Smallest Clinically Meaningful Improvement in Amputation-Related Pain and Brief Pain Inventory Scores as Defined by Patient Reports of Global Improvement After Cryoneurolysis: a Retrospective Analysis of a Randomized, Controlled Clinical Trial

BACKGROUND

The smallest meaningful improvement in pain scores (minimal clinically important difference [MCID]) after an analgesic intervention is essential information when both interpreting published data and designing a clinical trial. However, limited information is available for patients with chronic pain conditions, and what is published is derived from studies involving pharmacologic and psychological interventions. We here calculate these values based on data collected from 144 participants of a previously published multicenter clinical trial investigating the effects of a single treatment with percutaneous cryoneurolysis.

METHODS

In the original trial, we enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction. At both baseline and 4 months (primary end point), participants rated their phantom limb pain based on a numeric rating scale (NRS) and their interference of pain on physical and emotional functioning as measured with the Brief Pain Inventory's interference subscale. They subsequently qualitatively defined the change using the 7-point ordinal Patient Global Impression of Change (PGIC). The smallest clinically meaningful improvements in phantom limb pain and Brief Pain Inventory scores were calculated using an anchor-based method based on the PGIC.

RESULTS

The median (interquartile range [IQR]) phantom pain NRS (0-10) improvements at 4 months considered small, medium, and large were 1 [1-1], 3 [3-4], and 4 [3-6], respectively. The median improvements in the Brief Pain Inventory interference subscale (0-70) associated with a small, medium, and large analgesic changes were 16 [6-18], 24 [22-31], and 34 [22-46]. The proportions of patients that experienced PGIC ≥5 were 33% and 36% in the active and placebo groups, respectively. The relative risk of a patient experiencing PGIC ≥5 in the active group compared to the sham group with 95% confidence interval was 0.9 (0.6-1.4), P = .667.

CONCLUSIONS

Amputees with phantom limb pain treated with percutaneous cryoneurolysis rate analgesic improvements as clinically meaningful similar to pharmacologic treatments, although their MCID for the Brief Pain Inventory was somewhat larger than previously published values. This information on patient-defined clinically meaningful improvements will facilitate interpretation of available studies and guide future trial design.

Opioid use in cancer patients compared with noncancer pain patients in a veteran population

BACKGROUND

Opioid safety initiatives may secondarily impact opioid prescribing and pain outcomes for cancer care.

METHODS

We reviewed electronic health record data at a tertiary Veterans Affairs system (VA Palo Alto) for all patients from 2015 to 2021. We collected outpatient Schedule II opioid prescriptions data and calculated morphine milligram equivalents (MMEs) using Centers for Disease Control and Prevention conversion formulas. To determine the clinical impact of changes in opioid prescription, we used the highest level of pain reported by each patient on the 0-to-10 Numeric Rating Scale in each year, categorized into mild (0-3), moderate (4-6), and severe (7 and above).

RESULTS

Among 89 569 patients, 9073 had a cancer diagnosis. Cancer patients were almost twice as likely to have an opioid prescription compared with noncancer patients (69.0% vs 36.7%, respectively). The proportion of patients who received an opioid prescription decreased from 27.1% to 18.1% (trend P < .01) in cancer patients and from 17.0% to 10.2% in noncancer patients (trend P < .01). Cancer and noncancer patients had similar declines of MMEs per year between 2015 and 2019, but the decline was more rapid for cancer patients (1462.5 to 946.4, 35.3%) compared with noncancer patients (1315.6 to 927.7, 29.5%) from 2019 to 2021. During the study period, the proportion of noncancer patients who experienced severe pain was almost unchanged, whereas it increased among cancer patients, reaching a significantly higher rate than among noncancer patients in 2021 (31.9% vs 27.4%, P < .01).

CONCLUSIONS

Our findings suggest potential unintended consequences for cancer care because of efforts to manage opioid-related risks.

National review of acute pain service utilization, models of care, and clinical practices within the Veterans Health Administration

INTRODUCTION

The Veterans Health Administration (VHA) is the largest healthcare network in the USA and has been a national leader in opioid safety for acute pain management. However, detailed information on the availability and characteristics of acute pain services within its facilities is lacking. We designed this project to assess the current state of acute pain services within the VHA.

METHODS

A 50-question electronic survey developed by the VHA national acute pain medicine committee was emailed to anesthesiology service chiefs at 140 VHA surgical facilities within the USA. Data collected were analyzed by facility complexity level and service characteristics.

RESULTS

Of the 140 VHA surgical facilities contacted, 84 (60%) completed the survey. Thirty-nine (46%) responding facilities had an acute pain service. The presence of an acute pain service was associated with higher facility complexity level designation. The most common staffing model was 2.0 full-time equivalents, which typically included at least one physician. Services performed most by formal acute pain programs included peripheral nerve catheters, inpatient consult services, and ward ketamine infusions.

CONCLUSIONS

Despite widespread efforts to promote opioid safety and improve pain management, the availability of dedicated acute pain services within the VHA is not universal. Higher complexity programs are more likely to have acute pain services, which may reflect differential resource distribution, but the barriers to implementation have not yet been fully explored.

Association of Patient Race and Hospital with Utilization of Regional Anesthesia for Treatment of Postoperative Pain in Total Knee Arthroplasty: A Retrospective Analysis Using Medicare Claims

BACKGROUND

Regional anesthesia for total knee arthroplasty has been deemed high priority by national and international societies, and its use can serve as a measure of healthcare equity. The association between utilization of regional anesthesia for postoperative pain and (1) race and (2) hospital in patients undergoing total knee arthroplasty was estimated. The hypothesis was that Black patients would be less likely than White patients to receive regional anesthesia, and that variability in regional anesthesia would more likely be attributable to the hospital where surgery occurred than race.

METHODS

This study used Medicare fee-for-service claims for patients aged 65 yr or older who underwent primary total knee arthroplasty between January 1, 2011, and December 31, 2016. The primary outcome was administration of regional anesthesia for postoperative pain, defined as any peripheral (femoral, lumbar plexus, or other) or neuraxial (spinal or epidural) block. The primary exposure was self-reported race (Black, White, or Other). Clinical significance was defined as a relative difference of 10% in regional anesthesia administration.

RESULTS

Data from 733,406 cases across 2,507 hospitals were analyzed: 90.7% of patients were identified as White, 4.7% as Black, and 4.6% as Other. Median hospital-level prevalence of use of regional anesthesia was 51% (interquartile range, 18 to 79%). Black patients did not have a statistically different probability of receiving a regional anesthetic compared to White patients (adjusted estimates: Black, 53.3% [95% CI, 52.5 to 54.1%]; White, 52.7% [95% CI, 52.4 to 54.1%]; P = 0.132). Findings were robust to alternate specifications of the exposure and outcome. Analysis of variance revealed that 42.0% of the variation in block administration was attributable to hospital, compared to less than 0.01% to race, after adjusting for other patient-level confounders.

CONCLUSIONS

Race was not associated with administration of regional anesthesia in Medicare patients undergoing primary total knee arthroplasty. Variation in the use of regional anesthesia was primarily associated with the hospital where surgery occurred.

EDITOR’S PERSPECTIVE

More Than a Perioperative Surgical Home: An Opportunity for Anesthesiologists to Advance Public Health

Public health and the medical specialty of anesthesiology have been closely intertwined throughout history, dating back to the 1800s when Dr. John Snow used contact tracing methods to identify the Broad Street Pump as the source of a cholera outbreak in London. During the COVID-19 pandemic, leaders in anesthesiology and anesthesia patient safety came forward to develop swift recommendations in the face of rapidly changing evidence to help protect patients and healthcare workers. While these high-profile examples may seem like uncommon events, there are many common modern-day public health issues that regularly intersect with anesthesiology and surgery. These include, but are not limited to, smoking; chronic opioid use and opioid use disorder; and obstructive sleep apnea. As an evolving medical specialty that encompasses pre- and postoperative care and acute and chronic pain management, anesthesiologists are uniquely positioned to improve patient care and outcomes and promote long-lasting behavioral changes to improve overall health. In this article, we make the case for advancing the role of the anesthesiologist beyond the original perioperative surgical home model into promoting public health initiatives within the perioperative period.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks

BACKGROUND

Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks.

METHODS

We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement.

RESULTS

A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research.

CONCLUSIONS

We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Rate of occurrence of respiratory complications in patients who undergo shoulder arthroplasty with a continuous interscalene brachial plexus block and associated risk factors

INTRODUCTION

Continuous interscalene nerve block techniques are an effective form of targeted non-opioid postoperative analgesia for shoulder arthroplasty patients. One of the limiting risks, however, is potential phrenic nerve blockade with resulting hemidiaphragmatic paresis and respiratory compromise. While studies have focused on block-related technical aspects to limit the incidence of phrenic nerve palsy, little is known about other factors associated with increased risk of clinical respiratory complications in this population.

METHODS

A single-institution retrospective cohort study was conducted using electronic health records from adult patients who underwent elective shoulder arthroplasty with continuous interscalene brachial plexus blocks (CISB). Data collected included patient, nerve block, and surgery characteristics. Respiratory complications were categorized into four groups (none, mild, moderate, and severe). Univariate and multivariable analyses were conducted.

RESULTS

Among 1025 adult shoulder arthroplasty cases, 351 (34%) experienced any respiratory complication. These 351 were subdivided into 279 (27%) mild, 61 (6%) moderate, and 11 (1%) severe respiratory complications. In an adjusted analysis, patient-related factors were associated with an increased likelihood of respiratory complication: ASA Physical Status III (OR 1.69, 95% CI 1.21 to 2.36); asthma (OR 1.59, 95% CI 1.07 to 2.37); congestive heart failure (OR 1.99, 95% CI 1.19 to 3.33); body mass index (OR 1.06, 95% CI 1.03 to 1.09); age (OR 1.02, 95% CI 1.00 to 1.04); and preoperative oxygen saturation (SpO2). For every 1% decrease in preoperative SpO2, there was an associated 32% higher likelihood of a respiratory complication (OR 1.32, 95% CI 1.20 to 1.46, p<0.001).

CONCLUSIONS

Patient-related factors that can be measured preoperatively are associated with increased likelihood of respiratory complications after elective shoulder arthroplasty with CISB.

Analysis of Twitter conversations in obstetric anesthesiology using the hashtag #OBAnes during the onset of the COVID-19 pandemic

BACKGROUND

#OBAnes is the most used hashtag in obstetric anesthesiology. The primary objective of the study was to characterize #OBAnes tweets at the onset of the COVID-19 pandemic.

METHODS

Observational study of all tweets using #OBAnes between June 30, 2019 and October 19, 2020. A list of 19 topics was compiled to categorize each tweet. All Twitter users were manually assigned into one of 19 Symplur Healthcare Stakeholder categories.

RESULTS

There were 12 431 tweets with #OBAnes during the study period, posted by 1704 unique users. The top user category was Doctor (n = 1211, 71%) with 9665 (78%) tweets. The top three topics identified within Twitter conversations were neuraxial anesthesia, COVID-19, and general anesthesia.

CONCLUSIONS

Twitter facilitated thousands of obstetric anesthesia-related discussions during the onset of the COVID-19 pandemic, with most conversations centering on anesthesia type (neuraxial or general anesthesia).

How large language models can augment perioperative medicine: a daring discourse

Interest in natural language processing, specifically large language models, for clinical applications has exploded in a matter of several months since the introduction of ChatGPT. Large language models are powerful and impressive. It is important that we understand the strengths and limitations of this rapidly evolving technology so that we can brainstorm its future potential in perioperative medicine. In this daring discourse, we discuss the issues with these large language models and how we should proactively think about how to leverage these models into practice to improve patient care, rather than worry that it may take over clinical decision-making. We review three potential major areas in which it may be used to benefit perioperative medicine: (1) clinical decision support and surveillance tools, (2) improved aggregation and analysis of research data related to large retrospective studies and application in predictive modeling, and (3) optimized documentation for quality measurement, monitoring and billing compliance. These large language models are here to stay and, as perioperative providers, we can either adapt to this technology or be curtailed by those who learn to use it well.

Patient-centered results from a multicenter study of continuous peripheral nerve blocks and postamputation phantom and residual limb pain: secondary outcomes from a randomized, clinical trial

INTRODUCTION

We previously reported that a 6-day continuous peripheral nerve block reduces established postamputation phantom pain. To provide patients and providers with the information to best inform treatment decisions, here we reanalyze the data and present the results in a more patient-centered format. We also provide information on patient-defined clinically relevant benefits to facilitate evaluation of available studies and guide future trial design.

METHODS

The original trial enrolled participants with a limb amputation and phantom pain who were randomized to receive a 6-day continuous peripheral nerve block(s) of either ropivacaine (n=71) or saline (n=73) in a double-masked fashion. Here we calculate the percentage of each treatment group that experienced a clinically relevant improvement as defined by previous studies as well as present what the participants of our study defined as small, medium, and large analgesic improvements using the 7-point ordinal Patient Global Impression of Change scale.

RESULTS

Among patients who were given a 6-day ropivacaine infusion, 57% experienced at least a 2-point improvement on the 11-point numeric rating scale in their average and worst phantom pain 4 weeks postbaseline as compared with 26% (p<0.001) for average and 25% (p<0.001) for worst pain in patients given a placebo infusion. At 4 weeks, the percentage of participants rating their pain as improved was 53% for the active vs 30% for the placebo groups (95% CI 1.7 (1.1, 2.7), p=0.008). For all patients combined, the median (IQR) phantom pain Numeric Rating Scale improvements at 4 weeks considered small, medium, and large were 2 (0-2), 3 (2-5), and 5 (3-7), respectively. The median improvements in the Brief Pain Inventory interference subscale (0-70) associated with small, medium, and large analgesic changes were 8 (1-18), 22 (14-31), and 39 (26-47).

CONCLUSIONS

Among patients with postamputation phantom pain, a continuous peripheral nerve block more than doubles the chance of a clinically relevant improvement in pain intensity. Amputees with phantom and/or residual limb pain rate analgesic improvements as clinically relevant similarly to other chronic pain etiologies, although their smallest relevant improvement in the Brief Pain Inventory was significantly larger than previously published values.

TRIAL REGISTRATION NUMBER

NCT01824082.

Acute pain service reduces barriers to buprenorphine/naloxone initiation by using regional anesthesia techniques

BACKGROUND

Medications for opioid use disorder (MOUD) are a life-saving intervention; thus, it is important to address barriers to successful initiation. Spasticity affects many patients with spinal cord injury and can be painful and physically debilitating. Chronic painful conditions can lead to the illicit use of non-prescribed opioids, but fear of pain is a barrier to the initiation of MOUD. In this case report, we describe the novel use of botulinum toxin A injections to treat abdominal spasticity and facilitate Acute Pain Service-led buprenorphine/naloxone initiation in a patient with opioid use disorder and severe abdominal spasticity due to spinal cord injury.

CASE PRESENTATION

A patient with C4 incomplete tetraplegia and opioid use disorder complicated by abdominal spasticity refractory to oral antispasmodics and self-treating with intravenous heroin was referred to the Acute Pain Service for inpatient buprenorphine/naloxone initiation. The patient began to fail initiation of buprenorphine/naloxone secondary to increased pain from abdominal spasms. The patient was offered ultrasound-guided abdominal muscle chemodenervation with botulinum toxin A, which resulted in the resolution of abdominal spasticity and facilitated successful buprenorphine/naloxone initiation. At 6 months post-initiation, the patient remained abstinent from non-prescribed opioids and compliant with buprenorphine/naloxone 8 mg/2 mg three times a day.

CONCLUSIONS

This case report demonstrates that inpatient buprenorphine/naloxone initiation by an Acute Pain Service can improve the success of treatment by addressing barriers to initiation. Acute Pain Service clinicians possess unique skills and knowledge, including ultrasound-guided interventions, that enable them to provide innovative and personalized approaches to care in the complex opioid use disorder population.

Barriers to Implementation of Telehealth Pre-anesthesia Evaluation Visits in the Department of Veterans Affairs

Background

Evaluations are conducted days or weeks before a scheduled surgical or invasive procedure involving anesthesia to assess patients' preprocedure condition and risk, optimize status, and prepare them for their procedure. The traditional pre-anesthesia evaluation is conducted in person, although telehealth modalities have been used for several years and have accelerated since the advent of the COVID-19 pandemic.

Methods

We surveyed 109 anesthesiology services to understand the barriers and facilitators to the adoption of telephone- and video-based pre-anesthesia evaluation visits within the US Department of Veterans Affairs (VA).

Results

The analysis included 55 responses from 50 facilities. Twenty-two facilities reported using both telephone and video, 11 telephone only, 5 video only, and 12 none of these modalities. For telehealth users, the ability to obtain a history of present illness, the ability to assess for comorbidities, and assess for health habits were rated highest while assessing nutritional status was lowest. Among nonusers of telehealth modalities, barriers to adoption included the inability to perform a physical examination and the inability to obtain vital signs. Respondents not using telephone cited concerns about safety, while respondents not using video also cited lack of information technology and staff support and patient-level barriers.

Conclusions

We found no significant perceived advantages of video over telephone in the ability to conduct routine pre-anesthesia evaluations except for the perceived ability to assess nutritional status. Clinicians with no telehealth experience cited the inability to perform a physical examination and obtain vital signs as the most significant barriers to implementation. Future work should focus on delineating the most appropriate and valuable uses of telehealth for pre-anesthesia evaluation and/or optimization.

Addition of dexamethasone to prolong peripheral nerve blocks: a ChatGPT-created narrative review

Chat Generative Pre-trained Transformer (ChatGPT), an artificial intelligence chatbot, produces detailed responses and human-like coherent answers, and has been used in the clinical and academic medicine. To evaluate its accuracy in regional anesthesia topics, we produced a ChatGPT review on the addition of dexamethasone to prolong peripheral nerve blocks. A group of experts in regional anesthesia and pain medicine were invited to help shape the topic to be studied, refine the questions entered in to the ChatGPT program, vet the manuscript for accuracy, and create a commentary on the article. Although ChatGPT produced an adequate summary of the topic for a general medical or lay audience, the review that were created appeared to be inadequate for a subspecialty audience as the expert authors. Major concerns raised by the authors included the poor search methodology, poor organization/lack of flow, inaccuracies/omissions of text or references, and lack of novelty. At this time, we do not believe ChatGPT is able to replace human experts and is extremely limited in providing original, creative solutions/ideas and interpreting data for a subspecialty medical review article.

Perioperative and anesthetic considerations for the management of neuromodulation systems

The use of neuromodulation systems is increasing for the treatment of various pathologies ranging from movement disorders to urinary incontinence to chronic pain syndromes. While the type of neuromodulation devices varies, they are largely categorized as intracranial (eg, deep brain stimulation), neuraxial (eg, spinal cord stimulation, dorsal root ganglion stimulation, and intrathecal drug delivery systems), or peripheral (eg, sacral nerve stimulation and peripheral nerve stimulation) systems. Given the increasing prevalence of these systems in the overall population, it is important for anesthesiologists, surgeons, and the perioperative healthcare team to familiarize themselves with these systems and their unique perioperative considerations. In this review, we explore and highlight the various neuromodulation systems, their general perioperative considerations, and notable special circumstances for perioperative management.

An exploratory analysis of pediatric anesthesia activity on Twitter using the #pedsanes hashtag

BACKGROUND

The use of social media within the medical field has rapidly evolved over the past two decades, with Twitter being one of the most common platforms of engagement. The use of hashtags such as #pedsanes has been reported as a community builder around the subject of pediatric anesthesia. Understanding the use of #pedsanes can inform dissemination of pediatric anesthesia content and discourse. We aimed to describe the distribution and patterns of tweets and contributors using #pedsanes across the globe.

METHODS

Using Tweetbinder (https://www.tweetbinder.com) and the R package "academictwitteR," we extracted tweets that included the hashtag "#pedsanes" from March 14, 2016 to March 10, 2022. Tweets were analyzed for frequency, type, unique users, impact and reach, language, content, and the most common themes.

RESULTS

A total of 58 724 tweets were retrieved; 22 071 (38.8%) were original tweets including 3247 replies, while 35 971 (61.2%) were retweets all generated by over 5946 contributors located in at least 122 countries. The frequency distribution of tweets gradually increased over time with peaks in activity corresponding to major pediatric anesthesia societal meetings and during the early phases of the COVID-19 pandemic. The most retweeted and most liked posts included images.

DISCUSSION

We report the widespread and increasing use of social media and the "#pedsanes" hashtag within the pediatric anesthesia and medical community over time. It remains unknown the extent to which Twitter hashtag activity translates to changes in clinical practice. However, the #pedsanes hashtag appears to play a key role in disseminating pediatric anesthesia information globally.

Multiorganizational consensus to define guiding principles for perioperative pain management in patients with chronic pain, preoperative opioid tolerance, or substance use disorder

Significant knowledge gaps exist in the perioperative pain management of patients with a history of chronic pain, substance use disorder, and/or opioid tolerance as highlighted in the US Health and Human Services Pain Management Best Practices Inter-Agency Task Force 2019 report. The report emphasized the challenges of caring for these populations and the need for multidisciplinary care and a comprehensive approach. Such care requires stakeholder alignment across multiple specialties and care settings. With the intention of codifying this alignment into a reliable and efficient processes, a consortium of 15 professional healthcare societies was convened in a year-long modified Delphi consensus process and summit. This process produced seven guiding principles for the perioperative care of patients with chronic pain, substance use disorder, and/or preoperative opioid tolerance. These principles provide a framework and direction for future improvement in the optimization and care of 'complex' patients as they undergo surgical procedures.

Knee Injury and Osteoarthritis Outcome Score Trajectories After Primary Total Knee Arthroplasty in United States Veterans

INTRODUCTION

The volume of total knee arthroplasty (TKA) procedures continues to increase, including among United States (US) veterans, but there is little data characterizing recovery using validated knee-related questionnaires.

METHODS

In this prospective cohort study, we sought to establish the feasibility of longitudinal characterization of recovery after TKA using the validated Knee Injury and Osteoarthritis Outcome Score (KOOS), specifically focusing on two of the KOOS subscales (pain and quality of life (QOL)). We solicited participants who agreed to fill out these knee-related questionnaires preoperatively and 3, 6, and 12 months after discharge following unilateral TKA within the Durham Veterans Affairs Health Care System. We examined rates of prospective completion of the KOOS and face validity of scores at each study time point. We transformed and reported scores on the 0-100 scale, with zero representing significant knee pain or poor QOL and 100 representing no knee pain or good QOL.

RESULTS

Of 200 US veterans presenting between May 2017 and 2018, 21 (10.5%) agreed to participate by filling out the KOOS questionnaire longitudinally from before surgery until one year after discharge. All 21 (100%) participants were male and completed the two KOOS subscale questions (pain and QOL) preoperatively. Of those, 16 (76.2%) also completed KOOS at 3 months, 16 (76.2%) at 6 months, and seven (33.3%) at 12 months. Compared to mean preoperative values (pain: 33.47 + 6.78, QOL: 11.91 + 4.99), the KOOS subscale scores had significantly improved by 6 months after TKA (pain: 74.41 + 10.72, QOL: 49.61 + 13.25) but plateaued at 12 months (pain: 74.60 + 20.80, QOL: 50.89 + 20.61). The magnitude of improvement in absolute scores, pain and QOL, was similar and significant at 12 months compared to preoperative values with an increase of 41.13 (p=0.007) and 38.98 (p=0.009), respectively.

CONCLUSION

Primary TKA in US veterans with advanced osteoarthritis may lead to improved patient-reported KOOS pain and QOL subscale measures at 12 months compared to preoperative scores, with the majority of improvement occurring by 6 months. Only one in ten US veterans approached preoperatively agreed to complete the validated knee-related outcomes questionnaire prior to undergoing TKA. About three-quarters of those veterans also completed it both three and six months after discharge. Collected KOOS subscale scores demonstrated face validity and showed substantial improvement in pain and QOL over the six-month postoperative period. Only one in three veterans who completed the KOOS questionnaire preoperatively also completed it at 12 months, but this does not support the feasibility of follow-up assessments beyond 6 months. To better understand longitudinal pain and QOL trajectories in US veterans undergoing primary TKA for advanced osteoarthritis and to improve study participation, additional research using the KOOS questionnaire may add further insights into this underreported population.

Changing a clinical pathway to increase spinal anesthesia use for elective hip arthroplasty: a single-centre historical cohort study

PURPOSE

International consensus recommendations support neuraxial anesthesia as the preferred anesthetic technique for total hip arthroplasty. We hypothesized that an institutional initiative to promote spinal anesthesia within a clinical pathway would result in increased use of this technique.

METHODS

We reviewed primary unilateral total hip arthroplasty data between June 2017 and June 2019-one year before vs one year after implementation. The primary outcome was rate of spinal anesthesia use. Secondary outcomes included postoperative pain scores and opioid use, rates of postoperative complications, and unplanned resource use. We built a run chart-tracking rates of spinal anesthesia; compared postoperative outcomes based on anesthetic technique; and developed a mixed model, multivariable logistic regression with margins analysis evaluating the use of spinal anesthesia.

RESULTS

The final sample included 172 patients (87 before and 85 after implementation) with no significant differences in baseline characteristics. For the primary outcome, 42/87 (48%) patients received spinal anesthesia before implementation compared with 48/85 (56%) postimplementation (unadjusted difference, 8%; 95% confidence interval, -7 to 23; P = 0.28). There were no differences in secondary outcomes. Factors associated with receipt of spinal anesthesia included American Society of Anesthesiologists Physical Status II (vs III), lower body mass index, and shorter case duration. Using a reduced mixed model, the average marginal effect was 10.7%, with an upper 95% confidence limit of 25.7%.

CONCLUSION

Implementation of a clinical pathway change to promote spinal anesthesia for total hip arthroplasty may not have been associated with increased use of spinal anesthesia, but utilization rates can vary widely. Baseline spinal anesthesia usage at our institution was higher than the USA national average, and many factors may influence choice of anesthesia technique. Patients who receive spinal anesthesia have decreased opioid requirements and pain scores postoperatively.

Erector spinae plane block versus fascia iliaca block after total hip arthroplasty: a randomized clinical trial comparing analgesic effectiveness and motor block

Background

Ultrasound-guided, supra-inguinal fascia iliaca block (FIB) provides effective analgesia after total hip arthroplasty (THA), but is complicated by high rates of motor block. The erector spinae plane block (ESPB) is a promising motor-sparing technique. In this study, we test the analgesic superiority of FIB over ESPB, while also comparing motor impairment.

Methods

In this randomized, observer-blinded clinical trial, patients scheduled for THA with spinal anesthesia were randomly assigned to receive either ultrasound-guided FIB or ESPB preoperatively. Primary outcome was morphine consumption at 24 hours after surgery. Secondary outcomes were: pain scores; assessment of sensory and motor block; incidence of postoperative nausea and vomiting and other complications; and development of chronic post-surgical pain.

Results

Sixty patients completed the study. There were no statistically-significant differences in morphine consumption at 24 hours (p = 0.68) or pain scores at any time point. FIB produced more reliable sensory block in the femoral nerve (p = 0.001) and lateral femoral cutaneous nerve (p = 0.018) distributions. However, quadriceps motor strength was better preserved in the ESPB group when compared to the FIB group (p = 0.002). No differences were observed for hip adduction motor strength (p = 0.253). No differences between groups were observed in terms of side effects or chronic pain incidence.

Consclusions

ESPB may represent a promising alternative to FIB for postoperative analgesia after THA. ESPB and FIB offer similar opioid-sparing benefits within the first day after surgery, but ESPB results in less quadriceps motor impairment.

Ultrasound-guided Percutaneous Cryoneurolysis to Treat Chronic Postamputation Phantom Limb Pain: A Multicenter Randomized Controlled Trial

BACKGROUND

Postamputation phantom pain is notoriously persistent with few validated treatments. Cryoneurolysis involves the application of low temperatures to reversibly ablate peripheral nerves. The authors tested the hypothesis that a single cryoneurolysis treatment would decrease phantom pain 4 months later.

METHODS

The authors enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. The primary outcome was the change in average phantom pain intensity between baseline and 4 months as measured with a numeric rating scale (0 to 10), after which an optional crossover treatment was offered. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction.

RESULTS

Pretreatment phantom pain scores were similar in both groups, with a median [quartiles] of 5.0 [4.0, 6.0] for active treatment and 5.0 [4.0, 7.0] for sham. After 4 months, pain intensity decreased by 0.5 [-0.5, 3.0] in patients given cryoneurolysis (n = 71) versus 0 [0, 3] in patients given sham (n = 73), with an estimated difference (95% CI) of -0.1 (-1.0 to 0.7), P = 0.759. Following their statistical gatekeeping protocol, the authors did not make inferences or draw conclusions on secondary endpoints. One serious adverse event occurred after a protocol deviation in which a femoral nerve cryolesion was induced just below the inguinal ligament-instead of the sensory-only saphenous nerve-which resulted in quadriceps weakness, and possibly a fall and clavicle fracture.

CONCLUSIONS

Percutaneous cryoneurolysis did not decrease chronic lower extremity phantom limb pain 4 months after treatment. However, these results were based upon the authors' specific study protocol, and since the optimal cryoneurolysis treatment parameters such as freeze duration and anatomic treatment location remain unknown, further research is warranted.

EDITOR’S PERSPECTIVE

Recommendations for anatomical structures to identify on ultrasound for the performance of intermediate and advanced blocks in ultrasound-guided regional anesthesia

Recent recommendations describe a set of core anatomical structures to identify on ultrasound for the performance of basic blocks in ultrasound-guided regional anesthesia (UGRA). This project aimed to generate consensus recommendations for core structures to identify during the performance of intermediate and advanced blocks. An initial longlist of structures was refined by an international panel of key opinion leaders in UGRA over a three-round Delphi process. All rounds were conducted virtually and anonymously. Blocks were considered twice in each round: for “orientation scanning” (the dynamic process of acquiring the final view) and for “block view” (which visualizes the block site and is maintained for needle insertion/injection). A “strong recommendation” was made if ≥75% of participants rated any structure as “definitely include” in any round. A “weak recommendation” was made if >50% of participants rated it as “definitely include” or “probably include” for all rounds, but the criterion for strong recommendation was never met. Structures which did not meet either criterion were excluded. Forty-one participants were invited and 40 accepted; 38 completed all three rounds. Participants considered the ultrasound scanning for 19 peripheral nerve blocks across all three rounds. Two hundred and seventy-four structures were reviewed for both orientation scanning and block view; a “strong recommendation” was made for 60 structures on orientation scanning and 44 on the block view. A “weak recommendation” was made for 107 and 62 structures, respectively. These recommendations are intended to help standardize teaching and research in UGRA and support widespread and consistent practice.

Core outcome set for peripheral regional anesthesia research: a systematic review and Delphi study

BACKGROUND/IMPORTANCE

There is heterogeneity among the outcomes used in regional anesthesia research.

OBJECTIVE

We aimed to produce a core outcome set for regional anesthesia research.

METHODS

We conducted a systematic review and Delphi study to develop this core outcome set. A systematic review of the literature from January 2015 to December 2019 was undertaken to generate a long list of potential outcomes to be included in the core outcome set. For each outcome found, the parameters such as the measurement scale, timing and definitions, were compiled. Regional anesthesia experts were then recruited to participate in a three-round electronic modified Delphi process with incremental thresholds to generate a core outcome set. Once the core outcomes were decided, a final Delphi survey and video conference vote was used to reach a consensus on the outcome parameters.

RESULTS

Two hundred and six papers were generated following the systematic review, producing a long list of 224 unique outcomes. Twenty-one international regional anesthesia experts participated in the study. Ten core outcomes were selected after three Delphi survey rounds with 13 outcome parameters reaching consensus after a final Delphi survey and video conference.

CONCLUSIONS

We present the first core outcome set for regional anesthesia derived by international expert consensus. These are proposed not to limit the outcomes examined in future studies, but rather to serve as a minimum core set. If adopted, this may increase the relevance of outcomes being studied, reduce selective reporting bias and increase the availability and suitability of data for meta-analysis in this area.

Single-injection regional analgesia techniques for mastectomy surgery: A network meta-analysis

BACKGROUND

Patients undergoing mastectomy surgery experience severe postoperative pain. Several regional techniques have been developed to reduce pain intensity but it is unclear, which of these techniques is most effective.

OBJECTIVES

To synthesise direct and indirect comparisons for the relative efficacy of different regional and local analgesia techniques in the setting of unilateral mastectomy. Postoperative opioid consumption at 24 h, postoperative pain at extubation, 1, 12 and 24 h, postoperative nausea and vomiting were collected.

DESIGN

Systematic review with network meta-analysis (PROSPERO:CRD42021250651).

DATA SOURCE

PubMed, Scopus, the Cochrane Central Register of Controlled Trials (from inception until 7 July 2021).

ELIGIBILITY CRITERIA

All randomised controlled trials investigating single-injection regional and local analgesia techniques in adult patients undergoing unilateral mastectomy were included in our study without any language or publication date restriction.

RESULTS

Sixty-two included studies randomising 4074 patients and investigating nine techniques entered the analysis. All techniques were associated with less opioid consumption compared with controls The greatest mean difference [95% confidence interval (CI)] was associated with deep serratus anterior plane block: mean difference -16.1 mg (95% CI, -20.7 to -11.6). The greatest reduction in pain score was associated with the interpectoral-pecto-serratus plane block (mean difference -1.3, 95% CI, -1.6 to - 1) at 12 h postoperatively, and with superficial serratus anterior plane block (mean difference -1.4, 95% CI, -2.4 to -0.5) at 24 h. Interpectoral-pectoserratus plane block resulted in the greatest statistically significant reduction in postoperative nausea/vomiting when compared with placebo/no intervention with an OR of 0.23 (95% CI, 0.13 to 0.40).

CONCLUSION

All techniques were associated with superior analgesia and less opioid consumption compared with controls. No single technique was identified as superior to others. In comparison, local anaesthetic infiltration does not offer advantages over multimodal analgesia alone.

TRIAL REGISTRATION

PROSPERO (CRD4202125065).

Regional anesthesia techniques and postoperative delirium: systematic review and meta-analysis

INTRODUCTION

Postoperative delirium is a frequent occurrence in the elderly surgical population. As a comprehensive list of predictive factors remains unknown, an opioid-sparing approach incorporating regional anesthesia techniques has been suggested to decrease its incidence. Due to the lack of conclusive evidence on the topic, we conducted a systematic review and meta-analysis to investigate the potential impact of regional anesthesia and analgesia on postoperative delirium.

EVIDENCE ACQUISITION

PubMed, Embase, and the Cochrane central register of Controlled trials (CENTRAL) databases were searched for randomized trials comparing regional anesthesia or analgesia to systemic treatments in patients having any type of surgery. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We pooled the results separately for each of these two applications by random effects modelling. Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the certainty of evidence and strength of conclusions.

EVIDENCE SYNTHESIS

Eighteen trials (3361 subjects) were included. Using regional techniques for surgical anesthesia failed to reduce the risk of postoperative delirium, with a relative risk (RR) of 1.21 (95% CI: 0.79 to 1.85); P=0.3800. In contrast, regional analgesia reduced the relative risk of perioperative delirium by a RR of 0.53 (95% CI: 0.42 to 0.68; P<0.0001), when compared to systemic analgesia. Post-hoc subgroup analysis for hip fracture surgery yielded similar findings.

CONCLUSIONS

These results show that postoperative delirium may be decreased when regional techniques are used in the postoperative period as an analgesic strategy. Intraoperative regional anesthesia alone may not decrease postoperative delirium since there are other factors that may influence this outcome.

Opioid-free anesthesia in oncologic surgery: the rules of the game

BACKGROUND

Opioids are frequently used in the postoperative period due to their analgesic properties. While these drugs reduce nociceptive somatic, visceral, and neuropathic pain, they may also lead to undesirable effects such as respiratory depression, urinary retention, nausea and vomiting, constipation, itching, opioid-induced hyperalgesia, tolerance, addiction, and immune system disorders. Anesthesiologists are in the critical position of finding balance between using opioids when they are necessary and implementing opioid-sparing strategies to avoid the known harmful effects. This article aims to give an overview of opioid-free anesthesia.

MAIN BODY

This paper presents an overview of opioid-free anesthesia and opioid-sparing anesthetic techniques. Pharmacological and non-pharmacological strategies are discussed, highlighting the possible advantages and drawbacks of each approach.

CONCLUSIONS

Choosing the best anesthetic protocol for a patient undergoing cancer surgery is not an easy task and the available literature provides no definitive answers. In our opinion, opioid-sparing strategies should always be implemented in routine practice and opioid-free anesthesia should be considered whenever possible. Non-pharmacological strategies such as patient education, while generally underrepresented in scientific literature, may warrant consideration in clinical practice.

The External Oblique Intercostal Block: Anatomic Evaluation and Case Series

STUDY OBJECTIVE

We report a modified block technique aimed at obtaining upper midline and lateral abdominal wall analgesia: the external oblique intercostal (EOI) block.

DESIGN

A cadaveric study and retrospective cohort study assessing the potential analgesic effect of the EOI block.

SETTING

Cadaver lab and operating room.

PATIENTS

Two unembalmed cadavers and 22 patients.

INTERVENTIONS

Bilateral ultrasound-guided EOI blocks on cadavers with 29 mL of bupivacaine 0.25% with 1 mL of India ink; single-injection or continuous EOI blocks in patients.

MEASUREMENTS

Dye spread in cadavers and loss of cutaneous sensation in patients.

MAIN RESULTS

In the cadaveric specimens, we identified consistent staining of both lateral and anterior branches of intercostal nerves from T7 to T10. We also found consistent dermatomal sensory blockade of T6-T10 at the anterior axillary line and T6-T9 at the midline in patients receiving the EOI block.

CONCLUSIONS

We demonstrate the potential mechanism of this technique with a cadaveric study that shows consistent staining of both lateral and anterior branches of intercostal nerves T7-T10. Patients who received this block exhibited consistent dermatomal sensory blockade of T6-T10 at the anterior axillary line and T6-T9 at the midline. This block can be used in multiple clinical settings for upper abdominal wall analgesia.

Assessment of Intercostal Nerve Block Analgesia for Thoracic Surgery: A Systematic Review and Meta-analysis

IMPORTANCE

The use of intercostal nerve block (ICNB) analgesia with local anesthesia is common in thoracic surgery. However, the benefits and safety of ICNB among adult patients undergoing surgery is unknown.

OBJECTIVE

To evaluate the analgesic benefits and safety of ICNB among adults undergoing thoracic surgery.

DATA SOURCES

A systematic search was performed in Ovid MEDLINE, Ovid Embase, Scopus, and the Cochrane Library databases using terms for ICNB and thoracic surgery (including thoracic surgery, thoracoscopy, thoracotomy, nerve block, intercostal nerves). The search and results were not limited by date, with the last search conducted on July 24, 2020.

STUDY SELECTION

Selected studies were experimental or observational and included adult patients undergoing cardiothoracic surgery in which ICNB was administered with local anesthesia via single injection, continuous infusion, or a combination of both techniques in at least 1 group of patients. For comparison with ICNB, studies that examined systemic analgesia and different forms of regional analgesia (such as thoracic epidural analgesia [TEA], paravertebral block [PVB], and other techniques) were included. These criteria were applied independently by 2 authors, and discrepancies were resolved by consensus. A total of 694 records were selected for screening.

DATA EXTRACTION AND SYNTHESIS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data including patient characteristics, type of surgery, intervention analgesia, comparison analgesia, and primary and secondary outcomes were extracted independently by 3 authors. Synthesis was performed using a fixed-effects model.

MAIN OUTCOMES AND MEASURES

The coprimary outcomes were postoperative pain intensity (measured as the worst static or dynamic pain using a validated 10-point scale, with 0 indicating no pain and 10 indicating severe pain) and opioid consumption (measured in morphine milligram equivalents [MMEs]) at prespecified intervals (0-6 hours, 7-24 hours, 25-48 hours, 49-72 hours, and >72 hours). Clinically relevant analgesia was defined as a 1-point or greater difference in pain intensity score at any interval. Secondary outcomes included 30-day postoperative complications and pulmonary function.

RESULTS

Of 694 records screened, 608 were excluded based on prespecified exclusion criteria. The remaining 86 full-text articles were assessed for eligibility, and 20 of those articles were excluded. All of the 66 remaining studies (5184 patients; mean [SD] age, 53.9 [10.2] years; approximately 59% men and 41% women) were included in the qualitative analysis, and 59 studies (3325 patients) that provided data for at least 1 outcome were included in the quantitative meta-analysis. Experimental studies had a high risk of bias in multiple domains, including allocation concealment, blinding of participants and personnel, and blinding of outcome assessors. Marked differences (eg, crossover studies, timing of the intervention [intraoperative vs postoperative], blinding, and type of control group) were observed in the design and implementation of studies. The use of ICNB vs systemic analgesia was associated with lower static pain (0-6 hours after surgery: mean score difference, -1.40 points [95% CI, -1.46 to -1.33 points]; 7-24 hours after surgery: mean score difference, -1.27 points [95% CI, -1.40 to -1.13 points]) and lower dynamic pain (0-6 hours after surgery: mean score difference, -1.66 points [95% CI, -1.90 to -1.41 points]; 7-24 hours after surgery: mean score difference, -1.43 points [95% CI, -1.70 to -1.17 points]). Intercostal nerve block analgesia was noninferior to TEA (mean score difference in worst dynamic panic at 7-24 hours after surgery: 0.79 points; 95% CI, 0.28-1.29 points) and marginally inferior to PVB (mean score difference in worst dynamic pain at 7-24 hours after surgery: 1.29 points; 95% CI, 1.16 to 1.41 points). The largest opioid-sparing effect of ICNB vs systemic analgesia occurred at 48 hours after surgery (mean difference, -10.97 MMEs; 95% CI, -12.92 to -9.02 MMEs). The use of ICNB was associated with higher MME values compared with TEA (eg, 48 hours after surgery: mean difference, 48.31 MMEs; 95% CI, 36.11-60.52 MMEs) and PVB (eg, 48 hours after surgery: mean difference, 3.87 MMEs; 95% CI, 2.59-5.15 MMEs).

CONCLUSIONS AND RELEVANCE

In this study, single-injection ICNB was associated with a reduction in pain during the first 24 hours after thoracic surgery and was clinically noninferior to TEA or PVB. Intercostal nerve block analgesia had opioid-sparing effects; however, TEA and PVB were associated with larger decreases in postoperative MMEs, suggesting that ICNB may be most beneficial for cases in which TEA and PVB are not indicated.

A multisociety organizational consensus process to define guiding principles for acute perioperative pain management

The US Health and Human Services Pain Management Best Practices Inter-Agency Task Force initiated a public-private partnership which led to the publication of its report in 2019. The report emphasized the need for individualized, multimodal, and multidisciplinary approaches to pain management that decrease the over-reliance on opioids, increase access to care, and promote widespread education on pain and substance use disorders. The Task Force specifically called on specialty organizations to work together to develop evidence-based guidelines. In response to this report's recommendations, a consortium of 14 professional healthcare societies committed to a 2-year project to advance pain management for the surgical patient and improve opioid safety. The modified Delphi process included two rounds of electronic voting and culminated in a live virtual event in February 2021, during which seven common guiding principles were established for acute perioperative pain management. These principles should help to inform local action and future development of clinical practice recommendations.

Peripheral nerve block anesthesia/analgesia for patients undergoing primary hip and knee arthroplasty: recommendations from the International Consensus on Anesthesia-Related Outcomes after Surgery (ICAROS) group based on a systematic review and meta-analysis of current literature

BACKGROUND

Evidence-based international expert consensus regarding the impact of peripheral nerve block (PNB) use in total hip/knee arthroplasty surgery.

METHODS

A systematic review and meta-analysis: randomized controlled and observational studies investigating the impact of PNB utilization on major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, thromboembolic, neurologic, infectious, and bleeding complications.Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, were queried from 1946 to August 4, 2020.The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess evidence quality and for the development of recommendations.

RESULTS

Analysis of 122 studies revealed that PNB use (compared with no use) was associated with lower ORs for (OR with 95% CIs) for numerous complications (total hip and knee arthroplasties (THA/TKA), respectively): cognitive dysfunction (OR 0.30, 95% CI 0.17 to 0.53/OR 0.52, 95% CI 0.34 to 0.80), respiratory failure (OR 0.36, 95% CI 0.17 to 0.74/OR 0.37, 95% CI 0.18 to 0.75), cardiac complications (OR 0.84, 95% CI 0.76 to 0.93/OR 0.83, 95% CI 0.79 to 0.86), surgical site infections (OR 0.55 95% CI 0.47 to 0.64/OR 0.86 95% CI 0.80 to 0.91), thromboembolism (OR 0.74, 95% CI 0.58 to 0.96/OR 0.90, 95% CI 0.84 to 0.96) and blood transfusion (OR 0.84, 95% CI 0.83 to 0.86/OR 0.91, 95% CI 0.90 to 0.92).

CONCLUSIONS

Based on the current body of evidence, the consensus group recommends PNB use in THA/TKA for improved outcomes.

RECOMMENDATION

PNB use is recommended for patients undergoing THA and TKA except when contraindications preclude their use. Furthermore, the alignment of provider skills and practice location resources needs to be ensured. Evidence level: moderate; recommendation: strong.