Lidocaine, as the only local anesthetic approved for intravenous administration in the clinic, can relieve neuropathic pain, hyperalgesia, and complex regional pain syndrome. Intravenous injection of lidocaine during surgery is considered as an effective strategy to control postoperative pain, but the mechanism of its analgesic effect has not been fully elucidated. This paper intends to review recent studies on the mechanism of the analgesic effect of lidocaine. To the end, we conducted an electronic search of the PubMed database. The search period was from 5 years before June 2019. Lidocaine was used as the search term. A total of 659 documents were obtained, we included 17 articles. These articles combined with the 34 articles found by hand searching made up the 51 articles that were ultimately included. We reviewed the analgesic mechanism of lidocaine in the central nervous system.

Background: Previous meta-analyses assessing anesthetic techniques in adult patients undergoing hip fractures surgery are available. However, whether the anesthetic technique is associated with risk of mortality and complications in geriatric patients with hip fractures remains unclear. This study was conducted to assess postoperative outcomes of anesthesia technique in geriatric patients undergoing hip fracture surgery. Methods: Cochrane Library, PubMed, EMBASE, MEDLINE, CNKI, and CBM were searched from inception up to May 25, 2018. Observational studies and randomized controlled trials (RCTs) that assessed the perioperative outcomes of technique of anesthesia (general or regional [epidural/spinal/neuraxial]) in geriatric patients (≥60 years old) undergoing hip fracture surgery were included. Two investigators independently screened studies for inclusion and performed data extraction. Heterogeneity was assessed by the I ² and Chi-square tests. The odds ratio (OR) of the dichotomous data, mean difference (MD) of continuous data, and 95% confidence intervals (CI) were calculated to assess the pooled data. Results: Eleven retrospective and 2 RCTs were included. There was no difference in 30-day mortality (OR = 0.96; 95% CI 0.86–1.08; P = .51) between the general and regional anesthesia groups. In-hospital mortality (OR = 1.26; 95% CI 1.17–1.36; P < .001), acute respiratory failure (OR = 2.66; 95% CI 2.34–3.02; P < .001), length of hospital stay (MD = 0.33; 95% CI 0.24–0.42; P < .001), and readmission (OR = 1.09; 95% CI 1.01–1.18; P = .03) were significantly reduced in the regional anesthesia group. Pneumonia (OR = 0.99; 95% CI 0.91–1.07; P = .79), heart failure (OR = 0.97; 95% CI 0.86–1.09; P = .62), acute myocardial infraction (OR = 1.07; 95% CI 0.99–1.16; P = .10), acute renal failure (OR = 1.32; 95% CI 0.97–1.79; P = .07), cerebrovascular accident (OR = 1.08; 95% CI 0.82–1.42; P = .58), postoperative delirium (OR = 1.51; 95% CI 0.16–13.97; P = .72), and deep vein thrombosis/pulmonary embolism (OR = 1.42; 95% CI 0.84–2.38; P = .19) were similar between the two anesthetic techniques. Conclusion: General anesthesia is associated with increased risk of in-hospital mortality, acute respiratory failure, longer hospital stays, and higher readmission. There is evidence to suggest that regional anesthesia is associated with improved perioperative outcomes. Large RCTs are needed to explore the most optimal anesthetic techniques for geriatric patients with hip fractures before drawing final conclusions. PROSPERO registration number: CRD42018093582.

To evaluate the analgesic efficacy of dexamethasone added to local anesthetics in ultrasound-guided transversus abdominis plane (TAP) block for the patients after abdominal surgery. PubMed, CENTRAL, EMBASE, Web of science were searched to identify eligible randomized controlled trials (RCTs) that compared dexamethasone added to local anesthetics in ultrasound-guided TAP block with control for postoperative analgesia in adult patients undergoing abdominal surgery. Primary outcomes included postoperative pain intensity, the time to the first request for additional analgesics, and opioid consumption over 24 h after surgery. Secondary outcome was the incidence of postoperative nausea and vomiting. Analysis was performed by RevMan 5.3 software and the quality of evidence was rated using GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. Nine RCTs involving 575 patients were included. Compared to the control, dexamethasone added to local anesthetics in ultrasound-guided TAP block significantly decreased visual analogue scale (VAS) scores at rest at 4h (mean difference [MD] = -1.01; 95% confidence intervals [CI], -1.29 to -0.73; P<0.00001; moderate quality of evidence), 6h (MD = -1.21; 95% CI, -1.74 to -0.69; P<0.00001; low quality of evidence), and 12h after surgery (MD = -0.79; 95% CI, -0.97 to -0.60; P<0.00001; moderate quality of evidence). No difference was found at 2h (MD = -0.64; 95% CI, -1.35 to 0.08; P = 0.08; low quality of evidence) and 24 h (MD = -0.41; 95% CI, -0.91 to 0.09; P = 0.11; moderate quality of evidence) in VAS scores. The time to the first request for additional analgesics was prolonged in the dexamethasone group (MD = 3.08; 95% CI, 2.37 to 3.78; P<0.00001; moderate quality of evidence). Opioid consumption over 24 h after surgery was also reduced (MD = -5.42; 95% CI, -8.20 to -2.63; P = 0.0001; low quality of evidence). Meanwhile, the incidence of postoperative nausea and vomiting was significantly decreased in the dexamethasone group (risk ratios [RR] = 0.40; 95% CI, 0.28 to 0.58; P<0.00001; high quality of evidence). No complications were reported in all the included studies. Dexamethasone added to local anesthetics in ultrasound-guided TAP block was a safe and effective strategy for postoperative analgesia in adult patients undergoing abdominal surgery.

Background: Perioperative neurocognitive disorders (PND) is a common postoperative complication including postoperative delirium (POD), postoperative cognitive decline (POCD) or delayed neurocognitive recovery. It is still controversial whether the use of intraoperative cerebral function monitoring can decrease the incidence of PND. The purpose of this study was to evaluate the effects of different cerebral function monitoring (electroencephalography (EEG) and regional cerebral oxygen saturation (rSO₂) monitoring) on PND based on the data from randomized controlled trials (RCTs). Methods: The electronic databases of Ovid MEDLINE, PubMed, EMBASE, Cochrane Library database were systematically searched using the indicated keywords from their inception to April 2020. The odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) were employed to analyze the data. Heterogeneity across analyzed studies was assessed with chi-square test and I² test. Results: Twenty two RCTs with 6356 patients were included in the final analysis. Data from 12 studies including 4976 patients were analyzed to assess the association between the EEG-guided anesthesia and PND. The results showed that EEG-guided anesthesia could reduce the incidence of POD in patients undergoing non-cardiac surgery (OR: 0.73; 95% CI: 0.57–0.95; P = 0.02), but had no effect on patients undergoing cardiac surgery (OR: 0.44; 95% CI: 0.05–3.54; P = 0.44). The use of intraoperative EEG monitoring reduced the incidence of POCD up to 3 months after the surgery (OR: 0.69; 95% CI: 0.49–0.96; P = 0.03), but the incidence of early POCD remained unaffected (OR: 0.61; 95% CI: 0.35–1.07; P = 0.09). The remaining 10 studies compared the effect of rSO₂ monitoring to routine care in a total of 1380 participants on the incidence of PND. The results indicated that intraoperative monitoring of rSO₂ could reduce the incidence of POCD (OR 0.53, 95% CI 0.39–0.73; P < 0.0001), whereas no significant difference was found regarding the incidence of POD (OR: 0.74; 95% CI: 0.48–1.14; P = 0.17). Conclusions: The findings in the present study indicated that intraoperative use of EEG or/and rSO₂ monitor could decrease the risk of PND. Trial registration: PROSPREO registration number: CRD42019130512.

Chronic pain remains to be a clinical challenge and is recognized as a major health problem with varying impacts on quality of life. Currently, the first-line therapy for chronic pain is opioids, which are often accompanied by unwanted psychoactive side effects. Thus, new and effective treatments for chronic pain are urgently needed and eagerly pursued. Inflammatory cytokines, especially interleukin-17 (IL-17), are reportedly potential therapeutic targets owing to their pivotal role in chronic pain from the neuroinflammation perspective. Recently, substantial evidence confirmed that IL-17 and IL-17 receptors (IL-17Rs) were increased in neuropathic, inflammatory, and cancer pain models. Notably, IL-17/IL-17R antibodies also reportedly relieve or cure inflammatory- and pain-related diseases. However, existing studies have reported controversial results regarding IL-17/IL-17Rs as potential therapeutic targets in diverse animal models of chronic pain. In this review, we present a summary of published studies and discuss the evidence, from basic to clinical to research, regarding the role and mechanism of action between IL-17 and diverse kinds of chronic pain in animal models and clinical patients. Furthermore, we evaluated IL-17-based therapy as a potential therapeutic strategy for inflammatory- and pain-related disease. Importantly, we also discussed clinical trials of IL-17/IL-17R targeting monoclonal antibodies. Overall, we found that IL-17 is a potential therapeutic target for chronic pain from the perspective of neuroinflammation.