Anti-Inflammatory Characteristics of Local Anesthetics: Inhibition of TNF-α Secretion of Lipopolysaccharide-Stimulated Leucocytes in Human Blood Samples

Trauma Patients and Acute Compartment Syndrome: Is There an Ariadne's Thread That Can Safely Guide the Anesthesiologist/Emergency Physician Out of the Labyrinth?

Trauma patients in the emergency department experience severe pain that is not always easy to manage. The risk of acute compartment syndrome further complicates the analgesic approach. The purpose of this review is to discuss relevant bibliography and highlight current guidelines and recommendations for the safe practice of peripheral nerve blocks in this special group of patients. According to the recent bibliography, peripheral nerve blocks are not contraindicated in patients at risk of acute compartment syndrome, as long as there is surveillance and certain recommendations are followed.

Modulation of Phospholipase A2 Membrane Activity by Anti-inflammatory Drugs

The phospholipase A2 (PLA2) superfamily consists of lipolytic enzymes that hydrolyze specific cell membrane phospholipids and have long been considered a central hub of biosynthetic pathways, where their lipid metabolites exert a variety of physiological roles. A misregulated PLA2 activity is associated with mainly inflammatory-derived pathologies and thus has shown relevant therapeutic potential. Many natural and synthetic anti-inflammatory drugs (AIDs) have been proposed as direct modulators of PLA2 activity. However, despite the specific chemical properties that these drugs share in common, little is known about the indirect modulation able to finely tune membrane structural changes at the precise lipid-binding site. Here, we use a novel experimental strategy based on differential scanning calorimetry to systematically study the structural properties of lipid membrane systems during PLA2 cleavage and under the influence of several AIDs. For a better understanding of the AIDs-membrane interaction, we present a comprehensive and comparative set of molecular dynamics (MD) simulations. Our thermodynamic results clearly demonstrate that PLA2 cleavage is hindered by those AIDs that significantly reduce the lipid membrane cooperativity, while the rest of the AIDs oppositely tend to catalyze PLA2 activity to different extents. On the other hand, our MD simulations support experimental results by providing atomistic details on the binding, insertion, and dynamics of each AID on a pure lipid system; the drug efficacy to impact membrane cooperativity is related to the lipid order perturbation. This work suggests a membrane-based mechanism of action for diverse AIDs against PLA2 activity and provides relevant clues that must be considered in its modulation.

Effect of anterior quadratus lumborum block with ropivacaine on the immune response after laparoscopic surgery in colon cancer: a substudy of a randomized clinical trial

BACKGROUND

Surgery induces a temporal change in the immune system, which might be modified by regional anesthesia. Applying a bilateral preoperative anterior quadratus lumborum block has proven to be a safe and effective technique in pain management after abdominal and retroperitoneal surgery, but the effect on the immune response is not thoroughly investigated.

METHODS

This study is a substudy of a randomized, controlled, double-blinded trial of patients undergoing laparoscopic hemicolectomy due to colon cancer. Twenty-two patients were randomized to undergo either a bilateral anterior quadratus lumborum nerve block with a total of 60 mL ropivacaine 0.375% or placebo with corresponding isotonic saline injections. The main objective of this exploratory substudy was to investigate the systemic immune response in the first postoperative day by examining changes in blood transcript levels (n=750) and stimulated secretion of cytokines (n=17) on ex vivo activation with microbial ligands and anti-CD3/CD28.

RESULTS

Using unsupervised data analysis tools, we observed no effect of the bilateral anterior quadratus lumborum nerve block on gene expression in immune cells (permutational multivariate analysis of variance using distance matrices: F=0.52, p=0.96), abundances of major immune cell populations (Wilcoxon rank-sum test: p>0.05), and stimulated cytokine secretion (Wilcoxon rank-sum test: p>0.05).

CONCLUSIONS

Our study provides evidence that administration of bilateral anterior quadratus lumborum nerve block as a part of a multimodal analgesic regimen in an enhanced recovery after surgery for laparoscopic hemicolectomy in this cohort does not alter the systemic immune response.Trial registration number NCT03570541.

Improvement in post-orthodontic chronic musculoskeletal pain after local anesthetic injections in the trigeminal area: a case series

Orthodontic treatment has been associated with chronic extraoral pain that is often resistant to common treatments such as drugs or physiotherapy, adversely affecting patients' quality of life. In this case series, we discuss the potential impact of orthodontics on chronic cervical spine pain or gonalgia and explore the long-term effect of local anesthetic injections as a possible therapeutic intervention. Six orthodontic patients with chronic cervical spine pain or gonalgia that substantially affected their quality of life were treated with injections of 0.5% procaine into individual lesions and at palpable points of tissue tension in the oral mucosa and extraoral myofascial areas. All patients in this case series reported significant improvement in their chronic pain, with no residual pain recorded at the 6-month follow-up. Injecting local anesthetic at stress points in the oral mucosal and extraoral myofascial regions may be an effective treatment for post-orthodontic neck and knee pain. Further research is required to better understand the potential benefits of this intervention for patients experiencing orthodontic-related musculoskeletal pain.

The Use of Intravenous Lidocaine in Perioperative Medicine: Anaesthetic, Analgesic and Immune-Modulatory Aspects

This narrative review provides an update on the applied pharmacology of lidocaine, its clinical scope in anaesthesia, novel concepts of analgesic and immune-modulatory effects as well as the current controversy around its use in perioperative opioid-sparing multi-modal strategies. Potential benefits of intravenous lidocaine in the context of cancer, inflammation and chronic pain are discussed against concerns of safety, toxicity and medico-legal constraints.