Regional Anesthesia and Pain Medicine最新文献

Introduction: Ultrasound-guided peripheral nerve block and radiofrequency ablation have been developed for pain management in various joints including the hip, knee and shoulder, but not the elbow. Precise three-dimensional (3D) localization of the articular branches and landmarks visible on ultrasound are needed. The objectives of this anatomical study were to determine the presence, course, frequency, landmarks and areas innervated by the articular branches supplying the posterior elbow joint.

Methods: In 12 upper extremity specimens, articular branches to the posterior elbow joint were dissected from brachial plexus to termination. Origin, course, frequency, capsular distribution and landmarks were documented. Data were reconstructed into 3D models and a 3D frequency map to visualize spatial relationships between the articular branches, capsule and landmarks.

Results: The superior part of the posterior capsule was innervated by the ulnar collateral nerve (92%) and lateral branch to triceps (100%). The lateral part was supplied by the nerve to anconeus (100%) and, when present, branch to extensor carpi ulnaris (58%). The medial part was supplied by the ulnar nerve through direct branches (92%) and branches to forearm flexors (100%). The medial and posterior antebrachial cutaneous nerves supplied the medial and lateral epicondylar areas, respectively (100%, 83%). Common landmarks included the epicondyles, olecranon, olecranon fossa, and margins of triceps.

Conclusions: The 3D data of the articular branches supplying the posterior elbow joint provide an anatomical basis for the development of peripheral nerve block and radiofrequency ablation protocols to treat elbow joint pain. Further anatomical and clinical studies are necessary to identify target sites and evaluate the proposed landmarks in vivo.

Background: Preservative-free chloroprocaine is a promising spinal anesthetic for ambulatory surgeries, offering a short duration of action and minimal side effects, which promote faster recovery and discharge. Thus, this study aimed to compare chloroprocaine hydrochloride to the widely used bupivacaine as a spinal anesthetic in ambulatory anorectal surgeries. We hypothesized that chloroprocaine will lead to quicker recovery and discharge, supporting its use in the ambulatory surgical setting.

Methods: In this double-blind randomized controlled trial, 110 patients were randomized to 1% chloroprocaine or 0.75% bupivacaine treatment groups. Due to the inability to place a spinal anesthetic, five patients were excluded (one in chloroprocaine and four in bupivacaine groups). The co-primary endpoints were recovery time (defined as the time of motor and sensory function return), and time discharge criteria were met. The secondary endpoint was the onset of transient neurological symptoms (TNS).

Results: The chloroprocaine group had a significantly shorter time to meet discharge criteria (191.4±6.6 min) than the bupivacaine group (230.9±9.4 min; p=<0.001). There were no significant differences between interventions for recovery time. No TNS were recorded within 24 hours after the procedure for both groups.

Conclusion: Our study demonstrated a significantly reduced time to meeting discharge criteria with chloroprocaine compared with bupivacaine without an increased risk of TNS. Our results support the use of chloroprocaine for spinal anesthesia in ambulatory anorectal surgeries.

Trial registration number: NCT03324984.

Liposomal bupivacaine (LB) has been the subject of a great deal of study, and some degree of controversy, since its development in the late 1990s. While some published studies are supportive of its efficacy, many others are not or demonstrate only marginal improvement in analgesia. This variable efficacy occurs in the face of markedly increased costs when compared with plain local anesthetics. In this education article, we trace the development of LB, summarize the important aspects of its pharmacology, and explore possible causes of its failure to fulfill the promise that the drug held when it was developed and approved. Finally, we discuss some aspects of perineural anatomy that might impact the potential of this drug to provide long-lasting analgesia.

The trial-to-implant ratio for spinal cord stimulation (SCS) has long served as a cornerstone metric for optimizing patient selection and cost containment. Historically, screening trials played a pivotal role in identifying non-responders, thereby minimizing unnecessary permanent implantations. The utility of the trial paradigm is supported by Medicare data from 2009, which reported a trial-to-implant ratio of 42.5%. However, advancements in SCS technology have significantly transformed the neuromodulation landscape and have been associated with higher rates of trial success. By 2018, the Medicare data showed trial-to-implant ratios exceeding 63%, with randomized clinical trials from 2020 to 2021 reporting ratios exceeding 80%-90%. These significant increases in trial-to-implant ratios suggest that only a minority of SCS candidates do not undergo a subsequent permanent device implantation. As such, re-evaluation of the trial-to-implant paradigm, from the perspective of practicing pain physicians in the USA, in light of evolving clinical practices and economic pressures, is warranted. This discourse explores the benefits and limitations of the trial-to-implant ratio, emphasizing its role as a safeguard against overutilization and a tool for standardizing clinical practices but weighed against its shortcomings including a lack of alignment with long-term outcomes, underscore the need for alternative metrics that include per capita trial utilization and explant-to-implant ratios. European responses to similar questions have resulted in utilizing validated symptom screening tools and direct-to-implant pathways in lieu of a screening trial altogether as potential strategies to optimize SCS utilization while maintaining cost-effectiveness. As healthcare systems adapt to advancements in neuromodulation, a balanced perspective on trial-to-implant ratios and complementary metrics is essential to ensure equitable access, sustainable outcomes and evidence-based care for the future of SCS therapy.

Background: Chlorhexidine is the preferred antiseptic for skin preparation owing to its superior antimicrobial efficacy compared with povidone-iodine. However, its supposed neurotoxicity-particularly in combination with alcohol-can cause catastrophic damage if inadvertently introduced into the neuraxial space during epidural or spinal anesthesia.

Case presentation: We describe a fatal case of arachnoiditis following unintentional intradural injection of alcohol-based chlorhexidine during epidural catheter placement for labor analgesia and report a literature review. Among 114 records, five case reports met the inclusion criteria. All patients were women receiving epidural or spinal anesthesia for obstetric or surgical procedures. Exposure involved either direct injection or contamination of anesthetic solutions with chlorhexidine. Onset ranged from immediate lumbar pain to delayed neurological deterioration. Reported outcomes included paraplegia, tetraplegia, hydrocephalus, syringomyelia, and profound functional loss. Therapeutic interventions-corticosteroids, neurosurgery, cerebrospinal fluid shunting, and analgesia-were ineffective in reversing deficits. Error prevention is essential and relies on the use of colored solutions, strict physical separation between chlorhexidine and other solutions used during procedures, the use of pre-impregnated applicators, or alternatively the use of naturally colored povidone-iodine, which may be less neurotoxic.

Conclusions: Accidental intradural or epidural administration of chlorhexidine is a rare but devastating event most often associated with poor outcomes. Prevention requires mandating colored antiseptics or enforcing strict handling protocols.

Introduction: Psychological comorbidities can negatively impact outcomes of spinal cord stimulation (SCS) for chronic pain. While psychological assessment is commonly required before SCS implantation, evidence supporting its impact on outcomes is limited, and such assessments may be unnecessary for many patients and contribute to delays in care. Our center implemented a screening tool incorporating validated questionnaires and a mental health checklist to triage the need for formal psychological evaluation. This prospective, observational cohort study compared outcomes of SCS trials and implants between patients who bypassed (fast track: FT) versus those who underwent a formal assessment by a psychologist (AP).

Methods: Data were collected from patients undergoing SCS trials between July 2017 and December 2021. The screening tool used thresholds on validated questionnaires assessing anxiety, depression, catastrophizing, and opioid misuse risk, along with a checklist capturing significant anxiety or depression, self-harm, substance abuse, or mental-health-related hospitalization. Patients screening positive underwent an AP; others proceeded directly to trial (FT). 1 year post implantation outcomes were collected, with successful implantation defined as ≥30% pain reduction from baseline.

Results: Of 171 patients (114 AP, 57 FT), trial-to-implant rates were similar (72% AP vs 70% FT, p=0.811). The proportion of responders at 1 year post implant was also comparable (53% AP vs 60% FT, p=0.927). Multivariate logistic regression identified that higher baseline pain intensity (adjusted OR (aOR) 0.70, 95% CI 0.53 to 0.92, p=0.011) and use of tricyclic antidepressants (aOR 0.15, 95% CI 0.04 to 0.56, p=0.005) were associated with implant failure, whereas pain duration >10 years was associated with implant success (aOR 3.09, 95% CI 1.06 to 9.02, p=0.039).

Conclusions: This screening tool effectively identifies patients who can bypass routine psychological assessment without compromising 1 year SCS outcomes. Implementation can streamline patient flow, reduce wait times, and reserve psychological resources for those who need formal evaluation.

Background: Previous studies provide conflicting evidence for ketamine's effectiveness in treating chronic pain, in the context of limited real-world evidence to augment clinical trial findings. We conducted a comparative effectiveness study with real-world data to assess the impact of ketamine infusions on pain-related healthcare utilization, to bridge the gap between clinical trials and real-life care.

Methods: We identified 118 subjects who received intravenous (IV) ketamine infusions for chronic pain between 2018 and 2022. Using the University of Pittsburgh's patient outcomes repository for treatment registry, we created a propensity score-matched control cohort of 118 subjects. Real-world data from the University of Pittsburgh Medical Center healthcare network was analyzed to compare unexpected pain-related healthcare utilization, including emergency room visits, urgent care visits, and hospital admissions. Utilization was assessed 6 months before and after ketamine infusion and compared with the matched control cohort.

Results: The ketamine cohort demonstrated a decrease in unexpected healthcare utilization 6 months after treatment compared with 6 months prior, while the control cohort showed an increase during the same period. Ketamine treatment was associated with a 45% reduction in pain-related visits compared with the control cohort (p<0.001).

Conclusions: IV ketamine was more effective than conventional therapy in reducing unexpected pain-related healthcare utilization for over 6 months in patients with chronic pain. Our study highlights the value of using real-world data and comparative effectiveness research to supplement clinical trials and enhance our understanding of the possible effects of outpatient ketamine infusion therapy.

Background: The Ehlers-Danlos syndromes (EDS) are a collection of heritable connective tissue disorders. Local anesthetic resistance is commonly reported by patients with EDS, but there is little clinical evidence to support this finding. We hypothesized that patients with EDS would have increased anesthetic resistance using lidocaine compared with healthy controls.

Methods: An interventional study design was used. Participants (total N=135: EDS n=91, healthy n=44) completed a series of sensation tests using a standardized 10 g monofilament following subcutaneous injection with saline or lidocaine at two separate sites on the right forearm in a randomized order. Participants rated their sensation at each site relative to non-anesthetized skin. Sensation was used as a surrogate measure of anesthetic effect. Participant ratings were converted into two measures: (1) a dichotomous variable to represent adequate anesthesia and (2) a delta sensation score. This study was registered on ClinicalTrials.gov (NCT05603741).

Results: Delta sensation scores were not different at 5 min post-injection between EDS and healthy participants (p=0.2), but were significantly different at 15 min (1 (0-2) arbitrary units (a.u.) vs 2 (1-2) a.u; p=0.002) and 30 min (1 (0-2) a.u. vs 2 (1-2) a.u.; p=0.003) post-injection. There was no difference in categorical "anesthesia" at 5 min between EDS and controls (p=0.2). A smaller proportion of EDS experienced "anesthesia" at 15 min (60% vs 84%, p=0.006) and 30 min (53% vs 80%, p=0.003) post-injection compared with healthy controls.

Conclusion: Patients with EDS experienced increased sensation with lidocaine, suggesting shorter duration of effect of lidocaine local anesthetic. This evidence validates previous patient reports and small case studies suggesting this phenomenon. Healthcare providers should be aware of this reduced effectiveness experienced by patients with EDS, to adjust care accordingly.

Trial registration number: NCT05603741.

Background: Corticosteroid injections (CSIs) are widely employed for chronic pain. These injections include peripheral nerve blocks and trigger point injections, injections of large appendicular joints, the axial facet and sacroiliac joints, and the epidural space. These injections may be performed in patients who have been recently vaccinated or plan to be vaccinated. This multisociety multispecialty position statement aims to develop evidence-based statements and recommendations (SRs) on the safe interval between CSIs and COVID-19 and influenza vaccine administration.

Methods: Development of the position statement was approved by the American Society of Regional Anesthesia and Pain Medicine Board of Directors and several other societies that agreed to participate. The scope of the SRs was agreed on to include the efficacy of COVID-19 and influenza vaccines, adverse events related to the CSIs, specifically the effect of CSIs on the hypothalamic-pituitary axis, incidence of COVID-19 in patients who had CSIs during the pandemic, incidence of influenza in patients who had CSIs during the influenza season, and recommend a reasonable interval between CSIs and COVID-19 and influenza vaccination 20 mg/day of prednisone s. Experts were assigned topics to perform a comprehensive literature review and draft SRs, which were refined and voted for consensus (≥75% agreement) using a modified Delphi process. A modified version of the US Preventive Services Task Force grading of evidence and strength of recommendation was followed.

Results: All SRs were approved by all participants after four rounds of discussion. The Practice Guidelines Committees and Boards of Directors of the participating societies also approved all SRs. If a vaccine has been recently administered or planned, then for non-urgent indications, the CSI should be offered at least 1 week before or after vaccine administration. For healthy patient(s), CSI, or vaccine administration may be performed without a 7-day interval after informed discussion with the patient and consent regarding the risk of blunted vaccine efficacy. For non-healthy patients, shared decision-making should include discussion of diminished vaccine effectiveness and the possibility of influenza or COVID-19 infection.

Conclusions: In this position statement, we provide recommendations on the optimal timing between CSIs and COVID-19 or influenza vaccine.

Background: Patients with entrapment of the superior cluneal nerve (SCN) experience pain and dysesthesia in the gluteal region. Ultrasound-guided injection is the preferred approach for the management of SCN entrapment. Mapping of the emerging sites of SCN branches is required to identify the optimal injection site of local anesthetics in the entrapment of the SCN.

Methods: Methods: a total of 10 lumbar-gluteal regions (obtained from six formalin-fixed cadavers) were dissected at ×16 magnification using a surgical microscope. The anatomical landmarks used in this study included the lumbar spinous processes, the posterior superior iliac spine (PSIS), the iliac crest and its highest point. A Cartesian coordinate system originating from the PSIS was established to label the emerging sites of each SCN branch. A reference line was identified connecting the highest point of the iliac crest with the PSIS.

Results: The SCN branches pierced the thoracolumbar fascia at a mean lateral distance (X-axis) of 6.6±1.1 cm and a mean vertical distance (Y-axis) of 6.8±1.3 cm relative to the reference line. Their distribution was systematically mapped and illustrated in proportion to this reference line, which had a mean length of 9.2±1.4 cm. In particular, in nine specimens, vascular structures were observed traversing the triangle of Petit, but no SCN branches were found within this anatomical landmark.

Conclusions: Injection into the lateral half of the reference line over the iliac crest, over a 3 cm² area, can produce high success in the management of SCN entrapment.