Rapid reversal of oral anticoagulation with warfarin by a prothrombin complex concentrate (Beriplex): efficacy and safety in 42 patients

Management of warfarin-related intracerebral hemorrhage

Warfarin-related intracerebral hemorrhage (WICH) is a medical and neurosurgical emergency with a 1-month mortality of approximately 50%. Warfarin is commonly is used in patients with atrial fibrillation to prevent ischemic stroke and to prevent progression of deep vein thrombosis to pulmonary embolism. Owing to the ageing population, and increased incidence of atrial fibrillation with age and warfarin use, the incidence of WICH is expected to rise in the future. When WICH occurs, immediate discontinuation of warfarin with rapid warfarin reversal remains the first-line intervention, often with neurosurgical intervention. The optimal agent for rapid warfarin anticoagulation reversal remains to be defined owing to the lack of prospective randomized trials. We review current literature and prospects for future research for this devastating neurologic emergency.

Prothrombin complex concentrate (Beriplex P/N) for emergency anticoagulation reversal: a prospective multinational clinical trial

BACKGROUND

Prothrombin complex concentrate (PCC) can substantially shorten the time needed to reverse antivitamin K oral anticoagulant therapy (OAT). OBJECTIVES. To determine the effectiveness and safety of emergency OAT reversal by a balanced pasteurized nanofiltered PCC (Beriplex P/N) containing coagulation factors II, VII, IX, and X, and anticoagulant proteins C and S.

PATIENTS AND METHODS

Patients receiving OAT were eligible for this prospective multinational study if their International Normalized Ratio (INR) exceeded 2 and they required either an emergency surgical or urgent invasive diagnostic intervention or INR normalization due to acute bleeding. Stratified 25, 35, or 50 IU kg(-1) PCC doses were infused based on initial INR. Study endpoints included INR normalization (

RESULTS

Forty-three patients, 26 requiring interventional procedures and 17 experiencing acute bleeding, received PCC infusions at a median rate of 7.5 mL min(-1) (188 IU min(-1)). At 30 min thereafter, INR declined to

CONCLUSIONS

PCC treatment serves as an effective rapid hemorrhage control resource in the emergency anticoagulant reversal setting. More widespread availability of PCC is warranted to ensure its benefits in appropriate patients.

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Anticoagulants/adverse effects
• Coumarins/adverse effects
• Drug Combinations
• Emergencies
• Europe/epidemiology
• Factor IX/adverse effects
• Factor IX/therapeutic use
• Factor VII/adverse effects
• Factor VII/therapeutic use
• Factor X/adverse effects
• Factor X/therapeutic use
• Female
• Hemorrhage/chemically induced
• Hemorrhage/drug therapy
• Hemorrhage/prevention & control
• Hemostatics/adverse effects
• Hemostatics/therapeutic use
• Humans
• International Normalized Ratio
• Israel/epidemiology
• Male
• Middle Aged
• Prospective Studies
• Prothrombin/adverse effects
• Prothrombin/therapeutic use
• Pulmonary Embolism/chemically induced
• Vitamin K/therapeutic use

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Affiliation(s)

I Pabinger Department of Internal Medicine, Division of Haematology and Haemostaseology, Medical University Vienna, Vienna, Austria
B Brenner
U Kalina
S Knaub
A Nagy
H Ostermann

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Role of prothrombin complex concentrates in reversing warfarin anticoagulation: a review of the literature

Over-anticoagulation is a common problem with warfarin therapy and can lead to major or life-threatening bleeding. The goal of urgent warfarin reversal is to elevate or replace vitamin K-dependent clotting factors. In the United States, fresh frozen plasma (FFP) is considered the standard of care for warfarin reversal. Prothrombin complex concentrates (PCCs) offer an alternative to FFP for rapidly replacing deficient clotting factors and correcting the international normalized ratio (INR). However, few prospective clinical trials have been conducted to evaluate the effectiveness of these concentrates relative to other treatment modalities. A review of the published literature over the last 30 years found that PCCs offer a rapid and specific method for replacing vitamin K-dependent clotting factors and restoring normal hemostasis in the context of over-coagulation. In those studies in which PCCs were compared with FFP, PCCs were found more effective in shortening the time to INR correction and were associated with a low risk of thrombotic adverse events. Evidence-based treatment guidelines are needed to optimize the use of PCCs for warfarin reversal.

Management of Excessive Anticoagulant Effect Due to Vitamin K Antagonists

Unexpectedly elevated INR values are commonly encountered in clinical practice. In the absence of bleeding, such values may be treated with either simple warfarin withdrawal or the administration of low doses of oral vitamin K. Oral vitamin K will more rapidly return the INR to the therapeutic reference interval; however, its impact on bleeding is unknown. If the INR is in excess of 10, most experts would recommend the administration of vitamin K and, in the case of active bleeding, additional administration of coagulation factors either in the form of fresh frozen plasma (FFP) or prothrombin complex concentrates (PCC). Coagulation factor replacement is required given the need to urgently correct the INR; however, vitamin K should not be forgotten since it is required to antagonize the effect of warfarin, preventing “rebound” anticoagulation after transfused coagulation factors are consumed. This paper will review the evidence supporting various treatment modalities and will provide suggestions for treatment. Future advances in this area will likely focus on evaluations of the relative merits of FFP and PCCs.

Beriplex P/N: an alternative to fresh frozen plasma in severe haemorrhage

The management of Jehovah's Witnesses suffering from severe haemorrhage can be very difficult. Those patients who are taking oral anticoagulant therapy pose an additional risk and the difficulty may be compounded by the development of coagulopathy. Several alternatives to blood products have been reported to be useful in this situation. We report the successful management of an emergency postsurgical wound bleeding in a Jehovah's Witness using Beriplex (a concentrate of factors II, VII, IX and X). The patient, who was taking warfarin, presented 10 days after an elective laminectomy with significant bleeding from the surgical wound and coagulopathy. Despite early surgical measures, there was continuing haemorrhage. This was arrested by giving Beriplex intra-operatively. To our knowledge this is the first reported case of the use of Beriplex in a Jehovah's Witness for control of emergency haemorrhage and coagulopathy.

Successful emergency reversal of phenprocoumon anticoagulation with prothrombin complex concentrate: a prospective clinical study

The present prospective study was designed to evaluate the effectiveness and safety of prothrombin complex concentrate (PCC) for emergency reversal of oral anticoagulation with phenprocoumon, a long-acting coumarin. Patients were eligible for study entry if they required emergency reversal of phenprocoumon anticoagulation because they needed invasive surgical or diagnostic procedures or were actively bleeding. Patients received one or more infusions of pasteurized nanofiltered PCC (Beriplex P/N). Primary study endpoints were changes in International Normalized Ratio, Quick value, factors II, VII, IX and X, and protein C 10, 30 and 60 min following PCC infusion. Eight adult patients were enrolled, seven requiring urgent invasive procedures and one experiencing intracranial bleeding. In the first infusion, patients received a median 3600 IU PCC at median infusion rate 17.0 ml/min. Mean (SD) baseline International Normalized Ratio was 3.4 (1.2). The International Normalized Ratio 10 min after PCC infusion declined to 1.3 or less in seven of eight patients and to 1.4 in one patient. After PCC infusion, the Quick value increased by a mean of 57% [confidence interval (CI), 45-69%], circulating factor II concentration by 85% (CI, 68-103%), factor VII by 51% (CI, 40-62%), factor IX by 61% (CI, 47-76%), factor X by 115% (CI, 95-135%) and protein C by 100% (CI, 82-117%). Clinical effectiveness of PCC treatment was rated 'very good' in seven patients and 'satisfactory' in one. No thromboembolic or other adverse events occurred. PCC treatment rapidly, effectively and safely reversed phenprocoumon anticoagulation in patients undergoing urgent invasive procedures or actively bleeding.

Coagulation factor concentrates: past, present, and future

Clotting factor transfusions are vital for people with diseases such as haemophilia. In the 1970s and 1980s, transfusions with pooled plasma led to a devastatingly high number of recipients becoming infected with blood-borne pathogens such as HIV and hepatitis C. This epidemic triggered the development of virus-free factor concentrates through a combination of improved donor selection and screening, effective virucidal technologies, and recombinant protein expression biotechnology. There is now a wide range of recombinant factor concentrates, and an impressive safety record with respect to pathogen transmission. However, remaining therapeutic challenges include the potential threat of transmission of prions and other pathogens, the formation of inhibitory alloantibodies, and the international disparity that exists in product availability due to differences in licensure status as well as prohibitively high costs. In the future, it is likely that bioengineered recombinant proteins that have been modified to enhance pharmacokinetic properties or reduce immunogenicity, or both, will be used increasingly in clinical practice.

Geriatric Trauma

Elderly trauma patients present unique challenges and face more significant obstacles to recovery than younger patients. Despite overall higher mortality, longer length of stay, increased resource use, and higher rates of discharge to rehabilitation, most elderly trauma patients return to independent or preinjury functional status. Critical to improving these outcomes is an understanding that although similar trauma principles apply to the elderly, these patients require more aggressive evaluation and resuscitation. This article reviews the recent developments in the literature regarding care of the elderly trauma patient.

The headache over warfarin in British neurosurgical intensive care units: a national survey of current practice

OBJECTIVE

To ascertain current British practice regarding the emergency medical management of patients who sustain a spontaneous intracerebral haemorrhage (ICH) whilst receiving warfarin therapy and to compare this with established national and international guidelines.

DESIGN

Standardised, telephone based, questionnaire survey.

SETTING

All 32 adult British neuroscience intensive care units (ICUs)

PARTICIPANTS

Duty consultant of each neuroscience ICU.

RESULTS

Response rate was 100%. The international normalised ratio (INR) would be reversed by over 90% of ICU consultants treating patients on warfarin with an ICH, except patients with mechanical heart valves (MHV), when only 59.4% would reverse. Prothrombin complex concentrate (PCC) was used by 15 ICUs (46.9%); however, only six units (18.8%) apply reversal strategies with PCC and intravenous vitamin K in accordance with national guidelines. Fresh frozen plasma (FFP) continues to be used by 71.9% of the ICUs. A protocol for warfarin reversal in ICH was present in five ICUs, of which four followed national guidelines. None of the units that use FFP had a protocol. Following ICH, two-thirds of the ICUs (65.6%) would commence bridging heparinisation in the first 4 days for MHV patients and 25% would recommence warfarin before, and 64.5% after, 7 days.

CONCLUSION

There is considerable variation in practice amongst clinicians who regularly manage these patients and, in most cases (81.2%), practice is not in keeping with national or international guidelines. This study has demonstrated the need amongst senior ICU clinicians for a heightened awareness of current treatment recommendations and the availability of effective haemostatic therapies.

Use of blood and blood products in trauma

According to the global study of the burden of disease, violence and accidental injury account for 12% of deaths worldwide; 30-40% of trauma mortality is attributable to haemorrhage. The highly complex haemostatic system is severely impaired as a result of haemorrhagic shock, acidosis, hypothermia, haemodilution, hyperfibrinolysis, and consumption of clotting factors. Thus it is important to prioritize the prevention of the development of coagulopathy. Timely transfusion of red blood cells and plasma products becomes essential to restore tissue oxygenation, support perfusion, and maintain the pool of active haemostatic factors. The limits to this strategy to compensate for the loss of blood and coagulation factors are discussed. In the absence of international guidelines, there is an ongoing debate about a generally accepted treatment algorithm, mass transfusion protocols, and adverse events that have been observed as a result of transfusion. Thus many recommendations are based upon expert opinion rather than on evidence. In this chapter we address key issues of transfusions of red blood cells and plasma products in the acute control of bleeding in traumatized patients.

Ultra-rapid management of oral anticoagulant therapy-related surgical intracranial hemorrhage

OBJECTIVE

Intracranial hemorrhage in patients receiving oral anticoagulant (OAC) therapy is associated with poor neurological outcome. Prothrombin complex concentrate (PCC) is the gold-standard therapy to normalize hemostasis but remains underused. Ultra-rapid reversal of anticoagulation could reduce the time to biological and surgical hemostasis, and might improve outcome. We report the use of bolus infusions of PCC to immediately reverse anticoagulation and allow for urgent neurosurgical care.

DESIGN

Prospective, observational study.

SETTING

Neurosurgical intensive care unit, university hospital.

PATIENTS AND PARTICIPANTS

Eighteen patients with OAC-associated intracranial hemorrhage requiring urgent neurosurgical intervention.

INTERVENTIONS

All patients received 20 UI/kg of PCC as an intravenous bolus infusion (3 min) and 5 mg of enteral vitamin K. Surgery was started immediately, without waiting for blood sample results.

MEASUREMENTS AND RESULTS

Serial blood samples were performed to assess prothrombin time. Coagulation was considered normal when the international normalized ratio was </= 1.5. All patients, including nine who were over-anticoagulated, had complete reversal of anticoagulation immediately after the bolus of PCC. No hemorrhagic or thrombotic adverse effect was observed intra- or postoperatively.

CONCLUSIONS

A bolus infusion of PCC completely reverses anticoagulation within 3 min. Neurosurgery can be performed immediately in OAC-related intracranial hemorrhage. This study shows that OAC-treated patients can be managed as rapidly as non-anticoagulated patients.

Treatment of warfarin-associated intracerebral hemorrhage: literature review and expert opinion

Wider use of oral anticoagulants has led to an increasing frequency of warfarin-related intracerebral hemorrhage (ICH). The high early mortality of approximately 50% has remained stable in recent decades. In contrast to spontaneous ICH, the duration of bleeding is 12 to 24 hours in many patients, offering a longer opportunity for intervention. Treatment varies widely, and optimal therapy has yet to be defined. An OVID search was conducted from January 1996 to January 2006, combining the terms warfarin or anticoagulation with intracranial hemorrhage or intracerebral hemorrhage. Seven experts on clinical stroke, neurologic intensive care, and hematology were provided with the available information and were asked to independently address 3 clinical scenarios about acute reversal and resumption of anticoagulation in the setting of warfarin-associated ICH. No randomized trials assessing clinical outcomes were found on management of warfarin-associated ICH. All experts agreed that anticoagulation should be urgently reversed, but how to achieve it varied from use of prothrombin complex concentrates only (3 experts) to recombinant factor VIIa only (2 experts) to recombinant factor VIIa along with fresh frozen plasma (1 expert) and prothrombin complex concentrates or fresh frozen plasma (1 expert). All experts favored resumption of warfarin therapy within 3 to 10 days of ICH in stable patients in whom subsequent anticoagulation is mandatory. No general agreement occurred regarding subsequent anticoagulation of patients with atrial fibrillation who survived warfarin-associated ICH. For warfarin-associated ICH, discontinuing warfarin therapy with administration of vitamin K does not reverse the hemostatic defect for many hours and is inadequate. Reasonable management based on expert opinion includes a wide range of additional measures to reverse anticoagulation in the absence of solid evidence.

Prothrombin complex concentrate versus recombinant factor VIIa for reversal of coumarin anticoagulation

INTRODUCTION

Prothrombin complex concentrate (PCC) is recommended for emergency reversal of oral coumarin anticoagulation. Recently, recombinant factor VIIa (rFVIIa) has also been investigated for this purpose, although no direct comparison of PCC and rFVIIa has been reported. This study was designed to compare the effectiveness of PCC and rFVIIa for reversal of both acute and sustained coumarin anticoagulation.

MATERIALS AND METHODS

In the acute model, rats received 2.5 mg.kg(-1) phenprocoumon, and reversal of anticoagulation by 4.88 mL.kg(-1) saline, 100 microg.kg(-1) rFVIIa (NovoSeven) or 50 U.kg(-1) PCC (Beriplex P/N) was assessed at 16 h. For the sustained model, a second phenprocoumon dose was administered at 24 h and anticoagulation reversal evaluated at 48 h. Study endpoints were activated partial thromboplastin time (aPTT), prothrombin time (PT) and tail tip bleeding.

RESULTS

Acute anticoagulation raised median PT to 4.3 fold the normal level. This elevation was nearly completely reversed both by rFVIIa and PCC. aPTT increase was minor. Effects of sustained anticoagulation were more severe and pervasive, with aPTT, PT and blood loss increasing to 7.7, 51 and 30 fold the control levels, respectively. In the sustained model, rFVIIa substantially reduced and PCC fully normalized PT. In this model, PCC also diminished aPTT (p<0.01), fully normalized blood loss (p<0.01) and shortened bleeding time (p=0.008), while rFVIIa was without significant effect on these endpoints.

CONCLUSIONS

In a sustained anticoagulation animal model designed to simulate standard long-term oral coumarin therapy in patients, PCC was more effective than rFVIIa in restoring hemostatic function.

Perioperative management of patients receiving vitamin K antagonists

PURPOSE

As the number of patients taking vitamin K antagonists (VKA) is growing, the clinician is increasingly faced with having to make decisions regarding anticoagulation therapy before, during and immediately after surgery. In this article we review the indications for VKA and assess their use in the perioperative period based on available pharmacological and clinical data.

SOURCE

An on-line computerized search of Medline was conducted limited to English and French language articles. The bibliographies of relevant articles and additional material from other published sources were retrieved and reviewed.

PRINCIPAL FINDINGS

Assessment of patients taking VKA who need surgery must include three factors: 1) the indication for anticoagulation, which determines the thromboembolic risk; 2) the pharmacokinetics of VKA, which determine the moment at which treatment should be discontinued; and 3) the type of surgery, which determines the hemorrhagic risk. Some patients will need to stop VKA treatment and start a substitution or "bridging" anticoagulant therapy, such as unfractionated heparin or low molecular weight heparin, prior to and after surgery. In patients requiring emergency surgery, prothrombin complex concentrate can be used to improve coagulation and is preferable to, although more expensive than fresh frozen plasma.

CONCLUSIONS

For the perioperative setting, further studies are required to determine the optimal substitution ("bridging") regimen and the clinical circumstances that necessitate substitution therapy.

Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms

BACKGROUND

An excessive anticoagulant effect because of coumarins is frequently encountered.

OBJECTIVE

To review available literature on the management of warfarin-associated coagulopathy and to propose evidence-based treatment algorithms.

METHODS

Data sources were Medline and Embase. Papers published between 1966 and December 2005 describing randomized trials or prospective cohort studies evaluating treatments for coumarin-associated coagulopathy were abstracted.

RESULTS

Low dose oral vitamin K rapidly and reliably returns the international normalized ratio (INR) to the usual therapeutic range in non-bleeding patients. Simple withholding of acenocumarol results in rapid correction of its anticoagulant effect. The impact of oral vitamin K on phenprocumon-associated coagulopathy cannot be determined from available literature. Intravenous vitamin K and coagulation factors should be given to patients with major or life-threatening hemorrhage. The optimal dose and type of coagulation factor is not known.

CONCLUSIONS

Vitamin K therapy is an effective treatment for INR prolongation in patients with coumarin-associated coagulopathy; coagulation factor replacement is required, in addition, in patients with major bleeding or with indication for immediate correction of their INR. Clinical trials powered to detect differences in rates of bleeding and thrombosis are now required to determine if vitamin K reduces the risk of bleeding without causing thrombosis in non-bleeding patients with prolonged INR.

Plasma and plasma products in the treatment of massive haemorrhage

Massive haemorrhage requires the use of plasma products when it is accompanied by a coagulopathy or when the more than one blood volume has been lost and intractable bleeding continues. The coagulopathy results from haemorrhagic shock, hypothermia, and activation, consumption and dilution of coagulation factors. Plasma products have a critical role in maintaining sufficient levels of coagulation proteins to ensure haemostasis can occur. Fresh frozen plasma is a source of all coagulation proteins and is required when the prothrombin time and activated partial thromboplastin time exceed 1.5 times the normal control. Cryoprecipitate is the plasma product of choice if fibrinogen, the most critical coagulation protein, is required rapidly and to maintain levels at >1g/L. Prothrombin complex concentrates, monocomponent factor therapy and fibrin sealants each have a role in specific clinical settings. Recombinant factor VIIa has now been shown to have a role in massive haemorrhage. Randomised controlled trials are currently underway to determine the optimal dose and timing of its administration. The physiology and management of the coagulation disturbance using plasma products in the massive haemorrhage of specific clinical situations are described.

Individualized dosing regimen for prothrombin complex concentrate more effective than standard treatment in the reversal of oral anticoagulant therapy: An open, prospective randomized controlled trial

Prothrombin Complex Concentrate (PCC) is indicated for the acute reversal of oral anticoagulation therapy. To compare the efficacy of a "standard" dosage of 20 ml PCC equivalent to about 500 IU factor IX (group A), and an "individualized" dosage based on a target-INR of 2.1 or 1.5, the initial-INR and the patient's body weight (group B), we performed an open, prospective, randomized, controlled trial. The in vivo response and in vivo recovery of factor II, VII, IX and X in these patients on oral anticoagulation was determined. Ninety three patients (group A: 47; group B: 46) with major bleedings or admitted for urgent (surgical) interventions were enrolled. PCC and Vitamin K (10 mg) were administered intravenously. We evaluated the effect of treatment by the decrease of INR and the clinical outcome. The number of patients reaching the target-INR 15 min after the dosage of PCC was significantly higher in the group treated with an "individualized" dosage, compared to the group treated with a standard dose, (89% versus 43%; p<0.001). So, we conclude that for the acute reversal of oral anticoagulant therapy, an "individualized" dosage regimen of PCC based on the target-INR, the initial-INR, and body weight of the patient, is significantly more effective in reaching the target-INR than a "standard" dosage. The in vivo response and in vivo recovery found in this study was higher then in patients with isolated factor deficiencies. This suggests that the pharmacokinetics in patients on oral anticoagulants may be different.

Vermeidung von Notfallsituationen bei gerinnungshemmender Therapie mit Vitamin-K-Antagonisten

Despite 50 years of clinical experience with vitamin K antagonists such as phenprocoumon or warfarin, many clinicians are uncertain how to start treatment, deal with overdose or bleeding complications, and how to bridge anticoagulation when treatment with vitamin K antagonists is interrupted. Patients with overdose of vitamin K antagonists or bleeding complications are treated with vitamin K, prothrombin complex concentrates (PCC), or recombinant factor VIIa. Rapid reversal of anticoagulation is only achieved by using PCC or recombinant factor VIIa. Both should be combined with vitamin K for a sustained effect. For elective surgery, treatment with vitamin K antagonists is paused and vitamin K given either orally or intravenously. Unfractionated or low molecular weight heparin is given when INR levels are below therapeutic range. Patients with contraindications to heparin may be treated with alternative anticoagulants such as danaparoid, lepirudin or fondaparinux.

Anticoagulation in the trauma patient

The trauma patient presents several challenges in areas of anticoagulation and haemostasis. Low molecular weight heparins are the mainstay of thrombopro phylaxis of trauma patients; however, new agents are being studied in trials and may soon be available. Patients already on oral anticoagulation may need reversal using plasma or prothrombin complex concentrates. Heparin-induced thrombo cytopenia needs a high index of suspicion and prompt treatment by clinicians treating trauma patients. Disseminated intravascular coagulation can be seen in the context of major trauma. Correction of the underlying cause and supportive blood component use are the mainstays of treatment.

Optimal dose of prothrombin complex concentrate for acute reversal of oral anticoagulation

We investigated optimal dose of prothrombin complex concentrate (PCC) for acute reversal of oral anticoagulation in patients with major hemorrhagic complications or who required invasive procedures. We also checked how rapidly international normalized ratio (INR) was reversed after PCC administration. INR was measured before and 10-60 min after administration of PCC with or without vitamin K in 42 patients (men 28, women 14, median age of 70 years old) who had received warfarin but required rapid reversal of INR because of a hemorrhagic complication or medical procedure. The amount of PCC administered was 200 IU in six patients, 500 IU in 30, 1000 IU in 3, and 1500 IU in the other 3. Additional administration of PCC was performed when the correction of INR was inadequate. In 10 of the 42 cases, INR was measured serially, before, 10 and 60 min and 12-24 h after the administration of PCC and vitamin K. In the six patients who received PCC of 200 IU, INR values of 3.34 median (range 2.06 to 5.08) decreased to 1.85 (range 1.23 to 2.43) significantly (Wilcoxon's rank sum test, p=0.028), but in three patients (50%), INR values were still above 2.0 after the administration. In 30 patients treated with PCC of 500 IU, values decreased from 2.49 median (range 1.54 to 10.00) to 1.19 (range 0.87 to 1.55) significantly (p<0.0001). The corrected INR values were below 1.5 in 25 of 26 patients (96%) who had initial INR values from 2.0 to 4.9. In four patients with initial INR of 5.0 or more, the reversed INR was below 1.5 in one (25%), between 1.5 and 2.0 in two (50%), and above 2.0 in one (25%) who had additional administration of 500 IU PCC lowering INR from 2.01 to 1.48. Values of INR in the six patients receiving 1000 IU or 1500 IU, INR decreased from 2.33 median (range 1.96 to 4.00) to 0.96 (range 0.87 to 1.24, p=0.028). In the 10 patients with serial measurement, INR changed from 2.67 median (range 2.05 to 10.00) to 1.17 (range 0.99 to 1.60) 10 min after the administration. The INR values remained stable 60 min and 12-24 h after the PCC administration. The 500 IU of PCC is likely to be optimal dose of PCC for emergent reversal of INR in patients requiring rapid correction of INR below 5.0, but to be inadequate dose in patients with INR of 5.0 or more. PCC administration with vitamin K may finish reversing INR rapidly within 10 min and keep the reversed INR values for 12-24 h.

Warfarin reversal

Warfarin is the most commonly used oral anticoagulant in the UK. It is associated with few side effects apart from haemorrhage. The most appropriate way to reverse the anticoagulant effect of warfarin depends on the clinical circumstances. In serious bleeding, rapid reversal is required, whereas in minor bleeding or asymptomatic over anticoagulation, a more leisurely approach is usually appropriate. This review discusses the current approaches to warfarin reversal in clinical practice. The development of a uniform approach to warfarin reversal in the Northern Region is described.

Efficacy and safety of a prothrombin complex concentrate (Octaplex®) for rapid reversal of oral anticoagulation

Bleeding is the most serious adverse event of oral anticoagulants and is a major cause of morbidity and mortality in such patients. Rapid reversal of anticoagulation in bleeding patients or prior to urgent surgery is mandatory. The therapeutic options in these situations include administration of fresh frozen plasma (FFP), and recently of prothrombin complex concentrates (PCCs). However, viral safety and thrombogenicity of PCCs remain issues of concern. In the present study, we administered Octaplex, a new solvent/detergent (S/D) treated and nanofiltered PCC, to excessively anticoagulated bleeding patients or to anticoagulated patients facing urgent surgery. Ten excessively anticoagulated patients with major bleeding and 10 anticoagulated patients awaiting surgery (median age 72.5 (43-83) years, 9 females) received a median dose of 26.1 IU/kg body weight (BW) of Octaplex for reversal of anticoagulation. Response to Octaplex was rapid with decline of INR within 10 min after Octaplex administration (from 6.1+/-2. to 1.5+/-0.3). Clinical response was graded as good in most patients (85%) and as moderate in the rest. Octaplex administration was uneventful in all patients. Following Octaplex administration, a small increase in F1+2 levels was observed in bleeding patients, whereas D-dimer level did not change significantly. We conclude that Octaplex is effective and safe in situations where rapid reversal of anticoagulation is needed.

Reversal of the International Normalized Ratio with recombinant activated factor VII in central nervous system bleeding during warfarin thromboprophylaxis: clinical and biochemical aspects

Major bleeding is a frequent and hazardous complication associated with thromboprophylaxis using vitamin-K antagonists (VKA). Suggested regimens for control of highly elevated International Normalized Ratio (INR) and hemorrhagic events during VKA treatment include administration of vitamin K, infusion of fresh frozen plasma (FFP) or a prothrombin complex concentrate (PCC). In contrast, this communication present the first report on the efficacious use of recombinant factor VIIa (rFVIIa) as additional therapy in seven patients presenting with central nervous system (CNS) bleeding emergencies. Pre-treatment INRs ranged from 1.7 to 6.6, and 10 min after a single dose of rFVIIa (10-40 microg/kg) all INRs were </= 1.5. Six patients underwent drainage of the CNS hematoma and all patients survived. No untoward biochemical signs of coagulation activation were detected and no incidence of thromboembolism was observed. In ex-vivo experimental studies, profiles of continuous whole blood clot formation were evaluated by thrombelastography in 25 patients on VKA treatment (INR 1.7-4.3), demonstrating a significantly prolonged initiation phase and diminished propagation of clot formation. Ex-vivo supplementation with rFVIIa to blood of six patients returned a distinct reduction of the prolonged initiation but variable changes in the maximum velocity of clot formation. The ex-vivo experiments and our clinical data support recent suggestions that rFVIIa might substitute for infusion of FFP or PCC in acute reversal of VKA treatment.

Correction of INR by prothrombin complex concentrate and vitamin K in patients with warfarin related hemorrhagic complication

We investigated the effect of prothrombin complex concentrate (PCC, median 500 IU) and vitamin K (10-20 mg) or either on blood coagulation and clinical findings in 17 patients with major hemorrhagic complication during warfarin treatment. Their international normalized ratio (INR) at admission was median 2.7 (2.0-above 10.0). In 11 patients treated with PCC and vitamin K, INR decreased to median 1.13 (0.91-1.36) 10 min after the administration with elevation of plasma levels of coagulant factors II, VII, IX, X and protein C.INR decreased abruptly after the administration of PCC without vitamin K in two patients but it increased again 12-24 h after, with decrease of coagulant factors levels. In one of them, a hematoma of the brain enlarged with INR re-increase 12-24 h after the administration. In four patients treated with vitamin K alone, INR decreased slowly from 2.69 (1.03-3.35) to 1.28 (1.25-1.44) 12-24 h after the administration in parallel with gradual increase of the coagulant factors.PCC administration with or without vitamin K seems to be more effective in rapidly correcting increased INR levels than vitamin K treatment without PCC. PCC without vitamin K may result in re-increase of INR and clinical deterioration.