKH, MAK, MAKH, KK and KKH, respectively. We observed substantial agreement in MAK and KK in a cohort of pediatric patients undergoing uncomplicated cardiac surgery. Our findings suggest that TEG®5000 and TEG®6s are interchangeable for assessing these parameters.

Viscoelastic testing: Critical appraisal of new methodologies and current literature

United States Food and Drug Administration (FDA)-approved viscoelastic testing (VET) methodologies have significantly changed in the last 10 years, with the availability of cartridge-based VET. Some of these cartridge-based methodologies use harmonic resonance-based clot detection. While VET has always allowed for the evaluation of real-time clot formation, cartridge-based VET provides increased ease of use as well as greater portability and robustness of results in out-of-laboratory environments. Here we review the use of VET in a variety of clinical contexts, including cardiac surgery, trauma, liver transplant, obstetrics, and hypercoagulable states such as COVID-19. As of now, high quality randomized trial evidence for new generation VET (TEG 6s, HemoSonics Quantra, ROTEM sigma) is limited. Nevertheless, the use of VET-guided transfusion algorithms appears to result in reduced blood usage without worsening of patient outcomes. Future work comparing the new generation VET instruments and continuing to validate clinically important cut-offs will help move the field of point-of-care coagulation monitoring forward and increase the quality of transfusion management in bleeding patients.

Tranexamic Acid Use in Pediatric Craniotomies at a Large Tertiary Care Pediatric Hospital: A Five Year Retrospective Study

Tranexamic acid (TXA), a synthetic antifibrinolytic drug, has proven efficacy and is recommended for major pediatric surgery to decrease perioperative blood loss. Accumulating evidence suggests that TXA reduces bleeding and transfusion in a variety of adult neurosurgical settings. However, there is a paucity of research regarding TXA indications for pediatric neurosurgery and thus, there are currently no recommendations for its use with this specific population. The objective of this study is to evaluate the existing practice of TXA administration for pediatric neurosurgery at a U.S. tertiary care pediatric hospital over a five-year period. The authors conclude that TXA administration is feasible and should be considered for pediatric neurosurgical cases where potential blood loss is a concern.

Plasma-Free Strategy for Cardiac Surgery with Cardiopulmonary Bypass in Infants < 10 kg: A Retrospective, Propensity-Matched Study

BACKGROUND

Infants < 10 kg undergoing cardiac surgery with cardiopulmonary bypass (CPB) may receive either fresh frozen plasma (FFP) or other solutions in the CPB priming volume. The existing comparative studies are controversial. No study addressed the possibility of total avoidance of FFP throughout the whole perioperative course in this patient population. This retrospective, non-inferiority, propensity-matched study investigates an FFP-free strategy compared to an FFP-based strategy.

METHODS

Among patients <10 kg with available viscoelastic measurements, 18 patients who received a total FFP-free strategy were compared to 27 patients (1:1.5 propensity matching) receiving an FFP-based strategy. The primary endpoint was chest drain blood loss in the first 24 postoperative hours. The level of non-inferiority was settled at a difference of 5 mL/kg.

RESULTS

The 24-h chest drain blood loss difference between groups was -7.7 mL (95% confidence interval -20.8 to 5.3) in favor of the FFP-based group, and the non-inferiority hypothesis was rejected. The main difference in coagulation profile was a lower level of fibrinogen concentration and FIBTEM maximum clot firmness in the FFP-free group immediately after protamine, at the admission in the ICU and for 48 postoperative hours. No differences in transfusion of red blood cells or platelet concentrate were observed; patients in the FFP-free group did not receive FFP but required a larger dose of fibrinogen concentrate and prothrombin complex concentrate.

CONCLUSIONS

An FFP-free strategy in infants < 10 kg operated with CPB is technically feasible but results in an early post-CPB coagulopathy that was not completely compensated with our bleeding management protocol.

Current hemoglobin thresholds in pediatric anesthesia - guidelines and studies

PURPOSE OF REVIEW

The use of restrictive transfusion triggers to avoid unnecessary transfusions is one important pillar of Patient Blood Management (PBM). For the safe application of this principle in pediatric patients, anesthesiologists need evidence-based guidelines for hemoglobin (Hb) transfusions thresholds in this specially vulnerable age-group.

RECENT FINDINGS

This review outlines recent prospective and observational studies examining transfusion thresholds in pediatrics. Recommendations to use transfusion triggers in the perioperative or intensive care setting are summarized.

SUMMARY

Two high-quality studies confirmed that the use of restrictive transfusion triggers in preterm infants in the intensive care unit (ICU) is reasonable and feasible. Unfortunately, no recent prospective study could be found investigating intraoperative transfusion triggers. Some observational studies showed wide variability in Hb levels before transfusion, a tendency toward restrictive transfusion practices in preterm infants, and liberal transfusion practices in older infants. Although there are comprehensive and useful guidelines for clinical practice in pediatric transfusion, most of them do not cover the intraoperative period in particular because of a lack of high-quality studies. This lack of prospective randomized trials focusing on intraoperative transfusion management remains a major problem for the application of pediatric PBM.

Association Between Plasma Fibrinogen Concentration After Cardiopulmonary Bypass and Postoperative Blood Loss in Children Undergoing Cardiac Surgery: A Retrospective Cohort Study

Background Intraoperative hypofibrinogenemia is a major factor associated with increased postoperative blood loss in adult cardiac surgery. However, previous pediatric studies on this topic did not sufficiently adjust for potential confounders and variations in surgeons' techniques. Therefore, evidence for the association between hypofibrinogenemia and postoperative blood loss after cardiac surgery in children remains insufficient. In this study, we aimed to evaluate the association between postoperative blood loss and hypofibrinogenemia by adjusting for potential confounders and the effects of differences in surgeons' techniques. Methodology This single-center, retrospective, cohort study included children who underwent cardiac surgery with cardiopulmonary bypass from April 2019 to March 2022. Multilevel logistic regression models with mixed effects were used to evaluate the association of major blood loss in the first six hours postoperatively with fibrinogen concentration at the end of cardiopulmonary bypass. The difference in the surgeon's techniques was adjusted as a random effect for the model. The model included potential confounders identified as risk factors in previous studies. Results A total of 401 patients were included. A fibrinogen concentration ≤150 mg/dL (adjusted odds ratio (aOR) = 2.08; 95% confidence interval (CI) = 1.18-3.67; p = 0.011) and the presence of cyanotic disease (aOR = 2.34; 95% CI = 1.10-4.97; p = 0.027) were associated with major blood loss in the first six postoperative hours. Conclusions A fibrinogen concentration ≤150 mg/dL and the presence of cyanotic disease were associated with postoperative blood loss in pediatric cardiac surgery. Maintaining a fibrinogen concentration >150 mg/dL is recommended, especially for patients with cyanotic diseases.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Patient Blood Management in adults and children: what have we achieved, and what still needs to be addressed?

An overview of Patient Blood Management (PBM), with its main scope to preserve the patient's own blood to improve the patient's outcome, is presented here, including the research gaps that needs to be addressed, particularly in the pediatric age group. Next, novel techniques to analyse PBM data and the challenges and strategies of PBM implementation will also be discussed.

Patient blood management in critically ill children undergoing cardiac surgery: A cohort study

OBJECTIVE

The objective of this study was to audit current patient blood management practice in children throughout cardiac surgery and paediatric intensive care unit (PICU) admission.

DESIGN

This was a prospective observational cohort study.

SETTING

This was a single-centre study in the cardiac operating room (OR) and PICU in a major tertiary children's hospital in Australia.

PATIENTS

Children undergoing corrective cardiac surgery and requiring admission to PICU for postoperative recovery were included in the study.

MEASUREMENTS AND MAIN RESULTS

Fifty-six patients and 1779 blood sampling episodes were audited over a 7-month period. The median age was 9 months (interquartile range [IQR] = 1-102), with the majority (n = 30 [54%]) younger than 12 months. The median number of blood sampling episodes per patient per day was 6.6 (IQR = 5.8-8.0) in total, with a median of 5.0 (IQR = 4.0-7.5) episodes in the OR and 5.0 (IQR = 3.4-6.2) episodes per day throughout PICU admission. The most common reason for blood tests across both OR and PICU settings was arterial blood gas analysis (total median = 86%, IQR = 79-96). The overall median blood sampling volume per kg of bodyweight, patient, and day was 0.63 mL (IQR = 0.20-1.14) in total. Median blood loss for each patient was 3.5 mL/kg per patient per day (IQR = 1.7-5.6) with negligible amounts in the OR and a median of 3.6 mL/kg (IQR = 1.7-5.7) in the PICU. The median Cell Saver® transfusion volume was 9.9 mL/kg per patient per day (IQR = 4.0-19.1) in the OR. The overall median volume of other infusion products (albumin 4%, albumin 20%, packed red blood cells) received by each patient was 20.1 mL/kg (IQR = 10.7-36.4) per day. Sampling events and blood loss were positively associated with PICU stay.

CONCLUSIONS

Patient blood management practices observed in this study largely conform to National Blood Authority guidelines. Further implementation projects and research are needed to accelerate implementation of known effective blood conservation strategies within paediatric critical care environments.

Improving Patient Blood Management Programs: An Implementation Science Approach

Organized patient blood management (PBM) programs function in numerous hospitals and health systems around the world contributing to improved patient outcomes as well as increased patient engagement, decreased resource use, and reductions in health care costs. PBM "programming" ranges from the implementation of single strategies/initiatives to comprehensive programs led by dedicated clinicians and PBM committees, employing the use of multiple PBM strategies. Frontline health care professionals play an important role in leading, implementing, operationalizing, measuring, and sustaining successful PBM programs. In this article, we provide practical implementation guidance to support key clinical, administrative, leadership, and structural elements required for the safe and comprehensive delivery of care in PBM programs at the local level.

Prophylactic Use of Antifibrinolytics During Pediatric Cardiac Surgery With Cardiopulmonary Bypass on Postoperative Bleeding and Transfusion: A Systematic Review and Meta-Analysis

OBJECTIVES

To determine the effect of intraoperative antifibrinolytics, including tranexamic acid (TXA), aminocaproic acid (EACA), or aprotinin, on bleeding in children undergoing cardiac surgery with cardiopulmonary bypass (CPB).

DATA SOURCES

Relevant articles were systematically searched from Ovid MEDLINE, Ovid EMBASE, CINAHL, Cochrane Library, and Web of Science to November 15, 2021.

STUDY SELECTION

Abstracts were screened, and full texts were reviewed using predetermined inclusion and exclusion criteria using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

DATA EXTRACTION

A standardized data extraction tool was used.

DATA SYNTHESIS

Sixty-eight studies including 28,735 patients were analyzed. TXA compared with placebo resulted in a mean decrease in chest tube output of 9.1 mL/kg (95% CI, 6.0-12.3 mL/kg), I2 equals to 65.2%, p value of less than 0.001, platelet requirement of 2.9 mL/kg (95% CI, 0.1-5.8 mL/kg), I2 =72.5%, p value less than 0.001 and plasma requirement of 4.0 mL/kg (95% CI, 0.6-7.2 mL/kg), I2 equals to 94.5%, p value less than0.001. Aprotinin compared with placebo resulted in a mean decrease in chest tube output of 4.3 mL/kg (2.4-6.2 mL/kg), I2 equals to 66.3%, p value of less than 0.001, platelet transfusion of 4.6 mL/kg (95% CI, 0.6-8.6 mL/kg), I2 equals to 93.6%, p value of less than 0.001, and plasma transfusion of 7.7 mL/kg (95% CI, 2.1-13.2 mL/kg), I2 equals to 95.3%, p value of less than 0.001. EACA compared with placebo resulted in a mean decrease in chest tube output of 9.2 mL/kg (2.3-21.0 mL/kg), I2 equals to 96.4%, p value of less than 0.001, RBC transfusion of 7.2 mL/kg (95% CI, 2.4-12.1 mL/kg), I2 equals to 94.5%, p value equals to 0.002, and platelet transfusion of 10.7 mL/kg (95% CI, 2.9-18.5 mL/kg), I2 equals to 0%, p value of less than 0.001. No statistical difference was observed in chest tube output when TXA was compared with aprotinin. Subgroup analysis of cyanotic patients showed a significant decrease in chest tube output, platelet requirement, and plasma requirement for patients receiving aprotinin. Overall, the quality of evidence was moderate.

CONCLUSIONS

Antifibrinolytics are effective at decreasing blood loss and blood product requirement in children undergoing cardiac surgery with CPB although the quality of evidence is only moderate.

Perioperative Pediatric Erythrocyte Transfusions: Incorporating Hemoglobin Thresholds and Physiologic Parameters in Decision-making

This article presents current literature and scientific evidence on hemoglobin thresholds and physiologic parameters to guide decisions regarding perioperative erythrocyte transfusions in pediatric patients based on the most up-to-date studies and expert consensus recommendations.

Use of Fresh-frozen Plasma in Newborn Infants

Nearly 10% of premature and critically ill infants receive fresh-frozen plasma (FFP) transfusions to reduce their high risk of bleeding. The authors have only limited data to identify relevant clinical predictors of bleeding and to evaluate the efficacy of FFP administration. There is still no consensus on the optimal use of FFP in infants who have abnormal coagulation parameters but are not having active bleeding. The aims of this review are to present current evidence derived from clinical studies focused on the use of FFP in neonatology and then use these data to propose best practice recommendations for the safety of neonates receiving FFP.

Transfusion therapy of neonatal and paediatric patients: They are not just little adults

Patient blood management (PBM) strategies are needed in the neonate and paediatric population, given that haemoglobin thresholds used are often higher than recommended by evidence, with exposure of children to potential complications without meaningful benefit. A literature review was performed on the following topics: evidence-based transfusions of blood components and pharmaceutical agents. Other topics reviewed included perioperative coagulation assessment and perioperative PBM. The Transfusion and Anaemia Expertise Initiative (TAXI) consortium published a consensus statement addressing haemoglobin (Hb) transfusion threshold in multiple subsets of patients. A multicentre trial (PlaNeT-2) reported a higher risk of bleeding and death or serious new bleeding among infants who received platelet transfusion at a higher (50 000/μl) compared to a lower (25 000/μl) threshold. Recent data support the use of a restrictive transfusion threshold of 25 000/μl for prophylactic platelet transfusions in preterm neonates. The TAXI-CAB consortium mentioned that in critically ill paediatric patients undergoing invasive procedures outside of the operating room, platelet transfusion might be considered when the platelet count is less than or equal to 20 000/μl and there is no benefit of platelet transfusion when the platelet count is more than 50 000/μl. There are limited controlled studies in paediatric and neonatal population regarding plasma transfusion. Blood conservation strategies to minimise allogenic blood exposure are essential to positive patient outcomes neonatal and paediatric transfusion practices have changed significantly in recent years since randomised controlled trials were published to guide practice. Additional studies are needed in order to provide practice change recommendations.

The Limits of Acute Anemia

For many years, physicians’ approach to the transfusion of allogeneic red blood cells (RBC) was not individualized. It was accepted that a hemoglobin concentration (Hb) of less than 10 g/dL was a general transfusion threshold and the majority of patients were transfused immediately. In recent years, there has been increasing evidence that even significantly lower hemoglobin concentrations can be survived in the short term without sequelae. This somehow contradicts the observation that moderate or mild anemia is associated with relevant long-term morbidity and mortality. To resolve this apparent contradiction, it must be recognized that we have to avoid acute anemia or treat it by alternative methods. The aim of this article is to describe the physiological limits of acute anemia, match these considerations with clinical realities, and then present “patient blood management” (PBM) as the therapeutic concept that can prevent both anemia and unnecessary transfusion of RBC concentrates in a clinical context, especially in Intensive Care Units (ICU). This treatment concept may prove to be the key to high-quality patient care in the ICU setting in the future.

Transfusion Strategies for Hemostatic Blood Products in Critically Ill Children: A Narrative Review and Update on Expert Consensus Guidelines

Critically ill children commonly receive coagulant products (plasma and/or platelet transfusions) to prevent or treat hemorrhage or correct coagulopathy. Unique aspects of pediatric developmental physiology, and the complex pathophysiology of critical illness must be considered and balanced against known transfusion risks. Transfusion practices vary greatly within and across institutions, and high-quality evidence is needed to support transfusion decision-making. We present recent recommendations and expert consensus statements to direct clinicians in the decision to transfuse or not to transfuse hemostatic blood products, including plasma, platelets, cryoprecipitate, and recombinant products to critically ill children.

Update on Applications and Limitations of Perioperative Tranexamic Acid

Tranexamic acid (TXA) is a potent antifibrinolytic with documented efficacy in reducing blood loss and allogeneic red blood cell transfusion in several clinical settings. With a growing emphasis on patient blood management, TXA has become an integral aspect of perioperative blood conservation strategies. While clinical applications of TXA in the perioperative period are expanding, routine use in select clinical scenarios should be supported by evidence for efficacy. Furthermore, questions regarding optimal dosing without increased risk of adverse events such as thrombosis or seizures should be answered. Therefore, ongoing investigations into TXA utilization in cardiac surgery, obstetrics, acute trauma, orthopedic surgery, neurosurgery, pediatric surgery, and other perioperative settings continue. The aim of this review is to provide an update on the current applications and limitations of TXA use in the perioperative period.

Viscoelastic Testing in Pediatric Mechanical Circulatory Support

Pediatric mechanical circulatory support can be lifesaving. However, managing anticoagulation is one of the most challenging aspects of care in patients requiring mechanical circulatory support. Effective anticoagulation is even more difficult in pediatric patients due to the smaller size of their blood vessels, increased turbulent flow, and developmental hemostasis. Recently, viscoelastic testing (VET) has been used as a qualitative measure of anticoagulation efficacy in patients receiving extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VAD). Thromboelastography (TEG®) and thromboelastometry (ROTEM®) provide a global qualitative assessment of hemostatic function from initiation of clot formation with the platelet-fibrin interaction, platelet aggregation, clot strength, and clot lysis. This review focuses on the TEG®/ROTEM® and important laboratory and patient considerations for interpretation in the ECMO and VAD population. We summarize the adult and pediatric ECMO/VAD literature regarding VET values, VET-platelet mapping, utility over standard laboratory monitoring, and association with outcome measures such as blood product utilization, bleeding, and thrombosis.

Efficacy and safety of aprotinin in paediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

The relicensing of aprotinin in Europe and Canada has stimulated discussions on its usefulness in paediatric cardiac surgery.

OBJECTIVE

To systematically evaluate the available evidence on the efficacy and safety of aprotinin in paediatric cardiac surgery.

DESIGN

Systematic review of all randomised and observational studies comparing aprotinin with tranexamic acid, epsilon aminocaproic acid, placebo or no drug in paediatric cardiac surgery. Meta-analyses were performed on efficacy and safety outcomes.

DATA SOURCES

PubMed, Cochrane Central Register of Controlled Trials, Web of Science and Embase were searched from January 2000 to March 2021.

ELIGIBILITY CRITERIA

Studies that enrolled children under 18 years undergoing cardiac surgery with cardiopulmonary bypass.

RESULTS

Thirty-two studies enrolling a total of 63 894 paediatric cardiac procedures were included. Aprotinin significantly reduced total blood loss [mean difference -4.70 ml kg-1, 95% confidence interval (CI), -7.88 to -1.53; P = 0.004], postoperative transfusion requirements and the incidence of surgical re-exploration for bleeding [odds ratio (OR) 0.74, 95% CI, 0.56 to 0.97; P = 0.03]. Aprotinin had no effects on 30-day mortality (OR 1.02, 95% CI, 0.93 to 1.11; P = 0.73) and on other safety outcomes, except for the incidence of renal replacement therapy (RRT), which was significantly increased in patients given aprotinin (OR 1.29, 95% CI, 1.08 to 1.54; P = 0.006). Findings from observational and randomised controlled trials did not largely differ. A sub-group analysis in neonates showed that aprotinin significantly reduced packed red blood cell transfusions and the incidence of postoperative surgical re-exploration for bleeding and/or tamponade. When compared with lysine analogues, aprotinin was more effective at reducing bleeding and transfusion without increasing the risk of side effects.

CONCLUSION

This meta-analysis suggests that aprotinin is effective and well tolerated in paediatric cardiac surgery. Given the large heterogeneity of the results and the risk of selection bias in observational studies, large randomised controlled trials are warranted.

Preoperative Iron Supplementation in Pediatric Cardiac Surgical Patients: A Preliminary Single-Center Experience

OBJECTIVE

To assess preoperative hemoglobin and perioperative red blood cell transfusion in children undergoing cardiac surgery after the implementation of a preoperative patient blood management (PBM) clinic with oral iron supplementation.

DESIGN

A retrospective analysis.

SETTING

A single tertiary hospital.

PARTICIPANTS

Patients who underwent cardiac surgery with cardiopulmonary bypass at the Hospital for Sick Children (Toronto, Canada) during a 12-month period before and following the implementation of a preoperative PBM clinic. Patients younger than 3 months of age, or who were admitted to the cardiac intensive care unit preoperatively, were excluded because they were not systematically assessed by the PBM clinic.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 296 patients were included in the authors' analysis. After adjustment for confounding factors (age at surgery, preoperative oxygen saturation, type of congenital heart disease, surgery type), they found that preoperative hemoglobin levels were significantly higher in children treated with iron supplementation (n = 201) compared to historic controls (n = 95) (13.9 [12.8-15.1] g/dL v 12.9 [11.7-15.0] g/dL, adjusted p = 0.001). The exposure rate to red blood cell transfusion (50% v 61%, adjusted p = 0.930) was not significantly different between groups. However, the volumes of allogeneic red blood cells (1.4 (0.0-14.0) mL/kg v 12.5 (0.0-23.0) mL/kg, adjusted p = 0.004) and autologous blood (11.0 (6.8-17.0) v 17.0 (11.0-31.0), adjusted p < 0.001) transfused were significantly reduced in children treated with iron supplementation.

CONCLUSIONS

Preoperative iron supplementation led to an increase in preoperative hemoglobin levels. The exact prevalence of iron deficiency and the effect of iron supplementation on perioperative allogeneic blood transfusion and long-term outcomes should be studied in a prospective randomized study.

Consensus Statement: Hemostasis Trial Outcomes in Cardiac Surgery and Mechanical Support

BACKGROUND

Research evaluating hemostatic agents for the treatment of clinically significant bleeding has been hampered by inconsistency and lack of standardized primary clinical trial outcomes. Clinical trials of hemostatic agents in both cardiac surgery and mechanical circulatory support, such as extracorporeal membrane oxygenation and ventricular assist devices, are examples of studies that lack implementation of universally accepted outcomes.

METHODS

A subgroup of experts convened by the National Heart, Lung, and Blood Institute and the US Department of Defense developed consensus recommendations for primary outcomes in cardiac surgery and mechanical circulatory support.

RESULTS

For cardiac surgery the primary efficacy endpoint of total allogeneic blood products (units vs mL/kg for pediatric patients) administered intraoperatively and postoperatively through day 5 or hospital discharge is recommended. For mechanical circulatory support outside the perioperative period the recommended primary outcome for extracorporeal membrane oxygenation is a 5-point ordinal score of thrombosis and bleeding severity adapted from the Common Terminology Criteria for Adverse Events version 5.0. The recommended primary endpoint for ventricular assist device is freedom from disabling stroke (Common Terminology Criteria for Adverse Events AE ≥ grade 3) through day 180.

CONCLUSIONS

The proposed composite risk scores could impact the design of upcoming clinical trials and enable comparability of future investigations. Harmonizing and disseminating global consensus definitions and management guidelines can also reduce patient heterogeneity that would confound standardized primary outcomes in future research.

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.

Optimizing fresh-frozen plasma transfusion in surgical neonates through thromboelastography: a quality improvement study

Fresh frozen plasma (FFP) is largely misused in the neonatal setting. The aim of the study is to evaluate the impact of a Thromboelastography (TEG)-based Quality Improvement (QI) project on perioperative FFP use and neonatal outcomes. Retrospective pre-post implementation study in a level-III NICU including all neonates undergoing major non-cardiac surgery before (01-12/2017) and after (01-12/2019) the intervention. In 2018, the intervention included the following: (1) Training on TEG, (2) Implementation of TEG, and (3) Algorithm for TEG-directed FFP administration in surgical neonates. We compared pre- vs post-intervention patient characteristics, hemostasis, and clinical management. Linear and logistic regression models were used to evaluate the impact of the project on main outcomes. We analyzed 139 neonates (pre-intervention: 72/post-intervention: 67) with a mean (± SD) gestational age (GA) 34.9 (± 5) weeks and birthweight 2265 (± 980) grams which were exposed to 184 surgical procedures (pre-intervention: 91/post-intervention: 93). Baseline characteristics were similar between periods. In 2019, prothrombin time (PT) was longer (14.3 vs 13.2 s; p < 0.05) and fibrinogen was lower (229 vs 265 mg/dl; p < 0.05), if compared to 2017. In 2019, the intraoperative exposure to FFP decreased (31% vs 60%, p < 0.001), while the pre-operative FFP use did not change. The reduction of intraoperative FFP did not impact on mortality and morbidity. Intraoperative FFP use was lower in the post-intervention even after controlling for GA, American Society of Anesthesiologists score, PT, and fibrinogen (Odds ratio: 0.167; 95% CI: 0.070, 0.371).   Conclusion: The TEG-based QI project for the management of FFP during neonatal surgery reduced intraoperative FFP exposure. What is Known: • PT and aPTT are poor predictors of bleeding risk in acquired neonatal coagulopathy, leading to likely unnecessary fresh frozen plasma (FFP) transfusion in the Neonatal Intensive Care Setting.  • As neonatal hemostasis is a delicate balance between the concomitant reduction of pro- and anti-coagulants drivers, thromboelastography (TEG) is a promising alternative for coagulation monitoring. What is New: • The implementation of TEG, training, and shared protocols contributed to reduced intraoperative FFP use, which was not associated with increased mortality or bleeding events. • These findings inform future research showing that there is clinical equipoise to allow for larger studies to confirm the use of TEG in NICUs and to identify TEG cut-offs for transfusion practice.

A Randomized Pilot Trial Assessing the Role of Human Fibrinogen Concentrate in Decreasing Cryoprecipitate Use and Blood Loss in Infants Undergoing Cardiopulmonary Bypass

The objective of this study was to determine whether treatment with human fibrinogen concentrate decreases the need for component blood therapy and blood loss in neonate and infant patients undergoing cardiopulmonary bypass. Pediatric patients (N = 30) undergoing elective cardiac surgery were randomized to receive human fibrinogen concentrate or placebo following cardiopulmonary bypass termination. The primary endpoint was the amount of cryoprecipitate administered. Secondary endpoints included estimated blood loss during the 24 h post-surgery; perioperative blood product transfusion; effects of fibrinogen infusion on global hemostasis, measured by laboratory testing and rotational thromboelastometry; and adverse events. No clinically significant differences were identified in baseline characteristics between groups. A significantly lower volume of cryoprecipitate was administered to the treatment group during the perioperative period [median (interquartile range) 0.0 (0.0-0.0) cc/kg vs 12.0 (8.2-14.3) cc/kg; P < 0.0001] versus placebo. No difference was observed between treatment groups in blood loss, laboratory coagulation tests, use of other blood components, or incidence of adverse events. FIBTEM amplitude of maximum clot firmness values was significantly higher among patients treated with human fibrinogen concentrate versus placebo (P ≤ 0.0001). No significant differences were observed in post-drug HEPTEM, INTEM, and EXTEM results. Human fibrinogen concentrate (70 mg/kg) administered after the termination of cardiopulmonary bypass reduced the need for transfusion with cryoprecipitate in a neonate and infant patient population.ClinicalTrials.gov identifier: NCT02822599.

Anesthetic Considerations in Pediatric Patients With Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) in pediatrics is a significant cause for morbidity and mortality in children. Congenital heart disease and cardiomyopathy are the leading etiologies of ADHF. It is common for these children to undergo diagnostic, therapeutic, or surgical procedure under anesthesia, which may be associated with significant morbidity and mortality. The importance of preanesthetic multidisciplinary planning with all involved teams, including anesthesia, cardiology, intensive care, perfusion, and cardiac surgery, cannot be emphasized enough. In order to safely manage these patients, it is imperative for the anesthesiologist to understand the complex pathophysiological interactions between cardiopulmonary systems and anesthesia during these procedures. This review discusses the etiology, pathophysiology, clinical manifestations, and perioperative management of these patients.

Red Blood Cell Transfusion

Red blood cell (RBC) transfusions are necessary to increase a patient's oxygen carrying capacity. The optimal transfusion trigger remains elusive, but a restrictive transfusion trigger of 7 g/dL has been shown in studies to reduce RBC transfusions without adversely affecting patient outcomes. Patient blood management programs have been shown effective at reducing RBC transfusions. Hemoglobin-based oxygen carriers and induced pluripotent stem cell derived RBCs are being developed to help mitigate RBC shortages and RBC transfusion limitations. Numerous challenges still exist that need to be overcome before they can have widespread clinical use.

Blood Conservation and Hemostasis Management in Pediatric Cardiac Surgery

Pediatric cardiac surgery is associated with significant perioperative blood loss needing blood product transfusion. Transfusion carries serious risks and implications on clinical outcomes in this vulnerable population. The need for transfusion is higher in children and is attributed to several factors including immaturity of the hemostatic system, hemodilution from the CPB circuit, excessive activation of the hemostatic system, and preoperative anticoagulant drugs. Other patient characteristics such as smaller relative size of the patient, higher metabolic and oxygen requirements make successful blood transfusion management extremely challenging in this population and require meticulous planning and multidisciplinary teamwork. In this narrative review we aim to summarize risks and complications associated with blood transfusion in pediatric cardiac surgery and also to summarize perioperative coagulation management and blood conservation strategies.

Perioperative blood conservation strategies for pediatric scoliosis surgery

PURPOSE

Many pediatric patients with severe scoliosis requiring surgery have baseline anemia. Pediatric scoliosis fusion surgery is associated with perioperative blood loss requiring transfusion. As such, many patients in this surgical population could benefit from a perioperative blood conservation program.

METHODS

Here we present a narrative review of perioperative blood conservation strategies for pediatric scoliosis surgery involving nurses, transfusion medicine physicians, anesthesiologists, surgeons, dieticians, perfusionists and neurophysiologists spanning the pre-, intra- and postoperative phases of care.

RESULTS

The review highlights how perioperative blood conservation strategies, have the potential to minimize exposures to exogenous blood products. Further, we describe a relevant example of blood conservation related to the care of a Jehovah's Witness patient undergoing staged scoliosis repair. Lastly, we outline areas which would benefit from clinical studies to further elucidate perioperative blood conservation interventions and their outcomes relevant to pediatric scoliosis surgery patients.

CONCLUSION

Interdisciplinary communication and meticulous blood conservation strategies are proving to be a means of reducing if not eliminating the need for allogeneic blood products for surgical correction of pediatric scoliosis.

Viscoelastic testing in pediatric patients

A tailored transfusion algorithm based on viscoelastic testing in the perioperative period or in trauma patients is recommended by guidelines for bleeding management. Bleeding management strategies in neonates and children are mostly extrapolated from the adult experience, as published evidence in the youngest age group is scarce. This manuscript is intended to give a structured overview of what has been published on the use of viscoelastic testing to guide bleeding management in neonates and children. Several devices that use either the traditional viscoelastic method or resonance viscoelastography technology are on the market. Reference ranges for children have been evaluated in only some of them. As most of the hemostasis maturation processes can be observed during the first year of life, adult reference ranges for viscoelastic testing could be applied over the age of 1 year. The majority of the published trials in children are based on retrospective analyses describing the correlation between viscoelastic testing and standard laboratory testing or focusing on the prediction of bleeding. Clinically more relevant studies in pediatric patients undergoing cardiac surgery have demonstrated that the implementation of a transfusion algorithm based on viscoelastic testing has significantly reduced transfusion requirements and that this approach has enabled a rapid detection of coagulation disorders in the presence of excessive bleeding. Although further studies are urgently needed, experts have reviewed the use of a transfusion algorithm based on viscoelastic testing in children as a feasible approach, as it has been shown to improve bleeding management and rationalize blood product transfusion.

Perioperative and Anesthetic Considerations in Tetralogy of Fallot With Pulmonary Atresia

Tetralogy of Fallot with pulmonary atresia (ToF-PA) is a rare diagnosis that includes an extraordinarily heterogeneous group of complex anatomical findings with significant implications for physiology and prognosis. In addition to the classic findings of ToF, this particular diagnosis is characterized by complete failure of forward flow from the right ventricle to the pulmonary arterial system. As such, pulmonary blood flow is entirely dependent on shunting from the systemic circulation, most frequently via a patent ductus arteriosus, major aortopulmonary collaterals, or a combination of the two. The pathophysiology of ToF-PA is largely attributable to the abnormalities of the pulmonary vasculature. Ultimately, these patients require operative intervention to create a reliable, controlled source of pulmonary blood flow and ideally complete intracardiac repair. Even after operative correction, these patients remain at risk for pulmonary arterial stenoses and pulmonary hypertension. Although there have been significant advances in surgical and interventional management of ToF-PA leading to dramatic improvements in survival and long-term functional status, there is ongoing debate about the optimal management strategy given the risk of development of irreversible abnormalities of the pulmonary vasculature and the morbidity and mortality associated with sometimes multiple, complex operative interventions often occurring early in infancy. This review will discuss the findings in patients with ToF-PA with a focus on the perioperative and anesthetic management and will highlight challenges faced by the anesthesiologist in caring for these patients.

Understanding and managing the complex balance between bleeding and thrombosis following cardiopulmonary bypass in paediatric cardiac surgical patients

Bleeding in the perioperative period of congenital heart surgery with cardiopulmonary bypass is associated with increased morbidity and mortality both from the direct effects of haemorrhage as well as the therapies deployed to restore haemostasis. Perioperative bleeding is complex and multifactorial with both patient and procedural contributions. Moreover, neonates and infants are especially at risk. The objective of this review is to summarise the evidence regarding bleeding management in paediatric surgical patients and identify strategies that might facilitate appropriate bleeding management while minimising the risk of thrombosis. We will address the use of standard and point-of-care tests, and the role of contemporary coagulation factors and other novel drugs.

Independent Risk Factors for RBC Transfusion in Children Undergoing Surgery. Analysis of 14,248 Cases at a German University Hospital

Background: paediatric patients are vulnerable to blood loss and even a small loss of blood can be associated with severe shock. In emergency situations, a red blood cell (RBC) transfusion may become unavoidable, although it is associated with various risks. The aim of this trial was to identify independent risk factors for perioperative RBC transfusion in children undergoing surgery. Methods: to identify independent risk factors for perioperative RBC transfusion in children undergoing surgery and to access RBC transfusion rates and in-hospital outcomes (e.g., length of stay, mortality, and typical postoperative complication rates), a monocentric, retrospective, and observational study was conducted. Descriptive, univariate, and multivariate analyses were performed. Results: between 1 January 2010 and 31 December 2019, data from n = 14,248 cases were identified at the centre. Analysis revealed an RBC transfusion rate of 10.1% (n = 1439) in the entire cohort. The independent predictors of RBC transfusion were the presence of preoperative anaemia (p < 0.001; OR = 15.10 with preoperative anaemia and OR = 2.40 without preoperative anaemia), younger age (p < 0.001; ORs between 0.14 and 0.28 for children older than 0 years), female gender (p = 0.036; OR = 1.19 compared to male gender), certain types of surgery (e.g., neuro surgery (p < 0.001; OR = 10.14), vascular surgery (p < 0.001; OR = 9.93), cardiac surgery (p < 0.001; OR = 4.79), gynaecology (p = 0.014; OR = 3.64), visceral surgery (p < 0.001; OR = 2.48), and the presence of postoperative complications (e.g., sepsis (p < 0.001; OR = 10.16), respiratory dysfunction (p < 0.001; OR = 7.56), cardiovascular dysfunction (p < 0.001; OR = 4.68), neurological dysfunction (p = 0.029; OR = 1.77), and renal dysfunction (p < 0.001; OR = 16.17)). Conclusion: preoperative anaemia, younger age, female gender, certain types of surgery, and postoperative complications are independent predictors for RBC transfusion in children undergoing surgery. Future prospective studies are urgently required to identify, in detail, the potential risk factors and impact of RBC transfusion in children.