Transfusion-free techniques in pediatric live donor liver transplantation

A Global Definition of Patient Blood Management

While patient blood management (PBM) initiatives are increasingly adopted across the globe as part of standard of care, there is need for a clear and widely accepted definition of PBM. To address this, an expert group representing PBM organizations, from the International Foundation for Patient Blood Management (IFPBM), the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA), the Society for the Advancement of Patient Blood Management (SABM), the Western Australia Patient Blood Management (WAPBM) Group, and OnTrac (Ontario Nurse Transfusion Coordinators) convened and developed this definition: "Patient blood management is a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment." The definition emphasizes the critical role of informed choice. PBM involves the timely, multidisciplinary application of evidence-based medical and surgical concepts aimed at screening for, diagnosing and appropriately treating anemia, minimizing surgical, procedural, and iatrogenic blood losses, managing coagulopathic bleeding throughout the care and supporting the patient while appropriate treatment is initiated. We believe that having a common definition for PBM will assist all those involved including PBM organizations, hospital administrators, individual clinicians and policy makers to focus on the appropriate issues when discussing and implementing PBM. The proposed definition is expected to continue to evolve, making this endeavor a work in progress.

Preoperative risk factors for intra-operative bleeding in pediatric liver transplantation

This study analyzes the preoperative risk factors for intra-operative bleeding in our recent series of pediatric LTs. Between November 2009 and November 2014, 84 consecutive isolated pediatric LTs were performed in 81 children. Potential preoperative predictive factors for bleeding, amount of intra-operative transfusions, postoperative course, and outcome were recorded. Cutoff point for intra-operative HBL was defined as intra-operative RBC transfusions ≥1 TBV. Twenty-six patients (31%) had intra-operative HBL. One-year patient survival after LT was 66.7% (CI 95%=[50.2-88.5]) in HBL patients and 83.8% (CI 95%=[74.6-94.1]) in the others (P=.054). Among 13 potential preoperative risk factors, three of them were identified as independent predictors of high intra-operative bleeding: abdominal surgical procedure(s) prior to LT, factor V level ≤30% before transplantation, and ex situ parenchymal transsection of the liver graft. Based on these findings, we propose a simple score to predict the individual hemorrhagic risk related to each patient and graft association. This score may help to better anticipate intra-operative bleeding and improve patient's management.

Coagulopathy and transfusion therapy in pediatric liver transplantation

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Should Jehovah's Witness patients be listed for heart transplantation?

This best evidence topic in Cardiac Surgery was written according to a structured protocol. The question addressed was: for [Jehovah's Witness patients with end-stage heart failure] can these patients undergo a [heart transplantation] without an increased rate of mortality. Altogether, 133 papers were found using the reported search strategy. Of those, 29 papers represented the best evidence to answer the clinical question. Five papers focusing on patients of the Jehovah's Witness (JW) faith who had end-stage heart failure were published. Successful heart transplantation was performed in a total of seven patients without mortality, re-exploration or blood transfusion. One patient had left ventricular reduction surgery twice and another patient had bypass surgery several years after transplantation. Other successful organ transplantations were also reported, including lung, liver, kidney and pancreas in both adult and paediatric patients of the JW faith, with comparable mortality and morbidity to non-JW patients. A publication bias is likely; nevertheless, we conclude that although there are no large studies directly focused on heart transplantation in JW patients, a multidisciplinary team approach to such surgery can make it technically feasible and without an increased mortality risk in suitable candidates. Therefore, such patients may be considered for heart transplantation under selected and favourable circumstances.

Klinische Aspekte der Therapie mit Erythrozyten

With the decreased risk of homologous blood transfusions, the costs of blood products have become increasingly important for hospitals with major surgical procedures and oncologic treatment. It is well established from clinical physiology that a hemoglobin concentration (cHb) lower than 6.21 mmol/l (10 g/dl) is enough to serve the oxygen demand of the tissues, but transfusion of erythrocytes is still liberally carried out. Data obtained from Jehovah's Witnesses, who categorically refuse blood transfusions, demonstrate that they have an outcome similar to patients who are transfused. The lessons we have learned from Jehovah's Witnesses should result in an emotionless discussion, and a reduction in transfusion requirements.