Local anesthetics differentially inhibit sympathetic neuron-mediated and C fiber-mediated synovial neurogenic plasma extravasation

Therapeutic Use of Low-Dose Local Anesthetics in Pain, Inflammation, and Other Clinical Conditions: A Systematic Scoping Review

The use of low-dose local anesthetics (LAs) has significantly transformed patient care by providing rapid and effective relief of pain and other clinical conditions while minimizing recovery time. This study aims to identify and describe the existing scientific evidence on the therapeutic use of low-dose LAs in various conditions and to identify gaps in the current literature in order to prioritize future research. This systematic scoping review adhered to the methodological guidelines outlined in the Arksey and O'Malley framework, which includes five distinct stages. Of the 129 studies included, 37.98% (n = 49) were clinical trials, 55.03% (n = 71) were observational studies, and 6.97% (n = 9) were systematic reviews. The most commonly reported indication for the use of low-dose LAs was chronic pain management (72.86%), followed by acute pain management (13.17%). Additionally, non-pain-related indications were also identified (13.95%). Overall, the administration of low-dose, short-acting LAs demonstrated favorable outcomes in terms of pain management and reduction in anxiety and depression scales, thereby having a positive impact on the patients' quality of life. This review represents the first systematic scoping review regarding the therapeutic role of LAs. To substantiate the reported positive effects on efficacy and safety, further rigorous research comprising larger, well-designed randomized controlled trials (RCTs) and long-term outcome monitoring is imperative.

Combine Approach of Proximal Fibula Osteotomy (PFO) Followed by Intra-Articular Dextrose Prolotherapy in Severe Medial Knee Osteoarthritis

Background

Knee osteoarthritis (OA) is a chronic and progressive degenerative disease. It resulted from mechanical and chemical disorders that damage the joint and the underlying bone. The management of knee OA is challenging due to poor self-regeneration of connective tissues. Surgical treatment with prolotherapy approaches was conducted to treat medial compartment knee OA.

Aim

To know the injection frequency to reach a 50% improvement in VAS score and WOMAC index.

Methods

Six patients who suffered from late-stage medial compartment knee OA underwent PFO followed by twelve sessions of intra-articular dextrose prolotherapy. The subjective pain score, visual analog scale (VAS), was assessed based on the patient subjectiveness before and after treatment. Patients marked the score from 0 to 10 cm to describe the current pain state. The functional index, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index used to evaluate the Patient's clinical symptoms. It ranges from 0 to 96 points consisting of three main sections: pain (total 20 points), stiffness (total: eight points), and physical function disability (total 68 points). Higher scores indicate severe symptoms and function.

Results

Four patients showed pain relief and functional improvement with more than 50% scores of VAS and WOMAC after the treatment. Two patients received more than twelve doses of intra-articular dextrose prolotherapy due to a lack of progress.

Conclusion

This study provides clinical evidence for a new treatment strategy for advanced knee OA. This combined therapy improves the patient's daily activity function and postpones the need for total knee arthroplasty (TKA).

Dioclea violacea lectin ameliorates inflammation in the temporomandibular joint of rats by suppressing intercellular adhesion molecule-1 expression

Inflammation of temporomandibular joint (TMJ) tissues are the most common cause of pain conditions associated with temporomandibular disorders (TMDs). After a tissue and/or neural damage, the inflammatory response is characterized by plasma extravasation and leukocytes infiltration in the TMJ tissues, which in turn, release inflammatory cytokines cascades responsible for inflammatory pain. Lectins are glycoproteins widely distributed in nature that may exhibit anti-inflammatory properties. This study demonstrated by molecular docking and MM/PBSA that the lectin from Dioclea violacea (DVL) interacts favorably with α-methyl-D-mannoside, N-acetyl-D-glucosamine, and core1-sialyl-Lewis X which are associated with leukocytes migration during an inflammatory response. Wistar rats pretreated with intravenously injection of DVL demonstrated a significant inhibition of plasma extravasation induced by carrageenan (a non-neurogenic inflammatory inductor) and mustard oil (a neurogenic inflammatory inductor) in the TMJ periarticular tissues (p < 0.05; ANOVA, Tukey's test). In addition, DVL significantly reduced carrageenan-induced leukocyte migration in the TMJ periarticular tissues mediated by down-regulation of ICAM-1 expression. These results suggest a potential anti-inflammatory effect of DVL in inflammatory conditions of TMJ.

Effect of a single intra-articular injection of bupivacaine on synovial fluid prostaglandin E2 concentrations in normal canine stifles

Objective

To identify if synovial fluid prostaglandin E₂ increases in response to a single intra-articular dose of bupivacaine in the normal canine stifle.

Results

There were no significant differences in synovial fluid prostaglandin E₂ (PGE₂) concentrations between treatment groups or over time within bupivacaine or saline groups. Samples requiring ≥ 3 arthrocentesis attempts had significantly higher PGE₂ concentrations compared to samples requiring 1 or 2 attempts. Following correction for number of arthrocentesis attempts, PGE₂ concentrations were significantly higher than baseline at 24 and 48 h in the bupivacaine group; however there were no significant differences between the bupivacaine and saline groups. In normal dogs, a single bupivacaine injection did not cause significant synovial inflammation, as measured by PGE₂ concentrations, compared to saline controls. Future research should minimize aspiration attempts and include evaluation of the synovial response to bupivacaine in clinical cases with joint disease.

Effects on hemodynamic variables and echocardiographic parameters after a stellate ganglion block in 15 healthy volunteers

BACKGROUND

The sympathetic nervous system has an important role in generating pain. Various pathomechanisms are involved that respond well to the application of local anesthetics (LA), for example to the stellate ganglion block (SGB).

OBJECTIVES

We wanted to know more about the effects of SGB on cardiovascular parameters.

METHODS

We included 15 healthy volunteers; another 15 healthy volunteers as a control group (sham injection of LA). In order to produce a more precise SGB, we employed only a small volume of LA (3mL), a LA with a lower permeability (procaine 1%), and a modified injection technique. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and echocardiographic parameters were recorded before and after SGB. We also investigated whether there are side differences (left and right SBG).

RESULTS

At baseline all parameters were within the normal range. After performing right and left SGB DBP significantly increased (on the right side from 68.73±8.61 to 73.53±11.10, p=0.015; on the left side from 70.66±13.01 to 77.93±10.40, p=0.003). In the control group no increase in DBP was observed. No side-specific differences were found, except a significant reduction in the maximum velocity of myocardial contraction during the systole with left-sided SGB.

CONCLUSIONS

Even with our methods we could not prevent the simultaneous occurrence of a partial parasympatholytic effect. For this reason, the SGB has only minor hemodynamic effects, which is desirable as it enhances the safety of the SGB.

Acute inflammation in the joint: its control by the sympathetic nervous system and by neuroendocrine systems

Inflammation of tissues is under neural control involving neuroendocrine, sympathetic and central nervous systems. Here we used the acute experimental inflammatory model of bradykinin-induced plasma extravasation (BK-induced PE) of the rat knee joint to investigate the neural and neuroendocrine components controlling this inflammation. 1. BK-induced PE is largely dependent on the sympathetic innervation of the synovium, but not on activity in these neurons and not on release of norepinephrine. 2. BK-induced PE is under the control of the hypothalamo-pituitary-adrenal (HPA) system and the sympatho-adrenal (SA) system, activation of both leading to depression of BK-induced PE. The inhibitory effect of the HPA system is mediated by corticosterone and dependent on the sympathetic innervation of the synovium. The inhibitory effect of the SA system is mediated by epinephrine and β2-adrenoceptors. 3. BK-induced PE is inhibited during noxious stimulation of somatic or visceral tissues and is mediated by the neuroendocrine systems. The nociceptive-neuroendocrine reflex circuits are (for the SA system) spinal and spino-bulbo-spinal. 4. The nociceptive-neuroendocrine reflex circuits controlling BK-induced PE are under powerful inhibitory control of vagal afferent neurons innervating the defense line (connected to the gut-associated lymphoid tissue) of the gastrointestinal tract. This inhibitory link between the visceral defense line and the central mechanisms controlling inflammatory mechanisms in body tissues serves to co-ordinate protective defensive mechanisms of the body. 5. The circuits of the nociceptive-neuroendocrine reflexes are under control of the forebrain. In this way, the defensive mechanisms of inflammation in the body are co-ordinated, optimized, terminated as appropriate, and adapted to the behavior of the organism.

Outcomes and cost-effectiveness of carpal tunnel injections using sonographic needle guidance

This randomized controlled study addressed whether sonographic needle guidance affected the outcomes of corticosteroid injection for symptomatic carpal tunnel syndrome. Seventy-seven symptomatic carpal tunnels were randomized to injection by either (1) conventional anatomic landmark palpation-guided injection or (2) sonographic image-guided injection, each using a two-step technique where 3 ml of 1% lidocaine was first injected to hydrodissect and hydrodisplace critical intra-carpal tunnel structures followed by injection with 80 mg of triamcinolone acetonide (2 ml). Baseline pain, procedural pain, pain at outcome (2 weeks and 6 months), responders, therapeutic duration, total cost, and cost per responder were determined. There were no complications in either treatment group. Relative to conventional anatomic landmark palpation-guided methods, sonographic guidance for injection of the carpal tunnel resulted in 77.1% reduction in injection pain (p<0.01), a 63.3% reduction in pain scores at outcome (p<0.014), 93.5% increase in the responder rate (p<0.001), 84.6% reduction in the non-responder rate (p<0.001), a 71.0% increase in therapeutic duration (p<0.001), and a 59.3% ($150) reduction in cost/responder/year for a hospital outpatient (p<0.001). However, despite improved outcomes, cost per patient per year was significantly increased for an outpatient in a physician's office and was neutral for a hospital outpatient. Sonographic needle guidance significantly improves the performance and clinical outcomes of injection of the carpal tunnel and is cost-effective for a hospital-based practice, but based on current reimbursements, it significantly increases overall costs for medical care delivered in a non-hospital-based physician practice.