Tips for Reading a Clinical Research Article

paper stackIt is getting more and more difficult to keep up with newly published articles even just in one medical subspecialty.  With so much to read, from background articles for research papers to articles for journal club to manuscript assignments as a peer reviewer, it is important to be efficient and attack every scientific article or manuscript strategically.

Clinical research is my focus area, but the following updated tips for interpreting a journal article may apply to other areas of research as well.

Background:  Do the authors summarize previously published studies leading up to the present study?  What don’t we already know about this topic?

  1. Do the authors do a good job justifying the reason for the study?  This should not be lengthy if there is clearly a need for the study.
  2. Do the authors present a hypothesis?  What is it?
  3. What is the primary aim/objective of the study?  Do the authors specific secondary aims/objectives?

Study Design:  Do the authors explicitly state the design used in the present study?  If so, what is it?

Retrospective (“case-control study”):  Starts with the outcome then looks back in time for exposure to risk factors or interventions

  1. Can calculate odds ratios to estimate relative risk.
  2. Cannot calculate risk/incidence (not prospective).

Cross-sectional (“prevalence study”):  Takes a snapshot of risk factors and outcome of interest at one point in time or over a specific period of time

  1. Can calculate prevalence.
  2. Cannot calculate risk/incidence (not longitudinal).

Prospective:  Gold standard for clinical research–may be observational or interventional/experimental.  Check if the study is prospectively registered (e.g., because most journals expect this.

Observational (“cohort study”)

  1. May or may not have a designated control group (can start with defined group and risk factors are discovered over time such as the Framingham Study).
  2. Can calculate incidence and relative risk for certain risk factors.
  3. Identify causal associations.

Interventional/Experimental (“clinical trial”)

  1. What is the intervention or experiment?
  2. Is there blinding?  If so, who is blinded:  single, double, or triple (statistician blinded)?
  3. Are the groups randomized?  How is this performed?
  4. Is there a sample size estimate and what is it based on (alpha and beta error, population mean and SD, expected effect size)?  This should be centered around the primary outcome.
  5. What are the study groups?  Are the groups independent or related?
  6. Is there a control group such as a placebo (for efficacy studies) or active comparator (standard of care)?

Measurements:  How are the outcome variables operationalized?  Check the validity, precision, and accuracy of the measurement tools (e.g., survey or measurement scale).

  1. Validity:  Has the tool been used before?  Is it reliable?  Does the tool make sense (face validity)?  Is the tool designed to measure the outcome of interest (construct validity)?
  2. Precision:  Does the tool hit the target?
  3. Accuracy:  Are the results reproducible?

Analysis:  What statistical tests are used and are they appropriate?  How do the authors define statistical significance (p-value or confidence intervals)?  How are the results presented in the paper and are they clear?

  1. Categorical variables with independent groups:  1 outcome and 2 groups = Chi square test (exact tests are used when n<5 in any field); multiple outcomes or multiple groups = Kruskal Wallis (with one-way ANOVA and post-hoc multiple comparisons test (e.g., Tukey-Kramer).
  2. Continuous variables with independent groups:  1 outcome and 2 groups = Student’s t test (if normal distribution) or Mann-Whitney U test (if distribution not normal); multiple outcomes or multiple groups = ANOVA with post-hoc multiple comparisons testing; multiple outcomes and multiple groups = linear regression.
  3. Continuous variables with related groups:  paired t test or repeated-measures ANOVA depending on the number of outcomes and groups.
  4. Are the results statistically significant?  Clinically significant?
  5. Do the results make sense?

Conclusions:  I personally tend to skip the discussion section of the paper at first and come up with my own conclusions based on the study results; then I read what the authors have to say later.

  1. Did the authors succeed in proving what they set out to prove?
  2. Read the discussion section.  Do you agree with the authors’ conclusions?
  3. What are possible future studies based on the results of the present study and how would you design the next study?

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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.


  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.

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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.


  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

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To the Next Generation of Physician Leaders

I was recently invited to visit an academic anesthesiology department to speak to the residents about becoming a leader (see SlideShare). In addition to recognizing the honor and privilege of addressing this important topic with the next generation of physician anesthesiologists, I had two other initial thoughts: 1) I must be getting old; and 2) This isn’t going to be easy.

Balloon FiestaI came up with a short list of lessons that I’ve learned over the years. While some examples I included are anesthesiology-specific, the lessons themselves are not. Please feel free to edit, adapt, and add to this list; then disseminate it to the future physician leaders who will one day take our places.

  1. First and foremost, be a good doctor. Always remember that we as physicians take an oath. In the modern version of the Hippocratic Oath commonly recited at medical school graduations today, we say, “May I always act so as to preserve the finest traditions of my calling and may I long experience the joy of healing those who seek my help.” As a physician anesthesiologist, we care for the most vulnerable of patients—those who under anesthesia cannot care for themselves. Examples of anesthesiologists who do not honor their calling exist in the news and even scientific journals, but we cannot follow this path. 


  2. Define your identity. We live in the era of the “provider,” and this sometimes causes role confusion from the perspective of our patients. Team PhotoWe also don’t tend to do ourselves any favors. How many times have you heard someone say, “Hi I’m [first name only] with anesthesia”? According to the American Society of Anesthesiologists newsletter, approximately 60% of the public may not know that physician anesthesiologists go to medical school. While every member of the anesthesia care team plays a crucial role, the next level of non-physician provider in this model has one-tenth the amount of clinical training when compared to a physician anesthesiologist at graduation. I’ve written before about what I love about being an anesthesiologist, and being the physician whom patients trust to keep them safe during surgery is a privilege which comes with a great deal of responsibility.
  3. Consider the “big picture.” The health care enterprise is constantly evolving. Today, the emphasis is on value and not volume. Value takes into account quality and cost with the highest quality care at the lowest cost being the ultimate goal. The private practice model of anesthesiology has changed dramatically in the last few years with the growth of “mega-groups” created by vertical and horizontal integration of smaller practices and sometimes purchased by private investors. In this environment, physician anesthesiologists and anesthesiology groups will have to consider ways they can add value, improve the patient experience, and reduce costs of care in order to stay relevant and competitive.
  4. Promote positive change. Observe, ask questions, hypothesize solutions, collect data, evaluate results, draw conclusions, and form new hypotheses—these are all elements of the scientific method and clinical medicine. These steps are also common to process improvement, making physicians perfectly capable of system redesign. The key is establishing your team’s mission and vision, strategic planning and goal-setting, and regularly evaluating progress. Books have been written on these subjects, so I can’t do these topics justice here. In my opinion, physicians offer an important and necessary perspective that cannot be lost as healthcare becomes more and more business-like.
  5. Be open to opportunities. Thomas Edison said, “Opportunity is missed by most people because it is dressed in overalls and looks like work.” I have written previously about the merits of saying yes. As a resident or new staff physician, it often seems impossible to get involved. However, most hospital committee meetings are open to guests. Consider going to one that covers a topic of interest and volunteer for a task if the opportunity presents itself. In addition, many professional societies invite members to self-nominate for committees or submit proposals for educational activities at their annual meetings.
  6. IMG_7673Thank your team. Taking the first steps on the path to leadership is not going to be easy. There will be many obstacles, not the least of which is time management. A high-functioning healthcare team of diverse backgrounds, skills, and abilities will accomplish much more than what an individual can do alone. Celebrate team wins. Respect each team member’s opinion even when it differs from yours.

A good leader should earn the trust of his or her team every day.

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Changing Clinical Practice Shouldn’t Take So Long

An interesting article I read recently confirmed previous studies’ estimation that it takes an average of 17 years before research evidence becomes widely adopted in clinical practice (1)–17 years!

In this article, Morris and colleagues differentiate “translational research” into two types: Type 1 (T1) which refers to experimental testing of basic science research findings in human subjects; and Type 2 (T2) which is the process of taking the results of clinical research and changing clinical practice based on them.

translating research to practice

In 2001, the Institute of Medicine released “Crossing the Quality Chasm: a New Health System for the 21st Century.” One of the ten rules for redesigning the system refers to evidence-based clinical decision-making. The report brief explicitly states: “Patients should receive care based on the best available scientific knowledge. Care should not vary illogically from clinician to clinician or from place to place.”

Changing physicians’ behavior is rarely easy (although occasionally it can be), and many smart people have tried to study what works and what doesn’t. One study published in JAMA that focused on physician adherence to practice guidelines identified 7 categories of change barriers (2):

  1. Lack of awareness (don’t know guidelines exist)
  2. Lack of familiarity (know guidelines exist but don’t know the details)
  3. Lack of agreement (don’t agree with recommendations)
  4. Lack of self-efficacy (don’t think they can do it)
  5. Lack of outcome expectancy (don’t think it will work)
  6. Inertia (don’t want to change)
  7. External barriers (want to change but blocked by system factors)

Outside of medicine, many industries have explored the reasons behind failure of change management or failure of implementation and have made suggestions intended to facilitate change. While these recommendations make sense, they are often easier said than done. In health care, there is a great deal of “dogma-logy” (the non-scientific practice of doing what you’ve been told to do based on no available evidence) that must be overcome. Implementation researchers suggest “incremental, context-sensitive, evidence-based management strategies for change implementation” and the need for local champions within front line staff (e.g., nurses and unit managers) to drive change (3). This is consistent with lean management. This still may not be enough, especially if the proposed change is perceived as being overly complex or just more work (4).

The evolution of modern communication may help overcome some of the perceived barriers (2). Use of social media, Twitter in particular, may be a powerful tool to rapidly disseminate new knowledge. It can be used to share new journal articles as they are published or exciting research results even before they are published. Physicians can follow their professional societies and scientific journals, but also follow thought leaders, business schools, and economic journals that post on organizational culture and change management. In the era of Twitter chats and “live-tweeting” medical conferences, lack of awareness (#1) or familiarity (#2) is no longer an acceptable excuse.

In addition, social media networks may also provide moral support (#4) through global conversations, and colleagues may provide real-life examples of successful implementation strategies (#5) that may help generate enough motivation to drive change (#6). However, sometimes inertia may be easy to overcome. According to Dr. Audrey Shafer, Stanford Professor and physician anesthesiologist, “There should be some acknowledgement of the complexity-to-benefit ratio. If complexity of the change is low, and the benefit high, then I believe the behavioral change is swifter. The prime example in my lifetime is the use of pulse oximetry. It may have been a long time from the concept of pulse oximetry until the first viable commercially available oximeter was available in clinical practice, but after an anesthesiologist used it once, he/she did not want to do another case without one.”

That still leaves lack of agreement (#3) and external barriers (#7). Even if you don’t agree with the scientific evidence, at least be open to observe. I really like the design thinking approach as described by Ideo and others and think it has a place in health care change implementation. You can download the free toolkit for educators here. I tweeted Ideo’s figure of the design process with its 5 phases recently and got a great response.

Tweet design

This approach makes a lot of sense in medicine. It has many similarities to the way we approach patient care: observe a diagnostic dilemma, order tests and interpret them, consider the differential diagnosis, attempt a treatment, and adjust treatment based on the observed outcome.

To overcome external barriers to change in health care, senior leaders must be engaged and actively participate in improvement efforts (5). I strongly encourage physicians to step up and take on some of these leadership roles. Sometimes saying “yes” to something that seems relatively small will lead to bigger opportunities down the road. By becoming leaders, physicians can be the ones to drive the change that they want to see in clinical practice.


  1. Morris ZS, Wooding S, Grant J. The answer is 17 years, what is the question: understanding time lags in translational research. J R Soc Med. 2011 Dec;104(12):510-20.
  2. Cabana MD, Rand CS, Powe NR, Wu AW, Wilson MH, Abboud PA, Rubin HR. Why don’t physicians follow clinical practice guidelines? A framework for improvement. JAMA. 1999 Oct 20;282(15):1458-65.
  3. Rangachari P, Rissing P, Rethemeyer K. Awareness of evidence-based practices alone does not translate to implementation: insights from implementation research. Qual Manag Health Care. 2013 Apr-Jun;22(2):117-25.
  4. Grol R. Successes and failures in the implementation of evidence-based guidelines for clinical practice. Med Care. 2001 Aug;39(8 Suppl 2):II46-54.
  5. Pronovost PJ, Berenholtz SM, Goeschel CA, Needham DM, Sexton JB, Thompson DA, Lubomski LH, Marsteller JA, Makary MA, Hunt E. Creating high reliability in health care organizations. Health Serv Res. 2006 Aug;41(4 Pt 2):1599-617.

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Why Doctors Should Be on Twitter

social-media-healthcareI am a physician, clinical researcher, and educator.

I am also on Twitter and tweet under the handle @EMARIANOMD.

Naturally you may ask:  “How does Twitter fit into a physician’s academic career?”  Some of the benefits that Twitter offers doctors have been described previously by Dr. Brian Secemsky and Dr. Marjorie Stiegler among others.  Here are a few reasons of my own:

  • Global Interaction:  Through Twitter I interact with people from around the world with similar interests.  Participating in Twitter chats like #healthxph or #hcldr can foster innovative ideas that may lead to research questions or other educational opportunities.  For example, by tweeting on #kneereplacement, I was invited by orthopedic surgeon, Dr. Brian Hatten, to revise the anesthesia information page on his site, My Knee Guide, an incredible online portal for people considering or undergoing knee replacement surgery.
  • Search Optimization:  On multiple occasions, I have found research articles that my traditional PubMed searches have missed through the tweets posted by colleagues.  I have even been able to relocate certain articles faster on Twitter than PubMed when I know they have been tweeted.  Researchers can think of hashtags (starting with “#”) essentially like keywords in the academic world.  I periodically check #anesthesia, #meded, #pain, and #kneereplacement for new articles related to my research interests.
  • Lifelong Learning:  When I was in training, I used to peruse the pages of JAMA and New England Journal of Medicine (NEJM) in addition to my own specialty’s journals.  Today, it’s difficult to even keep up with new articles just in my own subspecialty.  Now I follow JAMA and NEJM on Twitter.  By following journals, professional societies, and colleagues with similar interests, I honestly feel that my breadth of knowledge has increased beyond what I would have acquired on my own.
  • Research Promotion:  As a clinical researcher, my hope is that my study results will ultimately affect the care of patients.  Sadly, the majority of traditionally-published scientific articles will not be read by anyone besides the authors and reviewers.  Through Twitter, I can alert my followers when our research group publishes an article.  I also get feedback and “peer review” from colleagues around the world.  After a recent publication that I tweeted, I received comments from anesthesiologists in Canada and Europe within an hour!
  • Enriched Conference Experience:  A growing trend at medical conferences is “live-tweeting” the meeting.  One of my own issues when I attend or present at conferences is that I feel like I miss much of the meeting due to scheduling conflicts.  By living vicariously through my colleagues’ tweets at #ASRASpring15 for example, I can pick up pearls of wisdom from speakers in other sessions even while sitting in a different hall.  I can also “virtually” attend conferences by following tweets under the hashtags of meetings like #PCP15 in the Philippines  in the comfort of my own home.

I often get asked:  “Does anyone really care if I tweet what I eat for breakfast?”  Probably not.  The truth is that you don’t have to tweet anything at all if you don’t want to.   Up to 44% of Twitter accounts have never sent a tweet.   Of course, to be a physician actively engaged on Twitter requires respect for patient privacy and professionalism.  I recommend following Dr. John Mandrola’s 10 rules for doctors on social media.

In an interview during Stanford’s Big Data in Biomedicine Conference (video below), I had a chance to explain why I tweet.  I’ll admit that getting started is intimidating, but I encourage you to try it if you haven’t already.   I promise that you won’t regret it, and chances are that you’ll be very happy you did.  If you’re still too worried to take the leap, I suggest reading these tips from Marie Ennis-O’Connor to boost your confidence.  At least sign up, reserve your handle, and observe.

Observation is still a key part of the scientific method.

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Why the VA Inspires Me to be a Better Leader

VA_eagleInscribed on a plaque just below a statue of an eagle in front of my hospital is a famous quote from President Abraham Lincoln that begins, “To care for him who shall have borne the battle….”

It is the reason why the Veterans Affairs (VA) system exists.  It is the reason why we VA physicians come to work each day.

I am honored to care for our special patient population, and I admit to getting defensive when I hear negative, sensationalistic news about the VA.  In truth, VA physicians have good reasons to take pride in their health care system and should be inspired to take on leadership roles.

In 1994, the VA was by far the largest networked health care system in the US.  It consisted of 172 acute care hospitals, 350 hospital-based outpatient clinics, 206 counseling facilities, and 39 residential care facilities, with a budget of over $16 billion annually, and was “highly dysfunctional” according to an article co-authored by Kenneth W. Kizer, MD, MPH, the former Under Secretary of Health under President Clinton who headed the VA health care system from 1995-1999.

A decade later, the VA had turned around dramatically.  When Philip Longman, a writer with a long interest in health policy, looked for potential solutions to the healthcare crisis in the United States, he found his “muse” within the VA—not in the private sector.  He titled his 2007 book about the VA health care system:  Best Care Anywhere: Why VA Health Care is Better Than YoursWhat happened to make the VA go from worst to first?

In the mid-1990s, Dr. Kizer guided the VA to reset its focus on three core missions:

  • Providing medical care to eligible veterans to improve their health and functionality
  • Educating healthcare professionals
  • Conducting research to improve veteran care.

His strategies led to a dramatic transformation that took less than five years.  VA health care showed a statistically-significant improvement in all quality of care indicators after the reengineering when compared to the same indicators before, and these improvements were evident within the first two years.  By 2000, the VA outperformed Medicare hospitals on 12 of 13 quality of care indicators.  A comprehensive study using RAND Quality Assessment Tools showed that VA adherence to recommended processes of care exceeded a comparable national sample.  In terms of surgical care, the VA matched or outperformed non-VA programs in rates of morbidity and mortality.

Integral to this transformation was a remarkable nationwide rollout of an electronic health record in less than three years, with the last facility going live in 1999, long before most health care systems in the United States had even started.  Other notable achievements during this period of reengineering included:

  • 350,000 fewer inpatient admissions (FY 1999 vs. FY 1995) despite a 24% increase in patients treated overall;
  • A decrease in per-patient expenditures by 25%;
  • An increase in proportion of surgeries performed on an ambulatory basis (80% in FY 1999 vs. 35% in FY 1995);
  • A 10% increase in total number of surgeries performed with a decrease in 30-day morbidity and mortality;
  • VA health user satisfaction scores that exceeded the private sector; and
  • Realignment of the VA medical research program with establishment of a new translational research program, the Quality Enhancement Research Initiative (QUERI).

These achievements were not the result of one person’s efforts.  Change implementation required engagement of front line staff, especially the physicians and other health care providers.  Unfortunately last year’s VA waitlist scandal raised serious concerns related to veterans’ access to care, scheduling practices, and the reporting of performance metrics.  In an article published in the New England Journal of Medicine, Dr. Kizer expressed his concerns regarding variability in the quality of care provided within VA in 2014 when compared to other top-tier integrated healthcare systems.  Some VA hospitals performed remarkably well while others did not, and some facilities severely lacked personnel and resources.

Flags FlyingToday, there are approximately 9 million veterans enrolled in VA health care, and the VA needs physicians to step up and be leaders.  Advanced technology (e.g., secure messaging, e-consultation, and clinical video telehealth) already exists within the VA to streamline communication between patients and physicians and can be used to promote patient-centered, personalized health care and improve access.  Some of the highest impact medical research in the world takes place within VA, performed by VA physician scientists, and requires leaders to advocate for continued funding.  The results of these studies and others should form the basis of best clinical practices that VA physician leaders need to disseminate and implement at their respective facilities.  VA physicians have pioneered the field of simulation education, and this represents one tool that may be used to facilitate dissemination.  The VA has arguably the richest and most mature electronic health record in the country, if not the world; yet these data are not easily accessible.  Physicians on the front lines of patient care, those engaged in research, and those in leadership positions need to advocate for resources to develop real-time analytics and harness the power of our patients’ data to guide clinical care decisions and make the health care system adaptable to the changing needs of patients.

Finally, I call on VA physician leaders to be innovators, designing and studying new interdisciplinary coordinated models of care, to improve outcomes and then share these models with each other.  We physicians need to work together as “One VA” to decrease variability within the system and improve quality and value throughout.

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  1. Kizer KW, Dudley RA: Extreme makeover: Transformation of the veterans health care system. Annu Rev Public Health 2009; 30: 313-39
  2. Jha AK, Perlin JB, Kizer KW, Dudley RA: Effect of the transformation of the Veterans Affairs Health Care System on the quality of care. N Engl J Med 2003; 348: 2218-27
  3. Asch SM, McGlynn EA, Hogan MM, Hayward RA, Shekelle P, Rubenstein L, Keesey J, Adams J, Kerr EA: Comparison of quality of care for patients in the Veterans Health Administration and patients in a national sample. Ann Intern Med 2004; 141: 938-45
  4. Choi JC, Bakaeen FG, Huh J, Dao TK, LeMaire SA, Coselli JS, Chu D: Outcomes of coronary surgery at a Veterans Affairs hospital versus other hospitals. J Surg Res 2009; 156: 150-4
  5. Grover FL, Shroyer AL, Hammermeister K, Edwards FH, Ferguson TB, Jr., Dziuban SW, Jr., Cleveland JC, Jr., Clark RE, McDonald G: A decade’s experience with quality improvement in cardiac surgery using the Veterans Affairs and Society of Thoracic Surgeons national databases. Ann Surg 2001; 234: 464-72
  6. Matula SR, Trivedi AN, Miake-Lye I, Glassman PA, Shekelle P, Asch S: Comparisons of quality of surgical care between the US Department of Veterans Affairs and the private sector. J Am Coll Surg 2010; 211: 823-32
  7. Bakaeen FG, Blaustein A, Kibbe MR: Health care at the VA: recommendations for change. JAMA 2014; 312: 481-2
  8. Kizer KW, Jha AK: Restoring trust in VA health care. N Engl J Med 2014; 371: 295-7

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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.


  1. The Center for Disease Control and Prevention. FastStats: Inpatient Surgery. National Hospital Discharge Survey: 2010 table. 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.

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Tips for Future Physician Leaders

LeadershipCompass3This post has also been featured on

Our health care system needs more physician leaders. Physician-led accountable care organizations have been shown to improve the quality of patient care while reducing overall costs. Physicians, by their nature, tend to be goal-oriented, have the ability to gather and assimilate evidence, and make difficult decisions, but these traits do not always translate naturally into leadership skills. We are trained to make a diagnosis and map out a treatment plan in medical school and residency, but the typical curriculum does not include developing staff, leading teams, or strategic planning. One option to learn these skills is to get an MBA. However, going back to school is not an option for everyone (like me—at least not yet), and it may not be necessary. Besides first being a good doctor, here are a few tips that may help open up leadership opportunities:

1. Be open to possibilities. Sometimes an opportunity doesn’t always look like one. In other words, plans don’t always work out the way you think they will.

2. Say “yes” to things that sound like more work. Pick up that extra call or volunteer for that hospital committee. Saying “yes” can introduce you to many new people and experiences. If you say “yes” then follow through. New colleagues who see you as a finisher often go back to you again and introduce you to others.

3. Let people look after you. This may not be “mentorship” in the traditional sense. A friend of a friend or someone’s spouse you meet at a department function may introduce you to people with similar interests in clinical care, quality improvement, or research.

4. Give credit to others. “Taking credit” is not about featuring an individual or the leader—it should be about the group. You can’t implement change without a team, and as a leader you have to make sure the group gets the recognition it deserves.

5. Given the opportunity, lead and not just manage. “Leadership” and “management” are often used interchangeably (unfortunately), and managerial duties often come with any leadership position, but they are not the same. People want to follow a leader, not a manager.

In healthcare, a leader should set a good example of professionalism in clinical care, communications, and administrative work. A leader creates a shared vision for the group with a clear direction and celebration of the group’s accomplishments. A leader first invests in his or her staff members to develop them individually so their greater potential can benefit the group. A leader is inspired by his or her staff and is constantly listening and learning.

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Extending Nerve Block Pain Relief after Surgery: Review of the Evidence

nerve firingNerve blocks (also referred to as “regional anesthesia”) offer patients many potential advantages in the immediate postoperative period such as decreased pain, nausea and vomiting, and time spent in the recovery room (1,2). However, these beneficial effects are time-limited and do not last beyond the duration of the block (2). While the clinical effects of nerve blocks typically last long enough for patients to meet discharge eligibility from recovery and avoid hospitalization for pain control (3), these results can be easily negated if patients’ pain or opioid-related side effects warrant a return trip to the hospital and readmission following block resolution (4). Thus, extending block duration to provide longer-term, site-specific analgesia for patients on an ambulatory basis has been a high research priority. What options are currently available?

Continuous Peripheral Nerve Blocks

Continuous peripheral nerve block (CPNB) techniques (also known as perineural catheters) permit delivery of local anesthetic solutions to the site of a peripheral nerve on an ongoing basis (5). 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 (6,7). In a meta-analysis comparing CPNB to single-injection peripheral nerve blocks, CPNB results in lower patient-reported worst pain scores and pain scores at rest on postoperative day (POD) 0, 1, and 2 (8). Patients who receive CPNB also experience less nausea, consume less opioids, sleep better, and are more satisfied with pain management (8). We also know how CPNB works: local anesthetic medication interrupts nerve transmission, so patients experience decreased sensation.

Managing CPNB patients (especially at home) can sometimes be challenging, and not all patients are good candidates for outpatient perineural infusion (7). Patients must have a reliable means of follow-up and should have a caretaker at home for at least the first night after surgery (7). A health care provider must be available at all times to manage common issues associated with CPNB and call patients once daily to assess for analgesic efficacy and side effects (9). Patients, especially those undergoing lower extremity surgery, and their caretakers should receive clear instructions regarding the care of their infusion device and catheter as well as their anesthetized extremities (10,11) including fall precautions (12,13).

Although the optimal duration for CPNB is unknown, 2 to 7 days has been reported for orthopedic inpatients (14) with durations as long as 34 days under special circumstances (15). At the completion of the local anesthetic infusion, perineural catheters must be removed. To date, CPNB is the only technique that offers patients the longest potential duration of block paired with the ability to titrate to the desired level of block.

Despite more than a decade of published data supporting CPNB for extending the duration of postoperative pain control, adoption of these techniques is not universal. Many of the issues are arguably system-based, and the lack of a “block” room (16) or time pressure (17) may be responsible. However, lack of training in these techniques may also be a factor (18) or negative experiences with failed placement attempts using traditional techniques (19).

Adjuvants to Local Anesthetic Solutions for Single-Injection Peripheral Nerve Blocks

For nerve blocks intended to last 1-2 days, there are a few options.  Long-acting local anesthetics (e.g., bupivacaine, levobupivacaine, and ropivacaine) generally provide analgesia of similar duration for 24 hours or less (20-23). Several different drugs have been investigated for their potential to extend single-injection peripheral nerve block duration when added to local anesthetic solutions. Epinephrine when added to local anesthetic solutions provides vasoconstriction to decrease uptake but has little or no clinical effect on the duration of longer-acting local anesthetics (24). Opioids in general do not provide additional benefits in terms of duration (25) except for buprenorphine (26) although how it works is unclear. To date, there are insufficient data to support the addition of tramadol or neostigmine to local anesthetic solutions (25). Of the available adjuvants, clonidine has been demonstrated in clinical studies and systematic reviews to extend the duration of analgesia for intermediate-acting local anesthetics (e.g., mepivacaine) with few side effects in doses up to 150 mcg but probably do not extend long-acting local anesthetics (25,27). There has been increasing interest in dexamethasone as an adjuvant to local anesthetic solutions based on clinical reports of extended duration when added to intermediate-acting local anesthetics (28,29). The mechanism is not well understood and may be less pronounced with long-acting local anesthetics; one study reported block durations of only 22 hours with dexamethasone added to either ropivacaine or bupivacaine (30). Giving dexamethasone intravenously may actually produce the same effect (31). Caution is warranted when experimenting with adjuvant mixtures that have not been specifically approved for nerve blocks (i.e., “off-label” use) as many of the usual FDA safeguards have not been performed, and these drugs may contribute to neurotoxicity or other side effects not yet known.

Novel Extended-Duration Local Anesthetics

There has been interest in liposomal formulations of extended-release bupivacaine for regional anesthesia for over two decades (32,33). A recent formulation consisting of bupivacaine encapsulated in multivesicular liposomes to produce slow release is FDA-approved for local infiltration (34) but not yet for nerve blocks although this is expected soon. A nerve block with liposomal bupivacaine can be expected to last 1-3 days. Initial nerve block studies in animals suggest a lower maximum serum concentration with the liposomal formulation compared to plain bupivacaine (35)–unless co-administered with lidocaine which facilitates release of liposomal bupivacaine (36)–and epidural administration in human volunteers more than doubles duration of sensory block (37). Once it receives FDA approval, I expect many comparative studies versus CPNB for postoperative analgesia. There are still concerns regarding local anesthetic systemic toxicity with liposomal bupivacaine as well as prolonged motor block and unpleasant numbness given the drug’s long-lasting effects. In addition, there is no option for “giving more” to augment a block in the event of inadequate pain relief.

In summary, there are currently few options to extend the duration of regional analgesia at home beyond the one day expected from most single-injection nerve blocks. CPNB with plain local anesthetic perineural infusion is the most established way to provide days of postoperative pain control and allows titration, but training in insertion techniques and a system to manage ambulatory CPNB patients are necessary. Adjuvants or liposomal formulations of local anesthetics may offer potential options for limited extension of block duration, but further studies regarding efficacy and safety for regional anesthesia as well as comparative-effectiveness versus CPNB are necessary. For major surgery like total knee replacement, block duration of several days may be optimal (38).


  1. 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
  2. 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
  3. 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
  4. Williams BA, Kentor ML, Vogt MT, Vogt WB, Coley KC, Williams JP, Roberts MS, Chelly JE, Harner CD, Fu FH: Economics of nerve block pain management after anterior cruciate ligament reconstruction: potential hospital cost savings via associated postanesthesia care unit bypass and same-day discharge. Anesthesiology 2004; 100: 697-706
  5. Ilfeld BM: Continuous peripheral nerve blocks: a review of the published evidence. Anesth Analg 2011; 113: 904-25
  6. Ilfeld BM: Continuous peripheral nerve blocks in the hospital and at home. Anesthesiol Clin 2011; 29: 193-211
  7. Ilfeld BM, Enneking FK: Continuous peripheral nerve blocks at home: a review. Anesth Analg 2005; 100: 1822-33
  8. 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
  9. Ilfeld BM, Esener DE, Morey TE, Enneking FK: Ambulatory perineural infusion: the patients’ perspective. Reg Anesth Pain Med 2003; 28: 418-23
  10. 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
  11. Ilfeld BM, Moeller LK, Mariano ER, Loland VJ, Stevens-Lapsley JE, Fleisher AS, Girard PJ, Donohue MC, Ferguson EJ, Ball ST: Continuous peripheral nerve blocks: is local anesthetic dose the only factor, or do concentration and volume influence infusion effects as well? Anesthesiology 2010; 112: 347-54
  12. 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
  13. Ilfeld BM, Duke KB, Donohue MC: The association between lower extremity continuous peripheral nerve blocks and patient falls after knee and hip arthroplasty. Anesth Analg 2010; 111: 1552-4
  14. Capdevila X, Pirat P, Bringuier S, Gaertner E, Singelyn F, Bernard N, Choquet O, Bouaziz H, Bonnet F: Continuous peripheral nerve blocks in hospital wards after orthopedic surgery: a multicenter prospective analysis of the quality of postoperative analgesia and complications in 1,416 patients. Anesthesiology 2005; 103: 1035-45
  15. Stojadinovic A, Auton A, Peoples GE, McKnight GM, Shields C, Croll SM, Bleckner LL, Winkley J, Maniscalco-Theberge ME, Buckenmaier CC, 3rd: Responding to challenges in modern combat casualty care: innovative use of advanced regional anesthesia. Pain Med 2006; 7: 330-8
  16. Mariano ER, Chu LF, Peinado CR, Mazzei WJ: Anesthesia-controlled time and turnover time for ambulatory upper extremity surgery performed with regional versus general anesthesia. J Clin Anesth 2009; 21: 253-7
  17. Oldman M, McCartney CJ, Leung A, Rawson R, Perlas A, Gadsden J, Chan VW: A survey of orthopedic surgeons’ attitudes and knowledge regarding regional anesthesia. Anesth Analg 2004; 98: 1486-90, table of contents
  18. Hadzic A, Vloka JD, Kuroda MM, Koorn R, Birnbach DJ: The practice of peripheral nerve blocks in the United States: a national survey [p2e comments]. Reg Anesth Pain Med 1998; 23: 241-6
  19. Salinas FV: Location, location, location: Continuous peripheral nerve blocks and stimulating catheters. Reg Anesth Pain Med 2003; 28: 79-82
  20. 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
  21. 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
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