July 2014 - Newsletter

Ana Lopez and John Laur instructing workshop sessions at NYSORA

In this issue:

Quick Reference Guide for Regional Anesthesia in the Anticoagulated Patient

The number of anticoagulant medications being used in clinical practice has increased dramatically over the last few years as several new drugs have received approval from the United States Food and Drug Administration (FDA) for a variety of antithrombotic indications. Not only have these newer medications been quickly added to hospital formularies, they have also been increasingly prescribed in the outpatient setting for a variety of reasons: direct-to-consumer advertising, attractive route and dosing schedules, and obviation of required routine laboratory evaluation to assess therapeutic efficacy. Consequently, anesthesia providers are regularly encountering patients who take these medications in the perioperative setting.

This has challenged clinicians to remain knowledgeable about the pharmacokinetics of these drugs and their associated risks when regional anesthesia or analgesia techniques are considered. Unfortunately, current published anticoagulation guidelines for regional anesthesia and analgesia have not yet addressed many of these newer medications and, when recommendations are available, they often differ depending on the resource. Not only does this increase the complexity of clinical decision-making, it may also increase the risks for the patient given the likelihood that their provider may be unfamiliar with these new antithrombotic therapies and perform a regional anesthetic, and more specifically neuraxial procedures or deep plexus blocks, when the likelihood of bleeding complications is increased.

When faced with a patient who has recently taken an anticoagulant medication for which published guidelines are lacking, clinicians must independently decide, based on their understanding of pharmacokinetics and pharmacodynamics, how long this medication should be stopped before preceding with certain regional anesthesia and analgesia procedures without an unacceptable increase in the risks of bleeding complications. Additionally, following the performance of a neuraxial or deep plexus block procedure, including the removal of an indwelling catheter, clinicians must determine how long of a delay is required until the next dose of this medication can be administered.

At our institution, clinicians were often challenged to accurately and quickly make decisions when confronted with similar clinical scenarios. Because the potential complications associated with the performance of neuraxial or deep plexus block procedures can be devastating when residual anticoagulant medication effects exist, these types of procedures were often avoided due to a perceived increased risk of complications, even in patients with significant comorbidities in whom regional anesthesia may have been preferred.

In 2012, with the goal of simplifying the process by which anesthesiologists at our institution determine whether a patient being treated with anticoagulant medications was at an unacceptably increased risk of bleeding complications following the performance of a regional technique, a guideline reference chart was created by consolidating the available published guidelines from the American Society of Regional Anesthesia (ASRA)¹ and the European Society of Anesthesiology (ESA)². For anticoagulant agents that lacked formal published guidelines pharmacokinetic data (drug half-life) was used to estimate the recommended time interval between the last dose of a drug and the performance of a neuraxial or deep plexus procedure; it was generally assumed that 5 half-lives were necessary to achieve near complete resolution of drug effect. Longer durations were recommended if the clearance of a drug might be affected by renal insufficiency.

Since inception the reference chart has undergone several updates either as new recommendations were released or as new anticoagulant medications received FDA approval. It was first presented outside of our institution at a problem-based learning discussion during the annual NYSORA symposium in 2012. The most recent version of the reference chart (Figure 1) includes the recent recommendation from both ASRA and the FDA to allow at least four hours between the performance of a neuraxial procedure (such as epidural catheter removal) and the administration of the next dose of enoxaparin.³

The ubiquitous availability of this anticoagulation reference chart has allowed clinicians at our institution to more quickly and accurately determine if a patient is at an unacceptably increased risk of bleeding following a regional anesthetic procedure based on the currently available guidelines and/or pharmacologic data. It has become routinely used across the four hospitals within our health care system, not just by anesthesia providers, but also by clinicians in multiple specialties since the universal pre-procedure checklist at our institution now includes a step to review and consider the patient's current coagulation status before any invasive procedure. By consolidating this information into one easy to reference location we believe we have improved the efficiency of our operating rooms as well as the safety of our patients both within and beyond the walls of our operating rooms.

References:

1) Horlocker TT, Wedel DJ, Rowlingson JC, Enneking FK, Kopp SL, Benzon HT, Brown DL, Heit JA, Mulroy MF,     Rosenquist RW, Tryba M, Yuan CS. Regional anesthesia in the patient receiving antithrombotic or thrombolytic     therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition).     Reg Anesth Pain Med. 2010 Jan-Feb;35(1):64-101.
2) Gogarten W, Vandermeulen E, Van Aken H, Kozek S, Llau JV, Samama CM; European Scoeity of     Anaesthesiology. Regional anaesthesia and antithrombotic agents: recommendations of the European Society of     Anaesthesiology. Eur J Anaesthesiol. 2010 Dec;27(12):999-1015
3) Updated recommendations to decrease risk of spinal column bleeding and paralysis in patients on low molecular     weight heparins, http://www.asra.com/fda-annoucement-11-6-13.pdf, Nov.2013.

Daryl Henshaw, MD
J. Douglas Jaffe, D.O.
Robert S. Weller, MD

Robert S. Weller, Daryl Henshaw and J. Douglas Jaffe

Wake Forest School of Medicine Department of Anesthesiology Section of Regional Anesthesia and Acute Pain Management Winston Salem, NC 27157

NYSORA subspecialty focus workshop highlight - Pediatric Regional Anesthesia

In an effort to meet the demands of our delegates for basic and advanced workshops in a variety of specialized topics, this year the first Pediatric Regional Workshop will be held at NYSORA 2014. This workshop will focus on basic ultrasound based regional anesthesia techniques designed for novices and intermediate skill level practitioners who desire to learn more about the blocks provided every day in a busy pediatric practice. Delegates will become familiar with basic principles of ultrasonography and needle maneuvering, applied anatomy, and will scan pediatric models. Colleagues who are more advanced will be grouped together to allow for more rapid progression of topics and more advanced learning.

Course Instructors: Karen Boretsky MD and Steven Orebaugh MD

For more information visit NYSORA.com

NYSORA Latin America Personal Perspective

Javier Espinosa and Fellow ESOP scholar Alejandra Delgado

"¡Pura vida NYSORA!" would be a very traditional way to say "Hello!" My name is Javier Sevilla Espinoza and I am also a NYSORA ESOP Scholar. I study Anesthesiology in Costa Rica as a resident in the national hospital, Rafael Ángel Calderón Guardia. My hospital is located in San Jose, the capital city. It is one of the three major public hospitals that work with the social security.

The pain management in Costa Rica is a little different from the rest of the world. Anesthesiologists take care of the postoperative pain, while chronic pain is usually treated by physicians focused on palliative medicine. Nowadays it is changing due to regional anesthesia which offers new options for pain management.

Javier at NYORA Latin America in Florianopolis, Brasil

In my hospital regional anesthesia covers spinal blocks, epidural catheters, and regional blocks guided by neurostimulator (usually for upper limb). We do not have access to ultrasound. The anesthesiologists who have more experience with regional anesthesia are the ones who purchase their own ultrasound machines. In private medicine, ultrasound equipment is more prevalent for use in regional anesthesia.

Javier performing a Nerve stimulator - guided infraclavicular block on a 1 year old

Learning opportunities on ultrasound-guided regional anesthesia are limited at home. So in order to learn more we have to travel to other countries. I had the opportunity to attend the 1st NYSORA Latin America Symposium on Regional Anesthesia and Perioperative Medicine in Florianopolis. It was a great experience to get familiarized with regional anesthesia and all its benefits. The lecturing classes were very interesting and provided useful tips for everyday practice. The US workshops helped in acquiring the skills necessary for using the needle and US. Also, I had the chance to meet splendid people, doctors, professors, teachers, and friends, such as Dr. Helayel, Dr. Bollini, Dr. Hadzic, Dr. Gadsden, Dr. Shibata, and many others.

Delegates in session at 1st NYSORA Latin America Symposium

In my opinion regional anesthesia is a great option we can offer patients, not only for anesthesia but also as analgesia. However, not having an ultrasound machine available greatly limits our daily practice. Even so, I hope that in the near future, our patients will enjoy the benefits of this technique.

Program Chairs of 1st NYSORA Latin America Symposium, Florianapolis Brazil, Spring 2014

Featured Educational Video - Ultrasound-Guided Interscalene Brachial Plexus Block

NYSORA Symposiums and Workshops