Liver Transplantation Without the Use of Fresh Frozen Plasma

Analysis of the hemostatic therapy in liver transplantation guided by rotational thromboelastometry or conventional laboratory tests

BACKGROUND

Coagulopathy is quite common in chronic liver disease patients undergoing orthotopic liver transplantation (OLT). Diagnosis of intraoperative bleeding disorders is based on conventional laboratory tests (CLTs), and thus, the patients are frequently exposed to unnecessary transfusions of blood products. The present study aimed to analyze the intraoperative administration of blood products in patients undergoing OLT, using rotational thromboelastometry (ROTEM) or CLTs.

PATIENTS AND METHODS

A cohort comprising 153 patients undergoing OLT, of whom 82 were evaluated with ROTEM and 71 by CLTs. Both groups were analyzed intraoperatively: the transfusion of blood products.

RESULTS

The incidence of patients transfused with cryoprecipitate (CRYO) and/or fibrinogen concentrate (54.9 vs. 19.7%; P < 0.001) and prothrombin complex concentrate (PCC) (32.9 vs. 9.9%; P = 0.008) increased significantly in the ROTEM group than in CLT group, respectively. The amount of transfused patient with CRYO (7.6 vs. 1.2; P < 0.001), fibrinogen concentrate (0.8 vs. 0.2; P = 0.004) and PCC (1.4 vs. 0.2; P = 0.002) increased significantly in the ROTEM group than in the CLT group, respectively. In the analysis of fresh-frozen plasma (FFP), the incidence of transfused patients was significantly higher in the CLT group than in the ROTEM group (46.5 vs. 30.5%; P = 0.047, respectively), with a moderate correlation with red blood cells transfusion (r = 0.67, P < 0.001). The incidence of patients receiving antifibrinolytics was significantly higher in the CLT group than in the ROTEM group (85.9 vs. 47.6%; P < 0.001, respectively).

CONCLUSION

Transfusion protocol-based thromboelastometry was able to guide administration of hemostatic factors and reduced administration of FFP and antifibrinolytics.

Viscoelastic Monitoring to Guide Hemostatic Resuscitation in Liver Transplantation Surgery

Coagulopathic bleeding must be anticipated during liver transplantation (LT) surgery. Patients with end-stage liver disease (ESLD) often present with disease-related hematologic disturbances, including the loss of hepatic procoagulant and anticoagulant clotting factors and thrombocytopenia. Transplantation surgery itself presents additional hemostatic changes, including hyperfibrinolysis. Viscoelastic monitoring (VEM) is often used to provide targeted, personalized hemostatic therapies for complex bleeding states including cardiac surgery and major trauma. The use in these coagulopathic conditions led to its application to LT, although the mechanisms of coagulopathy in these patients are quite different. While VEM is often used during transplant surgeries in Europe and North America, evidence supporting its use is limited to a few small clinical studies. The theoretical and clinical applications of the standard and specialized VEM assays are discussed in the setting of LT and ESLD.

Clinical utility of viscoelastic tests of coagulation in patients with liver disease

The prothrombin time (PT) and international normalised ratio (INR) are used in scoring systems (Child-Pugh, MELD, UKELD) in chronic liver disease and as a prognostic tool and for dynamic monitoring of hepatic function in acute liver disease. These tests are known to be poor predictors of bleeding risk in liver disease; however, they continue to influence clinical management decisions. Recent work on coagulation in liver disease, in particular thrombin generation studies, has led to a paradigm shift in our understanding and it is now recognised that haemostasis is relatively well preserved. Whole blood global viscoelastic tests (TEG(®) /ROTEM(®) ) produce a composite dynamic picture of the entire coagulation process and have the potential to provide more clinically relevant information in patients with liver disease. We performed a systematic review of all relevant studies that have used viscoelastic tests (VET) of coagulation in patients with liver disease. Although many studies are observational and small in size, it is clear that VET provide additional information that is in keeping with the new concepts of how coagulation is altered in these patients. This review provides the basis for large scale, prospective outcome studies to establish the clinical value of these tests.

Use of higher thromboelastogram transfusion values is not associated with greater blood loss in liver transplant surgery

Plasma-containing products are given during the pre-anhepatic stage of liver transplant surgery to correct abnormal thromboelastogram (TEG) values and prevent blood loss due to coagulation defects. However, evidence suggests that abnormal TEG results do not always predict bleeding. We questioned what effect using higher TEG values to initiate treatment would have on blood loss. A single transfusion protocol was used for all patients who underwent liver transplantation between 2007 and 2010. Thirty-eight patients received coagulation products when standard TEG cutoff values were exceeded, whereas another 39 patients received coagulation products when the TEG values were 35% greater than normal. The results of postoperative coagulation tests for total blood loss and the use of blood products were compared for the 2 groups. When the critical TEG values for transfusion were higher, significantly fewer units of fresh frozen plasma (5.58 ± 6.49 versus 11.53 ± 6.66 U) and pheresis platelets (1.84 ± 1.33 versus 3.55 ± 1.43 U) were used. There were no differences in blood loss or postoperative blood product use. In conclusion, the use of higher critical TEG values to initiate the transfusion of plasma-containing products is not associated with increased blood loss. Further testing is necessary to identify what TEG value predicts bleeding due to a deficit in coagulation factors.

Risk factors and outcomes of massive red blood cell transfusion following living donor liver transplantation

OBJECTIVES

To identify the factors influencing blood loss and secondary blood transfusion and to investigate the outcomes of patients who underwent a massive blood transfusion (MBT) following living donor liver transplantation (LDLT).

METHODS

Patients who underwent primary adult-to-adult right hepatic lobe LDLT were included in the study, and were divided into the MBT group [≥6 red blood cell (RBC) units in 24 h] and the non-massive blood transfusion (NMBT) group (<6 RBC units in 24 h). All potential risk factors, length of intensive care unit (ICU) stay and long-term survival rate of the patients in the two groups were analyzed.

RESULTS

The data of 181 eligible patients were retrospectively analyzed. A decreased long-term survival rate, a higher incidence of postoperative infection and prolonged ICU stay were observed in the MBT group. No significant difference was observed in survival rate between patients having platelet transfusion>2 units and ≤2 units. Hemoglobin<100 g/L, platelet counts<70×10(9)/L, fibrinogen level<1.5 g/L and history of upper abdominal surgery were found to be independent risk factors.

CONCLUSIONS

Blood transfusion during LDLT can be predicted using preoperative variables. Massive RBC transfusion may lead to poor long-term survival, higher postoperative infection rate and prolonged ICU stay. Platelet transfusion may not be a risk factor for long-term survival.

Risk factors for bleeding and transfusion during orthotopic liver transplantation

OBJECTIVE

While orthotopic liver transplantation (OLT) can be associated with haemorrhage, the risk factors for bleeding and transfusion remain difficult to predict. Perioperative transfusion has potentially deleterious side effects and impairs graft and patient survival. Preoperative identification of patients at high risk of bleeding is of clinical interest to manage perioperative transfusion and blood product storage.

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

All OLT conducted between 2004 and 2008 in the University Hospital of Bordeaux were studied. Risk factors for bleeding greater than one blood volume and for massive red blood cell (RBC) transfusion were determined using univariate and multivariate analysis. Thresholds were determined with ROC curve analysis.

RESULTS

One hundred and forty-eight transplantations were studied. Preoperative haemoglobin and Child class A were independent protective risk factors for bleeding greater than one blood volume (OR 0.81 [0.67-0.98] and 0.27 [0.10-0.72], respectively). Preoperative Hb was a protective risk factor (OR 0.71 [0.58-0.88]) whereas history of oesophageal varicose bleeding was a risk factor (OR 4.67 [1.45-15.05]) for transfusion of more than eight RBC.

CONCLUSION

Risk factors for bleeding and transfusion during OLT identified in this study were of little clinical usefulness so blood products should always be available during the procedure.

Recombinant Human Coagulation Factor VIIa in Jehovah's Witness Patients Undergoing Liver Transplantation

Indisputably, liver transplantation is among the most technically challenging operations in current practice and is compounded by significant coagulopathy and portal hypertension. Recombinant human coagulation factor VIIa (rFVIIa) is a new product that was initially described to treat bleeding in hemophilia patients. We present in this paper 10 liver transplants in Jehovah's Witness patients using this novel product at University of Southern California–University Hospital. The subject population included nine males and one female with an average age of 50 years. Six patients underwent cadaveric and four live donor liver transplantation. Surgeries were conducted following our established protocol for transfusion-free liver transplantation, which includes preoperative blood augmentation, intraoperative blood salvage, acute normovolemic hemodilution, and postoperative blood conservation. Factor rFVIIa was used at a dose of 80 μg/kg intravenously just prior to the incision in all patients, and a second intraoperative dose was used in 3 patients. All living donor liver transplantation (LDLT) recipients did well and were discharged uneventfully with normal liver functions. Two of the six cadaveric recipients died. One patient died intraoperatively from acute primary graft nonfunction, and the other died 38 hours postoperatively from severe anemia. This report suggests factor rFVIIa might have a much broader application in surgery in the control of bleeding associated with coagulopathy.

Anesthesia for liver transplant surgery

Liver transplantation offers patients with liver disease an optimal chance for long-term survival. Current indications, preoperative assessment, patient selection, intraoperative anesthetic management and outcomes are described. The management of special situations, including retransplantation, pediatric transplantation, and fulminant hepatic failure are also reviewed. The success of liver transplantation has led to increased demand. This demand, coupled with a nonexpanding supply of deceased donor organs, has resulted in a shortage of grafts and prolonged waiting times. Novel solutions using segmental liver grafts from living donors, and the challenges associated with this approach, are discussed.

Institutional variability in transfusion practice for liver transplantation

We prospectively evaluated the institutional variability in perioperative transfusion therapy in orthotopic liver transplantation (OLT). Adult OLTs completed during a 12-mo period were studied until the 48th postoperative hour at 8 centers. A multivariate analysis using mixed-effects logistic regression included variables predisposing to blood loss and a center random effect. In addition, the influence of the calculated perioperative hemoglobin (Hb) loss on the individual probability of receiving red blood cells (RBCs), fresh frozen plasma (FFP), and platelets in excess of the overall median were explored. The analysis was performed on 301 cases. The overall median numbers transfused were 5 RBC units, 6 FFP units, and the median platelet dose was 5.10(11), with significant intercentric differences in the proportions of cases given more than the overall median. Intercentric differences remained significant after adjustment for factors independently associated with a large blood component use. Intercentric differences in RBCs, FFP, and platelet use decreased but persisted after adjustment for the perioperative Hb loss. Intercentric differences in RBC use disappeared after adjustment for the postoperative Hb concentration. The significant heterogeneity in transfusion therapy mandates reassessment of the rational use of blood products in OLT.

Effect of severe thrombocytopenia on patient outcome after liver transplantation

OBJECTIVE

The objective was to identify factors associated with thrombocytopenia and to assess to what extent thrombocytopenia increases bleeding complications in liver transplant patients.

DESIGN

Retrospective study.

SETTING

Surgical intensive care unit in a university hospital.

PATIENTS

One hundred and sixty-one patients admitted to the intensive care unit after liver transplantation.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

Incidence of thrombocytopenia was defined as a platelet count of <50 x 10(9)/l for at least 3 consecutive days, associated events for thrombocytopenia or bleeding were identified by a Cox proportional hazard analysis, and blood product consumption was studied. Thrombocytopenia occurred in 104 patients (65%) with a mortality rate of 18% compared with 2% in non-thrombocytopenic patients (p=0.002). Independent associated events for thrombocytopenia were need of dialysis (hazard ratio [HR], 2.30; 95% confidence interval (95% CI), 1.10-4.80) and value of preoperative platelet count (HR, 1.06; 95% CI, 1.01-1.12 by 10(4) platelet decrease). The unique associated event identified for significant bleeding was sepsis (HR, 34.80; 95% CI, 1.47-153.40). Severe thrombocytopenia led to an excess of blood product consumption (red blood cells and platelets units) during ICU stay.

CONCLUSION

Thrombocytopenia of <50 x 10(9)/l for 3 days is frequent after liver transplantation and as such is not an important contributor to bleeding. However, thrombocytopenia does reflect the severity of the postoperative course.

Fresh frozen plasma in patients with disseminated intravascular coagulation or in patients with liver diseases

Disseminated intravascular coagulation (DIC) and liver diseases are complex clinical conditions. Both disorders frequently disturb the finely tuned coagulation and fibrinolysis equilibrium. In DIC, a wide range of underlying disorders can induce a systemic activation of the coagulation system with generation of soluble fibrin, possible deposition of platelet-rich fibrin clots in the microvasculature and subsequent micro- or macroembolism, impaired organ perfusion and organ failure. Such coagulation activation depletes platelets, coagulation factors, and inhibitors and clinically can result in severe, sometimes untreatable bleeding, especially when bone marrow or liver function is diminished or invasive procedures are performed. In addition, a secondary counterbalancing activation of the fibrinolytic system to dissolve microcirculatory clots adds to the bleeding tendency. In conjunction with other options based on prompt and rigorous treatment of the underlying cause of DIC, fresh frozen plasma plays an important role in therapeutic management when overt bleeding is present or anticipated in DIC patients with disturbed coagulation or when an invasive procedure is being planned. In liver disease, factor and inhibitor synthesis in both the coagulation and fibrinolytic system is impaired, both quantitatively and qualitatively. This destabilizes the balance between the two systems. In addition, the clearance of activated coagulation factors and fibrin(ogen) degradation products (FDP) from the systemic circulation is impaired. In patients with liver diseases and acute or imminent bleeding, or before invasive procedures, fresh frozen plasma (FFP) offers advantages over clotting factor concentrates. However, hypervolemia following the required doses of FFP might pose a problem in some liver disease patients.The complex pathophysiology both in DIC and in liver disease requires early diagnosis and adequate management including plasma and platelet substitution after treatment of the underlying disease. Due to the heterogeneity of DIC and liver disease, prospective randomized trials are difficult to perform. Therefore, treatment recommendations are mostly empirical and less evidence-based. Therapy must be accompanied by close and repeated clinical and laboratory monitoring.

[Transfusion of fresh frozen plasma (FFP): audit of prescriptions]

OBJECTIVE

To review fresh frozen plasma (FFP) prescriptions and compare their validity to the legal french guidelines (law of the 12/03/91).

STUDY DESIGN

Assessment of all prescriptions has been carried out by a multidisciplinary committee.

PATIENTS

All the adults transfused with FFP over one year in a teaching hospital.

METHODS

Following each head of department's agreement and following a written notice to all prescribers within the hospital to inform them of the undergoing study and its methodological validation by the board of quality experts, each delivery of FFP was followed by a questionnaire addressed to the prescriber. A board of experts then assessed the significance of the prescription in accordance with the legal requirements after reviewing each medical file.

RESULTS

144 prescriptions to 89 patients were assessed: 23% were judged inappropriate by the experts and 6% did not respect the law. The inappropriate transfusions distribute as follows: intensive care patients (73% of which 80% in multiple organ failure (MOF) and 20% in haemorrhagic shock), cirrhotic patients (12%), patients treated with vitamin K antagonists (12%), obstetric patients (3%). Nine percent of the appropriate transfusions were judged in insufficient volume. The hospital mortality rate was 48%. Among prescribers, 59% were not aware of the law.

CONCLUSION

A significant proportion of FFP transfusions is inappropriate. This study, which is the first step of a quality assurance program, will be followed by local recommendations for clinical practice. The current standards of prescribing FFP are more restrictive than those defined in the legal french guidelines.

Haemostatic disorders during liver transplantation

Profound and complex coagulation disorders are encountered during liver transplantation. They include preoperative coagulation disorders related to the liver disease and haemostatic changes related to the procedure itself. They commonly lead to increased intraoperative bleeding, especially due to increased fibrinolysis, the contribution of which can be demonstrated by the relative efficacy of antifibrinolytics. Given the multifactorial nature of bleeding in liver transplantation, preoperative coagulation tests cannot predict blood loss even if some statistical relationship is occasionally found. Preoperative correction of coagulation defects has not been shown to be effective in reducing intraoperative bleeding. Throughout the procedure, a rapid and sensitive method for monitoring coagulation is necessary in order to guide the rational use of blood components and pharmacological agents. The usefulness of such a method to assist management of blood loss or blood component requirements is poorly documented and controversial.

New directions in perioperative management for pediatric solid organ transplantation

Advances in pediatric solid organ transplantation have furthered the understanding of end-organ failures and refined the strategies for perioperative management of these otherwise lethal diseases. As the donor pool expands, the number of transplantations increases and long-term survival continues to improve, more complete knowledge of the immunologic and pathologic processes will be gained. A thorough understanding of the principles of transplantation medicine remains essential for physicians to provide optimal perioperative care of pediatric organ transplant patients.