Treatment of warfarin-associated coagulopathy with vitamin K

Managing Micronutrient Deficiencies in High-Risk Patients: No Small Feat!

PURPOSE OF REVIEW

Micronutrients are vital dietary components for growth and development. Adequate intake of vitamins and minerals through diet is crucial for proper biomolecular and cellular functioning. Many developed countries supplement foods and micronutrient deficiencies are less common. However, many disease states impair micronutrient absorption, metabolism, and excretion. Thus, early recognition of the signs and symptoms of micronutrient deficiencies is critical for providers to improve quality of life and prevent complications in high-risk patients. This article reviews the basic function of micronutrients, recognizes the symptoms of each micronutrient deficiency, provides natural sources of intake, and discusses the diagnosis and supplementation of each micronutrient. High risk patients based on disease state for each micronutrient is discussed. In addition, Bariatric patients are a specific group at high risk of micronutrient deficiency and their management and supplementation for treatment is also covered.

RECENT FINDINGS

Micronutrients play a vital role in antioxidant defense, especially in critically ill patients, due to an increase in oxidative stress. Early intervention with high-dose supplementation with vitamin C, vitamin E, zinc and selenium may have beneficial effects. Micronutrients deficiency remains an issue for patients in the developed world. Providers should recognize patients who are at high risk for micronutrients deficiencies and provide proper screening and prompt supplementation after diagnosis to prevent complications of micronutrient deficiencies.

Anticoagulation therapy in atrial fibrillation after intracranial hemorrhage

Intracerebral hemorrhage (ICH) is severe and fatal complication of anticoagulant therapy with an incidence 0.3-0.7% per year. For patients with atrial fibrillation (AF) anticoagulants are administered for decreasing risk of stroke and systemic embolism. In this case the occurrence of intracranial bleeding is hard task for doctor. From the one side it is necessary to reverse the action of the drug for preventing the growth of hematoma. At the same time the discontinuation of therapy increases the risk of systemic embolism for patients with AF significantly. Clinical guidelines and studies have been reviewed about ICH during anticoagulant therapy. Nowadays there is no quality evidence about reversal of anticoagulant effects after ICH and optimal time of resumption of anticoagulant therapy. Firstly, we do not have large randomized controlled trials on this issue. The majority of clinical guidelines were based on retrospective studies and opinions of experts. Soon several randomized controlled trials will be finished and new data will be presented.

Management of antiplatelet or anticoagulant therapy in endoscopy: A review of literature

Endoscopic procedures hold a basal risk of bleeding that depends on the type of procedure and patients’ comorbidities. Moreover, they are often performed in patients taking antiplatelet and anticoagulants agents, increasing the potential risk of intraprocedural and delayed bleeding. Even if the interruption of antithrombotic therapies is undoubtful effective in reducing the risk of bleeding, the thromboembolic risk that follows their suspension should not be underestimated. Therefore, it is fundamental for each endoscopist to be aware of the bleeding risk for every procedure, in order to measure the risk-benefit ratio for each patient. Moreover, knowledge of the proper management of antithrombotic agents before endoscopy, as well as the adequate timing for their resumption is essential.

This review aims to analyze current evidence from literature assessing, for each procedure, the basal risk of bleeding and the risk of bleeding in patients taking antithrombotic therapy, as well as to review the recommendation of American society for gastrointestinal endoscopy, European society of gastrointestinal endoscopy, British society of gastroenterology, Asian pacific association of gastroenterology and Asian pacific society for digestive endoscopy guidelines for the management of antithrombotic agents in urgent and elective endoscopic procedures.

Coagulopathy reversal in intracerebral haemorrhage

As intracerebral hemorrahge becomes more frequent as a result of an aging population with greater comorbidities, rapid identification and reversal of precipitators becomes increasingly paramount. The aformentioned population will ever more likely be on some form of anticoagulant therapy. Understanding the mechanisms of these agents and means by which to reverse them early on is critical in managing the acute intracerebral hemorrhage.

Rapid and substantial increases in anticoagulant use and expenditure in Australia following the introduction of new types of oral anticoagulants

Objectives

To quantify changes in anticoagulant use in Australia since the introduction of Non-vitamin K antagonist anticoagulants (NOACs) and to estimate government expenditure.

Design

Interrupted-time-series analysis quantifying anticoagulant dispensing, before and after first Pharmaceutical Benefits Scheme (PBS) NOAC listing in August 2009 for venous thromboembolism prevention; and expanded listing for stroke prevention in non-valvular atrial fibrillation (AF) in August 2013, up to June 2016. Estimated government expenditure on PBS-listed anticoagulants.

Setting and participants

PBS dispensing in 10% random sample of Australians, restricted to continuous concessional beneficiaries dispensed oral anticoagulants from July 2005 to June 2016. Total PBS anticoagulant expenditure was calculated using Medicare Australia statistics.

Main outcome measures

Monthly dispensing and initiation of oral anticoagulants (warfarin, rivaroxaban, dabigatran or apixaban). Annual PBS anticoagulant expenditure.

Results

An estimated 149,180 concessional beneficiaries were dispensed anticoagulants (100% warfarin) during July 2005. This increased to 292,550 during June 2016, of whom 47.0%, 27.1%, 18.7% and 7.2% were dispensed warfarin, rivaroxaban, apixaban and dabigatran, respectively. Of 16,500 initiated on anticoagulants in June 2016, 24.3%, 38.2%, 30.0% and 7.5% were initiated on warfarin, rivaroxaban, apixaban, and dabigatran, respectively. Compared to July 2005-July 2013, from August 2013-June 2016, dispensings for all anticoagulants increased by 2,303 dispensings/month (p<0.001, 95%CI = [1,229 3,376]); warfarin dispensing decreased by 1,803 dispensings/month (p<0.001, 95%CI = [–2,606, –1,000]). Total PBS anticoagulant expenditure was $19.5 million (97.0% concessional) in 2008/09, of which 100% was warfarin and $203.3 million (86.2% concessional) in 2015/16, of which 11.2% was warfarin.

Conclusions

The introduction of the NOACs led to substantial increases in anticoagulant use and expenditure in Australia.

Management of patients on antithrombotic agents undergoing emergency and elective endoscopy: joint Asian Pacific Association of Gastroenterology (APAGE) and Asian Pacific Society for Digestive Endoscopy (APSDE) practice guidelines

This Guideline is a joint official statement of the Asian Pacific Association of Gastroenterology (APAGE) and the Asian Pacific Society for Digestive Endoscopy (APSDE). It was developed in response to the increasing use of antithrombotic agents (antiplatelet agents and anticoagulants) in patients undergoing gastrointestinal (GI) endoscopy in Asia. After reviewing current practice guidelines in Europe and the USA, the joint committee identified unmet needs, noticed inconsistencies, raised doubts about certain recommendations and recognised significant discrepancies in clinical practice between different regions. We developed this joint official statement based on a systematic review of the literature, critical appraisal of existing guidelines and expert consensus using a two-stage modified Delphi process. This joint APAGE-APSDE Practice Guideline is intended to be an educational tool that assists clinicians in improving care for patients on antithrombotics who require emergency or elective GI endoscopy in the Asian Pacific region.

Reversal of Anticoagulation and Management of Bleeding in Patients on Anticoagulants

Bleeding is the most common complication of all anticoagulants. Any bleeding patient on an anticoagulant should be risk-stratified based on hemodynamic instability, source of bleeding, and degree of blood loss. Although minor bleed may be managed with discontinuation of anticoagulant, major bleed may require transfusion of blood products and use of specific antidote. The residual effects of each anticoagulant may be monitored with distinct coagulation assay. Intravenous or oral vitamin K can reverse the effect of warfarin within 24 to 48 hours and is indicated for any bleeding, international normalized ratio of >10 or 4.5 to 10 in patients with other risk factors for bleeding. Fresh frozen plasma or prothrombin complex concentrate (PCC) may be necessary in major bleeding related to warfarin. Protamine sulfate reverses the effect of unfractionated heparin completely and of low-molecular-weight heparin (LMWH) partially. Idarucizumab has recently been approved in United States for dabigatran reversal, whereas andexanet alfa is expected to get approved in the near future for reversal of oral factor Xa inhibitors. The PCC may reverse the effect of rivaroxaban to some extent, but no data are available regarding reversal of apixaban and edoxaban. Aripazine has shown promising results to reverse the effects of LMWH, fondaparinux, and direct oral anticoagulants but is still in the developmental phase.

Establishing a rat model for the study of vitamin K deficiency

The main vitamin K-deficient model, minidose warfarin, is different from the pathological mechanism of vitamin K deficiency, which is a shortage of vitamin K. The objective of this study was to establish a new method of vitamin K-deficient model combining a vitamin K-deficient diet with the intragastrical administration of gentamicin in rats. The clotting was assayed by an automated coagulation analyser. The plasma PIVKA-II was assayed by ELISA. The vitamin K status was detected by an HPLC-fluorescence system. In the diet- and gentamicin-induced vitamin K-deficient 14-day group, the rats had undetected vitamin K1 and vitamin K2 in the liver and a prolonged APTT. In the 21-day group, there was also a prolonged PT and a decrease of the FIX activities. In the 28-day group, the undetected vitamin K1 and vitamin K2, the prolonged PT and APTT, and the decrease of the FII, FVII, FIX, and FX activities prompted the suggestion that there were serious deficiencies of vitamin K and vitamin K-dependent coagulation in rats. It is suggested that the diet- and gentamicin-induced vitamin K-deficient 14-day or 21-day model can be used for studies related to the status of vitamin K. The vitamin K-deficient 28-day model can be applied to research involving both the status of vitamin K and of vitamin K-dependent coagulation. In conclusion, the combination of a vitamin K-deficient diet with the administration of gentamicin results in a useful model of vitamin K-deficieny.

Risk of Procedural Hemorrhage

Patients who are critically ill and hospitalized often require invasive procedures as a part of their medical care. Each procedure carries a unique set of risks and associated complications, but common to all of them is the risk of hemorrhage. Central venous catheterization, arterial catheterization, paracentesis, thoracentesis, tube thoracostomy, and lumbar puncture constitute a majority of the procedures performed in patients who are hospitalized. In this article, the authors will discuss the risk factors for bleeding complications from each of these procedures and methods to minimize risk. Physicians often correct coagulopathy prior to procedures to decrease bleeding risk, but there is minimal evidence to support this practice.

Management of anticoagulation in patients with acute gastrointestinal bleeding

Acute gastrointestinal bleeding represents the most common adverse event associated with the use of oral anticoagulant therapy. Due to increasing prescription of anticoagulants worldwide, gastroenterologists are more and more called to deal with bleeding patients taking these medications. Their management is challenging because several issues have to be taken into account, such as the severity of bleeding, the intensity of anticoagulation, the patient's thrombotic risk and endoscopy findings. The recent introduction into the marketplace of new direct oral anticoagulants, for whom specific reversal agents are still lacking, further contributes to make the decision-making process even more demanding. Available evidence on this topic is limited and practice guidelines by gastroenterology societies only marginally address key issues for clinicians, including when and how to reverse coagulopathy, the optimal timing of endoscopy and when and how to resume anticoagulation thereafter. The present paper reviews the evidence in the literature and provides practical algorithms to support clinicians in the management of patients on anticoagulants who present with acute gastrointestinal bleeding.

Anticoagulant management of pregnant women with mechanical heart valve replacement during perioperative period

OBJECTIVE

To investigate the morbidity of complications and pregnancy outcomes in women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment with warfarin throughout the pregnancy, compare the prognosis and complications of patients who were treated with single oral warfarin treatment or the "bridging" therapy treatment, investigate the influence of using vitamin K1 before emergency cesarean section delivery on postoperative warfarin anticoagulant effect and to explore an appropriate anticoagulant regimen during perioperative period for pregnant women with mechanical heart valve replacement.

METHOD

46 pregnant women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment from October 2008 to October 2014 treated at West China Women's and Children's Hospital were retrospectively reviewed. Eight patients received emergency cesarean section (CS), while 38 patients received selective CS, in which 17 patients received single oral warfarin and 21 patients received "bridging" anticoagulation treatment during postoperative period. Morbidity of complications and the time to achieve the target INR after operation were compared.

RESULTS

The mechanical valves were at the mitral position in 35 (76.09 %) patients, at the aortic position in 2 (4.35 %) patient and at both the mitral and aortic position in 9 (19.57 %) patients. 46 full-term healthy babies were delivered and no maternal thromboembolic was observed during pregnancy. There was no significant difference of the amount of uterine bleeding between single oral warfarin group and "bridging" treatment group during postpartum period. In single oral warfarin group, one valve thrombosis was observed and led to sudden death. No periphery thrombosis, hematoma, general hemorrhage or other sign of over-anticoagulation was observed. The INR increased more slowly in the group who received emergency CS with preoperative application of vitamin K1 than other two groups.

CONCLUSION

The use of vitamin K1 preoperatively might result in warfarin resistance and discontinuation of warfarin therapy before selective CS might be more appropriate than application of vitamin K1. The "bridging" anticoagulation treatment which combines oral warfarin and subcutaneous LMWH might be more effective and safer than single oral warfarin therapy for patients with mechanical heart valve replacement during postoperative period, no matter selective or emergency CS. The safety of low-dose oral warfarin therapy throughout pregnancy is still under controversy.

Vitamin K for improved anticoagulation control in patients receiving warfarin

BACKGROUND

Effective use of warfarin involves keeping the international normalised ratio (INR) within a relatively narrow therapeutic range. However, patients respond widely to their dose of warfarin. Overcoagulation can lead to an increased risk of excessive bleeding, while undercoagulation can lead to increased clot formation. There is some evidence that patients with a variable response to warfarin may benefit from a concomitant low dose of vitamin K.

OBJECTIVES

To assess the effects of concomitant supplementation of low-dose oral vitamin K for anticoagulation control in patients being initiated on or taking a maintenance dose of warfarin.

SEARCH METHODS

To identify previous reviews, we searched the Database of Abstracts of Reviews of Effects (DARE via The Cochrane Library, Wiley) (Issue 2, 2011). To identify primary studies, we searched the Cochrane Central Register of Controlled Trials (CENTRAL via The Cochrane Library, Wiley) (Issue 2, 2014), Ovid MEDLINE (R) In-Process & Other Non-Indexed Citations database and Ovid MEDLINE (R) (OvidSP) (1946 to 25 February 2014), Embase (OvidSP) (1974 to week 8 of 2014), Science Citation Index Expanded™ & Conference Proceedings Citation Index - Science (Web of Science™) (1945 to 27 February 2014), and the NHS Economics Evaluations Database (NHS EED) (via The Cochrane Library, Wiley) (Issue 2, 2014). We did not apply any language or date restrictions. We used additional methods to identify grey literature and ongoing studies.

SELECTION CRITERIA

Randomised controlled trials comparing the addition of vitamin K versus placebo in patients initiating warfarin or already taking warfarin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected and extracted data from included studies. When disagreement arose, a third author helped reached a consensus. We also assessed risk of bias.

MAIN RESULTS

We identified two studies with a total of 100 participants for inclusion in the review. We found the overall risk of bias to be unclear in a number of domains. Neither study reported the time taken to the first INR in range. Only one study (70 participants) reported the mean time in therapeutic range as a percentage. This study found that in the group of participants deemed to have poor INR control, the addition of 150 micrograms (mcg) oral vitamin K significantly improved anticoagulation control in those with unexplained instability of response to warfarin. The second study (30 participants) reported the effect of 175 mcg oral vitamin K versus placebo on participants with high variability in their INR levels. The study concluded that vitamin K supplementation did not significantly improve the stability of anticoagulation for participants on chronic anticoagulation therapy. However, the study was only available in abstract form, and communication with the lead author confirmed that there were no further publications. Therefore, we interpreted this conclusion with caution. Neither study reported any thromboembolic events, haemorrhage, or death from the addition of vitamin K supplementation.

AUTHORS' CONCLUSIONS

Two included studies in this review compared whether the addition of a low dose (150 to 175 mcg) of vitamin K given to participants with a high-variability response to warfarin improved their INR control. One study demonstrated a significant improvement, while another smaller study (published in abstract only) suggested no overall benefit. Currently, there are insufficient data to suggest an overall benefit. Larger, higher quality trials are needed to examine if low-dose vitamin K improves INR control in those starting or already taking warfarin.

Trauma hemostasis and oxygenation research position paper on remote damage control resuscitation: definitions, current practice, and knowledge gaps

The Trauma Hemostasis and Oxygenation Research Network held its third annual Remote Damage Control Resuscitation Symposium in June 2013 in Bergen, Norway. The Trauma Hemostasis and Oxygenation Research Network is a multidisciplinary group of investigators with a common interest in improving outcomes and safety in patients with severe traumatic injury. The network's mission is to reduce the risk of morbidity and mortality from traumatic hemorrhagic shock, in the prehospital phase of resuscitation through research, education, and training. The concept of remote damage control resuscitation is in its infancy, and there is a significant amount of work that needs to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical in these patients. If shock and coagulopathy can be rapidly identified and minimized before hospital admission, this will very likely reduce morbidity and mortality. This position statement begins to standardize the terms used, provides an acceptable range of therapeutic options, and identifies the major knowledge gaps in the field.

Acquired absolute vitamin K deficiency in a patient undergoing warfarin therapy

We report a case of absolute vitamin K deficiency (VKD) diagnosed by measuring serum VK levels in an elderly woman undergoing warfarin therapy. A 78-year-old woman was admitted to our hospital because of dyspnea and sore throat diagnosed as pharyngitis 1 week before admission. On admission, the sore throat had exacerbated and dyspnea developed. She had history of atrial fibrillation, for which warfarin 1.5 mg/d was started approximately 10 years prior and her international normalized ratio (INR) had been maintained at an acceptable therapeutic level. Blood results revealed unmeasurable INR and abnormally prolonged activated partial thromboplastin time (APTT). She was diagnosed with adenoiditis and warfarin-related coagulopathy and administered intravenous VK (20 mg) and fresh frozen plasma (FFP; 4 U), which improved INR and APTT. Since the coagulopathy responded to intravenous VK administration, the patient was clinically diagnosed with warfarin-related relative VKD. Approximately 1 month later, she returned with complaints of sore throat. Blood results indicated abnormal INR (7.22) and APTT (N80.0 s). She was diagnosed with recurrent adenoiditis and VK deficient coagulopathy. The patient’s serum VK levels were low (VK1 level, 0.13 ng/mL; VK2 levels, 0.85 ng/mL). Initial treatment of VK (20 mg) and FFP followed by intravenous VK (20 mg/d) for 6 days, her symptoms dissipated. Warfarin was suspected to have caused absolute VKD. Severe coagulopathy in patients undergoing warfarin therapy is primarily caused by, relative VKD. However, the possibility of warfarin-related absolute VKD should be suspected when INRis not sufficiently improved by intravenous VK administration.

Some hemostatic parameters in women with obstetric hemorrhage in Sokoto, Nigeria

Obstetric hemorrhage is the leading cause of maternal mortality and morbidity worldwide. This study was carried out to investigate the effect of obstetric hemorrhage on the prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet count (PLC). Women with obstetric hemorrhage were divided into two categories, women with antepartum hemorrhage (APH) and those with postpartum hemorrhage (PPH). Pregnant women without hemorrhage were included as controls. Eighty-six pregnant women aged 18–45 years (mean age 36.25 ± 10.50 years) were presented to the Obstetrics and Gynaecology Department of Maryam Abacha Women and Children Hospital in Sokoto Metropolis, Sokoto State, Nigeria with history of obstetric hemorrhage. Forty-three age-matched nonhemorrhaging parturient women were included as controls. The determination of PT and APTT was done by manual methods using commercially prepared Diagen reagent kits, whereas PLC was done by manual methods using a hemocytometer. The results of PT and APTT were significantly higher among women with APH (20.7 ± 4.226 seconds and 46.04 ± 8.689 seconds, respectively) and among women with PPH (23.17 ± 2.708 seconds and 53.78 ± 4.089 seconds, respectively) compared to normal pregnant women (15.85 ± 0.8930 seconds and 36.225 ± 5.010 seconds, respectively) (P = 0.0001). Similarly, the PLC was significantly higher among normal pregnant women compared to those with APH and PPH (291.425 ± 75.980 × 10⁹ compared to 154.83 ± 47.019 × 10⁹ and 136.43 ± 43.894 × 10⁹, respectively) (P = 0.0001). The PT and APTT of women who presented with PPH were significantly higher compared to those who presented with APH (23.17 ± 2.708 seconds and 53.78 ± 4.089 seconds versus 20.7 ± 4.226 seconds and 46.04 ± 8.689 seconds, respectively) (P = 0.02 and P = 0.04, respectively). The PLC was significantly higher among women who presented with APH compared to those who presented with PPH (P = 0.01). The PT and APTT values were higher in the third trimester among women with APH (24.38 ± 2.33 seconds and 52.25 ± 6.71 seconds, respectively), PPH (24.75 ± 2.63 seconds and 58.25 ± 2.53 seconds, respectively), and control women (16.00 ± 0.82 seconds and 34.42 ± 5.59 seconds, respectively) compared to those in first and second trimester. The PLC was significantly lower in the third trimester among APH, PPH, and normal pregnant women (131 ± 23.02 × 10⁹, 99 ± 21.46 × 10⁹, and 192.86 ± 25.44 × 10⁹, respectively). PT and APTT values correlated positively and significantly with trimester (r = 0.52 and 0.65, respectively; P = 0.01). The PLC of women with APH, PPH, and normal control women correlated negatively with trimester (r = −0.36, −0.54, and −0.28, respectively; P = 0.05). Obstetrics hemorrhage compounded the hemostatic status of pregnant women in Sokoto, Nigeria. There is need for the provision of rapid diagnosis of coagulopathy to guide the provision of best therapeutic management options.

Reversal of oral anticoagulation

Although the use of dabigatran and rivaroxaban are increasing, data on the reversal of their effects are limited. The lack of reliable monitoring methods and specific reversal agents renders treatment strategies empirical, and as a result, treatment consists mainly of supportive measures. Therefore, we performed a systematic search of the PubMed database to find studies and reviews pertaining to oral anticoagulation reversal strategies. This review discusses current anticoagulation reversal recommendations for the oral anticoagulants warfarin, dabigatran, and rivaroxaban for patients at a heightened risk of bleeding, actively bleeding, or those in need of preprocedural anticoagulation reversal. We highlight the literature that shaped these recommendations and provide directions for future research to address knowledge gaps. Although reliable recommendations are available for anticoagulation reversal in patients treated with warfarin, guidance on the reversal of dabigatran and rivaroxaban is varied and equivocal. Given the increasing use of the newer agents, focused research is needed to identify effective reversal strategies and develop and implement an accurate method (assay) to guide reversal of the newer agents. Determining patient-specific factors that influence the effectiveness of reversal treatments and comparing the effectiveness of various treatment strategies are pertinent areas for future anticoagulation reversal research.