Cite as: Nanda M, Meng H. Literature review - November 2024. ASRA Pain Medicine News 2024;49. https://doi.org/10.52211/asra110124.016.

Acute Pain

By Jeffrey Grzybowski, MD, Monika Nanda, MBBS, MPH, FASA, and Marcelle Blessing, MD

The Effect of Opioid-Free Anesthesia with Transversus Abdominis Plane Block on Patients Undergoing Laparoscopic Sleeve Gastrectomy: Randomized Controlled Study

Zhou X et al. J Pain Res 2024;17:2881-90. https://doi.org/10.2147/JPR.S471813

Summary by Jeffrey Grzybowski, MD

Introduction: Patients undergoing laparoscopic bariatric surgery are at high risk for sleep apnea (78.3%) and postoperative nausea and vomiting (PONV) (80%), which significantly affect postoperative recovery. Conducting anesthesia in this population is challenging due to the increased risk of opioid-related adverse events. This trial assesses the feasibility and efficacy of an opioid-free anesthesia (OFA) protocol with a transversus abdominis plane (TAP) block.

Methods: Adult patients undergoing inpatient laparoscopic sleeve gastrectomy were randomized into a control or OFA group. All patients underwent general anesthesia with standardized induction medications. After endotracheal intubation, patients in the OFA group received bilateral ultrasound-guided TAP blocks (ropivacaine 0.3%, 20mL). All patients received 5 mg dexamethasone and 8 mg ondansetron for PONV prophylaxis. Both groups received propofol infusions, sevoflurane, and cisatricurium intraoperatively. During maintenance, the OFA group was administered a continuous intravenous infusion of dexmedetomidine (0.2-0.3 mcg/kg/h) and esketamine (0.3 mg/kg/h). The control group received repetitive doses of sufentanil (0.3 mcg/kg).

Results: Seventy-one patients were analyzed. The OFA group exhibited a significantly reduced need for antiemetic rescue (p= 0.035) compared to the control group. Visual Analog Scale (VAS) for postoperative pain was considerably lower in the OFA group (p<0.01) than in the control group through 24 hours. The length of hospital stay was significantly different with the OFA group having a shorter stay (5.81.0 days) in contrast to the control group (6.61.1 days) (p=0.002).

Key Point: An OFA protocol including TAP blocks, dexmedetomidine, and esketamine for patients undergoing laparoscopic sleeve gastrectomy offered advantages over opioid-based anesthesia in terms of PONV, pain control, and a shorter hospital stay.

Comparing the Clinical Features of Lateral and Medial Approaches of Costoclavicular Technique Versus Traditional Lateral Sagittal Technique as Infraclavicular Brachial Plexus Block Methods: A Randomized Controlled Trial

Bingül ES et al. BMC Anesthesiol 2024; 24(1):254. https://doi.org/10.1186/s12871-024-02645-z

Summary by Monika Nanda, MBBS, MPH, FASA

Introduction: This study evaluated the performance of three infraclavicular brachial plexus block (ICB) techniques, focusing on the medial and lateral approaches of the costoclavicular block compared to the traditional lateral sagittal approach. It aimed to clarify which approach provided the fastest onset time for sensory and motor blockades.

Methods: This randomized controlled trial involved 56 adult patients scheduled for upper extremity surgery, who were divided into three groups: lateral costoclavicular block (CLB), medial costoclavicular block (CMB), and lateral sagittal block (LSB). All groups received a mixture of 20 mL of 0.5% bupivacaine and 10 mL of 2% lidocaine. Sensory and motor block onset times, block performance features, and complications were compared. Primary and secondary endpoints were sensory and motor block onset times, respectively, and patient/surgeon satisfaction and procedural difficulty were recorded.

Results: The fastest sensory and motor block onset times were observed in the CLB group, with median sensory block times of 10 minutes for CLB, 10 minutes for CMB, and 15 minutes for LSB (p < 0.05). CLB also had the fastest motor block onset at 15 minutes (p = 0.004). All blocks achieved 100% success. No significant differences were found in block performance properties or complications except for a higher incidence of vascular puncture in the CMB group (28%).

Key Point: The lateral costoclavicular approach provides faster sensory and motor block onset than other techniques, making it an efficient and effective option for ICBs.

Comparison Of Analgesic Efficacy of Continuous Perineural Catheter, Liposomal Bupivacaine, And Dexamethasone as An Adjuvant For Interscalene Block In Total Shoulder Arthroplasty: A Triple Blinded Randomized Controlled Trial

Article Reference: Poonam PBH et al. J Shoulder Elbow Surg 2022; S1058-2746(24)00547-0. https://doi.org/10.1016/j.jse.2024.06.014

Summary by Marcelle Blessing, MD

Introduction: Liposomal bupivacaine (LB) and perineural dexamethasone extend the duration of analgesia for interscalene blocks (ISB). This study aimed to compare these adjuvants with the gold standard, interscalene catheters (ISC), for quality and duration of analgesia in patients undergoing total shoulder arthroplasty (TSA).

Methods: In this single-center, prospective, triple-blinded, randomized controlled trial, patients presenting for elective TSA were randomized into three groups: Group A (control) plain bupivacaine with perineural bupivacaine catheter, Group B bupivacaine with dexamethasone and sham catheter, and Group C bupivacaine with LB and sham catheter. The primary outcome was the highest numeric rating scale measured on arrival to the post-anesthesia care unit (PACU) and at 6, 12, 24, and 36 hours postoperatively. The secondary outcomes included first analgesic request, intraoperative opioid use, total inpatient opioid use, arm weakness, arm numbness, time of analgesia duration, time of motor recovery, sensory testing to pinprick, hand strength, and PACU and hospital length of stay.

Results: Ninety patients were randomized into the three groups, but only 72 were included in the final analysis because of failure to adhere to the study protocol. There was no difference in the worst pain scores between the three groups. There were no differences in sleep quality or satisfaction between the three groups. There were no significant adverse events.

Key Point: A single injection ISB with bupivacaine combined with either dexamethasone or LB provides similar analgesic quality and duration to an ISC.

Chronic Pain

By Peyton J. Murin, MD, Vinita Singh, MD, MSCR, and Howard Meng, MD

Randomized Placebo-Controlled Trial of 60-day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain and Improved Function After Knee Replacement

Goree JH et al. Neuromodulation 2024;27(5):847-61. https://doi.org/10.1016/j.neurom.2024.03.001

Summary by Peyton J. Murin, MD

Introduction: Approximately 20% of patients following total knee arthroplasty (TKA) will experience persistent postoperative pain. Treatment options for this pain are limited, including minimally invasive interventions, opioids, and nonopioid medications. Preliminary evidence in the literature suggests that peripheral nerve stimulation (PNS) could be an efficacious therapy for persistent postoperative pain after TKA; however, there is a need for a double-blind, placebo-controlled trial.

Methods: Patients age >21 with postoperative pain intensity ≥5/10 (question 5, BPI Short Form) following TKA were randomized into PNS or placebo groups. Patients in both groups underwent ultrasound-guided lead placement targeting the femoral and sciatic nerves. Patients in the PNS group received stimulation, while patients in the placebo group received a similar device and sham stimulation. The leads were indwelling for 8 weeks. The primary outcome was the proportion of patients with ≥50% baseline pain reduction during weeks 5 to 8. Functional outcomes (6-minute walk test, WOMAC score, and quality of life) were also evaluated.

Results: A total of 52 cases were included in the final analysis. A larger proportion of patients in the PNS group showed ≥50% pain reduction (60% vs. 24%, P=0.028) and improvement in quality of life (90% vs. 55%, P=0.031) than the placebo group. The total WOMAC score was lower (62% ± 28% vs. 35% ± 34%, P=0.006), and the distance walked was higher (+47% vs. −9% change from baseline; P=0.048) in the PNS group compared to the placebo group.

Key Point: This study demonstrates PNS can improve persistent pain and function after TKA.

Hyaluronate Acid Plus Platelet-Rich Plasma Is Superior to Steroids for Pain Relief Less Than 6 Months Using Injection Therapy of Partial Rotator Cuff Tears: A Systematic Review and Network Meta-analysis

Weninger V et al. Arthroscopy 2024;S0749-8063(24)00258-5. https://doi.org/10.1016/j.arthro.2024.03.035

Summary by Vinita Singh, MD, MSCR

Introduction: Steroids, viscosupplements, and various orthobiologic injections are often used for the symptomatic treatment of rotator cuff tears. This study compares the efficacy of various injections for partial thickness rotator cuff tears (PTRCT).

Methods: A systematic review and network meta-analysis was conducted of studies comparing the efficacy of steroids, hyaluronic acid (HA), platelet-rich plasma (PRP), HA plus PRP, and adipose-derived regenerative cells in PTRCT. Studies that evaluated partial thickness tears (not full thickness), confirmed by MRI, and without other associated pathology were included. The primary outcomes were the VAS for pain and functional outcomes: Constant-Murley Shoulder Outcome Score (CMS) and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. A total of seven studies were found to be eligible. The mean and standard deviation of change in clinical scores from baseline to different post-treatment intervals (up to 6 months) were extracted for each treatment.

Results: The combination of HA + PRP had the highest likelihood of reducing pain and improving function in the short term (HA + PRP: VAS [0-4 weeks]: mean difference: -0.99 [95% CI, -1.62 to -0.36]; CMS [0-3 months]: 20.56 [95% CI, 16.18 to 24.94]). No meaningful difference was found between HA + PRP and other treatments after 6 months.

Key Point: Based on this network meta-analysis, a combination of HA and PRP appears to be most effective for PTRCT in the short term when compared to other injectable treatments such as steroids.

Pain Reduction with Oral Methotrexate in Knee Osteoarthritis – A Randomized, Placebo-Controlled Clinical Trial (PROMOTE)

Kingsbury SR et al. Ann Intern Med 2024;177(9):1145-56. https://doi.org/10.7326/M24-0303

Summary by Howard Meng, MD

Introduction: Symptomatic knee osteoarthritis (KOA) affects 364 million adults globally. Current pharmacological treatments for KOA are limited by lack of efficacy or the presence of contraindications. Methotrexate is a standard of care in inflammatory arthritis with potential therapeutic benefits in symptomatic KOA. This trial was conducted to assess whether methotrexate improves knee pain.

Methods: This was a pragmatic, multicenter, superiority, double-blinded, randomized, 1:1 placebo-controlled trial. Participants with NRS >4/10 on most days in the past 3 months with inadequate response to medication were included. Participants were prescribed escalating doses of methotrexate starting at 10mg/week to a maximum of 25mg/week for 12 months. Participants continued their usual analgesics during the study. The primary endpoint was “average overall knee pain severity over the previous week” at 6 months.

Results: A total of 155 participants were randomized. Mean knee pain decreased from 6.4 (SD 1.8) at baseline to 5.1 (SD 2.32) at 6 months in the methotrexate group and 6.8 (SD, 1.62) at baseline to 6.2 (SD, 2.30) at 6 months in the placebo group. The primary intention to treat analysis demonstrated a significant reduction of 0.79 NRS in favor of methotrexate (95% CI, 0.08 to 1.51; P=0.03). Significant treatment group differences in favor of methotrexate at 6 months for WOMAC stiffness (0.60 points [CI, 0.01 to 1.18]; P=0.045) and function (5.01 points [CI, 1.29 to 8.74]; P=0.008).

Key point: Oral methotrexate added to usual medications demonstrated improved pain, stiffness, and function at 6 months for symptomatic KOA.