Regional Anesthesia and Pain Medicine最新文献

Background: The mechanism by which local anesthetics spread and produce analgesia in interfascial plane blocks remains unclear. Clinical efficacy often exceeds the visible spread of injectate on imaging. This cadaveric study quantified the distribution of bupivacaine within skeletal muscle and across fascial barriers to explore diffusion as a potential contributor to interfascial plane block dynamics.

Methods: Fresh and frozen-thawed human soleus muscles were injected with a mixture of bupivacaine and methylene blue, and samples were collected along and perpendicular to fiber orientation. Fresh lower limbs were used to assess transfascial transfer across sequential crural fasciae after injection with bupivacaine, iodinated contrast, and methylene blue. The limbs were imaged with CT and samples were collected from crural compartments separated by fascial layers. Finally, simulated posteromedial quadratus lumborum block was performed in fresh cadavers, with samples harvested from the quadratus lumborum, psoas major, and diaphragm. Bupivacaine concentrations were quantified using high-performance liquid chromatography-mass spectrometry.

Results: In fresh muscle, bupivacaine exhibited an anisotropic pattern, with concentration gradients decreasing more slowly along muscle fiber orientation than in transverse direction (p=0.0008). This directional difference disappeared in frozen-thawed tissue. Across fascial barriers, bupivacaine decreased exponentially with the distance from injection site, compatible with diffusion-driven transport, whereas methylene blue and iodinated contrast were not detected beyond the injected compartments. After simulated quadratus lumborum block, bupivacaine was detected in the psoas major (0.7-487.6 µg/g), quadratus lumborum (0.2-266.1 µg/g), and diaphragm (9.0-27.3 µg/g) despite no evident methylene blue spread.

Conclusions: Low-volume injectate of bupivacaine spread anisotropically within fresh muscle and permeated fascial barriers in ways not demonstrated by methylene blue or iodinated contrast. The exponential decrease of concentrations provides evidence that diffusion contributes to local anesthetic distribution and may help explain, at least in part, the broad and occasionally disproportionate sensory coverage observed clinically with interfascial plane blocks.

Background/importance: Existing systematic reviews and meta-analyses of randomized trials of spinal cord stimulation (SCS) for people with chronic pain have consistently excluded direct comparisons between different types of SCS and are therefore at major risk of publication bias.

Objective: The aim of this systematic review and network meta-analysis (NMA) was to combine both direct and indirect randomized trial evidence on treatment effects of SCS for pain intensity, physical function, and health-related quality of life (HRQoL).

Evidence review: MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and WikiStim were searched from inception to December 19, 2024 for parallel-arm randomized trials comparing SCS to conventional medical management (CMM), an active intervention (including other types of SCS) or placebo for adults with chronic pain. The measure of treatment effect for the primary outcome (pain intensity) and for secondary outcomes (physical function, HRQoL) was mean difference (MD) and 95% CI, and for responder rate was OR and 95% CI. NMA was performed in a frequentist framework.

Findings: 23 reports of 16 unique randomized trials were included. All but one trial was assessed as having a high risk of bias. Results of NMA show significant reductions in pain intensity scores (0-10) at last follow-up (within the first 24 months) were observed with all types of SCS compared with CMM, with MD range from -2.37 (95% CI -3.54 to -1.20) to -5.55 (95% CI -7.34 to -3.76; 15 trials, 1479 participants; low certainty evidence). Improvements in physical function (MD range from -0.20, 95% CI -10.24 to 9.85) to -31.04 (95% CI -44.36 to -17.33; 8 trials, 837 participants; low certainty evidence) and HRQoL (MD range from 0.15 (95% CI 0.09 to 0.20) to 0.29 (95% CI 0.20 to 0.37; 8 trials, 942 participants; moderate certainty evidence) were observed for SCS compared with CMM at 6 months. Patients were found to have a higher likelihood to be a responder to treatment (ie, ≥50% reduction in pain intensity) with all forms of SCS in comparison to CMM at last follow-up (OR range from 9.75 (95% CI 4.07 to 23.25) to OR 63.4 (18.76 to 212.55; 13 trials, 1887 participants; very low certainty evidence). Clinically meaningful improvements were observed for pain intensity, HRQoL, and in some comparisons for physical function.

Conclusions: There is low to moderate certainty of evidence that all types of SCS are superior to CMM for the management of chronic pain conditions.

Background and objectives: Most Regional Anesthesiology and Acute Pain Medicine (RAAPM) fellowship programs transitioned to virtual interviews in 2020 because of the COVID-19 pandemic. Then, the RAAPM fellowship match started in 2023 in order to make the application process more equitable. In this study, we surveyed RAAPM fellowship program directors (PDs) to determine how such major events of the early 2020s shaped the fellowship application process.

Methods: A 16-question survey was distributed to US RAAPM program directors. The survey aimed to assess whether PDs prefer the fellowship match over the previous rolling application format and to gauge PDs' confidence in using virtual interviews to evaluate applicants.

Results: 56 (71%) RAAPM program directors completed the survey. 79% of respondents participated in the inaugural match. 59% of PDs preferred the fellowship match over the rolling application format. The interview was rated the most important selection criterion. Of the 93% of PDs who switched to virtual interviews during the pandemic, only 4 PDs (7%) resumed in-person interviews in some capacity. Majority of PDs believed that virtual interviews were not inferior to in-person interviews for assessing applicants; 48% of respondents preferred virtual interviews over in-person interviews.

Conclusions: Most RAAPM programs continued to conduct virtual interviews exclusively. Majority of program directors preferred the fellowship match. PDs ranked the interview as the most important selection factor. Most PDs thought virtual interviews were not inferior to in-person interviews, but they remained divided on which format they prefer.

Objective: The study's primary objective was to compare the effectiveness of intra-articular platelet-rich plasma injections versus corticosteroid injections for the treatment of cervical facetogenic pain. Secondary aims were to compare self-rated disability, pain self-efficacy, and the safety of the procedure between groups.

Methods: A single-site randomized double-blind controlled trial with 40 participants assigned to receive either leucocyte-poor, low-concentrate platelet-rich plasma injections or corticosteroid injection without local anesthetic into the cervical facet joint under fluoroscopy. Outcomes were collected via telephone at 1, 3, and 6 months to determine treatment effectiveness.

Results: Low-concentrate platelet-rich plasma and corticosteroid injections had similar effects on cervical facetogenic pain intensity over a 6-month period post injection as demonstrated by a non-significant group-by-time interaction for Numeric Rating Scale scores (p>0.05). However, both groups showed a statistically significant decrease in cervical facetogenic pain intensity 1 month post treatment compared with baseline (p=0.02), while the platelet-rich plasma group also demonstrated a clinically significant decrease in pain intensity at the same time point. There was a significant interaction at 1 month post intervention for pain self-efficacy (p=0.04), with the platelet-rich plasma injection group showing a larger increase in pain self-efficacy compared with the corticosteroid injection group. No significant interaction was observed for self-rated disability; however, significant reductions were shown at 3 and 6 months post treatment compared with baseline in both groups (p<0.01). No significant differences between groups were reported for adverse events; however, those receiving platelet-rich plasma injection reported significantly less procedural pain (p=0.02).

Conclusion: Both platelet-rich plasma and corticosteroid injections induced similar improvements in cervical facetogenic pain intensity (1 month post) and self-rated disability (3 and 6 months post). Pain self-efficacy demonstrated a significant interaction with platelet-rich plasma injection showing greater improvement 1 month post. Additionally, both treatments exhibited a similar low prevalence of adverse events; however, those receiving platelet-rich plasma injection reported less procedural pain.

Background: During the postoperative period of elective cesarean section, intrathecal morphine is effective in the multimodal analgesic regimen, but can cause significant adverse effects. Bilateral posterior quadratus lumborum block could be alternatively used. The aim of this study was to compare efficacy and safety of both strategies as part of a multimodal analgesic regimen.

Methods: This was a prospective, randomized, blinded, controlled study. 104 parturients were randomly selected to receive intrathecal morphine or posterior quadratus lumborum block during cesarean section under spinal anesthesia. The primary endpoint was patient-controlled 24-hour cumulative intravenous morphine use. Secondary endpoints were 48-hour cumulative morphine use, static/dynamic pain scores, functional recovery (ObsQoR-11 questionnaire) and adverse effects.

Results: There was no statistical difference in the mean cumulative morphine dose at 24-hour between groups (posterior quadratus lumborum block group, 13.7 (97.5% CI 10.4 to 16.9) mg; intrathecal morphine group, 11.1 (97.5% CI 8.4 to 13.8) mg, p=0.111). Pain scores did not show any difference between groups, excepted at 6 hours for the pain at cough/movement in favor of the posterior quadratus lumborum block group (p=0.013). A better recovery quality was observed at 24 hours in the posterior quadratus lumborum block group (p=0.009). Pruritus was more frequent in intrathecal morphine group parturients (35% vs 2%) CONCLUSIONS: No difference in cumulative morphine dose at 24 hours was observed in posterior quadratus lumborum block group compared with intrathecal morphine group. Posterior quadratus lumborum block can be considered an alternative to intrathecal morphine in cesarean postoperative analgesia, especially in cases of intolerance to morphine.

Trial registration number: NCT04755712.

Backgrounds: Ultrasound-guided proximal and distal approaches of the intercostobrachial nerve (ICBN) blocks facilitate analgesia for upper arm and axillary surgery, though success rates vary and lack clinical comparison. This study compared their anesthetic and analgesic efficacy as an adjunct to the supraclavicular brachial plexus block for upper arm arteriovenous access surgery.

Methods: 60 end-stage renal disease patients undergoing upper arm arteriovenous access were randomly assigned to receive either proximal or distal ICBN block using 10 mL of a mixture of levobupivacaine and lidocaine with epinephrine. The primary outcome was a successful ICBN block, defined as a cutaneous sensory blockade at both the medial upper arm and axilla 30 min after the block. Secondary outcomes included block performance, block-related complications, rate of surgical anesthesia, and postoperative analgesia.

Results: The proximal approach had a higher percentage of sensory blockade at the axilla (96.7% vs 73.3%, p=0.03), but comparable rates at the medial upper arm (96.7% vs 96.7%, p=1.00). Consequently, the proximal approach had a higher overall success rate (96.7% vs 73.3%, difference: 23.3%; 95% CI: 6.3%, 40.4%; p=0.03). Both groups had similar surgical anesthesia rates of 93.3%. No significant differences were found in performance time, procedural pain, or postoperative pain intensity.

Conclusions: Proximal ICBN block consistently reduced sensation in the medial upper arm and axilla, while one-quarter of distal blocks spared the axilla. Both approaches, in combination with a supraclavicular brachial plexus block, were effective for upper arm arteriovenous access procedures. However, the proximal approach may be preferable for axillary surgery.

Trial registration number: TCTR20200730006.