Comparison of lidocaine and ropivacaine stellate ganglion blockade in treating upper limb postherpetic neuralgia

Toxic effects of local anesthetics on rat fibroblasts: An in-vitro study

BACKGROUND

Infusion catheters facilitate a controlled infusion of local anesthetic (LA) for pain control after surgery. However, their potential effects on healing fibroblasts are unspecified.

METHODS

Rat synovial fibroblasts were cultured in 12-well plates. Dilutions were prepared in a solution containing reduced-serum media and 0.9% sodium chloride in 1:1 concentration. Each well was treated with 500 μl of the appropriate LA dilution or normal saline for 15- or 30-min. LA dilutions included: 0.5% ropivacaine HCl, 0.2% ropivacaine HCl, 1% lidocaine HCl and epinephrine 1:100,000, 1% lidocaine HCl, 0.5% bupivacaine HCl and epinephrine 1:200,000, and 0.5% bupivacaine HCl. This was replicated three times. Dilution of each LA whereby 50% of the cells were unviable (Lethal dose 50 [LD50]) was analyzed.

RESULTS

LD50 was reached for lidocaine and bupivacaine, but not ropivacaine. Lidocaine 1% with epinephrine is toxic at 30-min at 1/4 and 1/2 sample dilutions. Bupivacaine 0.5% was found to be toxic at 30-min at 1/2 sample dilution. Bupivacaine 0.5% with epinephrine was found to be toxic at 15- and 30-min at 1/4 sample dilution. Lidocaine 1% was found to be toxic at 15- and 30-min at 1/2 sample dilution. Ropivacaine 0.2% and 0.5% remained below LD50 at all time-points and concentrations, with 0.2% demonstrating the least cell death.

CONCLUSIONS

Though pain pumps are generally efficacious, LAs may inhibit fibroblasts, including perineural fibroblast and endoneurial fibroblast-like cells, which may contribute to persistent nerve deficits, delayed neurogenic pain, and negatively impact healing. Should a continuous infusion be used, our data supports ropivacaine 0.2%.

LEVEL OF EVIDENCE

Basic Science Study; Animal model.

Effect of Korean Medicine Treatment on Patients with Postherpetic Neuralgia: A Retrospective Chart Review

Evidence regarding Korean medicine treatment (KMT) for neuropathic pain is lacking. We aimed to identify the effects of integrative KMT in patients with postherpetic neuralgia (PHN). We retrospectively analyzed the electronic medical records of patients with PHN who received KMT at Kyung Hee University Korean Medicine Hospital between August 2021 and July 2022. We evaluated the effects of KMT-comprising acupuncture, pharmacopuncture, herbal medicine, cupping, and moxibustion-on pain intensity using the numerical rating scale (NRS), Short-Form McGill Pain Questionnaire (SF-MPQ), Hospital Anxiety and Depression Scale-Anxiety (HADS-A), Hospital Anxiety and Depression Scale-Depression (HADS-D), Daily Sleep Interference Scale (DSIS), Fatigue Severity Scale (FSS), and EuroQol-5D. Among 53 patients with PHN, 13 were included. The NRS score for worst pain over 1 week decreased from 6.54 ± 0.64 at baseline to 3.85 ± 0.63 at 8 weeks (41% reduction, p < 0.01), while that for average pain over 1 week decreased from 4.93 ± 0.67 at baseline to 3.08 ± 0.46 at 8 weeks (37% reduction, p < 0.01). From baseline to 8 weeks, there were significant reductions in the SF-MPQ, HADS-A, FSS, and EuroQol-5D scores. No adverse events were reported after KMT. Therefore, KMT may be an effective treatment option for patients with PHN.

Therapeutic Strategies for Postherpetic Neuralgia: Mechanisms, Treatments, and Perspectives

PURPOSE OF REVIEW

Postherpetic neuralgia is an annoying pain that mainly affects older people. In order to give patients more options, this review summarizes the pharmacological and interventional treatments for postherpetic neuralgia and updates the research on the efficacy, thereby providing doctors with more treatment options. The adverse effects and effective doses of its various treatments are also presented so that the therapy can be prescribed according to their concrete physical conditions. In a word, this review is dedicated to providing a comprehensive overview of the treatment options for postherpetic neuralgia and offering patients more choices.

RECENT FINDINGS

Combinational therapy is more excellent than monotherapy. The local anesthesia and gabapentin comprised outstanding compatibility. In addition, two therapeutic tools for PHN patients, especially for the intractable ones, electroacupuncture (EA), and osteopathic manipulative treatment (OMT), show their efficacy and become potential options to alleviate pain. In terms of treatment, guidelines recommend patients use tricyclic antidepressants (TCAs), gabapentin, pregabalin, and 5% lidocaine patches as the first-line medications, and gabapentin is investigated most, especially the gabapentin enacarbil (GEn). And drug efficacy can be limited by adverse effects and tolerated doses. Interventional treatments, with their invasiveness and operational difficulty, are usually considered for intractable patients. Combinational therapies may be used when a single therapy cannot achieve the desired effect. Therapies such as OMT and EA have also been proposed to palliate pain in some cases, and future directions of treatment may be investigated in Chinese medicine and acupuncture.

Novel Drug Targets and Emerging Pharmacotherapies in Neuropathic Pain

Neuropathic pain is a debilitating condition characterized by abnormal signaling within the nervous system, resulting in persistent and often intense sensations of pain. It can arise from various causes, including traumatic nerve injury, neuropathy, and certain diseases. We present an overview of current and emerging pharmacotherapies for neuropathic pain, focusing on novel drug targets and potential therapeutic agents. Current pharmacotherapies, including tricyclic antidepressants, gabapentinoids, and serotonin norepinephrine re-uptake inhibitors, are discussed, as are emerging treatments, such as ambroxol, cannabidiol, and N-acetyl-L-cysteine. Additionally, the article highlights the need for further research in this field to identify new targets and develop more effective and targeted therapies for neuropathic pain management.

Ultrasound-guided stellate ganglion block for the treatment of migraine in elderly patients: A retrospective and observational study

OBJECTIVES

This study aimed to assess the effectiveness and safety of ultrasound-guided stellate ganglion block (SGB) in the prophylactic treatment of migraine in the elderly.

BACKGROUND

Treatment of migraine in the elderly is often difficult and troublesome due to multiple comorbidities, drug interactions, and adverse effects (AEs). SGB may be an effective treatment approach for migraine in the elderly as its clinical use is rarely limited by concomitant diseases and age-related physiological changes; however, no studies have evaluated the effectiveness of SGB in the treatment of migraine in the elderly population.

METHODS

This is a retrospective observational case series study. We retrospectively analyzed patients with migraine aged ≥65 years, who underwent ultrasound-guided SGB for headache management between January 2018 and November 2022. Pain intensity using the numerical rating scale (NRS, 0-10), number of days with headache per month, duration of headache, and the consumptions of acute medications were recorded before SGB treatment, and at 1, 2, and 3 months after the last SGB. Safety assessment included thorough documentation of serious and minor AEs related to SGB.

RESULTS

Of 71 patients, 52 were analyzed in this study. After the final SGB, the NRS scores decreased significantly from a mean (± standard deviation [SD]) of 7.3 (1.2) at baseline to 3.3 (1.4), 3.1 (1.6), and 3.6 (1.6) at 1, 2, and 3 months, respectively (vs. baseline, p < 0.001). The mean (SD) number of headache days per month significantly reduced from 23.1 (5.5) to 10.9 (7.1) (p < 0.001), 12.7 (6.5) (p = 0.001), and 14.0 (6.8) days (p = 0.001) at the 1-, 2-, and 3-month follow-ups, respectively. The values of headache duration were also significantly lower at the 1-month (mean [SD] 12.5 [15.8] h, p = 0.001), 2-month (mean [SD] 11.3 [15.9] h, p = 0.001), and 3-month follow-ups (mean [SD] 14.3 [16.0] h, p = 0.001) compared to pre-treatment baseline (mean [SD] 22.7 [17.1] h). There were 33/52 (64%) patients experiencing at least a 50% reduction in acute medications consumption 3 months after the final SGB treatment. The overall AEs rate associated with ultrasound-guided SGB was 9.0% (26/290 SGBs). There were no serious AEs; all reported AEs were minor and transient.

CONCLUSIONS

Stellate ganglion block treatment could reduce pain intensity, headache frequency, and duration of migraine, thereby reducing the need for adjunctive medications in elderly patients. Ultrasound-guided SGB might be a safe and effective intervention for the treatment of migraine in elderly patients.