New anticoagulants and regional anesthesia

Mini-invasive methods of treatment of diabetic foot pain

Neuropathic pain occurs with diabetic polyneuropathy more often than with all polyneuropathies of another etiology. Because the cause of pain can rarely be cured, treatment is usually symptomatic. Neuropathic pain is usually poorly controlled by analgesics. Management of neuropathic pain is started with conservative pharmacotherapy before invasive pain management is applied. Although there are many drugs that can be used in patients with diabetic pain syndrome, pain syndrome can not be surely stoped with monotherapy. In addition, the patient may not tolerate the full therapeutic dose of the drug. All this dictates the need for combination therapy. It is believed that regional anesthesia as an independent type of analgesia or a component of combined anesthesia is the method of choice for the elderly and senile patients. The main reasons for this choice, when comparing regional anesthesia with narcosis, are less stressful response of the organism, absence of depression of the central nervous system, stable reliable analgesia with complete blockade of nociceptive reflexes with the provision of adequate muscle relaxation, prevention of neurovegetative reactions, which ultimately helps to reduce the incidence of postoperative complications and mortality. Clinicians have accumulated considerable experience demonstrating the need for regional analgesia in the management of diabetic foot pain.

The perioperative management of new direct oral anticoagulants: a question without answers

New direct oral anticoagulant agents (DOAC) are currently licensed for thromboprophylaxis after hip and knee arthroplasty and for longterm prevention of thromboembolic events in non-valvular atrial fibrillation as well as treatment and secondary prophylaxis of venous thromboembolism. Some other medical indications are emerging. Thus, anaesthesiologists are increasingly likely to encounter patients on these drugs who need elective or emergency surgery. Due to the lack of experience and data, the management of DOAC in the perioperative period is controversial. In this article, we review available information and recommendations regarding the periprocedural management of the currently most clinically developed DOAC, apixaban, dabigatran, and rivaroxaban. We discuss two trends of managing patients on DOAC for elective surgery. The first is stopping the DOAC 1–5 days before surgery (depending on the drug, patient and bleeding risk) without bridging. The second is stopping the DOAC 5 days preoperatively and bridging with low-molecular-weight heparin. The management of patients on DOAC needing emergency surgery is also reviewed. As no data exist for the use of haemostatic products for the reversal of the anticoagulant effect in these cases, rescue treatment recommendations are proposed.

Update on Anticoagulation: What the Interventional Radiologist Needs to Know

The novel oral anticoagulants (NOACs) represent a major advance in the treatment of patients with nonvalvular atrial fibrillation and venous thromboembolism (VTE). They have several advantages over vitamin-K antagonists such as warfarin, including more predictable pharmacokinetics and improved safety, particularly with fatal bleeding and intracranial hemorrhage. However, several issues remain surrounding the use of NOACs in certain subpopulations and with the approach to reversal. The periprocedural management of anticoagulation with these relatively new agents can also present several challenges. This article reviews the basic pharmacology, efficacy, and safety of these drugs. Several populations at higher risk for complications with use of NOACs are discussed, including those undergoing procedures. Finally, several target-specific reversal agents have either received FDA approval or likely will be approved in the near future; these agents and their roles in the approach to anticoagulation reversal will also be discussed.

Balancing the risk of complications in foot and ankle surgical patients taking antithrombotic medication

This review intends to provide guidance regarding perioperative management of anticoagulation and antiplatelet drug therapy as they relate to foot and ankle surgery. Venous and arterial thromboembolism are conditions in which the blood clots inappropriately, causing considerable morbidity and mortality. With an increase in awareness of thromboembolic risk factors and expansion of therapeutic options, more patients are routinely taking antithrombotic medication. When these patients require invasive procedures, a decision needs to be made if antithrombotic medication should be held perioperatively and if additional precautions are needed in the interim. Understanding the factors affecting the management of thromboembolism during the perioperative period can reduce the potential for complications.

LEVELS OF EVIDENCE

Therapeutic, Level V: Expert opinion.

Management of non-vitamin K antagonist oral anticoagulants in the perioperative setting

The field of oral anticoagulation has evolved with the arrival of non-vitamin K antagonist oral anticoagulants (NOACs) including an anti-IIa agent (dabigatran etexilate) and anti-Xa agents (rivaroxaban and apixaban). The main specificities of these drugs are predictable pharmacokinetics and pharmacodynamics but special attention should be paid in the elderly, in case of renal dysfunction and in case of emergency. In addition, their perioperative management is challenging, especially with the absence of specific antidotes. Effectively, periods of interruption before surgery or invasive procedures depend on half-life and keeping a permanent balance between bleeding and thromboembolic risks. In addition, few data regarding the link between plasma concentrations and their effects are provided. Routine laboratory tests are altered by NOACs and quantitative measurements are not widely performed. This paper provides a review on the management of NOACs in the perioperative setting, including the estimation of the bleeding and thrombotic risk, the periods of interruption, the indication of heparin bridging, the usefulness of laboratory tests before surgery or invasive procedure, and the time of resuming. Most data are based on expert's opinions.

Perioperative management of patients receiving new oral anticoagulants: an international survey

New oral anticoagulants (NOACs) are increasingly replacing standard anticoagulants. These new drugs have been recently introduced in clinical practice, and specific knowledge regarding preoperative interruption, anticoagulation assessment, and reversal therapies is needed. In this article, 3 main areas related to perioperative NOACs management are discussed: (1) physicians' knowledge, (2) current practices, and (3) perspectives to improve management of patients treated with NOACs.

Periprocedural management of patients on anticoagulants

Every year, new studies are undertaken to address the complex issue of periprocedural management of patients on anticoagulants and antiplatelet medications. In addition, newer drugs add to the confusion among clinicians about how to best manage patients taking these agents. Using the most recent data, guidelines, and personal experience, this article discusses recommendations and presents simplified algorithms to assist clinicians in the periprocedural management of patients on anticoagulants.

Preventive strategies against bleeding due to nonvitamin K antagonist oral anticoagulants

Dabigatran etexilate (DE), rivaroxaban, and apixaban are nonvitamin K antagonist oral anticoagulants (NOACs) that have been compared in clinical trials with existing anticoagulants (warfarin and enoxaparin) in several indications for the prevention and treatment of thrombotic events. All NOACs presented bleeding events despite a careful selection and control of patients. Compared with warfarin, NOACs had a decreased risk of intracranial hemorrhage, and apixaban and DE (110 mg BID) had a decreased risk of major bleeding from any site. Rivaroxaban and DE showed an increased risk of major gastrointestinal bleeding compared with warfarin. Developing strategies to minimize the risk of bleeding is essential, as major bleedings are reported in clinical practice and specific antidotes are currently not available. In this paper, the following preventive approaches are reviewed: improvement of appropriate prescription, identification of modifiable bleeding risk factors, tailoring NOAC's dose, dealing with a missed dose as well as adhesion to switching, bridging and anesthetic procedures.

Alternative to oral dicoumarin anticoagulants: Considerations in dental care

Introduction: For over 50 years, vitamin K antagonists such as warfarin (Aldocumar®) and acenocoumarol (Sintrom®) have been the gold standard for reducing the risk of cerebrovascular events. In the last 5 years alternative anticoagulants have been evaluated that act directly upon a concrete target within the coagulation cascade, thereby affording a more predictable anticoagulant effect. The present study offers an update on the new oral anticoagulants and reviews the implications referred to the dental care of patients administered these substances. Material and methods: An exhaustive PubMed-Medline and Cochrane Library search was made of the main alternatives to conventional oral anticoagulation, covering those studies published in English and Spanish over the last 10 years. Specialized textbooks and pharmaceutical catalogs were also consulted. A total of 184 articles were identified, of which 76 met the inclusion criteria. Results: The new oral anticoagulants dabigatran, rivaroxaban and apixaban are safe and effective, and offer a series of advantages, including rapid action, no need for constant monitoring, few drug and food interactions, and a broad therapeutic margin. These drugs are expensive, however, and some lack a specific antidote, while others must be administered twice a day. Regarding the dental treatment of patients receiving these drugs, suspension or modification of the background medication is not required when performing invasive dental procedures, except where indicated by the prescribing physician. Conclusions: The new oral anticoagulants do not pose significantly greater risks than conventional oral anticoagulants when providing invasive dental treatment, and their suspension is not strictly required in such situations.

Key words:Dabigatran, rivaroxaban, apixaban, dental, hemostasis.

Use of new oral anticoagulants in antiphospholipid syndrome

The current mainstay of treatment of thrombotic APS is long-term anticoagulation with oral vitamin K antagonists (VKA) such as warfarin. However, the use of warfarin is problematic, particularly in patients with antiphospholipid syndrome (APS). The new oral anticoagulants (NOAC) include dabigatran etexilate (Pradaxa®), a direct thrombin inhibitor, and rivaroxaban (Xarelto®), Apixaban (Eliquis) and Edoxaban (Lixiana®), which are direct anti-Xa inhibitors. Unlike warfarin, these agents do not interact with dietary constituents and alcohol, have few reported drug interactions, and monitoring of their anticoagulant intensity is not routinely required due to their predictable anticoagulant effects. In this chapter, we discuss clinical and laboratory aspects of NOAC. These agents have been approved for several therapeutic indications based on phase III prospective randomised controlled clinical trials using warfarin at a target INR of 2.5 (i.e. range 2.0-3.0) as the comparator. However these trials may not be directly applicable to patients with antiphospholipid syndrome (APS) where prospective clinical studies of NOAC are the way forward.

Managing New Oral Anticoagulants in the Perioperative and Intensive Care Unit Setting

Managing patients in the perioperative setting receiving novel oral anticoagulation agents for thromboprophylaxis or stroke prevention with atrial fibrillation is an important consideration for clinicians. The novel oral anticoagulation agents include direct Factor Xa inhibitors rivaroxaban and apixaban, and the direct thrombin inhibitor dabigatran. In elective surgery, discontinuing their use is important, but renal function must also be considered because elimination is highly dependent on renal elimination. If bleeding occurs in patients who have received these agents, common principles of bleeding management as with any anticoagulant (including the known principles for warfarin) should be considered. This review summarizes the available data regarding the management of bleeding with novel oral anticoagulation agents. Hemodialysis is a therapeutic option for dabigatran-related bleeding, while in vitro studies showed that prothrombin complex concentrates are reported to be useful for rivaroxaban-related bleeding. Additional clinical studies are needed to determine the best method for reversal of the novel oral anticoagulation agents when bleeding occurs.

New oral anticoagulants for stroke prevention in atrial fibrillation: more choices bring more challenges

For patients with atrial fibrillation, anticoagulant therapy is essential to reduce the risk of ischemic stroke that is associated with this arrhythmia. Historically, warfarin has been the preferred treatment for patients at moderate to high risk despite many potential limitations. With the development of newer oral anticoagulants, clinicians now have 3 additional options: dabigatran, rivaroxaban, and apixaban. Although these agents clearly offer some advantages over warfarin, they may not be appropriate for all patients. This article will discuss factors that should be considered when selecting among these various anticoagulants.

[Management of direct action oral anticoagulants in the peri-operative period and invasive techniques]

The new direct-acting oral anticoagulants (ACOD) in patients on prolonged treatment require the need to balance the risk of haemorrhage by administering them against the risk of thrombosis on withdrawing them. Recommendations for their management are proposed in the present article: A) Thromboprophylaxis and general anaesthesia: the performing of regional anaesthesia if administered with an ACOD as thromboprophylaxis requires some safety intervals based on their pharmacokinetic parameters; B) Management of ACOD in elective surgery: in patients with normal renal function and a low haemorrhage/thrombosis risk, stop the ACOD two days before the surgery; it the haemorrhage/thrombosis risk is high and/or renal function is impaired, therapy with a low molecular weight heparin is proposed from 5 days prior to the surgery, and C) Management of ACOD in urgent surgery and associated haemorrhage: the systematic prophylactic administration of haemostatics is recommended. In the event of acute bleeding that may place the life of the patient at risk (due to volume or location), the administration of concentrated prothrombin complex, fresh plasma, or factor VIIa, must be assessed, together with general control measures of acute haemorrhage. These recommendations should be considered in the context of the use drugs that do have a specific antidote, where their monitoring by the usual coagulation tests is not routine, and with those in which there is limited experience. We believe they need to be reviewed in the future, depending on further studies and clinical experience obtained.

Anticoagulants: newer ones, mechanisms, and perioperative updates

With a growing number of new anticoagulant/antiplatelet agents being developed, it is likely that an increasing number of patients taking these drugs will present for surgery and other procedures. A familiarity with mechanisms of action and drug interactions helps to maintain optimal patient safety in the perioperative period. Furthermore, it is crucial for anesthesiologists to remain current on recommendations regarding discontinuation or need to continue the newer anticoagulants/antiplatelet drugs in patients presenting for surgery and/or regional anesthesia. Further studies are needed for monitoring of many of these newer agents and to identify antidotes.

Managing anticoagulated patients during neuraxial anaesthesia

The widespread use of central neuraxial block (CNB) and the prevalence of anticoagulation for different indications have led to an inevitable overlap between the two. The most serious complication of CNB in anticoagulated patients is the risk of spinal/epidural haematoma. Performing CNB in these patients is a complex decision that should take into account the twin risks of bleeding and venous/arterial thrombosis if anticoagulation therapies were to be stopped. Various guidelines have been issued to achieve normal haemostasis and thus allow safe administration of CNB. However, the evidence base for many such recommendations is weak, relying mainly on case reports, small studies and pharmacokinetics of the drugs. Given these limitations it is crucial to fully assess individual risk factors and understand anticoagulant pharmacokinetics in order to appropriately set time intervals for catheter insertion/removal. This paper will review traditional and newer anticoagulation/antiplatelet therapies with a view to improving the management of anticoagulated patients undergoing CNB.