Differences in the association between epidural analgesia and length of stay by surgery type: an observational study

INTRODUCTION

Despite a decline in the use of thoracic epidural analgesia related in part to concerns for delayed discharge, it is unknown whether changes in length of stay (LOS) associated with epidural analgesia vary by surgery type. Therefore, we determined the degree to which the association between epidural analgesia (vs no epidural) and LOS differed by surgery type.

METHODS

We conducted an observational study using data from 1747 patients who had either non-emergent open abdominal, thoracic, or vascular surgery at a single tertiary academic hospital. The primary outcome was hospital LOS and the incidence of a prolonged hospital LOS defined as 21 days or longer. Secondary endpoints included escalation of care, 30-day all-cause readmission, and reason for epidural not being placed. The association between epidural status and dichotomous endpoints was examined using logistic regression.

RESULTS

Among the 1747 patients, 85.7% (1499) received epidural analgesia. 78% (1364) underwent abdominal, 11.5% (200) thoracic, and 10.5% (183) vascular surgeries. After adjustment for differences, receiving epidural analgesia (vs no epidural) was associated with a 45% reduction in the likelihood of a prolonged LOS (p<0.05). This relationship varied by surgery type: abdominal (OR 0.42, 95% CI 0.23 to 0.79, p<0.001), vascular (OR 1.66, 95% CI 0.17 to 16.1, p=0.14), and thoracic (OR 1.07, 95% CI 0.20 to 5.70, p=0.93). Among abdominal surgical patients, epidural analgesia was associated with a median decrease in LOS by 1.4 days and a 37% reduction in the likelihood of 30-day readmission (adjusted OR 0.63, 0.41 to 0.97, p<0.05). Among thoracic surgical patients, epidural analgesia was associated with a median increase in LOS by 3.2 days.

CONCLUSIONS

The relationship between epidural analgesia and LOS appears to be different among different surgical populations.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

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.

The association of prescription opioid use with incident cancer: A Surveillance, Epidemiology, and End Results-Medicare population-based case-control study

BACKGROUND

Cancer is the second leading cause of death globally, and researchers seek to identify modifiable risk factors Over the past several decades, there has been ongoing debate whether opioids are associated with cancer development, metastasis, or recurrence. Basic science, clinical, and observational studies have produced conflicting results. The authors examined the association between prescription opioids and incident cancers using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. A complex relation was observed between prescription opioids and incident cancer, and cancer site may be an important determinant.

METHODS

By using linked SEER cancer registry and Medicare claims from 2008 through 2013, a case-control study was conducted examining the relation between cancer onset and prior opioid exposure. Logistic regression was used to account for differences between cases and controls for 10 cancer sites.

RESULTS

Of the population studied (n = 348,319), 34% were prescribed opioids, 79.5% were white, 36.9% were dually eligible (for both Medicare and Medicaid), 13% lived in a rural area, 52.7% had ≥1 comorbidity, and 16% had a smoking-related diagnosis. Patients exposed to opioids had a lower odds ratio (OR) associated with breast cancer (adjusted OR, 0.96; 95% CI, 0.92-0.99) and colon cancer (adjusted OR, 0.90; 95% CI, 0.86-0.93) compared with controls. Higher ORs for kidney cancer, leukemia, liver cancer, lung cancer, and lymphoma, ranging from lung cancer (OR, 1.04; 95% CI, 1.01-1.07) to liver cancer (OR, 1.19; 95% CI, 1.08-1.31), were present in the exposed population.

CONCLUSIONS

The current results suggest that an association exists between prescription opioids and incident cancer and that cancer site may play an important role. These findings can direct future research on specific patient populations that may benefit or be harmed by prescription opioid exposure.

Association of Length of Time Spent in the United States With Opioid Use Among First-Generation Immigrants

This cross-sectional study uses Medical Expenditure Panel Survey data to examine the association of the length of time a first-generation immigrant has spent in the United States with the likelihood of opioid use.

Characterizing Anesthetic Management and Perioperative Outcomes Associated with a Novel, Fusionless Scoliosis Surgery in Adolescents

Anterior vertebral tethering (AVT) is a novel "fusionless" surgical approach to correct scoliosis. This study aims to characterize the anesthetic management and perioperative outcomes of AVT and traditional posterior spinal fusion (PSF) after establishing the technique at our institution. Scoliosis correction procedures performed in patients aged 10 to 21 years between January 2014 and August 2017 were identified in the electronic medical record. Patient characteristics and perioperative data about anesthetic use and pain management were extracted. Descriptive statistics were generated. Thirty-five patients undergoing AVT and 40 patients undergoing PSF met inclusion criteria. Preoperative fluoroscopy-guided epidural placement was used only in the AVT group (86%). The worst pain score on postoperative day (POD) 1 after AVT was a mean (SD) of 5.6 (2.3), with average pain scores on subsequent days ranging from 2.9 (1.2) to 3.6 (1.7). Total in-hospital opioid consumption in morphine milligram equivalents was 70 (76.6) for AVT and 193.4 (137.2) for PSF (P < .01). Discharge occurred on POD 4.4 (1.4) for AVT and POD 6.2 (1.9) for PSF (P < .01). The worst pain score on POD 1 for PSF was 6.6 (2.1), and average pain scores ranged from 3.7 (1.8) to 4.2 (1.8). These results help inform about the expected recovery profile and narcotic requirement after AVT and PSF.

Subanesthetic ketamine infusions for the management of pediatric pain in non-critical care settings: An observational analysis

BACKGROUND

Guidelines issued by the American Society of Regional Anesthesia and Pain Medicine suggest that ketamine infusions for acute pain management are advantageous as a primary treatment or as an opioid adjunct. Despite significant data regarding its use in adult patients, there remains a paucity of information related to its quality and side effect profile in pediatrics and how it can be effectively used. We aimed to summarize our practice of utilizing ketamine for pediatric pain management in non-critical care settings.

METHODS

Patients aged 0-21 years receiving low-dose ketamine infusions (≤0.3 mg/kg/hour) in inpatient care units over five years were retrospectively analyzed. Demographics, specific quality metrics, and side effects were quantified.

RESULTS

About 172 patients received 270 subhypnotic ketamine infusions. The median duration of the infusions was 63.8 hours and 0.2 mg/kg/hour for the highest dose. The primary indication for ketamine was chronic pain exacerbation (83.3%). Despite similar opioid consumption, there was a significant reduction in mean verbal pain scores before (8.9 ± 1.9, P < .001) and after ketamine (6.5 ± 2.7, P < .001) use. Although there were 52 incidences of some side effect (neurologic excitability [10.4%]; over-sedation [7.4%]; rapid response team alerts [1.1%]), none resulted in termination of the infusion or escalations in care.

CONCLUSION

Ketamine can effectively be used as part of a multimodal analgesic regimen in pediatric patients in non-critical care settings. Our five-year experience using low-dose ketamine infusions highlights an acceptable side effect profile, with no attributable escalations in care or serious adverse events.

Settled science or unwarranted variation in local anesthetic dosing? An analysis from an International Registry of Regional Anesthesiology

BACKGROUND

Variation in clinical practice is often considered unwarranted when it does not reflect patient preference or evidence-based medicine. Complications from regional anesthesia such as nerve injury and systemic toxicity are dose dependent. It is currently unclear if there is significant variation with the dosing of local anesthetics (LA) in the context of the modern practice of peripheral regional anesthesia.

METHODS

We analyzed data from the International Registry of Regional Anesthesia that include prospective data on peripheral regional anesthesia procedures from 21 centers located around the world. Using data from years 2011 to 2017, our primary aim was to characterize the degree of variation in dosing of LA for the top 10 most commonly performed single injection peripheral nerve blocks. Our secondary aim was to identify potential drivers of this variation.

RESULTS

Among the 26 457 peripheral blocks performed, mean (±SD) LA dose per block in ropivacaine equivalents was 125.1±51.2 mg and 1.6±0.7 for mg/kg. There was large variation across all block types, with the highest variation (measured by interdecile range) in axillary blocks (143.8 mg) and lowest in interscalene blocks (83.3 mg). In a regression analysis, dose was primarily associated with the hospital (Cohen's f=0.37) where the block was administered and block type (f=0.38), less so with age (f=0.02), weight (f=0.12), gender (f=0.05) or LA (f=0.17) used. Hospital site had strong impact on variation in LA dose (f=0.88). Variation was not significantly associated with number of blocks performed by hospital site.

CONCLUSIONS

Large variation in dosing for regional blocks exists within and among hospitals, which is unlikely to be warranted. For many blocks, the variation of dosing is larger than the mean dose. Hospital site had strong impact on variation in LA dose and moderate impact on mean LA dose.

The Stress Hormone Cortisol Enhances Interferon-υ-Mediated Proinflammatory Responses of Human Immune Cells

BACKGROUND

Cortisol is a prototypical human stress hormone essential for life, yet the precise role of cortisol in the human stress response to injury or infection is still uncertain. Glucocorticoids (GCs) such as cortisol are widely understood to suppress inflammation and immunity. However, recent research shows that GCs also induce delayed immune effects manifesting as immune stimulation. In this study, we show that cortisol enhances the immune-stimulating effects of a prototypical proinflammatory cytokine, interferon-υ (IFN-υ). We tested the hypothesis that cortisol enhances IFN-υ-mediated proinflammatory responses of human mononuclear phagocytes (monocyte/macrophages [MOs]) stimulated by bacterial endotoxin (lipopolysaccharide [LPS]).

METHODS

Human MOs were cultured for 18 hours with or without IFN-υ and/or cortisol before LPS stimulation. MO differentiation factors granulocyte-macrophage colony stimulating factor (GM-CSF) or M-CSF were added to separate cultures. We also compared the inflammatory response with an acute, 4-hour MO incubation with IFN-υ plus cortisol and LPS to a delayed 18-hour incubation with cortisol before LPS exposure. MO activation was assessed by interleukin-6 (IL-6) release and by multiplex analysis of pro- and anti-inflammatory soluble mediators.

RESULTS

After the 18-hour incubation, we observed that cortisol significantly increased LPS-stimulated IL-6 release from IFN-υ-treated undifferentiated MOs. In GM-CSF-pretreated MOs, cortisol increased IFN-υ-mediated IL-6 release by >4-fold and release of the immune stimulant IFN-α2 (IFN-α2) by >3-fold, while suppressing release of the anti-inflammatory mediator, IL-1 receptor antagonist to 15% of control. These results were reversed by either the GC receptor antagonist RU486 or by an IFN-υ receptor type 1 antibody antagonist. Cortisol alone increased expression of the IFN-υ receptor type 1 on undifferentiated and GM-CSF-treated MOs. In contrast, an acute 4-hour incubation of MOs with IFN-υ and cortisol showed classic suppression of the IL-6 response to LPS.

CONCLUSIONS

These results reveal a surprisingly robust proinflammatory interaction between the human stress response hormone cortisol and the immune activating cytokine IFN-υ. The results support an emerging physiological model with an adaptive role for cortisol, wherein acute release of cortisol suppresses early proinflammatory responses but also primes immune cells for an augmented response to a subsequent immune challenge. These findings have broad clinical implications and provide an experimental framework to examine individual differences, mechanisms, and translational implications of cortisol-enhanced immune responses in humans.

Anaesthetic care of patients undergoing primary hip and knee arthroplasty: consensus recommendations from the International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) based on a systematic review and meta-analysis

BACKGROUND

Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes.

METHODS

The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, 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, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations.

RESULTS

The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87.

CONCLUSIONS

Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation.

RECOMMENDATION

neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty.

TRIAL REGISTRY NUMBER

PROSPERO CRD42018099935.

Trends in Prescription Pain Medication Use by Race/Ethnicity Among US Adults With Noncancer Pain, 2000-2015

OBJECTIVES

To examine national trends in the use of various pharmacological pain medication classes by race/ethnicity among the US pain population.

METHODS

We used data from the Medical Expenditure Panel Survey to conduct a nationally representative, serial cross-sectional study of the noninstitutionalized US adult population from 2000 to 2015. We identified adults with moderate or severe self-reported pain and excluded individuals with cancer. We used complex survey design to provide national estimates of the percentage of adults with noncancer pain who received prescription pain medications among 4 groups: non-Hispanic White, non-Hispanic Black, Hispanic or Latino, and other.

RESULTS

The age- and gender-adjusted percentage of prescription opioid use increased across all groups, with the greatest increase among non-Hispanic White individuals. By 2015, the percentage of non-Hispanic Black adults using opioids approximated that of non-Hispanic White adults-in 2015, approximately 23% of adults in these 2 groups used opioids.

CONCLUSIONS

To our knowledge, this is the first evidence of a narrowing divide in opioid prescribing by race. However, in the context of the national epidemic of opioid-related addiction and mortality, opioid-related risks do not appear commensurate with the purported benefits.

Prescription Opioid Use and Satisfaction With Care Among Adults With Musculoskeletal Conditions

PURPOSE

In the current payment paradigm, reimbursement is partially based on patient satisfaction scores. We sought to understand the relationship between prescription opioid use and satisfaction with care among adults who have musculoskeletal conditions.

METHODS

We performed a cross-sectional study using nationally representative data from the 2008-2014 Medical Expenditure Panel Survey. We assessed whether prescription opioid use is associated with satisfaction with care among US adults who had musculoskeletal conditions. Specifically, using 5 key domains of satisfaction with care, we examined the association between opioid use (overall and according to the number of prescriptions received) and high satisfaction, defined as being in the top quartile of overall satisfaction ratings.

RESULTS

Among 19,566 adults with musculoskeletal conditions, we identified 2,564 (13.1%) who were opioid users, defined as receiving 1 or more prescriptions in 2 six-month time periods. In analyses adjusted for sociodemographic characteristics and health status, compared with nonusers, opioid users were more likely to report high satisfaction with care (odds ratio = 1.32; 95% CI, 1.18-1.49). According to the level of use, a stronger association was noted with moderate opioid use (odds ratio = 1.55) and heavy opioid use (odds ratio = 1.43) (P <.001 for trend).

CONCLUSIONS

Among patients with musculoskeletal conditions, those using prescription opioids are more likely to be highly satisfied with their care. Considering that emerging reimbursement models include patient satisfaction, future work is warranted to better understand this relationship.

Using an international clinical registry of regional anesthesia to identify targets for quality improvement

BACKGROUND

Despite the widespread use of regional anesthesia, limited information on clinical performance exists. Institutions, therefore, have little knowledge of how they are performing in regard to both safety and effectiveness. In this study, we demonstrate how a medical institution (or physician/physician group) may use data from a multicenter clinical registry of regional anesthesia to inform quality improvement strategies.

METHODS

We analyzed data from the International Registry of Regional Anesthesia that includes prospective data on peripheral regional anesthesia procedures from 19 centers located around the world. Using data from the clinical registry, we present summary statistics of the overall safety and effectiveness of regional anesthesia. Furthermore, we demonstrate, using a variety of performance measures, how these data can be used by hospitals to identify areas for quality improvement. To do so, we compare the performance of 1 member institution (a US medical center in New Hampshire) to that of the other 18 member institutions of the clinical registry.

RESULTS

The clinical registry contained information on 23,271 blocks that were performed between June 1, 2011, and May 1, 2014, on 16,725 patients. The overall success rate was 96.7%, immediate complication rate was 2.2%, and the all-cause 60-day rate of neurological sequelae was 8.3 (95% confidence interval, 7.2- 9.7) per 10,000. Registry-wide major hospital events included 7 wrong-site blocks, 3 seizures, 1 complete heart block, 1 retroperitoneal hematoma, and 3 pneumothoraces. For our reference medical center, we identified areas meriting quality improvement. Specifically, after accounting for differences in the age, sex, and health status of patient populations, the reference medical center appeared to rely more heavily on opioids for postprocedure management, had higher patient pain scores, and experienced delayed discharge when compared with other member institutions.

CONCLUSIONS

To our knowledge, this is the first large-scale effort to use a clinical registry to provide comparative outcome rates representing the safety and effectiveness of regional anesthesia. These results can be used to help inform quality improvement strategies.

Glucocorticoids enhance the in vivo migratory response of human monocytes

Glucocorticoids (GCs) are best known for their potent anti-inflammatory effects. However, an emerging model for glucocorticoid (GC) regulation of in vivo inflammation also includes a delayed, preparatory effect that manifests as enhanced inflammation following exposure to an inflammatory stimulus. When GCs are transiently elevated in vivo following exposure to a stressful event, this model proposes that a subsequent period of increased inflammatory responsiveness is adaptive because it enhances resistance to a subsequent stressor. In the present study, we examined the migratory response of human monocytes/macrophages following transient in vivo exposure to stress-associated concentrations of cortisol. Participants were administered cortisol for 6h to elevate in vivo cortisol levels to approximate those observed during major systemic stress. Monocytes in peripheral blood and macrophages in sterile inflammatory tissue (skin blisters) were studied before and after exposure to cortisol or placebo. We found that exposure to cortisol induced transient upregulation of monocyte mRNA for CCR2, the receptor for monocyte chemotactic protein-1 (MCP-1/CCL2) as well as for the chemokine receptor CX3CR1. At the same time, mRNA for the transcription factor IκBα was decreased. Monocyte surface expression of CCR2 but not CX3CR1 increased in the first 24h after cortisol exposure. Transient exposure to cortisol also led to an increased number of macrophages and neutrophils in fluid derived from a sterile inflammatory site in vivo. These findings suggest that the delayed, pro-inflammatory effects of cortisol on the human inflammatory responses may include enhanced localization of effector cells at sites of in vivo inflammation.

Musculoskeletal sonopathology and ultrasound-guided regional anesthesia

The use of real-time ultrasound guidance has revolutionized the practice of regional anesthesia. Ultrasound is rapidly becoming the technique of choice for nerve blockade due to increased success rates, faster onset, and potentially improved safety. In the course of ultrasound-guided regional anesthesia, unexpected pathology may be encountered. Such anomalous or pathological findings may alter the choice of nerve block and occasionally affect surgical management. This case series presents a variety of musculoskeletal conditions that may be encountered during ultrasound-guided regional anesthesia practice.

Electron microscopy evaluation of block needle-related trauma to the tibial nerve

BACKGROUND

Direct puncture by a needle is a risk factor for nerve damage. This investigation used scanning electron microscopy (SEM) to attempt to visualize the damage caused by different needles.

METHOD

A 15 cm section of the tibial nerve was removed from the ankle of a patient undergoing below-the-knee amputation. The nerve specimen was punctured perpendicular to the fibers once by each of four needles: an insulated 22 G short-beveled (30 degrees), a 25 G long-beveled Quincke spinal needle, an 18 G Tuohy, and a 25 G Whitacre pencil point. The distal and proximal ends on either side of the needles were marked and the nerve was sectioned into 0.5 cm pieces. Each sample was preserved and then prepared for SEM. The needle tract was observed for evidence of mechanical damage at magnifications between x 47 and x 102 using SEM.

RESULTS

The epineurium, perineurium, fascicles, endoneurium, and vessels were identified in each sample. In both the short-beveled and the Whitacre samples, all fascicles along with the surrounding perineurium were intact. In both the Tuohy and the Quincke samples, obvious transection of fascicles and disruption of the perineurium were observed.

CONCLUSIONS

This investigation suggests that both the Tuohy and the Quincke needles may be more likely to cause trauma to the tibial nerve than either the short-beveled or the Whitacre needles.

Ultrasound-guided posterior approach for the placement of a continuous interscalene catheter

BACKGROUND AND OBJECTIVES

The posterior approach to performing a continuous brachial plexus block at the level of the nerve roots has been described using traditional superficial landmarks. We describe an ultrasound-guided approach for the placement of a continuous interscalene brachial plexus catheter at the level of the nerve roots using a posterior approach. In addition, we provide the clinical characteristics of the first 16 catheters placed at our institution utilizing this approach.

METHODS

Sixteen patients having major shoulder surgery underwent ultrasound-guided placement of a posterior interscalene catheter at the level of the nerve roots. After generation of an optimized short axis image of the neural and vascular structures in the midneck, a 17-gauge Tuohy needle was directed into the skin between the levator scapulae and middle scalene muscles. Using the in plane approach, the needle was advanced until the tip was located between C5 and C6 nerve roots. Following a bolus injection of local anesthetic, a catheter was threaded 2 to 4 cm and secured. Visualization of the spread of local anesthetic through the catheter was used to dynamically confirm correct perineural catheter location. The characteristics of these catheters were assessed including dislodgment, postoperative opioid consumption, complications, and patient satisfaction.

RESULTS

All 16 catheters were successfully placed. There were no unintended catheter dislodgments. Patient satisfaction was high and postoperative opioid consumption was minimal.

CONCLUSIONS

Results suggest the use of ultrasound for placing a continuous interscalene nerve catheter via the posterior approach is a viable technique that offers an alternative to the more conventional non-image-guided superficial landmark techniques.

Ultrasound guidance in regional anesthesia: state of the art review through challenging clinical scenarios

Ultrasound guided regional anesthesia (UGRA) for peripheral nerve blockade is becoming increasingly popular. The advantage of ultrasound technology is that it affords the anesthesiologist the real time ability to visualize neural structures, needle advancement, and local anesthetic spread. Recent data suggest that UGRA generates improved success rates and reductions in performance times in comparison to traditional approaches. Further, the use of ultrasound technology in peripheral nerve blocks has provided insight into needle-nerve interactions, revealing distinct limitations of nerve stimulator techniques. Given that UGRA requires a unique set of skills, formal standards and guidelines are currently being developed by leadership societies in order to foster education and training. This review article, in a case vignette format, highlights important techniques, concepts, and limitations regarding the use of ultrasound to facilitate regional anesthesia. Clinically relevant aspects of ultrasound physics are also discussed.

Regional anesthesia meets ultrasound: a specialty in transition

Despite its well-known benefits, regional anesthesia has not attained the stature, simplicity, and safety of general anesthesia. Many of the challenges and clinical failures of regional anesthetic techniques can be attributed to fact that neurovascular anatomy is highly variable. Furthermore, current nerve localization techniques provide little or no information regarding the anatomical spread local anesthesia. Recently, ultrasound technology has been utilized by anesthesiologists in an attempt to minimize many of the drawbacks of traditional nerve block techniques. This review article will update the reader on the current status of ultrasound-guided regional anesthesia, provide an evidence-based context, and supply key facts regarding ultrasound physics. In the process, we will also highlight several possible limitations of ultrasound techniques including learning curve issues, costs, and artifact generation.

Orthopaedic anesthesia - part 1. Commonly used anesthetic agents in orthopaedics

Anesthesia is a broad discipline; for orthopaedic applications, the type and location of the planned orthopaedic procedure is important in the selection of the most appropriate anesthetic agent and technique. The purpose of this overview is to: 1. highlight the role of several anesthetic agents commonly used in an orthopaedic setting and 2. to familiarize the orthopaedist with those techniques of regional anesthesia that have implications for emergency rooms and other ambulatory settings. Because the subject matter is expansive in scope, it is necessary to address each of the above objectives separately, in two different articles. Part 1 describes anesthetic agents, whereas Part 2 encompasses techniques of administering regional anesthesia.

Orthopaedic anesthesia - part 2. Common techniques of regional anesthesia in orthopaedics

Anesthesia may be considered in terms of two categories: general and regional. The aim of general anesthesia is to induce analgesia, sedation, amnesia, suppression of autonomic reflexes, and relaxation of muscles. Regional anesthesia is more site-specific and is typically divided into three categories based on the location of injection: 1. a central neuraxial block is an injection of an anesthetic drug into the epidural or intrathecal space; 2. a peripheral nerve block is an injection near the nerve or plexus supplying the area under operation; and 3. a field block is an injection into the adjoining tissues with subsequent diffusion into the surgical area (in orthopaedics, it is typically employed for minor procedures of the hand or foot). Of these three categories of regional anesthesia (i.e., neuraxial, peripheral, and field blocks), this article focuses on the latter two. Although neuraxial blocks comprise an important part of regional anesthesia, they are typically performed by anesthesiologists in an operative setting for major procedures of the lower extremities. The intent of this article is to familiarize the orthopaedist with techniques that have implications for emergency rooms and other ambulatory settings in which regional techniques are sometimes favored over general alternatives because they entail less risk of systemic side effects and may involve more cost-effective use of resources.

Use of a nerve stimulator does not improve the efficacy of ultrasound-guided supraclavicular nerve blocks

OBJECTIVE

To evaluate the efficacy of nerve stimulation as an adjunct to ultrasound-guided supraclavicular nerve blocks.

DESIGN

Prospective database review.

SETTING

Tertiary-care medical center.

MEASUREMENTS

The records of 94 consecutive adult patients requiring surgery below the elbow and consenting to receive regional anesthesia were studied. The focus of this study was on supraclavicular nerve block using ultrasound guidance for nerve identification and needle localization. A nerve stimulator with a motor response lower than 0.5 mA was used for confirmation of findings. An ultrasound image was considered adequate if two trunks of the brachial plexus were visualized and if the needle was completely seen on the long axis. A successful block was defined as one that sufficed as the sole anesthetic without conversion to general anesthesia. Motor and sensory examination findings on the upper extremity were also evaluated.

RESULTS

74 patients had an adequate ultrasound image. Of the 64 patients with a positive motor response, 88% had a successful block, as compared with 90% of the 10 patients without a motor response (relative risk, 1.09; 95% confidence interval, 0.79-1.51; P = 0.52). Neither multivariate correction for baseline characteristics nor inclusion of the 20 patients with inadequate ultrasound images changed the results.

CONCLUSION

For adequately imaged ultrasound-guided supraclavicular nerve blocks, a positive motor response to nerve stimulation does not increase the success rate of the block. In addition, the high false-negative rate suggests that these blocks are usually effective, even in the absence of a motor response. Nerve stimulation as an adjunct to ultrasound guidance may have a limited role.

Characterizing Novice Behavior Associated With Learning Ultrasound-Guided Peripheral Regional Anesthesia

BACKGROUND AND OBJECTIVES

Ultrasound-guided regional anesthesia is a rapidly growing field. There exists little information regarding the competencies involved with such a practice. The objective of this exploratory study was to characterize the behavior of novices as they undertook the challenges of learning a new technique. In addition to assessing for both committed errors and accuracy, we aimed to identify previously unrecognized quality-compromising behaviors that could help structure effective training interventions.

METHODS

By using detailed video analyses, the performances of 6 anesthesia residents were evaluated while on a dedicated 1-month rotation in ultrasound-guided regional anesthesia. From these video reviews, we assessed accuracy, errors committed, performance times, and searched for previously unrecognized quality-compromising behaviors.

RESULTS

A total of 520 nerve blocks were videotaped and reviewed. All residents performed at least 66 nerve blocks, with an overall success rate of 93.6% and 4 complications. Both speed and accuracy improved throughout the rotation. There were a total of 398 errors committed, with the 2 most common errors consisting of the failure to visualize the needle before advancement and unintentional probe movement. Five quality-compromising patterns of behavior were identified: (1) failure to recognize the maldistribution of local anesthesia, (2) failure to recognize an intramuscular location of the needle tip before injection, (3) fatigue, (4) failure to correctly correlate the sidedness of the patient with the sidedness of the ultrasound image, and (5) poor choice of needle-insertion site and angle with respect to the probe preventing accurate needle visualization.

CONCLUSIONS

Based on the analysis of the committed errors and the identification of quality-compromising behaviors, we are able to recommend important targets for learning in future training and simulation programs.

Ultrasound guidance in peripheral regional anesthesia: philosophy, evidence-based medicine, and techniques

PURPOSE OF REVIEW

This article introduces the use of ultrasound to facilitate peripheral regional anesthesia.

RECENT FINDINGS

Regional anesthesia, despite its well known clinical benefits, has not gained the popularity of general anesthesia. This is secondary to multiple shortcomings including a defined failure rate, lack of simplicity, and the potential for patient discomfort or injury. Many of the negative aspects of regional anesthesia evolve from the reality that current nerve-localization techniques are unreliable. Given the great variation in human anatomy it is not surprising that even the most veteran clinician can be challenged by techniques that demand anatomical assumptions. The recent use of ultrasound imaging for nerve localization is an innovative application of an old technology which addresses many of the shortcomings of current techniques. Specifically, ultrasound imaging allows the operator to see neural structures, guide the needle under real-time visualization, navigate away from sensitive anatomy, and monitor the spread of local anesthetic.

SUMMARY

Ultrasound technology represents an ideal mechanism by which the regional anesthesiologist can attain the safety, speed, and efficacy of general anesthesia. Ultimately, it is the correct peri-neural spread of local anesthetic around a nerve that provides safe, effective, and efficient anesthetic conditions.

An abnormal clinical course of an ultrasound-guided supraclavicular brachial plexus block using 0.375% bupivacaine

We report on the case of a reappearance of a supraclavicular nerve block after the apparent initiation of its resolution in a 21-year-old athlete undergoing repair of a valgus impaction syndrome of his right elbow. The patient's anesthetic management consisted of a supraclavicular nerve block and general anesthesia. The patient was discharged home with an apparent resolving nerve block. He returned to the hospital urgently when, at 7 hours after blockade, he lost all motor-sensory function in his arm. His workup ultimately yielded negative results, and the block resolved at 23 hours. In addition to documenting an abnormal course of a supraclavicular block, this case report questions the appropriateness of placing long-acting nerve blocks in outpatients.

Ultrasound guidance improves the success rate of a perivascular axillary plexus block

BACKGROUND

Traditional approaches to performing brachial plexus blocks via the axillary approach have varying success rates. The main objective of this study was to evaluate if a specific technique of ultrasound guidance could improve the success of axillary blocks in comparison to a two injection transarterial technique.

METHODS

Fifty-six ASA physical status I-III patients presenting for elective hand surgery were prospectively randomized to receive an axillary block performed by either a transarterial technique (Group TA) or an ultrasound-guided perivascular approach (Group US). Both groups received a total of 30 ml of 1.5% lidocaine (225 mg) with 5 microg/ml epinephrine. Patients were then evaluated for block onset in specific nerve distributions and whether or not the block acted as a surgical anesthetic.

RESULTS

Group TA sustained more failures defined as conversion to general anesthesia or the inability to localize the artery [Group TA eight patients (29%) vs. Group US in which 0 patients required conversion to general anesthesia (0%) P < 0.01]. Group US demonstrated a reduction in performance times vs. Group TA (7.9 +/- 3.9 min vs. 11.1 +/- 5.7 min, P < 0.05). By 30 min post-injection, there were no significant differences between groups TA and US in terms of the proportion of patients demonstrating a complete motor or sensory loss.

CONCLUSION

Ultrasonographic guidance improves the overall success rate of axillary blocks in comparison to a transarterial technique.