Changing trends in transfusion practice in liver transplantation. Curr Opin Organ Transplant. 2008;13:304-309. [PMID: 18685322 DOI: 10.1097/mot.0b013e3282faa0dd]

Predictors of intraoperative massive transfusion in orthotopic liver transplantation

BACKGROUND

Although transfusion management has improved during the last decade, orthotopic liver transplantation (OLT) has been associated with considerable blood transfusion requirements which poses some challenges in securing blood bank inventories. Defining the predictors of massive blood transfusion before surgery will allow the blood bank to better manage patients' needs without delays. We evaluated the predictors of intraoperative massive transfusion in OLT.

STUDY DESIGN AND METHODS

Data were collected on patients who underwent OLT between 2007 and 2017. Repeat OLTs were excluded. Analyzed variables included recipients' demographic and pretransplant laboratory variables, donors' data, and intraoperative variables. Massive transfusion was defined as intraoperative transfusion of ≥10 units of packed red blood cells (RBCs). Statistical analysis was performed using SPSS version 17.0.

RESULTS

The study included 970 OLT patients. The median age of patients was 57 (range: 16-74) years; 609 (62.7%) were male. RBCs, thawed plasma, and platelets were transfused intraoperatively to 782 (80.6%) patients, 831 (85.7%) patients, and 422 (43.5%) patients, respectively. Massive transfusion was documented in 119 (12.3%) patients. In multivariate analysis, previous right abdominal surgery, the recipient's hemoglobin, Model for End Stage Liver Disease (MELD) score, cold ischemia time, warm ischemia time, and operation time were predictive of massive transfusion. There was a direct significant correlation between the number of RBC units transfused and plasma (Pearson correlation coefficient r = .794) and platelets (r = .65).

DISCUSSION

Previous abdominal surgery, the recipient's hemoglobin, MELD score, cold ischemia time, warm ischemia time, and operation time were predictive of intraoperative massive transfusion in OLT.

Super-massive transfusion during liver transplantation

BACKGROUND

Massive hemorrhage and transfusion during liver transplantation (LT) present great challenges. We aimed to investigate the incidence and risk factors for super-massive transfusion (SMT) and survival outcome and factors that negatively affect survival in patients who received SMT during LT.

STUDY DESIGN AND METHODS

We included adult patients undergoing LT from 2004 to 2019. SMT was defined as transfusion of ≥50 units of red blood cells (RBC) during LT. Independent risk factors were identified by multivariable logistic regression. Ninety-day survival was recorded and factors that negatively affected survival were analyzed by the Cox survival test.

RESULTS

Of 2772 patients, 158 (5.6%) received SMT during LT. Mean RBC transfusion was 72.6 (±23.4) units with a maximum of 168 units. Four variables (MELD-Na score, previous upper abdominal surgery, portal vein thrombosis, and remote retransplant) were independent risk factors for SMT (odds ratio 1.800-8.274, 95% CI 1.008-16.685, all p < .005). The 90-day survival rate in SMT patients was 81.6%. Preoperative pulmonary hypertension and massive postreperfusion transfusion negatively affected 90-day survival (hazard ratio 2.658-4.633, 95% CI 1.144-10.130, and all p < .05).

CONCLUSIONS

In this large retrospective study, we found that SMT occurred in a small percentage of patients and was associated with relatively satisfactory short-term survival. Identification of preoperative risk factors for SMT and factors that negatively affect survival improve our understanding of this unique LT patient population.

Viscoelastic Management of Coagulopathy during the Perioperative Period of Liver Transplantation

Viscoelastic testing (VET) in liver transplantation (LT) has been used since its origin, in combination with standard laboratory testing (SLT). There are only a few, small, randomized controlled trials that demonstrated a reduction in transfusion rates using VET to guide coagulation management. Retrospective analyses contrasting VET to SLT have demonstrated mixed results, with a recent concern for overtreatment and the increase in postoperative thrombotic events. An oversight of many studies evaluating VET in LT is a single protocol that does not address the different phases of surgery, in addition to pre- and postoperative management. Furthermore, the coagulation spectrum of patients entering and exiting the operating room is diverse, as these patients can have varying anatomic and physiologic risk factors for thrombosis. A single transfusion strategy for all is short sighted. VET in combination with SLT creates the opportunity for personalized resuscitation in surgery which can address the many challenges in LT where patients are at a paradoxical risk for both life-threatening bleeding and clotting. With emerging data on the role of rebalanced coagulation in cirrhosis and hypercoagulability following LT, there are numerous potential roles in VET management of LT that have been unaddressed.

Validation of 5 models predicting transfusion, bleeding, and mortality in liver transplantation: an observational cohort study

BACKGROUND

Historically, orthotopic liver transplantation (OLT) has been associated with massive blood loss, blood transfusion and morbidity. In order to predict such outcomes five nomograms have been published relating to transfusions and morbidity associated with OLTs. These nomograms, developed on the basis of three cohorts of patients consisting of 406, 750, and 800 having undergone OLTs, aimed to predict a transfusion of ≥1 red blood cell unit (RBC), a transfusion of >2 RBC units, a blood loss of >900 ml, as well as one-month and one-year survival rates. The aim of this study was to validate these five nomograms in a contemporary, independent cohort of patients.

METHODS

Five nomograms were previously developed based on 406, 750, and 800 OLTs. In this study we performed a temporal validation of these nomograms on contemporary patients that consisted of three cohorts of 800, 250, and 200 OLTs. Logistic regression coefficients from the historic development cohorts were applied to the three contemporary temporal validation cohorts.

RESULTS

The most accurate nomogram was able to predict transfusion of ≥1 RBC units with an area under the curve (AUC) was 0.91. The second-best nomogram was able to predict bleeding of >900 ml with an AUC of 0.70. T he AUC of the third nomogram (transfusion of >2 RBC units) was 0.70. However, is temporal validation was suboptimal, due to a low prevalence of OLTs transfused with >2 RBC units. The last 2 nomograms exhibited clearly suboptimal AUC values of 0.54 and 0.61.

CONCLUSION

Two of the five nomograms predict blood transfusion and blood loss with excellent accuracy. Transfusion of ≥1 RBC unit and blood loss of >900 ml can be predicted on the basis of these nomograms. However, these nomograms are not accurate to predict one-month and one-year survival rates. These results should be further cross-validated, ideally prospectively, in additional external independent cohorts.

Lack of alloimmunization to the D antigen in D-negative orthotopic liver transplant recipients receiving D-positive red blood cells perioperatively

BACKGROUND AND OBJECTIVES

D-negative patients undergoing orthotopic liver transplantation (OLT) might require a large number of red blood cell (RBC) units, which can impact the inventory of D-negative blood. The blood bank might need to supply these patients with D-positive RBCs because of inventory constraints. This study evaluates the prevalence of anti-D formation in D-negative OLT patients who received D-positive RBCs perioperatively, as this will assist in successful patient blood management.

MATERIALS AND METHODS

This was a retrospective study performed at a single academic medical centre. Electronic medical records for all 1052 consecutive patients who underwent OLT from January 2007 through December 2017 were reviewed. D-negative patients who were transfused perioperatively with D-positive RBCs and had antibody screening at least 30 days after transfusion were included.

RESULTS

Of a total of 155 D-negative patients, 23 (14.8%) received D-positive RBCs perioperatively. Seventeen patients were included in the study. The median age was 54 years (range 36-67 years); 13 (76.5%) were male. The median number of D-positive RBC units transfused perioperatively was 7 (range 1-66 units). There was no evidence of D alloimmunization in any patient after a median serologic follow-up of 49.5 months (range 31 days to 127.7 months). The average number of antibody screening post OLT was 7.29.

CONCLUSION

Our study showed that transfusion of D-positive RBCs in D-negative OLT recipients is a safe and acceptable practice in the setting of immunosuppression. This practice allows the conservation of D-negative RBC inventory.

Rotation thromboelastometry velocity curve predicts blood loss during liver transplantation

BACKGROUND

Patients undergoing liver transplantation (LT) have a high risk of bleeding. The goal of this study was to assess whether the first derivative of the velocity waveform (V-curve) generated by whole blood rotation thromboelastometry (ROTEM^®) can predict blood loss during LT.

METHODS

Preoperative V-curve parameters were retrospectively evaluated in 198 patients. Patients were divided into quartiles based on blood loss: low (LBL) in the first quartile and high (HBL) in the higher quartiles. A subgroup analysis was performed with patients stratified according to cirrhosis aetiology. A logistic regression model and receiver operator characteristics (ROC) curve were used to test the capacity of the V-curve, to discriminate between LBL and HBL.

RESULTS

In the HBL group, the V-curve showed a lower maximum velocity of clot generation (MaxVel), a lower area under maximum velocity curve (AUC), and a higher time-to-maximum velocity (t-MaxVel) than in the LBL group. t-MaxVel was the only parameter showing a capacity to discriminate between the two groups, with a ROC area of 0.69 (95% CI; 0.62-0.74). The ROC area was 0.78 (95% CI; 0.75-0.83) for the 148 patients with cirrhosis, 0.73 (0.60-0.82) for patients with viral hepatitis and 0.83 (0.78-0.96) for patients with alcoholic hepatitis, the group that showed the best discriminative capacity. Moderate but significant correlations were found between all parameters of V-curve and BL.

CONCLUSIONS

Pre-transplant V-curve obtained from ROTEM is a promising tool for predicting BL risk during LT, particularly in patients with cirrhosis.

Position of the French Working Group on Perioperative Haemostasis (GIHP) on viscoelastic tests: What role for which indication in bleeding situations?

PURPOSE

Viscoelastic tests (VETs), thromboelastography (TEG^®) and thromboelastometry (ROTEM^®) are global tests of coagulation performed on whole blood. They evaluate the mechanical strength of a clot as it builds and develops after coagulation itself. The time required to obtain haemostasis results remains a major problem for clinicians dealing with bleeding, although some teams have developed a rapid laboratory response strategy. Indeed, the value of rapid point-of-care diagnostic devices such as VETs has increased over the years. However, VETs are not standardised and there are few recommendations from the learned societies regarding their use. In 2014, the recommendations of the International Society of Thrombosis and Haemostasis (ISTH) only concerned haemophilia. The French Working Group on Perioperative haemostasis (GIHP) therefore proposes to summarise knowledge on the clinical use of these techniques in the setting of emergency and perioperative medicine.

METHODS

A review of the literature.

PRINCIPAL FINDINGS

The role of the VETs seems established in the management of severe trauma and in cardiac surgery, both adult and paediatric. In other situations, their role remains to be defined: hepatic transplantation, postpartum haemorrhage, and non-cardiac surgery. They must be part of the global management of haemostasis based on algorithms defined in each centre and for each population of patients. Their position at the bedside or in the laboratory is a matter of discussion between clinicians and biologists.

CONCLUSION

VETs must be included in algorithms. In consultation with the biology laboratory, these devices should be situated according to the way each centre functions.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

Preoperative Thromboelastography as a Sensitive Tool Predicting Those at Risk of Developing Early Hepatic Artery Thrombosis After Adult Liver Transplantation

BACKGROUND

Whilst causes of hepatic artery thrombosis (HAT) after liver transplantation (LT) are multifactorial, early HAT (E-HAT) remains pertinent complication impacting on graft and patient survival. Currently there is no screening tool that would identify patients with increased risk of developing E-HAT.

METHODS

We analyzed the native procoagulant state of LT recipients, identified through pretransplant thromboelastographic (TEG) data among other known risk factors, to identify risk factors for E-HAT.

RESULTS

The outcomes of 828 adult patients undergoing LT between 2008 and 2013 were analyzed. Overall, 79 (9.5%) patients experienced HAT, E-HAT was diagnosed in 23, and in the remainder this was "late" HAT. The maximum amplitude (MA) on preoperative TEG was significantly higher in patients diagnosed with E-HAT compared with those who did not (71.2 mm vs 57.9 mm; P < 0.0001). Receiver operating characteristic analysis with the cutoff value for MA of 65 mm or greater returned area under the curve of 0.750 (P < 0.001) predicting E-HAT with a sensitivity of 70%. A total of 7% of patients with an MA of 65 mm or greater went on to develop E-HAT (hazard ratio, 5.28; 95% confidence interval, 2.10-12.29; P < 0.001), whereas only 1.2% patients with an MA less than 65 mm experienced E-HAT.

CONCLUSIONS

Preoperative TEG may reliably identify group of recipients at greater risk of developing E-HAT, and intense surveillance and anticoagulation prophylaxis may avoid this serious complication after LT.

Massive haemorrhage in liver transplantation: Consequences, prediction and management

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

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.

Reducing transfusion requirements in liver transplantation

Liver transplantation (LT) was historically associated with massive blood loss and transfusion. Over the past two decades transfusion requirements have reduced dramatically and increasingly transfusion-free transplantation is a reality. Both bleeding and transfusion are associated with adverse outcomes in LT. Minimising bleeding and reducing unnecessary transfusions are therefore key goals in the perioperative period. As the understanding of the causes of bleeding has evolved so too have techniques to minimize or reduce the impact of blood loss. Surgical “piggyback” techniques, anaesthetic low central venous pressure and haemodilution strategies and the use of autologous cell salvage, point of care monitoring and targeted correction of coagulopathy, particularly through use of factor concentrates, have all contributed to declining reliance on allogenic blood products. Pre-emptive management of preoperative anaemia and adoption of more restrictive transfusion thresholds is increasingly common as patient blood management (PBM) gains momentum. Despite progress, increasing use of marginal grafts and transplantation of sicker recipients will continue to present new challenges in bleeding and transfusion management. Variation in practice across different centres and within the literature demonstrates the current lack of clear transfusion guidance. In this article we summarise the causes and predictors of bleeding and present the evidence for a variety of PBM strategies in LT.

Transfusion management and immunohematologic complications in liver transplantation: experience of a single institution

OBJECTIVE

Liver transplantation (LT) has traditionally been associated with major blood loss and consequently high blood transfusion requirements. Our objective was to analyze transfusion management and incidence of immunohematologic complications in patients undergoing LT at our institution.

METHODS

A retrospective analysis of immunohematologic events and transfusion outcomes was carried out at La Fe University Hospital in Valencia. Data from 654 patients were reviewed: 654 underwent only one LT while 36 underwent second LT.

RESULTS

Patients received a median of 3 red blood cell (RBC) concentrates, 2 platelets concentrates (PCs) and 2 fresh frozen plasma units (FFPs). Variables significantly influencing RBC transfusions were: the MELD score, hemoglobin levels, and the platelet counts before LT. 27 patients (4.1%) had a positive antibody screening before transplant. Immunohematologic events occurred in 8% of the patients, mostly in the first month after LT, and involved hemolysis in 13 cases. Mortality was significantly higher in patients developing immunohematologic disorders (42.8 vs. 18.3%; p < 0.001). In the multivariable analysis, only ABO minor incompatibility between donor and recipient significantly increased the appearance of immunohematologic incidences (OR 4.92, 95% CI 2.31-10.50; p < 0.001).

CONCLUSION

Transfusion management of patients that underwent LT can be complicated by immunohematologic problems. Blood banks should implement the DAT test in each transfusion to detect them.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Risk Factors Associated with Reoperation for Bleeding following Liver Transplantation

Introduction. This study's objective was to identify risk factors associated with reoperation for bleeding following liver transplantation (LTx). Methods. A retrospective study was performed at a single institution between 2001 and 2012. Operative reports were used to identify patients who underwent reoperation for bleeding within 2 weeks following LTx (operations for nonbleeding etiologies were excluded). Results. Reoperation for bleeding was observed in 101/928 (10.8%) of LTx patients. The following characteristics were associated with reoperation on multivariable analysis: recipient MELD score (OR 1.06/MELD unit, 95% CI 1.03, 1.09), number of platelets transfused (OR 0.73/platelet unit, 95% CI 0.58, 0.91), and aminocaproic acid utilization (OR 0.46, 95% CI 0.27, 0.80). LTx patients who underwent reoperation for bleeding had a longer ICU stay (5 days ± 7 versus 2 days ± 3, P < 0.001) and hospitalization (18 days ± 9 versus 10 days ± 18, P < 0.001). The risk of death increased in patients who underwent reoperation for bleeding (HR 1.89, 95% CI 1.26, 2.85). Conclusion. Reoperation for bleeding following LTx was associated with increased resource utilization and recipient mortality. A lower threshold for intraoperative platelet transfusion and antifibrinolytics, especially in patients with high lab-MELD score, may decrease the incidence of reoperation for bleeding following LTx.

Is "intra-operating room" thromboelastometry useful in liver transplantation? A case-control study in 303 patients

Coagulation monitoring during liver transplantation (LT) is, even today, fundamental to reduce blood loss during surgery. Thromboelastometry (TEM) is a proven technique for controlling the various parameters that influence coagulation. However, there are no studies linking "intra-operating room" TEM (orTEM) with LT outcomes. We describe a case-control study in 303 liver graft recipients analyzing variables associated with operative complications and long-term LT outcomes. The results showed that orTEM reduced the use of blood products in patients with Model for End-Stage Liver Disease scores of ≥ 21, retransplantation, and high surgical difficulty and important intraoperative bleeding. In addition, results in survival and postoperative complications were better when orTEM was used. In conclusion, we confirm that use of orTEM is associated with less use of blood products and a lower rate of complications after LT.

Single-center transfusion rate for 555 consecutive liver transplantations: impact of two eras

Orthotopic liver transplantation (OLT) is the treatment of choice for patients with acute or chronic end-stage liver disease, irresectable primary liver tumor, and metabolic disorders. Historically, OLT has been associated with considerable blood loss and the need for transfusions. However, over the years there has been reduction is need for blood products. The aim of this article was to compare two distinct eras for perioperative blood transfusion rate among patients undergoing OLT; Era I, 200 transplantations in 188 patients, and Era II, 355 transplantations in 339 patients. The donor mean age was 33.70 (Era I) versus 35.34 (Era II). Cause of death in both eras was traumatic brain injury followed by cerebral vascular accident. Organ recipient data showed a mean age of 48.87 (Era I) versus 46.49 (Era II). During Era I patients with Child B (56.8%) prevailed, followed by Child C (35.4%) and Child A (7.8%). In Era II also patients with Child B (53.1%) prevailed, followed by Child C (39.6%) and Child A (7.3%). The prevalence of hepatocellular carcinoma (HCC) during Era I was 9% (18) and in Era II 20% (71). The use of blood products in the perioperative period: was as follows packed red blood cells 1.76 (Era I) versus 0.57 (Era II) units; fresh frozen plasma 1.89 (Era I) versus 0.49 (Era II) units; platelets 2.16 (Era I) versus 0.28 (Era II) units; and cryoprecipitate 0.08 (Era I) versus 0.03 (Era II) units. OLT using the piggyback technique was performed with a transfusion rate below <30%, and it reduced blood loss and prevented severe hemodynamic instability.

Transfusion and coagulation management in liver transplantation

There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation.

Massive blood transfusion after the first cut in liver transplantation predicts renal outcome and survival

INTRODUCTION

Transfusion requirements of blood products may provide useful prognostic factors for the prediction of short-term patient mortality and renal outcome after liver transplantation.

PATIENTS AND METHODS

Two hundred ninety-one consecutive liver transplants in adults were analysed retrospectively. Combined and living-related liver transplants were excluded. The amount of transfused packed red blood cells (PRBC) and units of platelets (UP) within the first 48 h were investigated as prognostic factors to predict short-term patient mortality and renal outcome. Receiver operating characteristic (ROC) curve analysis with area under the curve (AUC), Hosmer-Lemeshow tests and Brier scores were used to calculate overall model correctness, model calibration and accuracy of prognostic factors. Cut-off values were determined with the best Youden index.

RESULTS

The potential clinical usefulness of PRBC as a prognostic factor to predict 30-day mortality (cut-off 17.5 units) and post-transplant haemodialysis (cut-off 12.5 units) could be demonstrated with AUCs >0.7 (0.712 and 0.794, respectively). Hosmer-Lemeshow test results and Brier scores indicated good overall model correctness, model calibration and accuracy. The UP proved as an equally clinically useful prognostic factor to predict end-stage renal disease (cut-off 3.5 units; AUC = 0.763). The association of cut-off levels of PRBC with patient survival (p < 0.001, log-rank test) and dialysis-free survival (p < 0.001, log-rank test) was significant (cut-off levels 17.5 and 12.5 units, respectively) as well as the association of UP with dialysis-free survival (p < 0.001, log-rank test) (cut-off level 3.5 units).

CONCLUSIONS

The impressive discriminative power of these simple prognostic factors for the prediction of outcome after liver transplantation emphasizes the relevance of strategies to avoid excessive transfusion requirements.

Changes in transfusion practice over time in adult patients undergoing liver transplantation

OBJECTIVE

The aim of this study was to investigate changes in transfusion practice over time in liver transplantation surgery and to evaluate potential causes for changes in practice and report associated perioperative morbidity and mortality.

DESIGN

A retrospective cohort study.

SETTING

A single tertiary referral academic hospital.

PARTICIPANTS

Two cohorts of 100 sequential adult primary liver transplant recipients: Early practice (1990-1991) and recent practice (2005-2006).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Perioperative transfusion and hemoglobin data were recorded. Mortality and postoperative complications were identified up to 30 days postoperatively. Appropriate intergroup statistical comparisons were made; p ≤ 0.05 was considered statistically significant. Compared with the early group, the recent group had significantly fewer perioperative allogeneic red blood cell transfusions, intraoperative autotransfusions, and transfusions of other blood products. No change in perioperative transfusion triggers was identified. There were no significant alterations in perioperative morbidity or mortality.

CONCLUSIONS

When compared with patients in the early group, recent cohort patients received significantly fewer blood transfusions. The authors attribute this observation to changes in surgical technique rather than a significant alteration in transfusion triggers over the studied time period.

The impact of perioperative transfusion of blood products on survival after pediatric liver transplantation

Intraoperative transfusion of red blood cells (RBC) is associated with adverse outcome after LT in adult patients. This relationship in pediatric patients has not been studied in depth, and its analysis is the scope of this study. Forty-one variables associated with outcome, including blood product transfusions, were studied in a cohort of 243 pediatric patients undergoing a cadaveric LT between 2002 and 2009 at the General Hospital of Bergamo. Multivariate stepwise Cox proportional hazards models were adopted with adjustment by propensity scores to minimize factors associated with the use of blood products. Median age at transplant was 1.37 yr. In uni- and multivariate analyses, perioperative transfusion of FFP and RBC was an independent risk factor for predicting one-yr patient and graft survival. The effect on one-yr survival was dose-related with a hazard ratio of 3.15 for three or more units of RBC (p = 0.033) and 3.35 for three or more units of FFP (p = 0.021) when compared with 1 or no units transfused. The negative impact of RBC and FFP transfusion was confirmed by propensity score-adjusted analysis. These findings may have important implications for transfusion practice in the LT pediatric recipients.

An assessment of thromboelastometry to monitor blood coagulation and guide transfusion support in liver transplantation

BACKGROUND

Rotation thromboelastometry (TEM) has been proposed as a convenient alternative to standard coagulation tests in guiding the treatment of coagulopathy during orthotopic liver transplantation (OLT). This study was aimed at assessing the value of TEM in monitoring blood coagulation and guide transfusion support in OLT.

STUDY DESIGN AND METHODS

Standard coagulation and TEM (EXTEM and FIBTEM) tests were performed at four preestablished intraoperative time points in 236 OLTs and prospectively recorded in a dedicated database together with the main operative and transfusion data. Transfusion thresholds were based on standard coagulation tests. Spearman's rank correlation (ρ), linear regression, and receiver operating characteristic curves were used when appropriate.

RESULTS

EXTEM maximum clot firmness (MCF(EXTEM)) was the TEM variable that best correlated with the platelet (PLT) and fibrinogen levels (ρ = 0.62 and ρ = 0.69, respectively). MCF(FIBTEM) correlated with fibrinogen level (ρ = 0.70). EXTEM clot amplitude at 10 minutes (A10(EXTEM)) was a good linear predictor of MCF(EXTEM) (R(2) =0.93). The cutoff values that best predicted the transfusion threshold for PLTs and fibrinogen were A10(EXTEM) = 35 mm and A10(FIBTEM) = 8 mm. At these values, the negative and positive predictive accuracies of TEM to predict the transfusion thresholds were 95 and 27%, respectively.

CONCLUSION

A10(EXTEM) is an adequate TEM variable to guide therapeutic decisions during OLT. Patients with A10(EXTEM) of greater than 35 mm are unlikely to bleed because of coagulation deficiencies, but using A10(EXTEM) of not more than 35 mm as the sole transfusion criterion can lead to unnecessary utilization of PLTs and fibrinogen-rich products.

Early detection of the graft failure after pediatric liver transplantation: a Bergamo experience

BACKGROUND

Effective indicators of the early graft failure after pediatric liver transplantation are currently a crucial question. The aim of this study was to analyze retrospectively laboratory parameters that may help anticipate an early graft loss (GL).

METHODS

The 131 pediatric liver transplantations, performed in our hospital from January 2002 to December 2005, were reviewed. Post-operative laboratory parameters, collected in the first 36 h of the Paediatric Intensive Care Unit (PICU) stay, were analyzed for children with both graft survival and GL. Receiver operating characteristics analysis was used to identify the optimal cut-off for the laboratory parameters. Multivariate logistic regression analysis was used to calculate the adjusted risk of GL for the prognostic parameters identified.

RESULTS

The mean age at transplant was 1.1 years. The two groups were comparable for all recipient and donor variables considered. Children with GL showed significantly higher levels of ammonia and transaminase at the admission to the PICU and higher levels of prothrombin time, creatinine, lactate and a lower level of platelets at the 36 h of PICU. The laboratory parameters over the cut-off value by the multivariate logistic regression identified all early thromboses earlier than Doppler ultrasound.

CONCLUSIONS

This study suggests that routine blood tests may help to anticipate an early loss of liver grafts in children after transplantation and may improve our diagnostic investigation in the case of thrombosis suspicion. Further validation by a prospective study is needed to carefully assess the sensitivity and specificity of the identified criteria.

Intraoperative management of liver transplant patients

Liver transplantation for end-stage liver disease results in excellent outcomes. Patient and graft outcome is closely monitored on a national level, and 1-year survival is between 80% and 95%. Liver transplantation relies on a multidisciplinary approach, with close involvement of anesthesiologists and intensivists. However, intraoperative care of these patients remains inconsistent and is highly institution dependent. This brief-review article will focus on controversial topics of intraoperative care. Existing evidence on intraoperative monitoring, intraoperative fluid and transfusion management, electrolyte and glucose management, postoperative patient disposition, and, lastly, anesthesia team management will be reviewed.

Anesthesia care for liver transplantation

Intraoperative transfusion practices for liver transplantation have evolved dramatically since the first transplants of the 1960s. It is important for today's clinicians to be current in their understanding of how transplant patients should be managed with regard to their coagulation profile, volume status, and general hemodynamic state. The anesthesia team is presented with the unique task of manipulating this tenuous balance in a rapid and precise manner when managing patients undergoing liver transplantation. Although significant progress has been made in reducing blood product administration, it is still common to encounter large volume blood loss in these cases. Increasingly, clinicians are challenged to justify transfusion practices with a stronger evidentiary base. The current state of the literature for transfusion guidelines and blood product management in this particular patient subset will be discussed, as well as a variety of means (both pharmacologic and otherwise) used to reduce the need for transfusion. The aim was to review the latest evidence on these topics, as well as to highlight areas that need further clarification regarding their role in the optimal care of these patients.