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.

Factor XIII levels, clot strength, and impact of fibrinogen concentrate in infants undergoing cardiopulmonary bypass: a mechanistic sub-study of the FIBCON trial

BACKGROUND

Acquired factor XIII (FXIII) deficiency after major surgery can increase postoperative bleeding. We evaluated FXIII contribution to clot strength and the effect of fibrinogen concentrate administration on FXIII activity in infants undergoing cardiac surgery using cardiopulmonary bypass.

METHODS

We conducted a prospectively planned, mechanistic sub-study, nested within the Fibrinogen Concentrate Supplementation in the Management of Bleeding During Paediatric Cardiopulmonary Bypass: A Phase 1B/2A, Open-Label Dose Escalation Study (FIBCON) trial, which investigated fibrinogen concentrate supplementation during cardiopulmonary bypass (ISRCTN: 50553029) in 111 infants (median age 6.4 months). The relationships between platelet number, fibrinogen concentration, and FXIII activity with rotational thromboelastometry clot strength (EXTEM-MCF) in blood taken immediately before cardiopulmonary bypass and after separation from bypass were estimated using multivariable linear regression. Changes in coagulation variables over time were quantified using a generalised linear model comparing three groups: fibrinogen concentrate-supplemented infants, placebo, and a third cohort with lower bleeding risk.

RESULTS

Overall, 48% of the variability (multivariable R²) in EXTEM-MCF clot strength was explained by three factors: the largest contribution was from FXIII activity (partial R²=0.21), followed by platelet number (partial R²=0.14), and fibrinogen concentration (partial R²=0.095). During cardiopulmonary bypass, mean platelet count fell by a similar amount in the three groups (-36% to -41%; interaction P=0.98). Conversely, fibrinogen concentration increased in all three groups: 132% in the fibrinogen concentrate-supplemented group, 26% in the placebo group, and 51% in the low-risk group. A similar increase was observed for FXIII activity (61%, 23%, and 25%, respectively; interaction P<0.0001).

CONCLUSIONS

FXIII contribution to clot strength is considerable in infants undergoing cardiac surgery. Fibrinogen concentrate supplementation also increased FXIII activity, and hence clot strength.

CLINICAL TRIAL REGISTRATION

ISRCTN: 50553029.

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.

Patient Blood Management: Improving Outcomes for Millions While Saving Billions. What Is Holding It Up?

Patient blood management (PBM) offers significantly improved outcomes for almost all medical and surgical patient populations, pregnant women, and individuals with micronutrient deficiencies, anemia, or bleeding. It holds enormous financial benefits for hospitals and payers, improves performance of health care providers, and supports public authorities to improve population health. Despite this extraordinary combination of benefits, PBM has hardly been noticed in the world of health care. In response, the World Health Organization (WHO) called for its 194 member states, in its recent Policy Brief, to act quickly and decidedly to adopt national PBM policies. To further support the WHO's call to action, this article addresses 3 aspects in more detail. The first is the urgency from a health economic perspective. For many years, growth in health care spending has outpaced overall economic growth, particularly in aging societies. Due to competing economic needs, the continuation of disproportionate growth in health care spending is unsustainable. Therefore, the imperative for health care leaders and policy makers is not only to curb the current spending rate relative to the gross domestic product (GDP) but also to simultaneously improve productivity, quality, safety of patient care, and the health status of populations. Second, while PBM meets these requirements on an exceptional scale, uptake remains slow. Thus, it is vital to identify and understand the impediments to broad implementation. This includes systemic challenges such as the so-called "waste domains" of failure of care delivery caused by malfunctions of health care systems, failure of care coordination, overtreatment, and low-value care. Other impediments more specific to PBM are the misperception of PBM and deeply rooted cultural patterns. Third, understanding how the 3Es-evidence, economics, and ethics-can effectively be used to motivate relevant stakeholders to take on their respective roles and responsibilities and follow the urgent call to implement PBM as a standard of care.

Making patient blood management the new norm(al) as experienced by implementors in diverse countries

BACKGROUND

Patient blood management (PBM) describes a set of evidence-based practices to optimize medical and surgical patient outcomes by clinically managing and preserving a patient's own blood. This concepts aims to detect and treat anemia, minimize the risk for blood loss and the need for blood replacement for each patient through a coordinated multidisciplinary care process. In combination with blood loss, anemia is the main driver for transfusion and all three are independent risk factors for adverse outcomes including morbidity and mortality. Evidence demonstrates that PBM significantly improves outcomes and safety while reducing cost by macroeconomic magnitudes. Despite its huge potential to improve healthcare systems, PBM is not yet adopted broadly. The aim of this study is to analyze the collective experiences of a diverse group of PBM implementors across countries reflecting different healthcare contexts and to use these experiences to develop a guidance for initiating and orchestrating PBM implementation for stakeholders from diverse professional backgrounds.

METHODS

Semi-structured interviews were conducted with 1-4 PBM implementors from 12 countries in Asia, Latin America, Australia, Central and Eastern Europe, the Middle East, and Africa. Responses reflecting the drivers, barriers, measures, and stakeholders regarding the implementation of PBM were summarized per country and underwent qualitative content analysis. Clustering the resulting implementation measures by levels of intervention for PBM implementation informed a PBM implementation framework.

RESULTS

A set of PBM implementation measures were extracted from the interviews with the implementors. Most of these measures relate to one of six levels of implementation including government, healthcare providers, funding, research, training/education, and patients/public. Essential cross-level measures are multi-stakeholder communication and collaboration.

CONCLUSION

The implementation matrix resulting from this research helps to decompose the complexity of PBM implementation into concrete measures on each implementation level. It provides guidance for diverse stakeholders to design, initiate and develop strategies and plans to make PBM a national standard of care, thus closing current practice gaps and matching this unmet public health need.

Transfusion Outcomes in Patients Undergoing Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals

BACKGROUND

Surgical repair of tetralogy of Fallot and major aortopulmonary collaterals (TOF/MAPCAs) involves unifocalization of MAPCAs and reconstruction of the pulmonary arterial circulation. Surgical and cardiopulmonary bypass (CPB) times are long and suture lines are extensive. Maintaining patency of the newly anastomosed vessels while achieving hemostasis is important, and assessment of transfusion practices is critical to successful outcomes.

METHODS

Clinical, surgical, and transfusion data in patients with TOF/MAPCAs repaired at our institution (2013-2018) were reviewed. Types and volumes of blood products used in the perioperative period, in addition to the use of antifibrinolytics and/or procoagulants (factor VIII inhibitor bypassing activity [FEIBA]; anti-inhibitor coagulant complex), were assessed. Outcome measures included days on mechanical ventilation (DOMV), postoperative intensive care unit and hospital length of stay (LoS), and incidence of thrombosis.

RESULTS

Perioperative transfusion data from 279 patients were analyzed. Surgical (879 ± 175 minutes vs 684 ± 257 minutes) and CPB times (376 ± 124 minutes vs 234 ± 122 minutes) were longer in patients who received FEIBA than those who did not. Although the indexed volume of packed red blood cells (128.4 ± 82.2 mL/kg) and fresh frozen plasma (64.2 ± 41.1 mL/kg) was similar in patients who did and did not receive FEIBA, the amounts of cryoprecipitate (5.5 ± 5.2 mL/kg vs 5.8 ± 4.8 mL/kg) and platelets (19.5 ± 20.7 mL/kg vs 20.8 ± 13 mL/kg) transfused were more in those who did receive FEIBA.

CONCLUSION

Perioperative transfusion is an important component in the overall surgical and anesthetic management of patients with TOF/MAPCAs. The intraoperative use of FEIBA was not associated with a decrease in the amount of blood products transfused, DOMV, or LoS or with an increase in thrombotic complications.

Individualized, Intraoperative Dosing of Fibrinogen Concentrate for the Prevention of Bleeding in Neonatal and Infant Cardiac Surgery Using Cardiopulmonary Bypass (FIBCON): A Phase 1b/2a Randomized Controlled Trial

BACKGROUND

Mediastinal bleeding is common following pediatric cardiopulmonary bypass surgery for congenital heart disease. Fibrinogen concentrate (FC) represents a potential therapy for preventing bleeding.

METHODS

We performed a single-center, phase 1b/2a, randomized controlled trial on infants 2.5 to 12 kg undergoing cardiopulmonary bypass surgery, aimed at (1) demonstrating the feasibility of an intraoperative point-of-care test, rotational thromboelastometry, to screen out patients at low risk of postoperative bleeding and then guide individualized FC dosing in high-risk patients and (2) determining the dose, safety, and efficacy of intraoperative FC supplementation. Screening occurred intraoperatively 1-hour before bypass separation using the rotational thromboelastometry variable fibrinogen thromboelastometry maximum clot firmness (FibTEM-MCF; fibrinogen contribution to clot firmness). If FibTEM-MCF ≥7 mm, patients entered the monitoring cohort. If FibTEM-MCF ≤6 mm, patients were randomized to receive FC/placebo (2:1 ratio). Individualized FC dose calculation included weight, bypass circuit volume, hematocrit, and intraoperative measured and desired FibTEM-MCF. The coprimary outcomes, measured 5 minutes post-FC administration were FibTEM-MCF (desired range, 8-13 mm) and fibrinogen levels (desired range, 1.5-2.5 g/L). Secondary outcomes were thrombosis and thrombosis-related major complications and postoperative 24-hour mediastinal blood loss.

RESULTS

We enrolled 111 patients (cohort, n=21; FC, n=60; placebo, n=30); mean (SD) age, 6.4 months (5.8); weight, 5.9 kg (2.0). Intraoperative rotational thromboelastometry screening effectively excluded low-risk patients, in that none in the cohort arm (FibTEM-MCF, ≥7 mm) demonstrated clinically significant early postoperative bleeding (>10 mL/kg per 4 hours). Among randomized patients, the median (range) FC administered dose was 114 mg/kg (51-218). Fibrinogen levels increased from a mean (SD) of 0.91 (0.22) to 1.7 g/L (0.41). The postdose fibrinogen range was 1.2 to 3.3 g/L (72% within the desired range). The corresponding FibTEM-MCF values were as follows: pre-dose, 5.3 mm (1.9); post-dose, 13 mm (3.2). Ten patients (8 FC and 2 placebo) exhibited 12 possible thromboses; none were clearly related to FC. There was an overall difference in mean (SD) 24-hour mediastinal drain loss: cohort, 12.6 mL/kg (6.4); FC, 11.6 mL/kg (5.2); placebo, 17.1 mL/kg (14.3; ANOVA P=0.02).

CONCLUSIONS

Intraoperative, individualized dosing of FC appears feasible. The need for individualized dosing is supported by the finding that a 4-fold variation in FC dose is required to achieve therapeutic fibrinogen levels. Registration: URL: https://eudract.ema.europa.eu/; Unique identifier: 2013-003532-68. URL: https://www.isrctn.com/; Unique identifier: 50553029.

Recommendations on Selection and Processing of RBC Components for Pediatric Patients From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for selection and processing of RBC products in critically ill children developed by 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 clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The RBC processing subgroup included five 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

Five recommendations reached agreement (> 80%). Irradiated cellular products are recommended for children at risk of transfusion-associated graft versus host disease due to severe congenital or acquired causes of immune deficiency or when the blood donor is a blood relative. Washed cellular blood components and avoidance of other plasma-containing products are recommended for critically ill children with history of severe allergic reactions or anaphylaxis to blood transfusions, although patient factors appear to be important in the pathogenesis of reactions. For children with history of severe allergic transfusion reactions, evaluation for allergic stigmata prior to transfusion is recommended. In children with severe immunoglobulin A deficiency with evidence of antiimmunoglobulin A antibodies and/or a history of a severe transfusion reaction, immunoglobulin A-deficient blood components obtained either from an immunoglobulin A-deficient donor and/or washed cellular components is recommended.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative consensus conference developed recommendations for selection and processing of RBC units for critically ill children. Recommendations in this area are largely based on pediatric and adult case report data.

Recent innovations in perfusion and cardiopulmonary bypass for neonatal and infant cardiac surgery

The development and refinement of cardiopulmonary bypass (CPB) has made the repair of complex congenital heart defects possible in neonates and infants. In the past, the primary goal for these procedures was patient survival. Now that substantial survival rates have been achieved for even the most complex of repairs in these patients, focus has been given to the reduction of morbidity. Although a necessity for these complex neonatal and infant heart defect repairs, CPB can also be an important source of perioperative complications. Recent innovations have been developed to mitigate these risks and is the topic of this review. Specifically, we will discuss improvements in minimizing blood transfusions, CPB circuit design, monitoring, perfusion techniques, temperature management, and myocardial protection, and then conclude with a brief discussion of how further systematic improvements can be made in these areas.

Noteworthy Literature published in 2017 for Congenital Cardiac Anesthesiologists

This review focuses on the literature published during the 13 months from December 2016 to December 2017 that is of interest to anesthesiologists taking care of children and adults with congenital heart disease. Five themes are addressed during this time period and 100 peer-reviewed articles are discussed.