Regional Anesthesia and Pain Medicine最新文献

Objective: This study aimed to optimize the formulation of magnetically targeted lidocaine microspheres, reduce the microsphere particle size, and increase the drug loading and encapsulation rate of lidocaine. The optimized microspheres were characterized, and their pharmacokinetics and effective radii of action were studied.

Methods: The preparation of magnetically targeted lidocaine microspheres was optimized using ultrasonic emulsification-solvent evaporation. The Box-Behnken design method and response surface method were used for optimization. The optimized microspheres were characterized and tested for their in vitro release. Blood concentrations were analyzed using a non-compartment model, and the main pharmacokinetic parameters (half-life (t_1/2 ), maximum blood concentration, area under the blood concentration-time curve (AUC), time to peak (T_max ), and mean retention time (MRT) were calculated. Pathological sections were stained to study the safety of the microsphere tissues. A rabbit sciatic nerve model was used to determine the "standard time (t₀ )" and effective radius of the microspheres.

Results: The optimized lidocaine microspheres exhibited significantly reduced particle size and increased drug loading and encapsulation rates. Pharmacokinetic experiments showed that the t_1/2 , T_max , and MRT of magnetically targeted lidocaine microspheres were significantly prolonged in the magnetic field, and the AUC_0-48 and AUC_0-∞ were significantly decreased. Its pharmacodynamic radius was 31.47 mm.

Conclusion: Magnetically targeted lidocaine microspheres provide sustained long-lasting release, neurotargeting, nerve blocking, and high tissue safety. This preparation has a significantly low blood concentration and a slow release in vivo, which can reduce local anesthetic entry into the blood. This may be a novel and effective method for improving postoperative comfort and treating chronic pain. This provides a countermeasure for exploring the size of the magnetic field for the application of magnetic drug-carrying materials.

Background: There is a rising number of patients with left ventricular assist devices (LVADs) undergoing non-cardiac procedures, both emergent and elective. Historically, anesthetic options for these patients have been limited to general anesthesia. Limited data exists for the use of neuraxial anesthesia in patients with LVADs despite its common use in orthopedic procedures for non-LVAD patients. Given the benefits of neuraxial anesthesia and the rising population of LVAD patients undergoing elective procedures, a better understanding of LVAD patients' candidacy for neuraxial anesthesia needs further investigation.

Case presentation: We report the case of a patient with an LVAD who successfully underwent a total knee arthroplasty with neuraxial anesthesia at a tertiary academic center. Preoperative transthoracic echo demonstrated stable cardiac function and an ejection fraction of 10-15% with a HeartMate 3 LVAD. The primary anesthetic was a lumbar epidural that was slowly titrated to a surgical anesthetic level and an adductor canal peripheral nerve catheter was placed preoperatively for postoperative analgesia. The patient remained hemodynamically stable throughout the case, with a perfusionist monitoring the LVAD's function intraoperatively, and tolerated the anesthetic well. His postoperative course was uneventful.

Conclusion: Patients with LVADs should be considered candidates for neuraxial anesthesia with appropriate preoperative planning and perioperative management.

Background: Randomized clinical trials (RCTs) are considered the gold standard for evaluating the efficacy of healthcare interventions. However, conflicts of interest (COIs) can compromise the scientific integrity in these trials. This study characterized COIs in RCTs on spinal cord stimulation for chronic pain, focusing on the prevalence, disclosure, and monetary value of COIs.

Methods: This cross-sectional study analyzed RCTs published from January 1, 2013 to July 27, 2023. Primary outcomes included the presence, disclosure, and monetary value of COIs, while secondary outcomes assessed the presence of direct/indirect COIs, sponsor access to data, and associations between COIs and select variables, including journal impact factor, publication year, and study outcomes.

Results: Of 38 RCTs, 30 (78.9%) reported COIs. On average, 35.6% of authors per RCT had at least one COI, with a mean of 0.7 COIs per author. The mean annual monetary value of COIs was US$41,157.83 per author per RCT. 29 RCTs (76.3%) had undisclosed COIs, with an average of 24.2% of authors per RCT having undisclosed COIs. Sponsor access to data was reported in 67.6% of RCTs. No associations were observed between the mean percentage of authors with COIs and the monetary value of COIs and select dependent variables (impact factor, publication year, and study outcomes).

Conclusions: A substantial majority of RCTs reported COIs with many authors having undisclosed conflicts, highlighting the need for stringent COI disclosure guidelines to maintain research integrity. Expanding COI registry systems globally and increasing non-industry funding are crucial steps toward enhancing transparency and reducing biases in medical research.

Postmortem histology and in vivo, animal-based ultra-high-definition microultrasound demonstrate a complex array of non-communicating adipose tissue compartments enclosed by fascia. Classic nerve block mechanisms and histology do not consider this tissue. Injected local anesthetic agents can occupy any of these adipose compartments, which may explain the significant differences in outcomes such as success rates, onset time, block density, duration of nerve block, and secondary continuous block failure. Furthermore, these adipose tissue compartments may influence injection pressures, making conclusions about needle tip location unreliable. This educational review will explain the neural anatomy associated with these fatty compartments in detail and suggest how they may affect block outcomes.

Background/importance: Opioids continue to play a key role in managing acute postoperative pain, but their use contributes to adverse outcomes. Buprenorphine may offer effective analgesia with a superior safety profile.

Objective: To compare the efficacy and safety of buprenorphine with other opioids for acute postoperative pain management in adults.

Evidence review: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to February 2024. Randomized controlled trials comparing buprenorphine with other opioids for acute postoperative pain management in adults were included. Of 2421 records identified, 58 studies met inclusion criteria. Two reviewers independently extracted data and assessed risk of bias. Random-effects meta-analysis was performed using Stata/BE V.18. The primary outcome was pain intensity. Secondary outcomes included rescue analgesia use, duration of analgesia, and adverse effects.

Findings: Analysis of 41 comparisons (2587 participants) showed buprenorphine significantly reduced pain intensity compared with all other opioids (Hedges's g=-0.36, 95% CI=-0.59 to -0.14, p<0.001, 95% prediction interval (PI)=-1.70 to 0.97). This effect persisted when compared with full agonist opioid (FAO) alone (standardized mean difference -0.34, 95% CI=-0.59 to -0.10, p<0.001, 95% PI=-1.76 to 1.07). Patients receiving buprenorphine were less likely to require rescue analgesia (OR=0.40, 95% CI=0.26 to 0.63, p<0.001, 95% PI=0.12 to 1.36). Mean duration of analgesia was 8.5 hours (SD 1.84). There were no significant differences in other adverse effects including nausea and respiratory depression. Inconsistency was significant for pain intensity (I²=86.28%, 95% CI=81.55% to 88.99%) and moderate for rescue analgesia (I²=38.93%, 95% CI=1.44% to 64.37%). Risk of bias was low in 19 studies, with some concerns in 37 studies, and high in two studies.

Conclusions: Buprenorphine demonstrated superior efficacy in managing acute postoperative pain compared with FAOs, with a favorable safety profile and longer duration of action. These findings support the use of buprenorphine as a first-line opioid analgesic for acute postoperative pain management requiring opioid analgesia, potentially reducing opioid-related harm in the postoperative period.

Prospero registration number: CRD42023447715.

Introduction: Both the quadratus lumborum block (QLB) and the pericapsular nerve group (PENG) block provide effective postoperative analgesia after hip surgery while minimizing the impact on motor function. This study aimed to compare QLB and PENG in patients undergoing primary total hip arthroplasty (THA).

Methods: This superiority trial randomized patients scheduled for elective THA to receive a lateral QLB or a PENG with a lateral femoral cutaneous nerve (LFC) block for postoperative analgesia. Perioperative analgesic protocols were standardized. The primary outcome was postoperative cumulative opioid consumption measured over time up to 72 hours. Secondary outcomes included postoperative pain scores in the first 72 hours, time to ambulation, length of stay, and patient-reported functional outcome measures (Hip disability and Osteoarthritis Outcome Score for Joint Replacement and Patient-Reported Outcome Measures Information System-10 scores).

Results: This trial consented and randomized 106 subjects and 101 were included in the analysis: PENG (n=50), QLB (n=51). Mean (95% CI) opioid consumption in intravenous morphine milligram equivalents differed at 36 hours (mean difference (95% CI), 18.0 (0.80, 35.1); p=0.040), 48 hours (23.0 (5.20, 40.8); p=0.011), 60 hours (28.0 (9.24, 46.7); p=0.004), and 72 hours (33.0 (13.0, 53.0); p=0.001). There were no significant differences between treatment arms in average resting pain score, time to ambulation, rate of same-day discharge, length of stay, or patient-reported functional outcomes.

Conclusion: While both lateral QLB and PENG block+LFC block are effective analgesic methods for patients undergoing THA, patients receiving lateral QLB had decreased cumulative opioid consumption from 36 to 72 hours postoperative and lower pain scores with movement compared with patients receiving PENG+LFC blocks.

Trial registration number: NCT05710107.