Tag Archives: pain medicine

Why this is a great time to pursue a career in regional anesthesia

When you start saying “Back when I was in training…”, you are officially old.

Well, back when I was in training, I didn’t think regional anesthesia was a career path. We weren’t using ultrasound yet, and catheters were still experimental. Regional anesthesia was just part of anesthesiology, and there was a fairly limited set of blocks to offer patients. Besides spinals and epidurals, I was fortunate to learn how to do more peripheral techniques than most residents in my cohort: the femoral nerve block; proximal and distal sciatic nerve block; brachial plexus blocks (interscalene, infraclavicular, and axillary); and paravertebral block. All of these blocks were performed using landmarks to guide needle placement, and we used indirect needle tip position endpoints for confirmation (e.g. nerve stimulation or paresthesia).

Fast forward to today, and the subspecialty field of regional anesthesia and acute pain medicine (RAAPM) has exploded! The demand for better perioperative pain control that doesn’t depend solely on opioids has driven the development of advanced clinical fellowships in RAAPM for anesthesiologists who want to become acute pain medicine experts. A consortium of 14 medical organizations representing anesthesiology, pain medicine, surgical specialties, and hospitals has unanimously agreed on a set of principles to guide acute perioperative pain management, and included in these principles is access to a pain medicine specialist and the employment of multimodal analgesia with regional anesthesia techniques when indicated.

What does this mean for medical students and anesthesiology residents who are thinking about their careers? The future of RAAPM is bright! Considering that physicians work for about 30 years or more after completion of training, it’s really important to find a specialty, and even a subspecialty, that: 1) allows you to take good care of patients and be the kind of doctor you’ve been called to be; and 2) continues to evolve in innovative ways so you can keep learning new and exciting things.

I’ve written before about how much I love being an anesthesiologist, but I really love being a RAAPM subspecialist! There is nothing more satisfying than preventing and treating pain for patients who are undergoing surgery or suffering from traumatic injury. Today’s RAAPM fellowship curriculum trains anesthesiology residency graduates over the course of one year to become leaders with the knowledge and skills to perform a wide range of advanced procedures and manage acute pain services in any practice setting. New procedures to extend the benefits of regional analgesia beyond the first few postoperative days are currently being studied, as are new models of care such as transitional pain services that can add significant value to healthcare systems.

After fellowship is over, you join an incredible worldwide community of RAAPM experts who will support and mentor you throughout your career. Conferences feel like family reunions, and the leaders in the field whom you’ve looked up to become your friends.

To learn more about our RAAPM fellowship at Stanford, please visit our website. Information on other programs is available through ASRA Pain Medicine.

Related Posts:

Resetting the Bar for Acute Perioperative Pain Management

Despite previously published guidelines and practice recommendations, there remains unwarranted variation in the quality of pain management provided to patients having surgery. Unwarranted variations in healthcare are inconsistencies in clinical practice that have no basis in science or patient preference.

In 2019, the U.S. Health and Human Services (HHS) Pain Management Best Practices Inter-Agency Task Force published its report, which called on medical societies to work together to develop evidence-based guidelines to improve the quality of pain care delivery. The Task Force, which was Chaired by Stanford anesthesiology and pain medicine specialist Dr. Vanila Singh when she was Chief Medical Officer of HSS, recommended individualized, multimodal, and multidisciplinary approaches to pain management to help decrease an over-reliance on opioids, increase access to care, and promote widespread education on pain and substance use disorders.

Following the release of this Task Force report, leaders of the American Society of Anesthesiologists (ASA) decided to take action and launched a 2-year project. As Chair of the ASA Committee on Regional Anesthesia and Pain Medicine, I participated as a member of the steering committee and served as Co-Chair of the Pain Summit. ASA invited 13 other medical societies to join a new consortium dedicated to improving pain management (in alphabetical order):

  • American Academy of Orthopaedic Surgeons
  • American Academy of Otolaryngology-Head and Neck Surgery
  • American Association of Neurological Surgeons
  • American Association of Oral and Maxillofacial Surgeons
  • American College of Obstetricians and Gynecologists
  • American College of Surgeons
  • American Hospital Association
  • American Medical Association
  • American Society of Breast Surgeons
  • American Society of Plastic Surgeons
  • American Society of Regional Anesthesia and Pain Medicine
  • American Urological Association
  • Society of Thoracic Surgeons

For its first initiative, the consortium agreed to focus on the pain care of the routine, non-complex (i.e., opioid-naïve) adult surgical patient. Over the course of several months, using Delphi methodology and culminating in the first live virtual Pain Summit involving all participating societies, this multiorganizational consensus process resulted in the establishment of 7 guiding principles for acute perioperative pain management.

Now published in Regional Anesthesia & Pain Medicine, these principles are intended to help healthcare systems and individual clinicians provide better care for patients having surgery. These principles include the need for preoperative evaluation of medical and psychological conditions and potential substance use disorders, a focus on multimodal analgesia including nonpharmacologic interventions, use of validated pain assessment tools to guide and adjust treatment, and the importance of individualized care and education, among others.

The final seven principles are:

  1. Clinicians should conduct a preoperative evaluation including assessment of medical and psychological conditions, concomitant medications, history of chronic pain, substance use disorder, and previous postoperative treatment regimens and responses, to guide the perioperative pain management plan.
  2. Clinicians should use a validated pain assessment tool to track responses to postoperative pain treatments and adjust treatment plans accordingly.
  3. Clinicians should offer multimodal analgesia, or the use of a variety of analgesic medications and techniques combined with nonpharmacological interventions, for the treatment of postoperative pain in adults.
  4. Clinicians should provide patient and family-centered, individually tailored education to the patient (and/or responsible caregiver), including information on treatment options for managing postoperative pain, and document the plan and goals for postoperative pain management.
  5. Clinicians should provide education to all patients (adult) and primary caregivers on the pain treatment plan, including proper storage and disposal of opioids and tapering of analgesics after hospital discharge.
  6. Clinicians should adjust the pain management plan based on adequacy of pain relief and presence of adverse events.
  7. Clinicians should have access to consultation with a pain specialist for patients who have inadequately controlled postoperative pain or are at high risk of inadequately controlled postoperative pain at their facilities (e.g., long-term opioid therapy, history of substance use disorder).

The formation of this consortium is a critical first step to widespread quality improvement in perioperative pain management for surgical patients across the country. The fact that 14 professional healthcare organizations could agree on these 7 principles means that the bar for acute perioperative pain management has been reset.

The work product of this consortium can now form the basis of all future guidelines and influence the products of legislation and regulation that affect pain management for surgical patients. There is still so much work to do, however, and this consortium is already looking at how to tailor these principles to more complex surgical populations, better assess barriers to change implementation, and provide each organization’s members with the tools they need to improve acute perioperative pain management where they are.

Related Posts:

The Problem of Burnout in Anesthesiology

I have written previously about what I love about being an anesthesiologist and why I still love being an anesthesiologist after all these years.

Recent articles have drawn attention to the pervasive problem of burnout among anesthesiologists, and the numbers are alarming. The overall prevalence within anesthesiology is approximately 60%, and this rate varies by subspecialty with pain physicians being at highest risk.

Our writing group has published two letters in the Journal of Clinical Anesthesia that offer additional perspectives and highlight important work on this subject: “A field on fire: Why has there been so much attention focused on burnout among anesthesiologists?” and “Fighting burnout in the COVID-19 era is a family matter.”

The previously-published studies by Hyman et al and Afonso et al report data collected prior to the onset of the COVID-19 pandemic. While anesthesiologists were hailed as frontline heroes worldwide for their roles in the emergency response, airway management, and critical care of COVID-19 patients, their lives and their careers were also completely disrupted.

At work, anesthesiologists had to deal with confronting a previously unknown and highly transmissible respiratory pandemic, long hours and uncertain schedules, new personal protective equipment (PPE) protocols and PPE shortages, quarantines, and frequently-changing guidelines. Shelter-in-place orders led to school and office closures which added the stressors of working from home and virtual schooling on top of pandemic parenting, and women anesthesiologists were disproportionately affected.

Moving forward, the ongoing assessment and mitigation of burnout among anesthesiologists will take dedicated effort and leadership. Our letter recommends periodic evaluation of work-related risk factors and check-ins with anesthesiologist team members. Further, recognition of the challenges to work-life integration imposed by the COVID-19 pandemic warrants implementation of reliable interventions that may prevent the same issues from happening again in the future.

In addition, it may be more appropriate to promote wellness at the family level, rather than simply the individual level, because anesthesiologists cannot reasonably focus on their important physician roles when there are concurrent and competing stressors at home.

Related Posts:

7 Guiding Principles for Acute Perioperative Pain Management

I had the privilege of co-chairing the 2021 Pain Summit hosted by American Society of Anesthesiologists (ASA). In the months preceding the summit, ASA physician volunteers and staff as well as representatives from 14 other surgical specialty and healthcare organizations worked towards achieving consensus on a common set of principles to guide physicians and other clinicians who manage acute perioperative pain.

These 7 proposed principles are:

  1. Conduct a preoperative evaluation including assessment of medical and psychological conditions, concomitant medications, history of chronic pain, substance abuse disorder, and previous postoperative treatment regimens and responses, to guide the perioperative pain management plan.
  2. Use a validated pain assessment tool to track responses to postoperative pain treatments and adjust treatment plans accordingly.
  3. Offer multimodal analgesia, or the use of a variety of analgesic medications and techniques combined with nonpharmacological interventions, for the treatment of postoperative pain in adults.
  4. Provide patient and family-centered, individually tailored education to the patient (and/or responsible caregiver), including information on treatment options for managing postoperative pain, and document the plan and goals for postoperative pain management.
  5. Provide education to all patients (adult) and primary caregivers on the pain treatment plan, including proper storage and disposal of opioids and tapering of analgesics after hospital discharge.
  6. Adjust the pain management plan based on adequacy of pain relief and presence of adverse events.
  7. Have access to consultation with a pain specialist for patients who have inadequately controlled postoperative pain or at high risk of inadequately controlled postoperative pain at their facilities (e.g., long-term opioid therapy, history of substance use disorder).

This is the first project from this new collaborative, which focused on the adult surgical patient, and there are already plans for future projects. The participating organizations are:

  • American Academy of Orthopaedic Surgeons
  • American Academy of Otolaryngology-Head and Neck Surgery
  • American Association of Neurological Surgeons
  • American Association of Oral and Maxillofacial Surgeons
  • American College of Obstetricians and Gynecologists
  • American College of Surgeons
  • American Hospital Association
  • American Medical Association
  • American Society of Breast Surgeons
  • American Society of Plastic Surgeons
  • American Society of Regional Anesthesia and Pain Medicine
  • American Urological Association
  • Society of Thoracic Surgeons

Related Posts:

We Still Have an Opioid Epidemic

COVID-19 has changed every aspect of our personal and professional lives.

In the midst of this pandemic, we still have an opioid epidemic. It is not one thing unfortunately, and the Centers for Disease Control and Prevention (CDC) describe three distinct waves of opioid-related overdose deaths.

Centers for Disease Control and Prevention

Given the complexity of the opioid epidemic, we have to keep working within our spheres of influence. For those of us in anesthesiology, that means focusing on surgical patients: improving their outcomes and providing effective perioperative pain management along with opioid stewardship.

Dr. Chad Brummett and his colleagues at Michigan OPEN have been leading the way in procedure-specific opioid prescribing recommendations. Their process, which takes into account data from the Collaborative Quality Initiative (CQI), published studies, and expert input, specifically focuses on the perioperative care of patients who are not taking any opioids prior to surgery.

Continue reading We Still Have an Opioid Epidemic

Through multimodal analgesia, we prevent and treat pain in a variety of ways without depending solely on opioids.

At our institution, we offer patients regional anesthesia and have been able to decrease the amount of opioid pills that patients are given when they leave the hospital by basing the prescription on how much they use the prior day. Patients participate in this process, and we give them clear instructions on how to safety taper their opioids at home.

As a representative of the American Society of Anesthesiologists (ASA), I have been able to collaborate with surgical societies such as the American Society of Breast Surgeons and the American Academy of Orthopaedic Surgeons to develop pain management recommendations and toolkits that emphasize multimodal analgesia, use of regional anesthesia techniques for targeted non-opioid pain management when it is available, and opioid safety in the hospital and at home.

ASA-AAOS Pain Alleviation Toolkit

I also represent ASA as a member of the National Academy of Medicine (NAM) Action Collaborative Countering the U.S. Opioid Epidemic. The first discussion paper from the NAM pain management workgroup was released on Aug 10: Best Practices, Research Gaps, and Future Priorities to Support Tapering Patients on Long-Term Opioid Therapy for Chronic Non-Cancer Pain in Outpatient Settings. This paper highlights best practices in opioid tapering and identifies evidence gaps to drive future research.

Despite the massive amount of resources, human effort, and time dedicated to the fight against COVID-19, we have still managed to make progress in decreasing opioid-related risk in the perioperative period. However, there is still a lot of work left to do, and our patients are depending on us.

Related Posts:

Regional Anesthesia Education and Social Media

At the 2018 annual meeting of the European Society of Regional Anaesthesia and Pain Therapy (ESRA), I was invited to give a talk on regional anesthesia education and social media.  In case you missed it, I have posted my slides on SlideShare.

After my session, I was asked by ESRA to highlight some of the key points of my lecture:

Related Posts:

Why We Should Worry about Drug Shortages in Regional Anesthesia

The crisis of prescription opioid overuse and abuse has affected countries around the world, and anesthesiologists are well-positioned to make positive changes (1).  Even minor outpatient surgical procedures, and their associated anesthesia and analgesia techniques, can lead to long-term opioid use (2,3).  Patients who present for surgery with an active opioid prescription are very likely to still be on opioids after a year (4).

Anesthesiologists have been working to set up regional anesthesiology and acute pain medicine programs with careful coordination of inpatient and outpatient pain management to improve patient outcomes.  Regional anesthesia, especially with continuous peripheral nerve block (CPNB) techniques, has been shown repeatedly to reduce patients’ need for opioid analgesia (5).

Today, the crisis of drug shortages threatens to reverse the many advances in perioperative pain control that have been achieved.  Local anesthetics or “numbing medications” represent a class of drugs that is our strongest weapon against opioids.  These drugs (e.g., bupivacaine, lidocaine, ropivacaine) are currently in shortage.  Targeted injections of local anesthetic in the form of regional anesthesia eliminate sensation at the site of surgery and can obviate the need for injectable opioids (e.g., fentanyl, hydromorphone, morphine) which also happen to be in short supply.  Local anesthetics are also the critical ingredient in providing epidural pain relief and spinal anesthesia for childbirth.  Without them, new moms will miss the first moments of their babies’ lives.

The following are potential ramifications of the current drug shortages affecting anesthesia and pain management on patient care:

Decreased Quality of Acute Pain Management

Regional anesthesia techniques, which include spinal, epidural, and peripheral nerve blocks, offer patients many potential advantages in the perioperative and peripartum period.  Human studies have demonstrated the following benefits: decreased pain, nausea and vomiting, and time spent in the recovery room (6,7).  Long-acting local anesthetics (e.g., bupivacaine, levobupivacaine, and ropivacaine) generally provide analgesia of similar duration for 24 hours or less (8-11).  These clinical effects of nerve blocks typically last long enough for patients to meet discharge eligibility from recovery and avoid unnecessary hospitalization for pain control (12).  CPNB techniques (also known as perineural catheters) permit delivery of local anesthetic solutions to the site of a peripheral nerve on an ongoing basis (13).  Portable infusion devices can deliver a solution of plain local anesthetic for days after surgery, often with the ability to titrate the dose up and down or even stop the infusion temporarily when patients feel too numb (14,15).  In a meta-analysis comparing CPNB to single-injection peripheral nerve blocks in humans, CPNB results in lower patient-reported worst pain scores and pain scores at rest on postoperative day (POD) 0, 1, and 2 (16).  Patients who receive CPNB also experience less nausea, consume less opioids, sleep better, and are more satisfied with pain management (16).  By using local anesthetic medication to interrupt nerve transmission along peripheral nerves, patients continue to experience decreased sensation as long as the infusion is running.  A shortage of local anesthetic medications makes it impossible for anesthesiologists to provide this potent form of opioid-sparing pain control for all surgical patients.  This also means that local anesthetics cannot be administered by surgeons as wound infiltration to help patients with incisional pain, and epidural analgesia for laboring women may not be universally available.

Increased Incidence of Postoperative Complications

Based on the study by Memtsoudis and colleagues, overall 30-day mortality for total knee arthroplasty patients is lower for patients who receive regional anesthesia, either neuraxial and combined neuraxial-general anesthesia, compared to general anesthesia alone (17).  In most categories, the rates of occurrence of in-hospital complications (e.g. all-cause infections, pulmonary, cardiovascular, acute renal failure) are also lower for the neuraxial and combined neuraxial-general anesthesia groups vs. the general anesthesia only group, and transfusion requirements are lowest for neuraxial anesthesia patients compared to all other groups (17).  The inability to offer regional anesthesia (e.g., spinal or epidural) to all patients due to lack of local anesthetics therefore represents a threat to patient safety.

Increased Risk of Persistent Postsurgical Pain

Chronic pain may develop after many common operations including breast surgery, cesarean delivery, hernia repair, thoracic surgery, and amputation and is associated with severe acute pain in the postoperative period (18).  A Cochrane systematic review and meta-analysis reviewed published studies on this subject, and the results favor epidural analgesia for prevention of persistent postsurgical pain (PPSP) after thoracotomy and favor paravertebral block for prevention of PPSP after breast cancer surgery at 6 months (19).  Only regional blockade with local anesthetics can block patients’ sensation during and after surgery.  Without local anesthetics for nerve blocks, spinals, and epidurals, patients will experience greater than expected acute pain, require additional opioid treatment, and potentially be at higher risk of developing chronic pain.

Increased Health Care Costs

Approximately 31% of costs related to inpatient perioperative care is attributable to the ward admission (20).  Anesthesiologists as perioperative physicians have an opportunity to influence the cost of surgical care by decreasing hospital length of stay through effective pain management and by developing coordinated multi-disciplinary clinical pathways (21,22).  Regional anesthesia and analgesia can improve outcomes through integration into clinical pathways that involve a multipronged approach to streamlining surgical care (23,24).  Inadequate pain control can delay rehabilitation, prolong hospital admissions, increase the rate of readmissions (25), and increase the costs of hospitalization for surgical patients.

In summary, regional anesthesia and analgesia has been shown in multiple studies to improve outcomes for obstetric and surgical patients.  The current shortage of local anesthetics and other analgesic medications negatively affects quality of care and pain management and is a threat to patient safety.

References

  1. Alam A, Juurlink DN. The prescription opioid epidemic: an overview for anesthesiologists. Can J Anaesth 2016;63:61-8.
  2. Sun EC, Darnall BD, Baker LC, Mackey S. Incidence of and Risk Factors for Chronic Opioid Use Among Opioid-Naive Patients in the Postoperative Period. JAMA internal medicine 2016;176:1286-93.
  3. Rozet I, Nishio I, Robbertze R, Rotter D, Chansky H, Hernandez AV. Prolonged opioid use after knee arthroscopy in military veterans. Anesth Analg 2014;119:454-9.
  4. Mudumbai SC, Oliva EM, Lewis ET, Trafton J, Posner D, Mariano ER, Stafford RS, Wagner T, Clark JD. Time-to-Cessation of Postoperative Opioids: A Population-Level Analysis of the Veterans Affairs Health Care System. Pain Med 2016;17:1732-43.
  5. Richman JM, Liu SS, Courpas G, Wong R, Rowlingson AJ, McGready J, Cohen SR, Wu CL. Does continuous peripheral nerve block provide superior pain control to opioids? A meta-analysis. Anesth Analg 2006;102:248-57.
  6. Liu SS, Strodtbeck WM, Richman JM, Wu CL. A comparison of regional versus general anesthesia for ambulatory anesthesia: a meta-analysis of randomized controlled trials. Anesth Analg 2005;101:1634-42.
  7. McCartney CJ, Brull R, Chan VW, Katz J, Abbas S, Graham B, Nova H, Rawson R, Anastakis DJ, von Schroeder H. Early but no long-term benefit of regional compared with general anesthesia for ambulatory hand surgery. Anesthesiology 2004;101:461-7.
  8. Casati A, Borghi B, Fanelli G, Cerchierini E, Santorsola R, Sassoli V, Grispigni C, Torri G. A double-blinded, randomized comparison of either 0.5% levobupivacaine or 0.5% ropivacaine for sciatic nerve block. Anesth Analg 2002;94:987-90, table of contents.
  9. Hickey R, Hoffman J, Ramamurthy S. A comparison of ropivacaine 0.5% and bupivacaine 0.5% for brachial plexus block. Anesthesiology 1991;74:639-42.
  10. Klein SM, Greengrass RA, Steele SM, D’Ercole FJ, Speer KP, Gleason DH, DeLong ER, Warner DS. A comparison of 0.5% bupivacaine, 0.5% ropivacaine, and 0.75% ropivacaine for interscalene brachial plexus block. Anesth Analg 1998;87:1316-9.
  11. Fanelli G, Casati A, Beccaria P, Aldegheri G, Berti M, Tarantino F, Torri G. A double-blind comparison of ropivacaine, bupivacaine, and mepivacaine during sciatic and femoral nerve blockade. Anesth Analg 1998;87:597-600.
  12. Williams BA, Kentor ML, Vogt MT, Williams JP, Chelly JE, Valalik S, Harner CD, Fu FH. Femoral-sciatic nerve blocks for complex outpatient knee surgery are associated with less postoperative pain before same-day discharge: a review of 1,200 consecutive cases from the period 1996-1999. Anesthesiology 2003;98:1206-13.
  13. Ilfeld BM. Continuous peripheral nerve blocks: a review of the published evidence. Anesth Analg 2011;113:904-25.
  14. Ilfeld BM. Continuous peripheral nerve blocks in the hospital and at home. Anesthesiol Clin 2011;29:193-211.
  15. Ilfeld BM, Enneking FK. Continuous peripheral nerve blocks at home: a review. Anesth Analg 2005;100:1822-33.
  16. Bingham AE, Fu R, Horn JL, Abrahams MS. Continuous peripheral nerve block compared with single-injection peripheral nerve block: a systematic review and meta-analysis of randomized controlled trials. Reg Anesth Pain Med 2012;37:583-94.
  17. Memtsoudis SG, Sun X, Chiu YL, Stundner O, Liu SS, Banerjee S, Mazumdar M, Sharrock NE. Perioperative comparative effectiveness of anesthetic technique in orthopedic patients. Anesthesiology 2013;118:1046-58.
  18. Kehlet H, Jensen TS, Woolf CJ. Persistent postsurgical pain: risk factors and prevention. Lancet 2006;367:1618-25.
  19. Andreae MH, Andreae DA. Regional anaesthesia to prevent chronic pain after surgery: a Cochrane systematic review and meta-analysis. Br J Anaesth 2013;111:711-20.
  20. Macario A, Vitez TS, Dunn B, McDonald T. Where are the costs in perioperative care? Analysis of hospital costs and charges for inpatient surgical care. Anesthesiology 1995;83:1138-44.
  21. Ilfeld BM, Mariano ER, Williams BA, Woodard JN, Macario A. Hospitalization costs of total knee arthroplasty with a continuous femoral nerve block provided only in the hospital versus on an ambulatory basis: a retrospective, case-control, cost-minimization analysis. Reg Anesth Pain Med 2007;32:46-54.
  22. Jakobsen DH, Sonne E, Andreasen J, Kehlet H. Convalescence after colonic surgery with fast-track vs conventional care. Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland 2006;8:683-7.
  23. Macario A, Horne M, Goodman S, Vitez T, Dexter F, Heinen R, Brown B. The effect of a perioperative clinical pathway for knee replacement surgery on hospital costs. Anesth Analg 1998;86:978-84.
  24. Hebl JR, Kopp SL, Ali MH, Horlocker TT, Dilger JA, Lennon RL, Williams BA, Hanssen AD, Pagnano MW. A comprehensive anesthesia protocol that emphasizes peripheral nerve blockade for total knee and total hip arthroplasty. J Bone Joint Surg Am 2005;87 Suppl 2:63-70.
  25. Hernandez-Boussard T, Graham LA, Desai K, Wahl TS, Aucoin E, Richman JS, Morris MS, Itani KM, Telford GL, Hawn MT. The Fifth Vital Sign: Postoperative Pain Predicts 30-day Readmissions and Subsequent Emergency Department Visits. Ann Surg 2017;266:516-24.

Related Posts:

The Future of Acute Pain Medicine Training

AVC.Pain_We all know that not all pain is the same. While chronic pain can sometimes be palliated, “acute” pain (new onset, often with an identifiable cause) must be aggressively managed and, ideally, eliminated. This requires a systems-based approach led by physicians dedicated to understanding acute pain pathophysiology and investigating new ways to treat it. 

In December 2013, I submitted a 161-page letter to the Accreditation Council for Graduate Medical Education (ACGME) requesting that regional anesthesiology and acute pain medicine be considered for fellowship accreditation, with a lot of help from a small group of fellowship directors and colleagues from obstetric anesthesiology who recently went through the ACGME accreditation process for their fellowships. With no requests for further information, the Board of Directors of the ACGME informed me in the fall of 2014 that Regional Anesthesiology and Acute Pain Medicine (RAAPM) will be the next accredited subspecialty fellowship within the core discipline of Anesthesiology.  The draft program requirements have been posted online for public comments.  After the comment period, these program requirements will be revised and then finalized for posting by the ACGME. At that point, which may be as early as the end of this year, institutions with RAAPM fellowships will be invited to apply for accreditation.

I have received many questions from ASRA members about this process to date, so below I have provided some of my answers to the most common ones:

Why do we need “another” fellowship dedicated to pain medicine?  Although we already have a board-certified subspecialty of Pain Medicine within Anesthesiology, there is a growing demand for physicians who specialize in hospital-based acute pain medicine. For Pain Medicine fellows, the required “Acute Pain Inpatient Experience” may be satisfied by documented involvement with a minimum of only 50 new patients and the spectrum of pain diagnoses and treatments that they are required to learn during one year is vast. Further, Pain Medicine is a board-certified subspecialty of Emergency Medicine, Family Medicine, Physical Medicine and Rehabilitation, and Psychiatry and Neurology, in addition to Anesthesiology; graduates from any of these residency programs can be accepted into the one-year Pain Medicine fellowship and will not be as familiar with surgical or trauma-induced acute pain as an anesthesiology residency graduate. Anesthesiology is a hospital-based medical specialty, and anesthesiologists are physicians who focus on a  daily basis on the prevention and treatment of pain for their patients who undergo surgery, suffer trauma, or present for childbirth. History also supports the evolution of acute pain medicine through anesthesiology. The concept of an anesthesiology-led acute pain management service was described first in 1988 (1), but arguably the techniques employed in modern acute pain medicine and regional anesthesiology date back to Gaston Labat’s publication of Regional Anesthesia: Its Technic and Clinical Application in 1922, with advancement and refinement of this subspecialty in the 1960s and 1970s (2-6). Finally, a recent survey study shows that the great majority (83.7%) of practicing pain physicians in the United States focus only on chronic pain (7).

Why do anesthesiology residency graduates still need to do a fellowship in RAAPM? By the time they complete the core residency in anesthesiology today, not all residents have gained sufficient clinical experience to provide optimal care for the complete spectrum of issues experienced by patients suffering from acutely painful conditions, including the ability to reliably provide advanced interventional techniques proven to be effective in managing pain in the acute setting (8-12). We need physician leaders who can run acute pain medicine teams and design systems to provide individualized, comprehensive, and timely pain management for both medical and surgical patients in the hospital, expeditiously managing requests for assistance when pain intensity levels exceed those set forth in quality standards, or to prevent pain intensity from reaching such levels. The mission statement for the Acute Pain Medicine Special Interest Group within the American Academy of Pain Medicine provides clear justification.

Will RAAPM fellowship graduates get jobs when they are done? Although no one can make this guarantee, there are good reasons to think that there will be growing demand for RAAPM graduates in the future. In a survey of fellowship graduates and academic chairs published in 2005, 61 of 132 of academic chairs responded (46%), noting that future staffing models for their department will likely include an average of two additional faculty trained in regional anesthesiology and acute pain medicine (13). RAAPM fellowship graduates are the only physicians who can say that their subspecialty training is entirely dedicated to improving the patient experience. The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey is administered to a random sample of patients who have received inpatient care and receive government insurance through Center for Medicare and Medicaid Services (CMS). The survey consists of 32 questions and is intended to assess the “patient experience of care” domain in the value-based purchasing program. A hospital’s survey scores are publicly disclosed and make up 30% of the formula used to determine how much of its diagnosis-related group payment withholding will be paid by CMS at the end of each year. Of the 32 questions, 7 directly or indirectly relate to in-hospital pain management.

Are we ready for accreditation? Currently, there are over 60 institutions in the United States and Canada that list themselves as having nonaccredited fellowship training programs focused on RAAPM on the ASRA website. Since 2002, the group of regional anesthesiology and acute pain medicine fellowship directors has been meeting twice yearly at the ASRA Annual Spring Meeting and the American Society of Anesthesiologists (ASA) Annual Meeting in the fall. Despite not being an ACGME-accredited fellowship, this group, has been voluntarily engaged in developing and refining training guidelines as the foundation for the fellowship. These guidelines, originally published in Regional Anesthesia and Pain Medicine in 2005 (14) with a revision in 2011 (15) have been recently released as the third edition (16). Formal ACGME program requirements will serve as a measuring stick to hopefully ensure that the certificates that RAAPM fellowship graduates receive from all accredited programs will share some common value.

As with other medical subspecialties, acute pain medicine has emerged due to the need for trained specialists—in this case, those who possess the knowledge, skills, and abilities to efficiently manage a high volume of inpatient consultations, anticipate the analgesic needs of a wide range of patients based on preoperative risk, use a multimodal approach to manage and prevent pain when possible, and aggressively treat severe acute pain when it occurs to prevent it from transitioning into chronic pain. The RAAPM fellowship graduate must be a physician leader who is capable of collaborating with other healthcare providers in anesthesiology, surgery, medicine, nursing, pharmacy, physical therapy, and more to establish multidisciplinary programs that add value and improve patient care in the hospital setting and beyond.

This article originally appeared in the February 2016 issue of ASRA News.  As of October 2016, the regional anesthesiology and acute pain medicine is the newest accredited subspecialty fellowship within anesthesiology, and programs may now apply for accreditation to the ACGME.

REFERENCES

  1. Ready LB, Oden R, Chadwick HS, Benedetti C, Rooke GA, Caplan R, Wild LM. Development of an anesthesiology-based postoperative pain management service. Anesthesiology. 1988; 68:100-6.
  2. Winnie AP, Ramamurthy S, Durrani Z. The inguinal paravascular technic of lumbar plexus anesthesia: the “3-in-1 block.” Anesth Analg. 1973; 52:989-96.
  3. Winnie AP, Collins VJ. The subclavian perivascular technique of brachial plexus anesthesia. Anesthesiology. 1964; 25:353-63.
  4. Raj PP, Montgomery SJ, Nettles D, Jenkins MT Infraclavicular brachial plexus block–a new approach. Anesth Analg. 1973; 52:897-904.
  5. Raj PP, Parks RI, Watson TD, Jenkins MT. A new single-position supine approach to sciatic-femoral nerve block. Anesth Analg. 1975; 54:489-93.
  6. Raj PP, Rosenblatt R, Miller J, Katz RL, Carden E. Dynamics of local-anesthetic compounds in regional anesthesia. Anesth Analg 1977; 56: 110-7.
  7. Breuer B, Pappagallo M, Tai JY, Portenoy RK. U.S. board-certified pain physician practices: uniformity and census data of their locations. J Pain. 2007; 8: 244-50.
  8. Buvanendran A, Kroin JS. Multimodal analgesia for controlling acute postoperative pain. Curr Opin Anaesthesiol. 2009; 22: 588-93.
  9. Hebl JR, Dilger JA, Byer DE, Kopp SL, Stevens SR, Pagnano MW, Hanssen AD, Horlocker TT. A pre-emptive multimodal pathway featuring peripheral nerve block improves perioperative outcomes after major orthopedic surgery. Reg Anesth Pain Med. 2008; 33: 510-7.
  10. Jin F, Chung F. Multimodal analgesia for postoperative pain control. J Clin Anesth. 2001; 13: 524-39.
  11. Kehlet H, Dahl JB. The value of “multimodal” or “balanced analgesia” in postoperative pain treatment. Anesth Analg. 1993; 77: 1048-56.
  12. Young A, Buvanendran A.Recent advances in multimodal analgesia. Anesthesiol Clin. 2012; 30: 91-100.
  13. Neal JM, Kopacz DJ, Liguori GA, Beckman JD, Hargett MJ. The training and careers of regional anesthesia fellows–1983-2002. Reg Anesth Pain Med. 2005; 30: 226-32.
  14. Hargett MJ, Beckman JD, Liguori GA, Neal JM. Guidelines for regional anesthesia fellowship training. Reg Anesth Pain Med. 2005; 30: 218-25.
  15. Regional Anesthesiology and Acute Pain Medicine Fellowship Directors Group. Guidelines for fellowship training in regional anesthesiology and acute pain medicine: second edition, 2010. Reg Anesth Pain Med. 2011; 36: 282-8.
  16. Regional Anesthesiology and Acute Pain Medicine Fellowship Directors Group. Guidelines for fellowship training in regional anesthesiology and acute pain medicine: third edition, 2014. Reg Anesth Pain Med. 2015; 40: 213-7.

Related Posts:

Pain Medicine, Perioperative Surgical Home, and the Patient Experience

VAPAHealthcare around the world is changing. In the United States, healthcare reform has been focused on achieving the “triple aim” as described by Berwick (1). This triple aim encompasses 3 goals: improving the patient experience, reducing costs of care, and improving population health. The Perioperative Surgical Home (PSH) is a conceptual model introduced by the American Society of Anesthesiologists (ASA) in the past 5 years that may serve as an integrator to help hospitals achieve the triple aim (2). PSH is defined as “a patient-centered, physician anesthesiologist-led, multidisciplinary team-based practice model that coordinates surgical patient care throughout the continuum from the decision to pursue surgery through convalescence” (3). In reality, a PSH can take many forms, and the concept is analogous to the “Perioperative Medicine: the Pathway to Better Surgical Care” initiative by the Royal College of Anaesthetists in the United Kingdom. To date, there have been few published descriptions of actual PSH programs.

Role of Pain Medicine in the PSH

Pain medicine is woven throughout the three main elements of the PSH: preoperative preparation, intraoperative care, and postoperative recovery and rehabilitation (4). Preoperatively, anesthesiologists and pain medicine specialists have an opportunity to influence patient care by identifying patients who are considered high risk for surgery and tailor an individualized preoperative preparation plan for them. For example, the patient with chronic pain treated with long-acting opioids may benefit from optimizing the preoperative analgesic medication regimen, even tapering the opioid dose, or prescribing cognitive, behavioral, or physical therapy prior to elective major surgery like lower extremity joint replacement. During the intraoperative period, anesthetic protocols provide consistent care for surgical patients, and implementing clinical pathways that include regional anesthesia techniques have been shown to decrease perioperative opioid use and improve outcomes. For patients who have surgery, pain has a profound influence on the hospital experience. In the United States, the patient experience of care is one of three domains that influence hospital incentive payment amounts from the Center for Medicare and Medicaid Services. Patient experience is assessed using a survey, and 7 of 32 questions directly or indirectly relate to pain management (5). After the immediate postoperative period, integrated pain management can help patients achieve physical therapy goals and facilitate the transition to after-hospital rehabilitation. For challenging patients with chronic pain, this process may require careful coordination between the in-hospital anesthesiologist, outpatient pain clinic physician, and primary care physician (4).

Thinking Beyond Pain

The practice of anesthesiology in the United States is evolving, and there is a greater emphasis on demonstrating value. Anesthesiologists have historically been successful in establishing perioperative clinical pathways that improve acute pain management especially in orthopedic surgery, and setting up regional anesthesia and acute pain medicine programs has played a key role (6). However, competing priorities require revision of clinical pathways from time to time. For example, concerns regarding quadriceps muscle weakness with femoral nerve blocks (7) and the potential for falls (8) have led to innovations in selective nerve block techniques for knee replacement patients (9) and greater achievements in functional rehabilitation (10). By establishing a PSH model, anesthesiologists have greater opportunity but also greater responsibility for reducing perioperative complications that may or may not typically be considered within the realm of anesthesiology (11).

Future Directions

physical_med_rehab_indexTo date, anesthetic interventions focused on targeting acute pain have not demonstrated long-term functional benefits (12,13). Perhaps implementation of a PSH with better care coordination that includes individualized preoperative preparation and follow-up after surgery during rehabilitation will have greater potential for positive long-term outcomes. In addition to improvements in functional outcomes, a PSH may be able to provide patients a smoother transition from hospital to home in terms of pain management and decrease the incidence of chronic pain after common elective procedures like joint replacement (14). Finally, more health economic research is needed to prove the financial benefits of a PSH in terms of cost savings for hospitals.

In summary, the PSH is a model that can be applied many ways to provide coordinated care of the surgical patient from the decision to proceed with surgery through convalescence. Pain medicine plays an integral role in any PSH implementation. However, to be effective, anesthesiologists as leaders of the PSH need to target improvement strategies beyond pain outcomes and the immediate postoperative period.

References

  1. Berwick DM, Nolan TW, Whittington J: The triple aim: care, health, and cost. Health Aff (Millwood) 2008; 27: 759-69
  2. Vetter TR, Boudreaux AM, Jones KA, Hunter JM, Jr., Pittet JF: The perioperative surgical home: how anesthesiology can collaboratively achieve and leverage the triple aim in health care. Anesth Analg 2014; 118: 1131-6
  3. Mariano ER, Walters TL, Kim TE, Kain ZN: Why the perioperative surgical home makes sense for veterans affairs health care. Anesth Analg 2015; 120: 1163-6
  4. Walters TL, Mariano ER, Clark JD: Perioperative Surgical Home and the Integral Role of Pain Medicine. Pain Med 2015; 16: 1666-72
  5. Mariano ER, Miller B, Salinas FV: The expanding role of multimodal analgesia in acute perioperative pain management. Adv Anesth 2013; 31: 119-136
  6. Mariano ER: Making it work: setting up a regional anesthesia program that provides value. Anesthesiol Clin 2008; 26: 681-92, vi
  7. Charous MT, Madison SJ, Suresh PJ, Sandhu NS, Loland VJ, Mariano ER, Donohue MC, Dutton PH, Ferguson EJ, Ilfeld BM: Continuous femoral nerve blocks: varying local anesthetic delivery method (bolus versus basal) to minimize quadriceps motor block while maintaining sensory block. Anesthesiology 2011; 115: 774-81
  8. Feibel RJ, Dervin GF, Kim PR, Beaule PE: Major complications associated with femoral nerve catheters for knee arthroplasty: a word of caution. J Arthroplasty 2009; 24: 132-7
  9. Lund J, Jenstrup MT, Jaeger P, Sorensen AM, Dahl JB: Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand 2011; 55: 14-9
  10. Mudumbai SC, Kim TE, Howard SK, Workman JJ, Giori N, Woolson S, Ganaway T, King R, Mariano ER: Continuous adductor canal blocks are superior to continuous femoral nerve blocks in promoting early ambulation after TKA. Clin Orthop Relat Res 2014; 472: 1377-83
  11. Kim TE, Mariano ER: Developing a Multidisciplinary Fall Reduction Program for Lower-Extremity Joint Arthroplasty Patients. Anesthesiol Clin 2014; 32: 853-864
  12. Ilfeld BM, Ball ST, Gearen PF, Mariano ER, Le LT, Vandenborne K, Duncan PW, Sessler DI, Enneking FK, Shuster JJ, Maldonado RC, Meyer RS: Health-related quality of life after hip arthroplasty with and without an extended-duration continuous posterior lumbar plexus nerve block: a prospective, 1-year follow-up of a randomized, triple-masked, placebo-controlled study. Anesth Analg 2009; 109: 586-91
  13. Ilfeld BM, Shuster JJ, Theriaque DW, Mariano ER, Girard PJ, Loland VJ, Meyer S, Donovan JF, Pugh GA, Le LT, Sessler DI, Ball ST: Long-term pain, stiffness, and functional disability after total knee arthroplasty with and without an extended ambulatory continuous femoral nerve block: a prospective, 1-year follow-up of a multicenter, randomized, triple-masked, placebo-controlled trial. Reg Anesth Pain Med 2011; 36: 116-20
  14. Lavand’homme PM, Grosu I, France MN, Thienpont E: Pain trajectories identify patients at risk of persistent pain after knee arthroplasty: an observational study. Clin Orthop Relat Res 2014; 472: 1409-15

Related Posts:

Multimodal Pain Relief after Knee Replacement

Knee-pain 2Knee replacement is one of the most commonly performed operations in the United States with over 700,000 procedures performed annually (1). Besides providing anesthesia care in the operating room, anesthesiologists are dedicated to providing the best perioperative pain management in order to improve patients’ function and facilitate rehabilitation after surgery. In the past, pain management was limited to the use of opioids (narcotics). Opioids only attack pain in one way, and just adding more opioids does not usually lead to better pain control.

In 2012, the American Society of Anesthesiologists (ASA) published its guidelines for acute pain management in the perioperative setting (2). This document recommends “multimodal analgesia” which means that two or more classes of pain medications or therapies, working with different mechanisms of action, should be used in the treatment of acute pain.

While opioids are still important pain medications, they should be combined with other classes of medications known to help relieve postoperative pain unless contraindicated. These include:

  • Non-steroidal anti-inflammatory drugs (NSAIDs): Examples include ibuprofen, diclofenac, ketorolac, celecoxib. NSAIDs act on the prostaglandin system peripherally and work to decrease inflammation.
  • Acetaminophen: Acetaminophen acts on central prostaglandin synthesis and provides pain relief through multiple mechanisms.
  • Gabapentinoids: Examples include gabapentin and pregabalin. These medications are membrane stabilizers that essentially decrease nerve firing.

The ASA also strongly recommends the use of regional analgesic techniques as part of the multimodal analgesic protocol when indicated.

Epidural Analgesia

When compared to opioids alone, epidural analgesia produces lower pain scores and shorter time to achieve physical therapy goals (3). However, higher dose of local anesthetic (numbing medicine) may lead to muscle weakness that can limit activity (4). In addition, epidural analgesia can lead to common side effects (urinary retention, dizziness, itchiness) and is not selective for the operative leg, meaning that the non-operative leg may also become numb.

Femoral Nerve Block

A peripheral nerve block of the femoral nerve is specific to the operative leg. When compared to opioids alone, a femoral nerve block provides better pain control and leads to higher patient satisfaction (5). One area of controversy is whether a single-injection nerve block or catheter-based technique is preferred. There is evidence to support the use of continuous nerve block catheters to extend the pain relief and opioid-sparing benefits of nerve blocks in patients having major surgery like knee replacement. When a continuous femoral nerve block catheter is used, the pain relief is comparable to an epidural but without the epidural-related side effects (6). One legitimate concern raised over the use of femoral nerve blocks in knee replacement patients is the resulting quadriceps muscle weakness (7).

From Gray's Anatomy
From Gray’s Anatomy

Saphenous Nerve Block (Adductor Canal Block)

The saphenous nerve is the largest sensory branch of the femoral nerve and can be blocked within the adductor canal to provide postoperative pain relief and facilitate rehabilitation (8, 9). In healthy volunteers, quadriceps strength is better preserved when subjects receive an adductor canal block compared to a femoral nerve block (10).

In actual knee replacement patients, quadriceps function decreases regardless of nerve block type after surgery but to a lesser degree with adductor canal blocks (11). Recently there have been reports of quadriceps weakness resulting from adductor canal blocks and catheters that have affected clinical care (12, 13).

Fall Risk

According to a large retrospective study of almost 200,000 cases, the incidence of inpatient falls for patients after TKA is 1.6%, and perioperative use of nerve blocks is not associated with increased risk (14). Patient factors that increase the risk of falls include higher age, male sex, sleep apnea, delirium, anemia requiring blood transfusion, and intraoperative use of general anesthesia (14). The bottom line is that all knee replacement patients are at increased risk for falling due to multiple risk factors, and any clinical pathway should include fall prevention strategies and an emphasis on patient safety.

Other Local Anesthetic Techniques

In addition to a femoral nerve or adductor canal block, a sciatic nerve block is sometimes offered to provide a “complete” block of the leg. There are studies for and against this practice. Arguably, the benefit of a sciatic nerve block does not last beyond the first postoperative day (15). Surgeon-administered local anesthetic around the knee joint (local infiltration analgesia) can be combined with nerve block techniques to provide additional postoperative pain relief for the first few hours after surgery (16, 17).

For more information about anesthetic options for knee replacement, please see my post on My Knee Guide.

References

  1. The Center for Disease Control and Prevention. FastStats: Inpatient Surgery. National Hospital Discharge Survey: 2010 table. http://www.cdc.gov/nchs/fastats/inpatient-surgery.htm. Accessed January 30, 2015.
  2. American Society of Anesthesiologists Task Force on Acute Pain M: Practice guidelines for acute pain management in the perioperative setting: an updated report by the American Society of Anesthesiologists Task Force on Acute Pain Management. Anesthesiology 2012, 116(2):248-273.
  3. Mahoney OM, Noble PC, Davidson J, Tullos HS: The effect of continuous epidural analgesia on postoperative pain, rehabilitation, and duration of hospitalization in total knee arthroplasty. Clin Orthop Relat Res 1990(260):30-37.
  4. Raj PP, Knarr DC, Vigdorth E, Denson DD, Pither CE, Hartrick CT, Hopson CN, Edstrom HH: Comparison of continuous epidural infusion of a local anesthetic and administration of systemic narcotics in the management of pain after total knee replacement surgery. Anesth Analg 1987, 66(5):401-406.
  5. Chan EY, Fransen M, Parker DA, Assam PN, Chua N: Femoral nerve blocks for acute postoperative pain after knee replacement surgery. Cochrane Database Syst Rev 2014, 5:CD009941.
  6. Barrington MJ, Olive D, Low K, Scott DA, Brittain J, Choong P: Continuous femoral nerve blockade or epidural analgesia after total knee replacement: a prospective randomized controlled trial. Anesth Analg 2005, 101(6):1824-1829.
  7. Charous MT, Madison SJ, Suresh PJ, Sandhu NS, Loland VJ, Mariano ER, Donohue MC, Dutton PH, Ferguson EJ, Ilfeld BM: Continuous femoral nerve blocks: varying local anesthetic delivery method (bolus versus basal) to minimize quadriceps motor block while maintaining sensory block. Anesthesiology 2011, 115(4):774-781.
  8. Jenstrup MT, Jaeger P, Lund J, Fomsgaard JS, Bache S, Mathiesen O, Larsen TK, Dahl JB: Effects of adductor-canal-blockade on pain and ambulation after total knee arthroplasty: a randomized study. Acta Anaesthesiol Scand 2012, 56(3):357-364.
  9. Hanson NA, Allen CJ, Hostetter LS, Nagy R, Derby RE, Slee AE, Arslan A, Auyong DB: Continuous ultrasound-guided adductor canal block for total knee arthroplasty: a randomized, double-blind trial. Anesth Analg 2014, 118(6):1370-1377.
  10. Kwofie MK, Shastri UD, Gadsden JC, Sinha SK, Abrams JH, Xu D, Salviz EA: The effects of ultrasound-guided adductor canal block versus femoral nerve block on quadriceps strength and fall risk: a blinded, randomized trial of volunteers. Reg Anesth Pain Med 2013, 38(4):321-325.
  11. Jaeger P, Zaric D, Fomsgaard JS, Hilsted KL, Bjerregaard J, Gyrn J, Mathiesen O, Larsen TK, Dahl JB: Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty: a randomized, double-blind study. Reg Anesth Pain Med 2013, 38(6):526-532.
  12. Chen J, Lesser JB, Hadzic A, Reiss W, Resta-Flarer F: Adductor canal block can result in motor block of the quadriceps muscle. Reg Anesth Pain Med 2014, 39(2):170-171.
  13. Veal C, Auyong DB, Hanson NA, Allen CJ, Strodtbeck W: Delayed quadriceps weakness after continuous adductor canal block for total knee arthroplasty: a case report. Acta Anaesthesiol Scand 2014, 58(3):362-364.
  14. Memtsoudis SG, Danninger T, Rasul R, Poeran J, Gerner P, Stundner O, Mariano ER, Mazumdar M: Inpatient falls after total knee arthroplasty: the role of anesthesia type and peripheral nerve blocks. Anesthesiology 2014, 120(3):551-563.
  15. Abdallah FW, Brull R: Is sciatic nerve block advantageous when combined with femoral nerve block for postoperative analgesia following total knee arthroplasty? A systematic review. Reg Anesth Pain Med 2011, 36(5):493-498.
  16. Mudumbai SC, Kim TE, Howard SK, Workman JJ, Giori N, Woolson S, Ganaway T, King R, Mariano ER: Continuous adductor canal blocks are superior to continuous femoral nerve blocks in promoting early ambulation after TKA. Clin Orthop Relat Res 2014, 472(5):1377-1383.
  17. Mariano ER, Kim TE, Wagner MJ, Funck N, Harrison TK, Walters T, Giori N, Woolson S, Ganaway T, Howard SK: A randomized comparison of proximal and distal ultrasound-guided adductor canal catheter insertion sites for knee arthroplasty. J Ultrasound Med 2014, 33(9):1653-1662.

Related Posts: