Indications for prothrombin complex concentrates in massive transfusions

[Management of Massive Intraoperative Blood Loss Using a Case Study]

Massive intraoperative bleeding is a major and potentially life-threatening complication during surgical procedures. The lethal triade of hemorrhagic shock with metabolic acidosis, hypothermia and coagulopathy enhances bleeding tendency. Avoiding this vitious circle requires a well-structured and standardized procedure. Primary goals include the maintenance of adequate tissue oxygenation, restauration of proper coagulatory function, normothermia and homeostasis of acid-base and electrolyte balance. In the present article, these therapeutic goals and their pathophysiological background are illustrated with a clinical case example.

Hemostasis in liver disease: implications of new concepts for perioperative management

The hemostatic profile of patients with liver diseases is frequently profoundly different from that of healthy individuals. These complex alterations lead to abnormal results from routine laboratory tests, but because of the nature of these assays, they fail to accurately represent the patient's hemostatic state. Nevertheless, based on abnormal laboratory coagulation values, it has long been assumed that patients with liver disease have a natural bleeding tendency and are protected from thrombosis. This assumption is false; the average patient with liver disease is actually in a state of "rebalanced hemostasis" that can relatively easily be tipped toward both bleeding and thrombosis. The new paradigm of rebalanced hemostasis has strong implications for the clinic, which are presented in this review. There is no evidence that prophylactic transfusion of plasma helps to prevent procedure-related bleeding. In addition, the presence of independent risk factors such as poor kidney status or infections should be carefully assessed before invasive procedures. Furthermore, central venous pressure plays an important role in the risk of bleeding in patients with liver diseases, so during procedures, a restrictive infusion policy should be applied. Finally, thrombosis prophylaxis should not be withheld from patients with cirrhosis or acute liver failure, and clinicians should be alert to the possibility of thrombosis occurring in these patients.

Prothrombin complex concentrate in the reduction of blood loss during orthotopic liver transplantation: PROTON-trial

BACKGROUND

In patients with cirrhosis, the synthesis of coagulation factors can fall short, reflected by a prolonged prothrombin time. Although anticoagulants factors are decreased as well, blood loss during orthotopic liver transplantation can still be excessive. Blood loss during orthotopic liver transplantation is currently managed by transfusion of red blood cell concentrates, platelet concentrates, fresh frozen plasma, and fibrinogen concentrate. Transfusion of these products may paradoxically result in an increased bleeding tendency due to aggravated portal hypertension. The hemostatic effect of these products may therefore be overshadowed by bleeding complications due to volume overload.In contrast to these transfusion products, prothrombin complex concentrate is a low-volume highly purified concentrate, containing the four vitamin K dependent coagulation factors. Previous studies have suggested that administration of prothrombin complex concentrate is an effective method to normalize a prolonged prothrombin time in patients with liver cirrhosis. We aim to investigate whether the pre-operative administration of prothrombin complex concentrate in patients undergoing liver transplantation for end-stage liver cirrhosis, is a safe and effective method to reduce perioperative blood loss and transfusion requirements.

METHODS/DESIGN

This is a double blind, multicenter, placebo-controlled randomized trial.Cirrhotic patients with a prolonged INR (≥1.5) undergoing liver transplantation will be randomized between placebo or prothrombin complex concentrate administration prior to surgery. Demographic, surgical and transfusion data will be recorded. The primary outcome of this study is RBC transfusion requirements.

DISCUSSION

Patients with advanced cirrhosis have reduced plasma levels of both pro- and anticoagulant coagulation proteins. Prothrombin complex concentrate is a low-volume plasma product that contains both procoagulant and anticoagulant proteins and transfusion will not affect the volume status prior to the surgical procedure. We hypothesize that administration of prothrombin complex concentrate will result in a reduction of perioperative blood loss and transfusion requirements. Theoretically, the administration of prothrombin complex concentrate may be associated with a higher risk of thromboembolic complications. Therefore, thromboembolic complications are an important secondary endpoint and the occurrence of this type of complication will be closely monitored during the study.

TRIAL REGISTRATION

The trial is registered at http://www.trialregister.nl with number NTR3174. This registry is accepted by the ICMJE.

Massive transfusion in traumatic shock

BACKGROUND

Hemorrhage after trauma is a common cause of death in the United States and globally. The primary goals when managing traumatic shock are the restoration of oxygen delivery to end organs, maintenance of circulatory volume, and prevention of ongoing bleeding through source control and correction of coagulopathy. Achieving these goals may require massive transfusion of blood products. Although use of blood products may be lifesaving, dose-related adverse effects are well described.

DISCUSSION

Complications of massive transfusion include interdependent derangements such as coagulopathy, hypothermia, acidosis, and electrolyte abnormalities, as well as infectious and immunomodulatory phenomena. This article explores the pathogenesis, implications, prevention, and treatment of these complications through the use of massive transfusion protocols. Particular attention is given to the optimal ratio of blood products transfused in large volume resuscitation and prevention of secondary coagulopathy.

CONCLUSIONS

Observational data indicate that the development and use of a massive transfusion protocol may reduce the morbidity and mortality associated with large-volume resuscitation of patients with hemorrhagic shock. Such protocols should include a pre-defined ratio of packed red blood cells, fresh frozen plasma, and platelets transfused; most commonly, the ratio used is 1:1:1. Additionally, such protocols should monitor for and correct hypothermia, hypofibrinogenemia, and electrolyte disturbances such as hypocalcemia and hyperkalemia.

Use of prothrombin complex concentrates: 4-year experience of a national aeromedical retrieval service servicing remote and rural areas

INTRODUCTION

Prothrombin complex concentrates (PCCs) are recommended as first-line treatment for acquired or congenital factor II, VII, IX and X deficiencies in situations of major haemorrhage. The Emergency Medical Retrieval Service (EMRS) provides critical care and aeromedical retrieval to patients in remote and rural Scotland. It has an important role in the care of these patients.

METHOD

We sought to determine the incidence of haemorrhage requiring PCC administration in our cohort of patients, and to assess compliance with current national guidelines regarding their storage and use. We searched our database for all patients that received PCCs, or met current guidelines for their administration, and followed them through to hospital discharge. We also conducted a telephone survey of all hospitals served by the EMRS to determine compliance with national standards.

RESULTS

During the 42-month study period, 1170 retrieval missions were conducted. Twenty-six retrieved patients had a congenital or acquired clotting factor deficiency and seven met criteria for PCC administration. Of these, only three received PCCs prior to transfer to definitive care. Telephone survey revealed that all the rural general hospitals were served by the EMRS stock PCCs, but only one out of 15 GP-led community hospitals had access to PCCs.

CONCLUSIONS

In the remote and rural setting where access to definitive care may be limited or delayed, timely administration of PCCs in appropriate patients may improve outcomes. As many rural hospitals do not have access to PCCs, the ability of the EMRS to provide this treatment may improve patient care.

Safety of prothrombin complex concentrates for rapid anticoagulation reversal of vitamin K antagonists. A meta-analysis

Prothrombin complex concentrates (PCCs) are recommended as the treatment of choice in warfarin-related coagulopathy. However, the risk of thromboembolic complications associated with their use is not well defined. We performed a meta-analysis to estimate the rate of thromboembolic complications in patients receiving vitamin K antagonists (VKAs) treated with PCCs for bleeding or before urgent surgery. Medline and Embase databases were searched. Two reviewers performed study selection and extracted data independently. Studies providing data on incidence of thromboembolic complications in VKA-treated patients were eligible for the study. Weighted mean proportion of the rate of thromboembolic complications and the mortality rate were calculated. Twenty-seven studies (1,032 patients) were included. Seven studies used 3-factor, and 20 4-factor PCCs. Twelve patients had a thromboembolic complication (weighted mean 1.4%; 95% CI 0.8-2.1), of which two were fatal. The incidence of thromboembolic events was 1.8% (95% CI 1.0-3.0) in patients treated with 4-factor PCCs, and 0.7% (95% CI 0.0-2.4) in patients treated with 3-factor PCCs. Total mortality rate was 10.6% (95% CI 5.9-16.6). In conclusion, our results suggest there is a low but quantifiable risk of thromboembolism in VKA-treated patients receiving PCCs for anticoagulation reversal. These findings should be confirmed in randomised, controlled trials.

Prothrombin complex concentrate in surgical patients: retrospective evaluation of vitamin K antagonist reversal and treatment of severe bleeding

Introduction

Prothrombin complex concentrates are recommended for rapid reversal of vitamin K anticoagulants. As they normalize levels of vitamin K dependent clotting factors and re-establish hemostasis, they may also be used as adjunctive therapy in patients with major bleeding. The aim of this study was to retrospectively evaluate the efficacy of prothrombin complex concentrates in the surgical setting.

Methods

The case notes of 50 patients requiring urgent oral anticoagulation reversal (n = 12) or with severe perioperative coagulopathic bleeding (n = 38) who received an infusion of prothrombin complex concentrate (Beriplex P/N(R) 500) at the surgical department of the University of Munich Hospital, Germany were retrospectively reviewed. Efficacy of prothrombin complex concentrate application was evaluated using the Quick test, reported as an international normalized ratio, hemodynamic measurements and requirement for blood products. Safety assessments included whole blood hemoglobin levels and specific parameters of organ dysfunction.

Results

Baseline characteristics were comparable, except that mean baseline international normalized ratio and hemoglobin levels were significantly higher (P < 0.01) in anticoagulation reversal than in bleeding patients. In anticoagulation reversal, the international normalized ratio was significantly reduced (from 2.8 +/- 0.2 at baseline to 1.5 +/- 0.1, P < 0.001) after one prothrombin complex concentrate infusion (median dose 1500 IU; lower quartile 1,000, upper quartile 2,000). No major bleeding was observed during surgery after prothrombin complex concentrate administration. Only one patient received platelets and red blood cell transfusion after prothrombin complex concentrate administration. In bleeding patients, infusion of prothrombin complex concentrate (median dose 2,000 IU; lower quartile 2,000, upper quartile 3,000) significantly reduced the INR from 1.7 +/- 0.1 at baseline to 1.4 +/- 0.1 (P < 0.001). This decrease was unrelated to fresh frozen plasma or vitamin K administration. Bleeding stopped after prothrombin complex concentrate administration in 4/11 (36%) patients with surgical bleeding and 26/27 (96%) patients with diffuse bleeding. Hemoglobin levels increased significantly from baseline in bleeding patients (P < 0.05) and mean arterial pressure stabilized (P < 0.05). No thrombotic events or changes in organ function were reported in any patient.

Conclusions

Prothrombin complex concentrate application effectively reduced international normalized ratios in anticoagulation reversal, allowing surgical procedures and interventions without major bleeding. In bleeding patients, the improvement in coagulation after prothrombin complex concentrate administration was judged to be clinically significant.

Prothrombin complex concentrates: a brief review

Prothrombin complex concentrates are haemostatic blood products containing four vitamin K-dependent clotting factors (II, VII, IX and X). They are a useful, reliable and fast alternative to fresh frozen plasma for the reversal of the effects of oral anticoagulant treatments (vitamin K antagonists). They are sometimes used for factor II or factor X replacement in patients with congenital or acquired deficiencies. They are widely prescribed in Europe. Several retrospective and prospective studies have demonstrated their efficacy in normalizing coagulation and in helping to control life-threatening bleeding. Few side-effects, mainly thromboembolic events, have been reported. The link between these events and prothrombin complex concentrate infusion has, however, often been brought into question. The use of prothrombin complex concentrates in new promising indications such as the management of massive bleeding requires prospective studies providing a high level of evidence in a high-risk setting.

Thrombomodulin accelerates activated protein C production and inhibits thrombin generation in the plasma of disseminated intravascular coagulation patients

Thrombomodulin (TM) has been under development as a medicine for disseminated intravascular coagulation (DIC), and is expected to exhibit strong anticoagulant activity by inhibiting thrombin generation via the acceleration of protein C activation. In the present study, we examined the pharmacological action of TM in plasma obtained from DIC patients. TM was found to inhibit thrombin generation and accelerate activated protein C (APC) production at 0.3-30 TM units/ml in plasma obtained from DIC patients irrespective of their underlying disorders. In addition, there was a positive correlation between the inhibition of thrombin generation and the amount of APC produced. Thrombin generation was inhibited by over 50% when the plasma level of APC was increased by more than 0.2 microg/ml. These results indicate that TM inhibits thrombin generation in plasma obtained from DIC patients by accelerating APC production. Moreover, the results imply that the thrombin generation test may be a good method to speculate the efficacy of TM on every patient before the administration of TM.

Vitamin K-dependent coagulation factors and fibrinogen levels in FFP remain stable upon repeated freezing and thawing

BACKGROUND

FFP is considered adequate for transfusion up to 24 hours after thawing and is currently used most often to replace deficient clotting factors, such as in warfarin overdose. We set to examine the levels of vitamin K-dependent factors (i.e., prothrombin, FVII, F IX, FX), as well as fibrinogen, upon twice freezing and thawing of FFP. If factor levels in refrozen FFP remain within normal limits, this component can possibly be transfused, thus avoiding wastage of precious blood components.

STUDY DESIGN AND METHODS

Twenty units of FFP, five units of each blood group A, B, AB, and O, were thawed, and aliquots were taken for measurement of coagulation factors. The plasma units were then kept for 24 hours at 4 degrees C, at which point a second aliquot was taken, The remaining FFP units were refrozen and kept at -80 degrees C for 1 week. The above procedure was then repeated. Coagulation-factor activity and fibrinogen level were measured by the coagulation analyzer.

RESULTS

The mean levels of prothrombin, FVII, F IX, FX, and fibrinogen of each blood group (A, B, AB, and O) were calculated for each of four time points and found not statistically different (p > 0.05). Therefore, the rest of the analysis was done for all 20 FFP units as one group. The mean +/- SD levels of each coagulation factor at each time point demonstrated that all levels were within normal limits of all factors measured and that for none of the factors was there a significant decay of activity.

CONCLUSIONS

The levels of prothrombin, FVII, F IX, FX, and fibrinogen remain stable and adequate for transfusion in twice-thawed-and-refrozen FFP. This component can be safely used for transfusion as a source of vitamin K-dependent clotting factors and fibrinogen.

Massive blood transfusion in the elective surgical setting

Massive haemorrhage in elective surgery can be either anticipated (e.g. organ transplantation) or unexpected. Management requires early recognition, securing haemostasis and maintenance of normovolaemia. Transfusion management involves the transfusion of packed red cells, platelet concentrates and plasma (fresh frozen plasma and cryoprecipitate). Blood product support should be based on clinical judgment and be guided by repeated laboratory tests of coagulation. Although coagulation tests may not provide a true representation of in vivo haemostasis, they do assist in management of haemostatic factors. Below critical levels (prothrombin time or activated partial thromboplastin time >1.8; fibrinogen <1.0 g/l; platelet count < 80 x 10(9) 1(-1)) it is difficult to achieve haemostasis. Despite seemingly adequate blood component therapy there remain situations where haemorrhage is uncontrollable. In this setting, alternative approaches must be considered. These include the use of other blood products (e.g. prothrombin complex concentrates; fresh whole blood; fibrin glue) and pharmacological agents (e.g. aprotinin). Complications of massive transfusion result in significant morbidity and mortality. These may be secondary to the storage lesion of the transfused blood products, disseminated intravascular coagulation, hypothermia or hypovolaemic shock. The use of fresh blood products and leucocyte-reduced packed red cells and platelets, may minimise some of the adverse clinical sequelae.

Massive transfusion in dogs: 15 cases (1997-2001)

OBJECTIVE

To determine clinical characteristics of dogs that received massive transfusion and identify the underlying diseases, complications, and outcomes.

DESIGN

Retrospective study.

ANIMALS

15 dogs.

PROCEDURE

Medical records of dogs receiving a massive blood transfusion were evaluated for transfusion volume, underlying disease process or injury, benefits and complications of transfusion, and outcome. A massive transfusion was defined as transfusion of a volume of blood products in excess of the patient's estimated blood volume (90 ml/kg [40 ml/lb]) in a 24-hour period or transfusion of a volume of blood products in excess of half the patient's estimated blood volume in a 3-hour period.

RESULTS

Six dogs had intra-abdominal neoplasia resulting in hemoabdomen, 3 had suffered a traumatic incident resulting in hemoabdomen, and 6 had non-traumatic, non-neoplastic blood loss. Mean volumes of packed RBC and fresh-frozen plasma administered were 66.5 ml/kg (30 ml/lb) and 22.2 ml/kg (10 ml/lb), respectively. All dogs evaluated developed low ionized calcium concentrations and thrombocytopenia. Transfusion reactions were recognized in 6 dogs. Four dogs survived to hospital discharge.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that massive transfusion is possible and potentially successful in dogs. Predictable changes in electrolyte concentrations and platelet count develop.