Systemic lidocaine shortens length of hospital stay after colorectal surgery: a double-blinded, randomized, placebo-controlled trial

The use of lidocaine infusion in laparoscopic cholecystectomy: An updated systematic review and meta-analysis

ABSTRACT

Being one of the most common abdominal surgical procedures, numerous techniques have been adapted to decrease post-operative pain post cholecystectomy. However, the efficacy of intravenous (IV) lidocaine in managing post operative pain after LC is still controversial, according to many recent studies. This study aims to detect the effectiveness of IV lidocaine compared to other medications in managing post-operative pain. PubMed, Scopes, Web of Science and Cochrane Library were searched for eligible studies from inception to June 2023, and a systematic review and meta-analysis was done. According to eligibility criteria, 14 studies (898 patients) were included in our study. The pooled results of the included studies showed that the pain score after 6, 12 and 24 h after the surgery was significantly lower in those who received IV lidocaine as a painkiller (Visual Analogue Scale [VAS] 6H, mean difference [MD] = -1.20, 95% confidence interval [CI] = -2.20, -0.20, P = 0.02; I2 = 98%, VAS 12H, MD = -0.90, 95% CI = -1.52, -0.29, P = 0.004; I2 = 96% and VAS 24H, MD = -0.86, 95% CI = -1.48, -0.24, P = 0.007; I2 = 92%). In addition, IV lidocaine is associated with a significant decrease in the opioid requirement after the surgery (opioid requirements, MD = -29.53, 95% CI = -55.41, -3.66, P = 0.03; I2 = 98%). However, there was no statistically significant difference in the incidence of nausea and vomiting after the surgery between the two groups (nausea and vomiting, relative risk = 0.91, 95% CI = 0.57, 1.45, P = 0.69; I2 = 50%). Lidocaine infusion in LC is associated with a significant decrease in post operative pain and in opioid requirements after the surgery.

Pharmacologic prevention and therapy of postoperative paralytic ileus after gastrointestinal cancer surgery: systematic review and meta-analysis

BACKGROUND

Postoperative paralytic ileus (POI) is a significant concern following gastrointestinal tumor surgery. Effective preventive and therapeutic strategies are crucial but remain elusive. Current evidence from randomized-controlled trials on pharmacological interventions for prevention or treatment of POI are systematically reviewed to guide clinical practice and future research.

MATERIALS AND METHODS

Literature was systematically searched for prospective randomized-controlled trials testing pharmacological interventions for prevention or treatment of POI after gastrointestinal tumor surgery. Meta-analysis was performed using a random effects model to determine risk ratios and mean differences with 95% CI. Risk of bias and evidence quality were assessed.

RESULTS

Results from 55 studies, involving 5078 patients who received experimental interventions, indicate that approaches of opioid-sparing analgesia, peripheral opioid antagonism, reduction of sympathetic hyperreactivity, and early use of laxatives effectively prevent POI. Perioperative oral Alvimopan or intravenous administration of Lidocaine or Dexmedetomidine, while safe regarding cardio-pulmonary complications, demonstrated effectiveness concerning various aspects of postoperative bowel recovery [Lidocaine: -5.97 (-7.20 to -4.74)h, P <0.0001; Dexmedetomidine: -13.00 (-24.87 to -1.14)h, P =0.03 for time to first defecation; Alvimopan: -15.33 (-21.22 to -9.44)h, P <0.0001 for time to GI-2 ] and length of hospitalization [Lidocaine: -0.67 (-1.24 to -0.09)d, P =0.02; Dexmedetomidine: -1.28 (-1.96 to -0.60)d, P =0.0002; Alvimopan: -0.58 (-0.84 to -0.32)d, P <0.0001] across wide ranges of evidence quality. Perioperative nonopioid analgesic use showed efficacy concerning bowel recovery as well as length of hospitalization [-1.29 (-1.95 to -0.62)d, P =0.0001]. Laxatives showed efficacy regarding bowel movements, but not food tolerance and hospitalization. Evidence supporting pharmacological treatment for clinically evident POI is limited. Results from one single study suggest that Neostigmine reduces time to flatus and accelerates bowel movements [-37.06 (-40.26 to -33.87)h, P <0.0001 and -42.97 (-47.60 to -38.35)h, P <0.0001, respectively] with low evidence quality.

CONCLUSION

Current evidence concerning pharmacological prevention and treatment of POI following gastrointestinal tumor surgery is limited. Opioid-sparing concepts, reduction of sympathetic hyperreactivity, and laxatives should be implemented into multimodal perioperative approaches.

Perioperative Immunosuppressive Factors during Cancer Surgery: An Updated Review

Surgical excision of the primary tumor represents the most frequent and curative procedure for solid malignancies. Compelling evidence suggests that, despite its beneficial effects, surgery may impair immunosurveillance by triggering an immunosuppressive inflammatory stress response and favor recurrence by stimulating minimal residual disease. In addition, many factors interfere with the immune effectors before and after cancer procedures, such as malnutrition, anemia, or subsequent transfusion. Thus, the perioperative period plays a key role in determining oncological outcomes and represents a short phase to circumvent anesthetic and surgical deleterious factors by supporting the immune system through the use of synergistic pharmacological and non-pharmacological approaches. In line with this, accumulating studies indicate that anesthetic agents could drive both protumor or antitumor signaling pathways during or after cancer surgery. While preclinical investigations focusing on anesthetics' impact on the behavior of cancer cells are quite convincing, limited clinical trials studying the consequences on survival and recurrences remain inconclusive. Herein, we highlight the main factors occurring during the perioperative period of cancer surgery and their potential impact on immunomodulation and cancer progression. We also discuss patient management prior to and during surgery, taking into consideration the latest advances in the literature.

Effects of intravenous lidocaine on postoperative pain and gastrointestinal function recovery following gastrointestinal surgery: a meta-analysis

INTRODUCTION

The full extent of intravenous lidocaine's effectiveness in alleviating postoperative pain and enhancing gastrointestinal function recovery remains uncertain.

EVIDENCE ACQUISITION

We conducted an exhaustive search of databases to identify randomized controlled trials that compared intravenous lidocaine infusion's efficacy to that of a placebo or routine care in patients undergoing gastrointestinal surgery. The primary outcome measure was resting pain scores 24 h postoperatively. We utilized a random-effects model based on the intention-to-treat principle for the overall results.

EVIDENCE SYNTHESIS

This study included twenty-four trials with 1533 patients. Intravenous lidocaine significantly reduced resting pain scores 24 h after gastrointestinal surgery (twenty trials, SMD -0.67, 95% CI -1.09 to -0.24, P=0.002, I2 = 90%). This finding was consistent in subgroup analyses and sensitivity analyses. The benefit was also observed at other resting and moving time points (1, 2, 4, and 12 h) postoperatively. Intravenous lidocaine significantly decreased opioid consumption within 24 h after surgery (eleven trials, SMD: -1.19; 95% CI: -1.99 to -0.39; P=0.003). Intravenous lidocaine also shortened the time to bowel sound (MD: -8.51; 95% CI: -14.59 to -2.44; P=0.006), time to first flatus (MD: -6.00; 95% CI: -9.87 to -2.13; P=0.002), and time to first defecation (MD: -9.77; 95% CI: -17.19 to -2.36; P=0.01).

CONCLUSIONS

Perioperative intravenous lidocaine can alleviate acute pain and expedite gastrointestinal function recovery in patients undergoing gastrointestinal surgery. However, the results should be interpreted with caution due to substantial heterogeneity. Further large-scale studies are necessary to validate these findings.

Perioperative intravenous lidocaine in thoracoscopic surgery for improved postoperative pain control: a randomized, placebo-controlled, double-blind, superiority trial

Background

Pain, including associated pain management, remains a burden on patients after thoracic surgery. Our objective was to investigate whether perioperative intravenous administration of lidocaine reduces postoperative morphine consumption and pain intensity after video-assisted thoracoscopic surgery (VATS).

Methods

In this double-blind, placebo-controlled superiority trial, patients undergoing VATS with a planned duration of ≤90 minutes were randomized within an intention-to-treat setting. Patients received either intravenous lidocaine or placebo as a bolus of 1.5 mg/kg 30 minutes before incision, followed by a continuous infusion of 3.0 mg/kg/hour until 2 hours after skin closure. Pain and morphine consumption were evaluated when resting and when coughing 1, 2, 4, 8, 16, 24, and 48 hours after skin closure and in a follow-up 14, 90, and 180 days postoperatively.

Results

Twenty-eight patients were included in the lidocaine group, 24 in the placebo group. Patients' characteristics and preoperative pain scores were similar in both groups. When coughing, patients of the lidocaine group had less pain within 24 hours after skin closure than the placebo group (4.60±1.64 vs. 5.52±1.65; P=0.02). Morphine consumption was not statistically significantly lower in lidocaine group (18.22±12.87 vs. 21.26±9.39 mg; P=0.26). There were no significant differences between groups in secondary outcomes.

Conclusions

Our results suggest that perioperative intravenous lidocaine administration reduces pain scores after VATS. The beneficial clinical effects are limited. Nevertheless, intravenous lidocaine may be helpful as part of a multimodal analgesia protocol or with patients in whom the use of other analgesics is contraindicated.

Trial Registration

ClinicalTrials.gov NCT03677817.

PROcedure-SPECific postoperative pain management guideline for laparoscopic colorectal surgery: A systematic review with recommendations for postoperative pain management

Colorectal cancer is the second most common cancer diagnosed in women and third most common in men. Laparoscopic resection has become the standard surgical technique worldwide given its notable benefits, mainly the shorter length of stay and less postoperative pain. The aim of this systematic review was to evaluate the current literature on postoperative pain management following laparoscopic colorectal surgery and update previous procedure-specific pain management recommendations. The primary outcomes were postoperative pain scores and opioid requirements. We also considered study quality, clinical relevance of trial design, and a comprehensive risk-benefit assessment of the analgesic intervention. We performed a literature search to identify randomised controlled studies (RCTs) published before January 2022. Seventy-two studies were included in the present analysis. Through the established PROSPECT process, we recommend basic analgesia (paracetamol for rectal surgery, and paracetamol with either a nonsteroidal anti-inflammatory drug or cyclo-oxygenase-2-specific inhibitor for colonic surgery) and wound infiltration as first-line interventions. No consensus could be achieved either for the use of intrathecal morphine or intravenous lidocaine; no recommendation can be made for these interventions. However, intravenous lidocaine may be considered when basic analgesia cannot be provided.

Inflammatory biomarker concentrations in dogs with gastric dilatation volvulus with and without 24-h intravenous lidocaine

Background

Canine gastric dilatation volvulus (GDV) is characterized by tissue ischemia, reperfusion, and systemic inflammation. Evidence exists that lidocaine exerts anti-inflammatory properties and potentially improves outcome.

Design and setting

Prospective, randomized observational cohort study in client-owned dogs with GDV.

Objective

The primary objective of the study was the determination of pro- and anti-inflammatory biomarker concentrations in dogs with GDV with and without intravenous (IV) lidocaine therapy. The second objective was the evaluation of side effects of lidocaine.

Methods

Of 35 dogs included in the study, 20 dogs were assigned to receive lidocaine (LIDO) (2 mg/kg initially, followed by a continuous infusion at a rate of 50 μg/kg/min over 24 h) and 15 dogs not to receive lidocaine (NO-LIDO). Plasma concentrations of cytokines interleukin (IL)-6, IL-7, IL-8, IL-10, IL-15, IL-18, interferon gamma, keratinocyte chemotactic-like, monocyte chemotactic protein, and C-reactive protein (CRP) were measured at admission (prior any therapeutic intervention, T0), immediately after surgery (T1), at 24 h (T24), and at 48 h (T48) post-surgery.

Results

No significant differences in concentrations of any cytokines were found between the LIDO- and the NO-LIDO group. Significant lower CRP concentrations (median [range]) were found in dogs with lidocaine compared to dogs without at T24 (97.5 pg/mL [46.3-161.7] vs. 127.9 pg/mL [26.9-182.0]; p = 0.046) and T48 (73.7 pg/mL [18.4-169.4] vs. 116.3 pg/mL [71.4-176.8]; p = 0.002). Dogs receiving lidocaine exhibited significantly impaired mentation, a prolonged period of anorexia, and longer hospitalization compared to dogs without lidocaine.

Conclusion

Lidocaine administration had no impact on the plasma levels of cytokines during the 48-h study period, but significantly lower CRP concentrations were found at T24 and T48. Lidocaine's potential side effects require careful decision making regarding its use.

Regional anesthesia and POCUS in the intensive care unit

This chapter focuses on resident recruitment and recent US National Resident Matching Program changes and the impact in the evaluation and ranking of applicants within the specialty of anesthesiology. Recruitment challenges are examined as well as program strategies and potential future directions. Also discussed are DEI initiatives within the recruitment process.

Perioperative Lidocaine Infusion Reduces Opioid Use in Enhanced Recovery After Surgery Patients Undergoing Laparoscopic Colectomy

BACKGROUND

Enhanced Recovery After Surgery (ERAS) programs have become a mainstay of modern surgical care, and efforts to decrease postoperative opioid consumption have been increasingly employed. A previous study from our institution demonstrated that ERAS protocols decreased opioid use in the first 48 hours after surgery by 61%. In the present study, a lidocaine infusion was added for postoperative pain control. The aim was to analyze the differences in opioid requirements with and without this infusion in the first 48 hours after laparoscopic colectomy in ERAS patients.

METHODS

Retrospective review of patients was conducted at an academically affiliated tertiary care hospital. The population included patients undergoing elective laparoscopic colon surgery enrolled in the ERAS program with the implementation of a lidocaine drip from June 2019 to October 2019, and compared to a previous patient cohort of ERAS patients evaluated without the lidocaine drip from September 2015 to May 2018.

RESULTS

The primary endpoint was postoperative opioid use in the first 48 hours based on IV morphine milligram equivalents (MME). Secondary measures included type of surgery, age, BMI, prior abdominal surgery, and prior opioid use. Median MMEs were 6.0 in the lidocaine infusion group and 12.5 in the group without lidocaine, representing a 52% reduction (p < 0.001).

DISCUSSION

This study demonstrates a significant reduction in post-op opioid use in ERAS patients who receive a lidocaine infusion after laparoscopic colectomy. Further studies should focus on measures to limit the treatment side effects in order to maximize the opioid-sparing benefits of this intervention.

Intraoperative intravenous infusion of lidocaine increases total and small vessel densities of sublingual microcirculation: a randomized prospective pilot study

OBJECTIVE

Multiple organ failure can occur as a result of postoperative complications. Research has indicated that the underlying mechanism of organ dysfunction is a microcirculation disorder. Because of its antioxidant and anti-inflammatory properties, lidocaine has the potential to improve microvascular blood flow. This study was performed to assess the effect of intraoperative intravenous lidocaine infusion on the microcirculation and determine the incidence of postoperative complications.

METHODS

In this prospective randomized double-blind pilot study, 12 patients scheduled for abdominal surgery were randomly allocated to receive an intraoperative infusion of either 1% lidocaine or the same volume of 0.9% sodium chloride solution. The microcirculation was monitored using sidestream dark-field imaging and the vascular occlusion test combined with near-infrared spectroscopy.

RESULTS

Lidocaine significantly increased the total vascular density and small vessel density after 2 hours of infusion, with preservation of 99% to 100% of the capillary perfusion in both groups. No patients developed organ failure.

CONCLUSIONS

An increase in vessel density may be beneficial in major abdominal surgeries because it is associated with better tissue perfusion and oxygen delivery. However, this finding requires further investigation in patients with increased surgical risk. Overall, this study indicates that lidocaine has potential to improve microvascular perfusion.Research Registry number: 9549 (https://www.researchregistry.com/browse-the-registry#home/registrationdetails/650ffd27b3f547002bd7635f/).

Lidocaine induces epithelial‑mesenchymal transition and aggravates cancer behaviors in non‑small cell lung cancer A549 cells

The effects of clinically relevant concentrations of lidocaine on epithelial-mesenchymal transition (EMT) and associated lung cancer behaviors have rarely been investigated. The aim of the present study was to assess the impact of lidocaine on EMT and its related phenomena, including chemoresistance. Lung cancer cell lines (A549 and LLC.LG) were incubated with various concentrations of lidocaine, 5-fluorouracil (5-FU) or both to test their effects on cell viability. Subsequently, the effects of lidocaine on various cell behaviors were assessed in vitro and in vivo using Transwell migration, colony-formation and anoikis-resistant cell aggregation assays, and human tumor cell metastasis in a chorioallantoic membrane (CAM) model quantitated by PCR analysis. Prototypical EMT markers and their molecular switch were analyzed using western blotting. In addition, a conditioned metastasis pathway was generated through Ingenuity Pathway Analysis. Based on these measured proteins (slug, vimentin and E-cadherin), the molecules involved and the alteration of genes associated with metastasis were predicted. Of note, clinically relevant concentrations of lidocaine did not affect lung cancer cell viability or alter the effects of 5-FU on cell survival; however, at this dose range, lidocaine attenuated the 5-FU-induced inhibitory effect on cell migration and promoted EMT. The expression levels of vimentin and Slug were upregulated, whereas the expression of E-cadherin was downregulated. EMT-associated anoikis resistance was also induced by lidocaine administration. In addition, portions of the lower CAM with a dense distribution of blood vessels exhibited markedly increased Alu expression 24 h following the inoculation of lidocaine-treated A549 cells on the upper CAM. Thus, at clinically relevant concentrations, lidocaine has the potential to aggravate cancer behaviors in non-small cell lung cancer cells. The phenomena accompanying lidocaine-aggravated migration and metastasis included altered prototypical EMT markers, anoikis-resistant cell aggregation and attenuation of the 5-FU-induced inhibitory effect on cell migration.

Intravenous lidocaine improves postoperative cognition in patients undergoing laparoscopic colorectal surgery: a randomized, double-blind, controlled study

BACKGROUND

The risk of postoperative cognitive dysfunction(POCD) in laparoscopic surgery should not be overlooked. Intravenous lidocaine can reduce perioperative inflammatory response in patients undergoing laparoscopic surgery, while the effect of intraoperative intravenous lidocaine on postoperative cognitive function in patients undergoing laparoscopic colorectal cancer surgery has not been well studied. We investigated whether intraoperative lidocaine improves postoperative cognitive function after laparoscopic radical resection for colorectal cancer.

METHODS

We conducted a prospective, randomized double blinded controlled trial to investigate the effect of intravenous lidocaine on rapid postoperative recovery in patients undergoing laparoscopic radical resection of colorectal cancer. The patients were randomly assigned to receive either intravenous lidocaine or saline. The primary outcome was cognitive dysfunction defined by a decrease from pre- to postoperative ≥ 2 of the Mini-Mental State Examination (MMSE) score, at the 3rd and the 7th postoperative days. Secondary outcomes were the MMSE raw score and parameters of the patients' postoperative recovery such as agitation and length of stay in the post-anaesthesia care unit (PACU), length of hospital stay, markers of inflammation (white blood cell count and CRP), and incidence of complications.

RESULTS

Seventy-three patients in the lidocaine group and 77 patients in the control group completed the trial. The rate of cognitive dysfunction was lower in the lidocaine group than that in the control group, both at the 3rd (18.57% vs. 63.64% for each group respectively; RR = 0.26, 95%CI = 0.19-0.32; p < 0.0001) and at the 7th postoperative day (12.33% vs. 53.25% for each group respectively; RR = 0.28, 95%CI = 0.22-0.35; P < 0.001). The postoperative MMSE scores were also higher in the lidocaine group than in the control group both at the 3rd (median 25 vs. 24 respectively) and at the 7th postoperative day (26 vs. 24 respectively). Also, patients in the lidocaine group displayed a lower white blood cell count than the control group at the 1st postoperative day (8.5 ± 2.7 vs. 10.4 ± 3.3; p < 0. 001). No differences were evidenced for the other secondary outcomes.

CONCLUSIONS

Intraoperative intravenous lidocaine can significantly improve postoperative cognitive function in patients undergoing laparoscopic radical resection of colorectal cancer.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (16/1/2022, registration number: ChiCTR2200055683).

The dose-response relationships of the direct scavenging activity of amide-based local anesthetics against multiple free radicals

This study aimed to illustrate the dose-response relationships of the direct scavenging activity of amide-based local anesthetics against multiple free radicals in vitro. We have demonstrated that amide-type local anesthetics selectively and directly scavenge some free radicals. Three kinds of free radicals were eliminated by all the four local anesthetics examined. Mepivacaine, lidocaine, bupivacaine, and dibucaine scavenged hydroxyl radicals in dose-dependent manners. Ascorbyl free radicals were also scavenged in dose-dependent manners, and lastly singlet oxygen was scavenged in dose-dependent manners. Three other free radicals were not scavenged by all of the four local anesthetics; tert-butoxyl radical was scavenged by all the anesthetics examined but dibucaine, nitric oxide by mepivacaine but not by the other three, and tyrosyl radical by mepivacaine and lidocaine but not by the other two. Some free radicals (superoxide anion, tert-butyl peroxyl radical, DPPH) were not scavenged by any of the four local anesthetics. The local anesthetics were also shown to inhibit lipid peroxidation by TBARS assay. These results suggest that local anesthetics have antioxidant properties through their free radical scavenging activities.

Systemic Anti-Inflammatory Effects of Intravenous Lidocaine in Surgical Patients: A Systematic Review and Meta-Analysis

There has recently been increasing evidence that the use of perioperative intravenous lidocaine infusion possesses analgesic, opioid-sparing and anti-inflammatory effects in surgical patients. Although opioid-sparing and analgesic properties have been strongly supported, the anti-inflammatory features are not well established in elective surgery. Therefore, the aim of this systematic review is to examine the effect of perioperative intravenous lidocaine infusion on postoperative anti-inflammatory status in patients undergoing elective surgery. A search strategy was created to identify suitable randomised clinical trials (RCTs) in PubMed, Scopus, Web of Science and Clinicaltrials.gov databases until January 2023. RCTs that evaluated the effect of intravenous lidocaine infusion, compared with placebo, on adult patients who underwent elective surgery, in inflammatory markers response were included. Exclusion criteria consisted of paediatric patients, animal studies, non-RCT methodology, intervention without intravenous lidocaine, inadequate control group, duplicated samples, ongoing studies and lack of any relevant clinical outcome measures. The following inflammatory markers-interleukin (IL)-6, tumour necrosis factor (TNF)-α, IL-1RA, IL-8, IL-10, C-reactive protein (CRP), IL-1, IL-1β, interferon (IFN)-γ, cortisol, IL-4, IL-17, high-mobility group protein B1 (HMGB1) and transforming growth factor (TGF)-β-were evaluated as outcomes in this review. A total of 21 studies, including 1254 patients, were identified. Intravenous lidocaine infusion significantly reduced the change from IL-6 baseline levels at the end of surgery compared to a placebo (standardised mean difference [SMD]: -0.647, 95% confidence interval [CI]: -1.034 to -0.260). Usage of lidocaine was associated with a significant reduction in other postoperative pro-inflammatory markers, such as TNF-α, IL-1RA, IL-8, IL-17, HMGB-1 and CRP. There was no significant difference in other markers, such as IL-10, IL-1β, IL-1, IFN-γ, IL-4, TGF-β and cortisol. This systematic review and meta-analysis provide support for the administration of perioperative intravenous lidocaine infusion as an anti-inflammatory strategy in elective surgery.

Efficacy of prolonged intravenous lidocaine infusion for postoperative movement-evoked pain following hepatectomy: a double-blinded, randomised, placebo-controlled trial

BACKGROUND

The analgesic effect of intravenous lidocaine varies with the duration of lidocaine infusion and surgery type. We tested the hypothesis that prolonged lidocaine infusion alleviates postoperative pain in patients recovering from hepatectomy over the first 3 postoperative days.

METHODS

Patients undergoing elective hepatectomy were randomly assigned to receive prolonged i.v. lidocaine treatment or placebo. The primary outcome was incidence of moderate-to-severe movement-evoked pain at 24 h postoperatively. The secondary outcomes included incidence of moderate-to-severe pain during movement and at rest throughout the first 3 postoperative days, postoperative opioid consumption, and pulmonary complications. Plasma lidocaine concentration was also monitored.

RESULTS

We enrolled 260 subjects. Intravenous lidocaine lowered the incidence of moderate-to-severe movement-evoked pain at 24 h and 48 h postoperatively (47.7% vs 67.7%, P=0.001; 38.5% vs 58.5%, P=0.001) and reduced movement-evoked pain scores (3.7 [1.7] vs 4.2 [1.6]; mean difference 0.5 [95% confidence interval {CI}: 0.1-0.9]; P=0.018) and morphine equivalent consumption (47.2 [16.7] mg vs 52.6 [19.2] mg; mean difference 5.4 mg [95% CI: 1.0-9.8]; P=0.016) at 24 h postoperatively. Lidocaine also lowered the incidence of postoperative pulmonary complications (23.1% vs 38.5%; P=0.007). Median plasma lidocaine concentrations were 1.5, 1.9, and 1.1 μg ml^-1 (inter-quartile ranges: 1.1-2.1, 1.4-2.6, and 0.8-1.6, respectively) after bolus injection, at the end of the surgery, and 24 h postoperatively.

CONCLUSIONS

Prolonged intravenous lidocaine infusion reduced the incidence of moderate-to-severe movement-evoked pain for 48 h after hepatectomy. However, the reduction in pain scores and opioid consumption by lidocaine was below the minimal clinically important difference.

CLINICAL TRIAL REGISTRATION

NCT04295330.

Comparison of Quality of Recovery (QoR-15) following the administration of intravenous lignocaine and fentanyl in patients undergoing septoplasty under general anaesthesia: A double-blinded, randomised, controlled trial

Background and Aims

Recovery from surgery and anaesthesia is usually observed through conventional indicators. The Quality of Recovery (QoR-15) score was specially designed to measure psychometric and functional recovery from the patient's perspective. This study aimed to evaluate QoR-15 following the administration of intravenous (IV) lignocaine or IV fentanyl in patients undergoing septoplasty surgery.

Methods

This randomised, controlled trial was conducted on 64 patients of American Society of Anesthesiologists (ASA) physical status I and II, of either sex, of ages between 18 and 60 years, and who were scheduled for septoplasty. The primary end point was to compare the quality of recovery following the administration of IV lignocaine(group L) and IV fentanyl (group F) using the QoR-15 score in patients undergoing septoplasty. Secondary end points were to compare postoperative analgesia, recovery characteristics, and adverse effects in both groups. Statistical analysis was done using the Shapiro-Wilk test, paired t test/ Wilcoxon signed-rank test, and unpaired t test/Mann-Whitney U test. A P-value <0.05 was considered statistically significant.

Results

There was a significant improvement in the postoperative QoR-15 score than in the preoperative score in both groups (P < 0.000). However, the postoperative QoR-15 score was significantly higher in group L compared to group F (P < 0.001). Total consumption of analgesic doses were reduced in group L (P=0.000). Time taken to achieve an Aldrete score >9 and gastrointestinal recovery was shorter in group L compared to group F.

Conclusion

Both IV lignocaine and IV fentanyl improved postoperative QoR-15 score; however, lignocaine had a higher postoperative QoR-15 score than fentanyl, in addition to showing early discharge readiness, better analgesia, and better recovery profile in patients following septoplasty surgery.

Appropriate Duration of Perioperative Intravenous Administration of Lidocaine to Provide Satisfactory Analgesia for Adult Patients Undergoing Colorectal Surgery: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Perioperative lidocaine infusion has been reported to alleviate pain intensity after colorectal surgery. However, there is no consensus on whether prolonged lidocaine infusion is more effective than short lidocaine infusion. This meta-analysis aimed to determine an appropriate duration of lidocaine infusion in patients undergoing colorectal surgery.

METHODS

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases to identify articles published before December 17, 2021. Randomized controlled trials comparing intravenous lidocaine with placebo for pain relief in patients undergoing colorectal surgery were included. The primary outcome was pain scores (visual analog scale [VAS], 0-10 cm) at 24 hours postoperatively at rest and on movement. Secondary outcomes included pain scores at 12, 48, and 72 hours postoperatively, analgesic consumption (mg), gastrointestinal function return (hour), length of hospital stay (days), and incidence of complications. According to the duration of lidocaine infusion, studies were grouped into infusion for at least 24 hours (prolonged lidocaine infusion) and less than 24 hours (short lidocaine infusion) to assess the impact of lidocaine infusion duration on the outcomes of interests. Quantitative analyses were performed using a random effects model.

RESULTS

Eleven studies with 548 patients were included. Five studies used prolonged lidocaine infusion, while 6 studies used short lidocaine infusion. Prolonged lidocaine infusion reduced postoperative pain scores versus placebo at 24 hours at rest (mean difference [MD], -0.91 cm; 95% confidence interval [CI], -1.54 to -0.28; P = .02) and on movement (MD, -1.69 cm; 95% CI, -2.15 to -1.22; P < .001), while short lidocaine infusion showed no benefit. Compared with placebo, prolonged lidocaine infusion reduced pain scores at 12 hours at rest and at 12 and 48 hours on movement, but short lidocaine infusion did not. However, there was no significant difference in pain scores between the prolonged and short lidocaine infusion groups at these time points. Compared with placebo, prolonged lidocaine infusion shortened the length of hospital stay (MD, -1.30 days; 95% CI, -1.72 to -0.88; P < .001) and time to first postoperative defecation (MD, -12.51 hours; 95% CI, -22.67 to -2.34; P = .02). There were no differences between groups regarding the other outcomes.

CONCLUSIONS

The analgesic effect of intravenous lidocaine may depend on the duration of infusion, and our results suggest that lidocaine infusion should be administered for at least 24 hours after colorectal surgery. Since overall evidence quality was low, further high-quality, large-sample trials are needed to explore an optimal lidocaine infusion strategy in patients undergoing colorectal surgery.

Analgesic efficacy of Intraoperative lidocaine infusion in patients undergoing thyroidectomy

OBJECTIVE

A significant proportion of patients may experience moderate pain requiring treatment in the postoperative first 24 h following thyroidectomy. The aim of this study was to investigate the evaluation of postoperative patient-reported pain from intraoperative intravenous infusion of lidocaine in patients undergoing thyroidectomy surgery.

METHODS

A total of 40 patients with American Society of Anesthesiologists physical status classifications I and II, aged 18-65 years, who were scheduled for elective thyroidectomy with the same indications under general anesthesia at the Ataturk University Medical Faculty's Ear, Nose, and Throat Clinic between November 2019 and February 2020, were divided into two equal groups as randomized and double-blind. Before induction of anesthesia, patients in the lidocaine group were given 1.5 mg/kg lidocaine IV bolus infusion during the operation and until the end of the first postoperative hour, followed by a continuous infusion of 1.5 mg/kg/h. Patients in the control group were given 0.9% isotonic solution according to the same protocol. In the postoperative period, 50 mg of dexketoprofen trometamol was administered and repeated every 12 h. Postoperative pain scores, additional analgesia, and side effects were recorded.

RESULTS

Postoperative pain scores were significantly lower in the lidocaine group (n=20) compared to the control group (n=20) at 30 min and 1st, 2nd, 4th, 8th, and 12th h postoperatively (p < 0.05). Additional analgesia requirements were also significantly lower in the lidocaine group than in the control group (p<0.05).

CONCLUSION

We recommended the use of intravenous lidocaine infusion intraoperatively in thyroidectomy surgery as it reduces pain scores.

Postoperative delirium, neuroinflammation, and influencing factors of postoperative delirium: A review

Postoperative delirium (POD) is an acute cognitive dysfunction that is mainly characterized by memory impairment and disturbances in consciousness. POD can prolong the hospital stay and increase the 1-month mortality rate of patients. The overall incidence of POD is approximately 23%, and its prevalence can go up to 50% in high-risk surgeries. Neuroinflammation is an important pathogenic mechanism of POD that mediates microglial activation and leads to synaptic remodeling. Neuroinflammation, as an indispensable pathogenesis of POD, can occur due to a variety of factors, including aseptic inflammation caused by surgery, effects of anesthetic drugs, disruption of the blood-brain barrier, and epigenetics. Understanding these factors and avoiding the occurrence of risk factors may help prevent POD in time. This review provides a brief overview of POD and neuroinflammation and summarizes various factors affecting POD development mediated by neuroinflammation, which may serve as future targets for the prevention and treatment of POD.

Lidocaine for Neuropathic Cancer Pain (LiCPain): study protocol for a mixed-methods pilot study

INTRODUCTION

Many patients experience unrelieved neuropathic cancer-related pain. Most current analgesic therapies have psychoactive side effects, lack efficacy data for this indication and have potential medication-related harms. The local anaesthetic lidocaine (lignocaine) has the potential to help manage neuropathic cancer-related pain when administered as an extended, continuous subcutaneous infusion. Data support lidocaine as a promising, safe agent in this setting, warranting further evaluation in robust, randomised controlled trials. This protocol describes the design of a pilot study to evaluate this intervention and explains the pharmacokinetic, efficacy and adverse effects evidence informing the design.

METHODS AND ANALYSIS

A mixed-methods pilot study will determine the feasibility of an international first, definitive phase III trial to evaluate the efficacy and safety of an extended continuous subcutaneous infusion of lidocaine for neuropathic cancer-related pain. This study will comprise: a phase II double-blind randomised controlled parallel-group pilot of subcutaneous infusion of lidocaine hydrochloride 10% w/v (3000 mg/30 mL) or placebo (sodium chloride 0.9%) over 72 hours for neuropathic cancer-related pain, a pharmacokinetic substudy and a qualitative substudy of patients' and carers' experiences. The pilot study will provide important safety data and help inform the methodology of a definitive trial, including testing proposed recruitment strategy, randomisation, outcome measures and patients' acceptability of the methodology, as well as providing a signal of whether this area should be further investigated.

ETHICS AND DISSEMINATION

Participant safety is paramount and standardised assessments for adverse effects are built into the trial protocol. Findings will be published in a peer-reviewed journal and presented at conferences. This study will be considered suitable to progress to a phase III study if there is a completion rate where the CI includes 80% and excludes 60%. The protocol and Patient Information and Consent Form have been approved by Sydney Local Health District (Concord) Human Research Ethics Committee 2019/ETH07984 and University of Technology Sydney ETH17-1820.

TRIAL REGISTRATION NUMBER

ANZCTR ACTRN12617000747325.

Impact of Perioperatively Administered Amino Acids, Lidocaine, and Magnesium on Inflammatory Response and Pain Associated with Abdominal Surgery: A Prospective Clinical Study

BACKGROUND Abdominal surgery is associated with a systemic inflammatory response which facilitates postoperative complications through immune imbalance and hypercatabolism. The aim of the study was to evaluate the effect of the combined perioperative lidocaine, magnesium, and amino acids on postoperative inflammation and pain. MATERIAL AND METHODS This prospective, randomized, double-blind study included 2 groups of patients undergoing abdominal surgery: Group 1 - receiving the aforementioned substances; and Group 2 - control (undergoing conventional general anesthesia). The following parameters were evaluated intraoperatively: arterial blood pressure, end-tidal CO₂ level, urine output, bispectral index, base excess, oxygen saturation, operating room temperature and body temperature (BT), opioid use, and surgery duration; and postoperatively: total leukocyte (WBC), neutrophil, lymphocyte and platelet count; fibrinogen, C-reactive protein (CRP), procalcitonin (PCT) and interleukin (IL)-6 levels; numeric rating scale (NRS) pain level, first flatus and bowel movement, and postoperative complications. The postoperative parameters were evaluated 2 h and 6 h postoperatively, as well as on postoperative days (POD) 1, 2, 3, and 5. RESULTS Group 1 showed lower counts of WBC, neutrophils, and lymphocytes and lower fibrinogen, CRP, PCT, IL-6, and BT in the first 5 POD, as well as NRS scores and time to first flatus/bowel movement. The groups did not differ significantly regarding postoperative complications. CONCLUSIONS The isolated effects of lidocaine, magnesium, and amino acids in surgery have been described previously. To the best of our knowledge, this is the first study to show the anti-inflammatory and analgesic effects of simultaneous use of these substances in abdominal surgery.

Tumor Necrosis Factor Alpha: Implications of Anesthesia on Cancers

Cancer remains a major public health issue and a leading cause of death worldwide. Despite advancements in chemotherapy, radiation therapy, and immunotherapy, surgery is the mainstay of cancer treatment for solid tumors. However, tumor cells are known to disseminate into the vascular and lymphatic systems during surgical manipulation. Additionally, surgery-induced stress responses can produce an immunosuppressive environment that is favorable for cancer relapse. Up to 90% of cancer-related deaths are the result of metastatic disease after surgical resection. Emerging evidence shows that the interactions between tumor cells and the tumor microenvironment (TME) not only play decisive roles in tumor initiation, progression, and metastasis but also have profound effects on therapeutic efficacy. Tumor necrosis factor alpha (TNF-α), a pleiotropic cytokine contributing to both physiological and pathological processes, is one of the main mediators of inflammation-associated carcinogenesis in the TME. Because TNF-α signaling may modulate the course of cancer, it can be therapeutically targeted to ameliorate clinical outcomes. As the incidence of cancer continues to grow, approximately 80% of cancer patients require anesthesia during cancer care for diagnostic, therapeutic, or palliative procedures, and over 60% of cancer patients receive anesthesia for primary surgical resection. Numerous studies have demonstrated that perioperative management, including surgical manipulation, anesthetics/analgesics, and other supportive care, may alter the TME and cancer progression by affecting inflammatory or immune responses during cancer surgery, but the literature about the impact of anesthesia on the TNF-α production and cancer progression is limited. Therefore, this review summarizes the current knowledge of the implications of anesthesia on cancers from the insights of TNF-α release and provides future anesthetic strategies for improving oncological survival.

Influence of Perioperative Anesthesia on Cancer Recurrence: from Basic Science to Clinical Practice

PURPOSEOF REVIEW

In this review, we will summarize the effects of these perioperative anesthetics and anesthetic interventions on the immune system and tumorigenesis as well as address the related clinical evidence on cancer-related mortality and recurrence.

RECENT FINDINGS

Cancer remains a leading cause of morbidity and mortality worldwide. For many solid tumors, surgery is one of the major therapies. Unfortunately, surgery promotes angiogenesis, shedding of circulating cancer cells, and suppresses immunity. Hence, the perioperative period has a close relationship with cancer metastases or recurrence. In the perioperative period, patients require multiple anesthetic management including anesthetics, anesthetic techniques, and body temperature control. Preclinical and retrospective studies have found that these anesthetic agents and interventions have complex effects on cancer outcomes. Therefore, well-planned, prospective, randomized controlled trials are required to explore the effects of different anesthetics and techniques on long-term outcomes after cancer surgery. Due to the conflicting effects of anesthetic management on cancer recurrence, further preclinical and clinical trials are required and beneficial to the development of systemic cancer therapies.

Intravenous lidocaine simultaneously infused with sufentanil to accelerate gastrointestinal function recovery in patients after thoracolumbar surgery: a prospective, randomized, double-blind controlled study

PURPOSE

Postoperative gastrointestinal dysfunction is one of the common complications of surgery, especially after surgery for a thoracolumbar spinal fracture. Intravenous lidocaine is a potential method to improve postoperative gastrointestinal function in surgical patients, reduce opioid use and shorten hospital stays. The purpose of this study is to explore the effect of intravenous lidocaine on the recovery of gastrointestinal function in patients after thoracolumbar surgery.

METHODS

In this study, 48 eligible patients undergoing elective thoracolumbar spine fractures resection and internal fixation surgery were enrolled to receive intravenous injections of lidocaine in different concentrations during the perioperative period. Patients were randomly divided into three groups: control group (group A), low concentration of lidocaine group (group B) and high concentration of lidocaine group (group C), 16 patients in each group. First postoperative exhaust time, numbers of bowel sound at preoperative and postoperative 3, 6, 12, 24 h, pain scores at postoperative 0, 3, 6, 12, 24, 48 h, total sufentanil use in PACU and perioperative periods, postoperative hospital stay and analgesic remedy within postoperative 48 h were recorded and compared. The primary endpoints include: the time of first flatus passage after the operation, the number of bowel sounds per minute counted with stethoscope at 30 min before anesthesia induction and at 3, 6, 12 and 24 h postoperative. The secondary endpoints included: the pain scores at PACU (after entering into PACU), 3, 6, 12, 24 and 48 h postoperative, the amount of sufentanil administrated by intravenous push during operation and the numbers of patients needed rescuing sufentanil in PACU, and the numbers of patients needed administration of gastric motility drugs or non-steroidal analgesics at ward within 48 h postoperation, length of hospital stay (from the first day after surgery to discharge from hospital) and the incidence of adverse reactions.

RESULTS

Compared with group A, the first postoperative exhaust time in group B and C occurred much earlier (23.3 ± 11.0 h vs. 16.0 ± 6.6 h, 16.6 ± 5.1 h, P < 0.05). Compared with preoperation, the numbers of bowel sound significantly increased at 24 h postoperatively in group B, while group B at 6 h and group C at 6 and 24 h postoperatively had significantly more active bowel sounds compared to group A (P < 0.05). There were no remarkable differences in VAS scores within 12 h postoperatively among three groups, and however, significantly lower VAS scores were found at 12, 24 and 48 h postoperatively in group C when comparing to Group A (p < 0.05). There was no statistical significance in the incidence of postoperative flatulence and nausea and vomiting, the number of patients needed rescuing sufentanil in PACU, the length of postoperative hospital stay and the number of patients requiring non-steroidal analgesics at ward within 48 h postoperation.

CONCLUSIONS

Intravenous lidocaine infusion together with patient-controlled analgesia of sufentanil expedited the early recovery of gastrointestinal function and improved analgesic quality of sefentanyl in patients undergoing thoracolumbar surgeries.

Evaluation of Propofol-Sparing Effect of Intravenous Lignocaine in Patients Undergoing Daycare Upper Gastrointestinal Endoscopic Procedures

Background Propofol is the most common sedative for endoscopies. Propofol alone may require larger doses for adequate level of sedation. Lignocaine is known for its anesthetic-sparing effect. We tested whether the addition of intravenous lignocaine to propofol-based sedation reduces its dose. Methods This prospective, randomized study was performed on 90 patients of 18 to 60 years of age, of either sex of the American Society of Anesthesiologists (ASA) Grade-I & II, and was divided into two groups. Group L + P received IV bolus of 1.5 mg/kg 2% lignocaine over 10 minutes followed by 1.5 mg/ kg/ h infusion and group NS + P- received the equivalent volumes of normal saline in bolus and infusion. Patients were induced with fentanyl (2 µg/kg) and propofol (1 mg/kg). To maintain an adequate sedation level, a supplemental bolus of 0.5 mg /kg propofol was administered. The outcomes recorded were the total and supplemental amount of propofol administered, as well as recovery time. Results The mean supplemental propofol for group L + P and group NS + P- 37.00 ± 29.93 and 58.67 ± 19.49 mg, respectively and mean total propofol consumption was 98.22 ± 34.00 mg and 131.11 ± 23.18 mg, respectively, (p < 0.001). Mean recovery time in group L + P was also shorter (5.22 ± 2.14 versus 9.96 ± 2.14). The incidence of adverse events like gag reflux, upper airway obstruction, pain on injection, and hypotension was significantly lower in group L + P (p < 0.05). Conclusion The addition of lignocaine to propofol-based sedation reduced the overall propofol requirement at the same time maintaining hemodynamic stability, spontaneous respiration, and early recovery.

Lidocaine enhances the efficacy of palbociclib in triple-negative breast cancer

The use of anesthetics in the surgical resection of tumors may influence the prognosis of cancer patients. Lidocaine, a local anesthetic, is known to act as a chemosensitizer and relieve pain in some cancers. In addition, palbociclib, a potent cyclin-dependent kinase (CDK) 4/6 inhibitor, has been approved for chemotherapy of advanced breast cancer. However, recent studies have revealed the acquired resistance of breast cancer cells to palbociclib. Therefore, the development of combination therapies that can extend the efficacy of palbociclib or delay resistance is crucial. This study investigated whether lidocaine would enhance the efficacy of palbociclib in breast cancer. Lidocaine synergistically suppressed the growth and proliferation of breast cancer cells by palbociclib. The combination treatment showed an increased cell cycle arrest in the G0/G1 phase by decreasing retinoblastoma protein (Rb) and E2F1 expression. In addition, it increased apoptosis by loss of mitochondrial membrane potential as observed by increases in cytochrome c release and inhibition of mitochondria-mediated protein expression. Additionally, it significantly reduced epithelial-mesenchymal transition and PI3K/AKT/GSK3β signaling. In orthotopic breast cancer models, this combination treatment significantly inhibited tumor growth and increased tumor cell apoptosis compared to those treated with a single drug. Taken together, this study demonstrates that the combination of palbociclib and lidocaine has a synergistic anti-cancer effect on breast cancer cells by the inhibition of the PI3K/AKT/GSK3β pathway, suggesting that this combination could potentially be an effective therapy for breast cancer.

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.

Lidocaine Infusion for the Management of Postoperative Pain and Delirium (LIMPP): protocol for a randomised control trial

INTRODUCTION

Postoperative delirium is a frequent adverse event following elective non-cardiac surgery. The occurrence of delirium increases the risk of functional impairment, placement to facilities other than home after discharge, cognitive impairment at discharge, as well as in-hospital and possibly long-term mortality. Unfortunately, there is a dearth of effective strategies to minimise the risk from modifiable risk factors, including postoperative pain control and the analgesic regimen. Use of potent opioids, currently the backbone of postoperative pain control, alters cognition and has been associated with an increased risk of postoperative delirium. Literature supports the intraoperative use of lidocaine infusions to decrease postoperative opioid requirements, however, whether the use of postoperative lidocaine infusions is associated with lower opioid requirements and subsequently a reduction in postoperative delirium has not been investigated.

METHODS AND ANALYSIS

The Lidocaine Infusion for the Management of Postoperative Pain and Delirium trial is a randomised, double-blinded study of a postoperative 48-hour infusion of lidocaine at 1.33 mg/kg/hour versus placebo in older patients undergoing major reconstructive spinal surgery at the University of California, San Francisco. Our primary outcome is incident delirium measured daily by the Confusion Assessment Method in the first three postoperative days. Secondary outcomes include delirium severity, changes in cognition, pain scores, opioid use, incidence of opioid related side effects and functional benefits including time to discharge and improved recovery from surgery. Lidocaine safety will be assessed with daily screening questionnaires and lidocaine plasma levels.

ETHICS AND DISSEMINATION

This study protocol has been approved by the ethics board at the University of California, San Francisco. The results of this study will be published in a peer-review journal and presented at national conferences as poster or oral presentations. Participants wishing to know the results of this study will be contacted directly on data publication.

TRIAL REGISTRATION NUMBER

NCT05010148.

Efficacy of systemic lidocaine in postoperative delirium in elderly patients undergoing laparoscopic colorectal surgery: study protocol for a multicentre, prospective, double-blind, randomised, parallel-group, superiority, placebo-controlled trial

INTRODUCTION

Systemic lidocaine may reduce pain intensity and accelerate postoperative recovery. However, the efficacy of systemic lidocaine in cognitive function has not been established. This study protocol is designed to clarify the effectiveness of lidocaine in postoperative delirium (POD) in elderly patients scheduled for elective laparoscopic colorectal surgery.

METHODS AND ANALYSIS

This is a prospective, multicentre, randomised, double-blind, parallel-group, placebo-controlled trial. One thousand and twenty elderly patients will be randomly allocated in a ratio of 1:1 to receive either systemic lidocaine (a bolus of 1.5 mg/kg, followed by an infusion of 1.5 mg/kg/hour until the end of the surgery) or identical volumes and rates of 0.9% saline. The primary outcome measure is the prevalence of POD during the first 5 postoperative days. Secondary outcomes include emergence agitation, the area under the curve of the Numeric Rating Scale pain scores over 48 hours, postoperative 48-hour cumulative opioid consumption, postoperative nausea and vomiting (PONV), recovery of bowel function, quality of recovery, and patient satisfaction with postoperative analgesia.

ETHICS AND DISSEMINATION

The Ethical Committee of the Fujian Provincial Hospital approved the study protocol (ref: K2021-06-018). Other participating subcentres must also obtain ethics committee approval before the start of the study. We will obtain written informed consent from each patient before they are randomised. This study will be presented at scientific conferences and submitted to international journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100050314.

A Randomized Controlled Trial Comparing Intravenous Lidocaine Infusion With Thoracic Epidural for Perioperative Analgesia and Quality of Recovery After Surgery in Laparoscopic Left-Sided Colon and Sphincter-Sparing Rectal Resection Surgery

Background Protocols for Enhanced Recovery after Surgery (ERAS) have been constantly evolving, and the best method of managing perioperative pain, especially in laparoscopic surgeries, is still debatable. The primary goal of these protocols is to steer toward opioid-sparing analgesia. Intravenous lidocaine, which has both analgesic and anti-inflammatory properties, may improve the overall recovery of patients. Objectives The aim of this randomized controlled trial was to compare the efficacy of intravenous lidocaine infusion (IVL) with thoracic epidural analgesia (TEA) in the management of perioperative pain and recovery in the laparoscopic left-sided colon and sphincter-sparing rectal surgery. Methods In this study, 37 patients were randomized to either the IVL group or the TEA group. IVL infusion was started before the surgical incision and stopped 30 minutes after transferring the patient to the postanesthesia care unit (PACU). Postoperative pain scores, opioid consumption, rescue analgesic doses, quality of recovery scores, time to discharge, and adverse events were recorded prospectively. Data were analyzed using two independent sample t-test and paired t-test, with p < 0.05 taken as statistically significant. Results The mean difference of overall NRS (numerical rating scale) pain scores in the ward was significantly higher in the IVL group as compared to the TEA group, which was 3.58 (2.29) vs 2.23 1.95) (p < 0.001). The IVL group required more mean rescue opioid boluses than the TEA group, which was 11.36 (8.684) vs 5.96 (6.215) (p < 0.001). However, both IVL and TEA groups had similar pain scores intraoperatively and in the PACU. Conclusions TEA provides better analgesia and decreased opioid requirements compared to intravenous lidocaine during the 24-hour period in the ward after laparoscopic left-sided colon and sphincter-sparing rectal surgery, although there was no difference in the quality of recovery between IVL and TEA groups.

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

Background. Local anesthetics (LAs) have potent anti-inflammatory properties. Inflammatory down-regulation is crucial in diseases with overactive immune reactions, such as acute respiratory distress syndrome (ARDS) and chronic inflammation. We investigated the influence of four LAs, procaine, lidocaine, mepivacaine, and bupivacaine, on the reduction of tumor necrosis factor-alpha (TNF-α) secretion in lipopolysaccharide (LPS)-activated human leucocytes. Methods. Blood samples of 28 individuals were stimulated with LPS. The reduction of TNF-α production by each of the four LAs added (0.5 mg/mL) was measured and correlated with biometric variables. A response was defined as reduction to <85% of initial levels. Results. All four LAs down-regulated the TNF-α secretion in 44−61%: Bupivacaine (44.4%), lidocaine (61.5%), mepivacaine (44.4%), and procaine (50% of the individuals, “responders”). The TNF-α secretion was reduced to 67.4, 68.0, 63.6, and 67.1% of the initial values in responders. The effects in both patients and healthy persons were the same. Interindividual responses to LAs were not correlated with the duration or type of complaints, basal TNF-α serum level, sex, BMI, or age of responders. Conclusions. Four clinically relevant LAs (amid-LA and ester-LA) attenuate the inflammatory response provoked by LPS. They are potential candidates for drug repositioning in treating overactive immune reactions and chronic inflammation.

Perioperative Dexmedetomidine or Lidocaine Infusion for the Prevention of Chronic Postoperative and Neuropathic Pain After Gynecological Surgery: A Randomized, Placebo-Controlled, Double-Blind Study

Introduction

The transition of acute to chronic postoperative pain (CPP) remains a significant burden to the rehabilitation of patients. The research for adjuvants to prevent CPP continues; among others, dexmedetomidine and lidocaine seem promising agents.

Methods

This is a long-term follow-up of a randomized, placebo-controlled, double-blind study on women who underwent open abdominal gynecological surgery and received dexmedetomidine or lidocaine or placebo infusion perioperatively (n = 81). The effect of these adjuvants on the development of CPP and neuropathic pain was assessed during a 12-month follow-up. Eighty-one (81) women ASA I–II, aged between 30 and 70 years, were randomly assigned to receive either dexmedetomidine (DEX group) or lidocaine (LIDO group) or placebo (CONTROL group) perioperatively. Before anesthesia induction, all patients received a loading intravenous dose of either 0.6 μg/kg dexmedetomidine or 1.5 mg/kg lidocaine or placebo, followed by 0.6 μg/kg/h dexmedetomidine or 1.5 mg/kg/h lidocaine or placebo until last suture. Patients were followed up to obtain the long-term outcomes at 3, 6, and 12 months. At these time-points, pain intensity was assessed with the Numerical Rating Scale, (NRS: 0–10) and the development of neuropathic elements with the Douleur Neuropathique 4 (DN4) score. Prognostic parameters that could affect chronic pain and its components were also identified.

Results

Data from 74 women were analyzed. Dexmedetomidine significantly reduced NRS scores comparing to placebo at 3 months (p = 0.018), while at 6 months, lidocaine was found superior to placebo (p = 0.02), but not to dexmedetomidine, in preventing neuropathic pain (DN4 < 4). Regarding secondary endpoints, higher NRS cough scores at 48 h were associated with statistically significant NRS and DN4 scores at 3, 6, and 12 months (p < 0.02). At 6 months, a statistically significant correlation was also found between higher NRS values and older age (p = 0.020).

Conclusions

Dexmedetomidine was superior to placebo regarding the duration and severity of CPP, while lidocaine exhibited a protective effect against neuropathic elements of CPP.

Trial registration

ClinicalTrials.gov identifier, NCT03363425.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-022-00361-5.

Intravenous Infusion of Lidocaine for Bowel Function Recovery After Major Colorectal Surgery: A Critical Appraisal Through Updated Meta-Analysis, Trial Sequential Analysis, Certainty of Evidence, and Meta-Regression

Background

Intravenous infusion of lidocaine (IVF-Lido) during the perioperative period is an option to accelerate bowel function recovery after major colorectal surgery. However, previous meta-analyses have shown inconsistent conclusions. Recent randomized controlled trials (RCTs) have been reported after the publication of a previous meta-analysis.

Aim

We conducted an updated and comprehensive meta-analysis to determine the effects of IVF-Lido on time to first flatus and defecation after major colorectal surgery.

Methods

We performed a systematic review according to the Preferred Reporting Items for the Systematic Reviews and Meta-Analysis Protocols 2020 guideline. Only RCTs were included. The revised Cochrane risk-of-bias tool was chosen for appraisal. Meta-analysis with meta-regression and trial sequential analysis was carried out. The Doi plot was presented to evaluate publication bias. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology was executed to evaluate the certainty of evidence (CoE).

Results

Thirteen RCTs with 696 participants were enrolled. IVF-Lido significantly decreased the time to first flatus [mean difference (MD) = −6.03 h; 95% confidence interval (CI): (−8.80, −3.26)] and first defecation [MD = −10.49 h; 95% CI: (−15.58, −5.41)]. Trial sequential analysis yielded identical results and ampleness of required information sizes. No obviousness in publication bias was detected, and the CoE in GRADE was low in both outcomes. Meta-regression showed that a significantly shorter time to the first defecation was associated with studies with more improvement in pain control in comparison of two groups and better-improved analgesia in the control group.

Conclusions

We discretionarily suggest the use of IVF-Lido on postoperative bowel function recovery following major colorectal surgery. Beyond the analgesic effects, IVF-Lido might have additional benefits when postoperative pain relief has already been achieved. Considering the high heterogeneity in this updated meta-analysis, more RCTs are needed.

Systematic Review Registration

https://inplasy.com/inplasy-2020-7-0023/, INPLASY [202070023].

Evaluation of lignocaine, dexmedetomidine, lignocaine-dexmedetomidine infusion on pain and quality of recovery for robotic abdominal hysterectomy: a prospective randomized controlled trial

Background: Acute postoperative pain is associated with poor quality of recovery after surgery. Perioperative use of intravenous lignocaine or dexmedetomidine have demonstrated better pain control, early return of bowel function, and effects on quality of recovery.

Methods: Ninety-six women planned for elective robotic abdominal hysterectomy were randomized into four groups. Groups received lignocaine infusion (1.5 mg.kg⁻¹ loading, 2 mg.kg⁻¹.h⁻¹ infusion) (Group I), dexmedetomidine infusion (1 µg.kg⁻¹ loading, 0.6 µg.kg⁻¹.h⁻¹ infusion) (Group 2), lidocaine (1.5 mg.kg⁻¹ loading, 2 mg.kg⁻¹.h⁻¹ infusion), and dexmedetomidine infusions (1 µg.kg⁻¹ loading, 0.5 µg.kg⁻¹.h⁻¹ infusion) (Group 3), and normal saline 10 mL loading, 1 mL.kg⁻¹.h⁻¹ infusion) (Group 4). Primary outcome was visual analogue pain scores at 1, 2, 4, 12, and 24 hours after surgery. Secondary outcomes included postoperative fentanyl requirement, time of return of bowel sounds and flatus, QoR15 score on day 1, 2, and discharge.

Results: The VAS was significantly lower in Groups 2 and 3 compared to Groups 1 and 4. Total postoperative fentanyl consumption in the first 24 hours was 256.25 ± 16.36 mcg (Group 1), 177.71 ± 16.81 mcg (Group 2), 114.17 ± 16.19 mcg (Group 3), and 304.42 ± 31.26 mcg (Group 4), respectively. Time to return of bowel sounds and passage of flatus was significantly shorter in Groups 2 and 3 (p < 0.01). QoR15 scores after surgery were higher in Group 3 compared to Groups 1, 2, and 4, (p < 0.01) respectively.

Conclusion: Combined infusion of lignocaine and dexmedetomidine significantly decreased postoperative pain, fentanyl consumption, and improved quality of recovery score after surgery in patients undergoing Robotic abdominal hysterectomy.

Perioperative Intravenous Lidocaine Infusion on Postoperative Recovery in Patients Undergoing Arthroscopic Rotator Cuff Repair Under General Anesthesia - A Randomized Controlled Trial

OBJECTIVE

Arthroscopic rotator cuff repair (ARCR) is known to cause severe postoperative pain which may interfere with recovery. Intravenous (IV) lidocaine has analgesic, anti-inflammatory, and anti-hyperalgesic effects, and is being used in various types of surgeries. However, the effect of IV lidocaine in ARCR is not well known.

MATERIALS AND METHODS

Ninety patients undergoing ARCR were randomly allocated to receive IV lidocaine (1.5▒mg/kg bolus of 1% lidocaine after anesthesia induction followed by a continuous infusion of 2▒mg/kg/h up to 1▒h after surgery) or an equal volume of saline. In both groups, an IV patient-controlled analgesia (PCA) device was used which contained fentanyl 10▒µg/mL, infused at 1▒mL/h with a 1▒mL bolus dose. The primary outcome was fentanyl requirements given via IV PCA during the first 24 hours after surgery. Perioperative pain scores and functional recovery were assessed as secondary outcomes.

RESULTS

The amount of fentanyl administered via IV PCA up to 24 hours after surgery was significantly lower in the Lidocaine group compared to the Control group (329 [256.2-428.3] vs. 394.5 [287.0-473.0], P=0.037) The number of PCA bolus attempts were lower in the Lidocaine group without statistical significance. There were no differences in postoperative pain scores or functional shoulder scores between the two groups.

DISCUSSION

IV lidocaine appears to be helpful in reducing opioid requirements during the acute postoperative period in patients undergoing ARCR. IV lidocaine may be a viable option as a component of multimodal analgesia in ARCR when regional analgesia is not possible.

Efficacy of intraoperative intravenous lidocaine for postoperative analgesia following bariatric surgery: a meta-analysis of randomized controlled studies

BACKGROUND

The impact of intravenous lidocaine in adults undergoing laparoscopic bariatric surgeries (LBS) remains unclear.

OBJECTIVES

This study aimed at investigating the effect of intravenous lidocaine on postoperative opioid consumption and recovery following LBS.

SETTING

Meta-analysis.

METHODS

We searched databases including MEDLINE, Embase, Google Scholar, and the Cochrane Library for randomized controlled trials that evaluated the use of intravenous lidocaine compared to placebo only prior to May 2021. The primary outcome was 24-hour postoperative opioid consumption, while secondary outcomes included pain score, quality of recovery (QOR)-40 score, length of hospital stay (LOS), and postoperative nausea/vomiting (PONV).

RESULTS

Seven trials (496 participants) were included. Intraoperative intravenous lidocaine significantly reduced 24-hour equivalent morphine consumption (mean difference [MD]: -11.97 mg; 95% confidence interval [CI]: -23.12 to -.83), pain score at 1 to 3 hours (MD: -.77; 95% CI: -1.5 to -.04), and LOS (MD: -8.93 hr; 95% CI: -13.41 to -4.44) without positive impact on 24-hour pain score and PONV. There was also an increase in time to first opioid requirement (MD: 20.23 min; 95% CI: 11.76-28.7) and QOR-40 score (MD: 24.38; 95% CI: 5.57-43.18). However, sensitivity analysis demonstrated evidence supporting the beneficial effect of lidocaine only for time to first opioid requirement and QOR-40. The associations of intraoperative intravenous lidocaine with reductions in morphine consumption, pain score at 1 to 3 hours, and LOS after LBS were also weak.

CONCLUSION

Intraoperative intravenous lidocaine during LBS prolonged time to first opioid requirement and improved quality of recovery postoperatively without 24-hour pain or nausea/vomiting benefits. Due to the small number of trials, larger studies are warranted to verify our findings.

Perioperative Intravenous Lidocaine and Metastatic Cancer Recurrence - A Narrative Review

Cancer is a major global health problem and the second leading cause of death worldwide. When detected early, surgery provides a potentially curative intervention for many solid organ tumours. Unfortunately, cancer frequently recurs postoperatively. Evidence from laboratory and retrospective clinical studies suggests that the choice of anaesthetic and analgesic agents used perioperatively may influence the activity of residual cancer cells and thus affect subsequent recurrence risk. The amide local anaesthetic lidocaine has a well-established role in perioperative therapeutics, whether used systemically as an analgesic agent or in the provision of regional anaesthesia. Under laboratory conditions, lidocaine has been shown to inhibit cancer cell behaviour and exerts beneficial effects on components of the inflammatory and immune responses which are known to affect cancer biology. These findings raise the possibility that lidocaine administered perioperatively as a safe and inexpensive intravenous infusion may provide significant benefits in terms of long term cancer outcomes. However, despite the volume of promising laboratory data, robust prospective clinical evidence supporting beneficial anti-cancer effects of perioperative lidocaine treatment is lacking, although trials are planned to address this. This review provides a state of the art summary of the current knowledge base and recent advances regarding perioperative lidocaine therapy, its biological effects and influence on postoperative cancer outcomes.

Reducing ileus after colorectal surgery: A network meta-analysis of therapeutic interventions

BACKGROUND

Several treatment strategies for avoiding post-operative ileus have been evaluated in randomised controlled trials. This network meta-analysis aimed to explore the relative effectiveness of these different therapeutic interventions on ileus outcome measures.

METHODS

A systematic literature review was performed to identify randomized controlled trials (RCTs) comparing treatments for post-operative ileus following colorectal surgery. A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method. Direct and indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analysis.

RESULTS

A total of 48 randomised controlled trials were included in this network meta-analysis reporting on 3614 participants. Early feeding was found to be the best treatment for time to solid diet tolerance and length of hospital stay with a probability of P = 0.96 and P = 0.47, respectively. Early feeding resulted in significantly shorter time to solid diet tolerance (Mean Difference (MD) 58.85 h; 95% Credible Interval (CrI) -73.41, -43.15) and shorter length of hospital stay (MD 2.33 days; CrI -3.51, -1.18) compared to no treatment. Epidural analgesia was ranked best treatment for time to flatus (P = 0.29) and time to stool (P = 0.268). Epidural analgesia resulted in significantly shorter time to flatus (MD -18.88 h; CrI -33.67, -3.44) and shorter time to stool (MD -26.05 h; 95% CrI -66.42, 15.65) compared to no intervention. Gastrograffin was ranked best treatment to avoid the requirement for post-operative nasogastric tube insertion (P = 0.61) however demonstrated limited efficacy (OR 0.50; CrI 0.143, 1.621) compared to no intervention. Nasogastric and nasointestinal tube insertion, probiotics, and acupuncture were found to be least efficacious as interventions to reduce ileus.

CONCLUSION

This network meta-analysis identified early feeding as the most efficacious therapeutic intervention to reduce post-operative ileus in patients undergoing colorectal surgery, in addition to highlighting other therapies that require further investigation by high quality study. In patients undergoing colorectal surgery, emphasis should be placed on early feeding as soon as can be appropriately initiated to support the return of gastrointestinal motility.

Effects of Systemic Lidocaine on Postoperative Recovery Quality and Immune Function in Patients Undergoing Laparoscopic Radical Gastrectomy

Objective

This study aimed to explore the effects of lidocaine on postoperative quality of recovery (QoR) and immune function in patients undergoing laparoscopic radical gastrectomy.

Methods

In total, 135 patients were enrolled and were equally randomized to receive low-dose lidocaine (Group LL: 1.5 mg/kg bolus followed by an infusion at 1.0 mg/kg/hour) or high-dose lidocaine (Group HL: 1.5 mg/kg bolus followed by an infusion at 2.0 mg/kg/hour) or Controls (Group C: received a volume-matched normal saline at the same rate). The primary outcome was a QoR-40 score on postoperative day (POD) 1. Secondary outcomes were a QoR-40 score on POD 3, levels of inflammatory factors (IL-6, IL-10, TNF-α) and CD4⁺T cells, CD8⁺T cells proportions, and CD4⁺/CD8⁺ cell ratios and postoperative recovery of bowel function.

Results

There were no statistically significant differences in patient characteristics at baseline. The total QoR-40 scores on POD 1 in Group HL (171.4±3.89) were higher than those in Group LL (166.20±4.05) and in Group C (163.40±4.38) (adjusted P<0.001). Differences in the dimension scores of QoR-40 for pain, physical comfort, and emotional state were significant across the three groups. Lidocaine administration significantly reduced the release of IL-6, IL-10, TNF-α, and attenuated immune changes induced by trauma. Kaplan–Meier curves showed that the median time to the first exhaust and defecation were shorter in the Group HL than in Groups LL and C (1.55 days vs 2.4 days vs 2.6 days, log rank P<0.0001; and 2.86 days vs 3.22 days vs 3.46 days, log rank P=0.002, respectively). Additionally, patients in lidocaine groups required less remifentanil consumption and experienced lower pain intensity, compared with the control group.

Conclusion

Systemic lidocaine improved postoperative recovery, alleviated inflammation and immunosuppression, and accelerated the return of bowel function, and is thus, worthy of clinical application.

Clinical Trials Registration

ChiCTR2000028934.

Intravenous Lignocaine-Fentanyl Versus Epidural Ropivacaine-Fentanyl for Postoperative Analgesia After Major Abdominal Oncosurgery: A Pilot Prospective Randomised Study

OBJECTIVE

Epidural injection of local anaesthetics and intravenous opioid injection are two common analgesic strategies following major abdominal oncosurgery. However, epidural local anaesthetics may cause haemodynamic instability while opioid injection is associated with sedation and postoperative ileus. Intravenous lignocaine is also used for postoperative analgesia, and combined use of opioids plus lignocaine can reduce the doses and adverse effects of the individual drugs. This study therefore compared the analgesic efficacy of intravenous lignocaine-fentanyl (IV) to epidural ropivacaine-fentanyl (EPI) after major abdominal oncosurgery.

METHODS

Sixty patients were randomised to IV and EPI groups. Patients in the IV group received preoperative intravenous bolus injections of lignocaine 1.5 mg kg^-1 and fentanyl 0.5 μg kg^-1, intraoperative infusions of lignocaine 1 mg kg^-1 h^-1 and fentanyl 0.5 μg kg^-1 h^-1, and postoperative infusions of lignocaine 0.5 mg kg^-1 h^-1 and fentanyl 0.25 μg kg^-1 h^-1. In the EPI group, patients received a 6-ml epidural bolus injection of ropivacaine 0.2% plus fentanyl 2 μg mL^-1, intraoperative infusion of 5 mL·h^-1 fentanyl and postoperative ropivacaine 0.1% plus fentanyl 1 μg mL^-1 infusion at 5 mL h^-1. All patients also received postoperative patient-controlled IV fentanyl as rescue analgesia. Patient-controlled fentanyl consumption was documented as the primary outcome for postoperative analgesic efficacy. Results were compared by Mann-Whitney U-test and Student's t-test using Statistical Package for Social Science (SPSS) software.

RESULTS

Median (min-max) rescue fentanyl requirement in the first 24 h postsurgery was comparable between IV and EPI groups [780 (340-2520) μg vs. 820 (140-2260) μg; p=0.6], as was postoperative pain score (p>0.05). The incidence of intraoperative hypotension requiring bolus mephenteramine injection was significantly higher in the EPI group than the IV group (36% vs. 17%; p<0.001).

CONCLUSION

Intravenous lignocaine-fentanyl and epidural ropivacaine-fentanyl have comparable postoperative analgesic efficacies after major open abdominal oncosurgery.

Local Anesthetics and Recurrence after Cancer Surgery-What's New? A Narrative Review

The perioperative use of regional anesthesia and local anesthetics is part of almost every anesthesiologist’s daily clinical practice. Retrospective analyses and results from experimental studies pointed towards a potential beneficial effect of the local anesthetics regarding outcome—i.e., overall and/or recurrence-free survival—in patients undergoing cancer surgery. The perioperative period, where the anesthesiologist is responsible for the patients, might be crucial for the further course of the disease, as circulating tumor cells (shed from the primary tumor into the patient’s bloodstream) might form new micro-metastases independent of complete tumor removal. Due to their strong anti-inflammatory properties, local anesthetics might have a certain impact on these circulating tumor cells, either via direct or indirect measures, for example via blunting the inflammatory stress response as induced by the surgical stimulus. This narrative review highlights the foundation of these principles, features recent experimental and clinical data and provides an outlook regarding current and potential future research activities.

Novel Opiate-Free Anesthetic Technique for Major Urologic Procedures

OBJECTIVES

We postulated that an opiate-free (OF) general anesthesia (GA) technique could adequately control a patient's pain without adversely affecting recovery. We compared patients undergoing major urologic procedures with and without opiate-based GA.

METHODS

A propensity-matched analysis was performed comparing hospital length of stay, postoperative nausea and vomiting, ileus occurrence, postanesthesia care unit, and total opiate consumption, as well as sedation and hemodynamic variables. The data are expressed as medians and were analyzed with the Wilcoxon rank-sum test. P < 0.05 indicate statistical significance.

RESULTS

In total, 166 patients were evaluated in both the OF group and the opiate-based treatment group. American Society of Anesthesiologists classification and age were comparable, with most surgeries being laparoscopic and confined to the bladder, kidney, and prostate gland. The median opiate consumption in morphine equivalents in the postanesthesia care unit was 7.7 mg (range 5-11.7 mg) for the OF cohort versus 11.7 mg (range 5-17.3 mg) for the control group (P < 0.001). Similarly, the median total postoperative opiate consumption in morphine equivalents was 23.9 mg (range 13.8-42.4 mg) for the OF group compared with 32.1 mg (range 17.38-57.51 mg) for the control group (P = 0.0081). The median hospital length of stay for the OF group was 1.4 days (range 1.2-2.3 days) versus 1.3 days (range 1.2-2.4 days) for the control group (P = 0.8466).

CONCLUSIONS

There was a statistically significant difference in opiate consumption postoperatively for patients who underwent an OF technique compared with a conventional opiate-based technique. This technique appears to be a possible alternative approach, without any apparent untoward consequences during admission.

Intravenous Infusion of Lidocaine Can Accelerate Postoperative Early Recovery in Patients Undergoing Surgery for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is defined by intermittent and recurrent episodes of partial or complete obstruction of the upper airway during sleep. Intermittent and recurrent hypoxia/reoxygenation is the main pathophysiological mechanism of OSA. Its consequences include systemic inflammation, activation of the sympathetic nervous system, and release of oxygen free radicals. Infusion of intravenous (IV) lidocaine has anti-inflammatory, antihyperalgesic, and analgesic properties, supporting its use as an anesthetic adjuvant. Lidocaine can reduce nociception and/or cardiovascular responses to surgical stress, as well as postoperative pain and/or analgesic requirements. Because of the high prevalence of OSA in obese patients, the use of opioids to manage postoperative pain in that population is often accompanied by the development of adverse respiratory events, such as hypoventilation and hypoxemia. IV infusion of lidocaine has been shown to enhance the quality of early recovery after laparoscopic bariatric and upper airway surgery. However, limited evidence exists regarding its use in patients undergoing surgery for OSA. In addition, whether IV infusion of lidocaine can improve postoperative early recovery in patients undergoing surgery for OSA remains unknown. Therefore, we hypothesized that IV infusion of lidocaine can improve postoperative early recovery in patients undergoing surgery for OSA. Perioperative infusion also may be a promising analgesic adjunct to enhanced recovery after surgery (ERAS) protocols.

Future in regional anesthesia and pain medicine: the pharmacological view

Local anesthetics are still incompletely understood, and none of the currently available drugs are optimal. The primary target of local anesthetics is the voltage-gated sodium channel (VGSC), where they lead to a temporary interruption of nerve conduction. Unfortunately, local anesthetics are neither specific at blocking a specific VGSC isoform, nor a specific cell type. We realize now that the old classification of A and C fibers according to myelin thickness is outdated, that next to differing myelin configuration, cells differ also by their molecular biology, and that there are close to 20 different neuronal subgroups when function is concerned. The ideal local anesthetic would only block sensory impulses, or even only painful impulses. In the search for that drug, several research avenues have been followed. First, efforts have been undertaken to extend duration of local anesthetics, by additives or extended-release formulation. Second, blockade of specific pain fibers has been attempted by targeting permanently charged anesthetics specifically into nociceptors. Third, blockade of specific isoforms using antibodies, and adaptation of naturally occurring neurotoxins has shown promise. Lastly, combination of local anesthetics with other analgesics may improve their duration of action.