Chapter 10: Anticoagulation Guidelines

INTRODUCTION

Patients seeking interventional treatment for chronic pain can have a variety of medical problems. The aging population in particular can present with complex medical conditions that require anticoagulation therapy.

In 2010, the American Society of Regional Anesthesia and Pain Medicine published a practice advisory regarding the use of regional anesthesia in patients receiving anticoagulation to enhance safety as well as quality patient care. The third edition of guidelines reports a consensus statement utilizing the collective experience of experts in neuraxial anesthesia and anticoagulation. The guidelines presented are comprehensive and based on case reports, clinical series, pharmacology, hematology and risk factors for surgical bleeding. This is a very complex issue for which there is no simple template to follow. Each case must be reviewed on an individual basis. There should be communication with the patient’s health care providers such as the cardiologist, regarding safest treatment options. This collaboration is essential in diminishing life-threatening bleeding complications associated with neuraxial anesthesia.

Typical scenarios interventional pain physicians encounter with patients on chronic anticoagulation therapy include:

• Patients on venous thromboembolic treatment

• Patients with vascular stents in place

• Epidural/spinal injections for patients having joint replacement surgery

• Extended period of DVT prophylaxis in orthopedic patients

The problems in patients who are on chronic anticoagulation therapy are:

• Therapy-associated mortality (5%-12%)

• Spontaneous bleeding requiring discontinuation of therapy (15%-20%)

• Heparin-induced immune-mediated thrombocytopenia (HIT) (3.5%-7%)

• 25% patients with HIT develop new venous and/or arterial thrombotic event

• Warfarin crosses placenta and cannot be given in pregnancy

• Dose adjustment of fondaparinux in patients with compromised renal function

This creates a challenge when preparing patients for invasive procedures. Patients undergoing interventional treatment for chronic pain, particularly neuraxial anesthesia, are at increased risk for complications associated with bleeding.

The risk of clinically significant bleeding is exacerbated by the following:

• Increased age

• Spinal cord or vertebral column abnormalities

• Coagulopathies

• Needle placement difficulties

• Continued anticoagulation with neuraxial catheter in place.¹

It is important to weigh the risk-benefit ratio when determining when to stop anticoagulant or antiplatelet therapy along with determining exactly when to restart treatment postintervention.

• The incidence of hemorrhagic complications and resulting neurologic deficit after neuraxial intervention is unknown.

• The incidence of bleeding is less than 1 in 150,000 epidurals and 1 in 220,000 spinal anesthetics.

• More recent surveys are revealing an incidence as high as 1 in 3000 in high-risk patient populations.

• High index of suspicion, prompt diagnosis, and treatment of bleeding is critical to decreasing the incidence of permanent neurological deficit.

A review of the literature from 1906 to 1994 by Vandermeulen et al⁴ reported:

• 61 cases of spinal hematoma reported to be associated with epidural or spinal anesthesia

• 60% of these cases occurred in the last 10 years of the study period

• 68% of the patients ...