Intraoperative systemic lidocaine for pre-emptive analgesics in subtotal gastrectomy: a prospective, randomized, double-blind, placebo-controlled study

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.

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.

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.

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.

Anaesthesia for Hepatic Resection Surgery

This article will focus on the perioperative management of hepatic resection for colorectal cancer (CRC) liver metastases (CLRMs) (the liver is the dominant metastatic site for CRC) within the context of the Enhanced Recovery After Surgery (ERAS) paradigm. It discusses the epidemiology and outcomes along with the history of hepatic resection surgery and pertinent anatomy. The discussion of the preoperative phase includes patient selection, assessment of liver functional status, and new developments in prehabilitation. The intraoperative phase details developments in surgical and anesthetic techniques to minimize liver hemorrhage and reduce the risk of postoperative hepatic failure. Newer analgesic options are included. Management of potential complications is outlined in the postoperative section followed by a description of current evidence for ERAS and future directions.

Effect of intravenous lidocaine on short-term pain after hysteroscopy: a randomized clinical trial

Background

The role of intravenous lidocaine infusion in endoscopic surgery has been previously evaluated for pain relief and recovery. Recently, it has been shown to reduce postoperative pain and opioid in patients undergoing endoscopic submucosal dissection. Similar to endoscopic submucosal dissection, operative hysteroscopy is also an endoscopic surgical procedure within natural lumens. The present study was a randomized clinical trial in which we evaluated whether intravenous lidocaine infusion would reduce postoperative pain in patients undergoing hysteroscopic surgery.

Objective

To evaluate whether intravenous lidocaine infusion could reduce postoperative pain in patients undergoing operative hysteroscopy.

Methods

Eighty-five patients scheduled to undergo elective hysteroscopy were randomized to receive either an intravenous bolus of lidocaine 1.5 mg.kg^-1 over 3 minutes, followed by continuous infusion at a rate of 2 mg.kg^-1. h^-1 during surgery, or 0.9% normal saline solution at the same rate. The primary outcome was to evaluate postoperative pain by Visual Analog Scale (VAS). Secondary outcomes included remifentanil and propofol consumption.

Results

In the lidocaine group, the VAS was significantly lower at 0.5 hour (p = 0.008) and 4 hours (p = 0.020). Patients in the lidocaine group required less remifentanil than patients in the control group (p < 0.001). However, there was no difference between the two groups in the propofol consumption. The incidence of throat pain was significantly lower in the lidocaine group (p = 0.019). No adverse events associated with lidocaine infusion were discovered.

Conclusion

Intravenous lidocaine infusion as an adjuvant reduces short-term postoperative pain in patients undergoing operative hysteroscopy.

The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety

Intravenous lidocaine is used widely for its effect on postoperative pain and recovery but it can be, and has been, fatal when used inappropriately and incorrectly. The risk-benefit ratio of i.v. lidocaine varies with type of surgery and with patient factors such as comorbidity (including pre-existing chronic pain). This consensus statement aims to address three questions. First, does i.v. lidocaine effectively reduce postoperative pain and facilitate recovery? Second, is i.v. lidocaine safe? Third, does the fact that i.v. lidocaine is not licensed for this indication affect its use? We suggest that i.v. lidocaine should be regarded as a 'high-risk' medicine. Individual anaesthetists may feel that, in selected patients, i.v. lidocaine may be beneficial as part of a multimodal peri-operative pain management strategy. This approach should be approved by hospital medication governance systems, and the individual clinical decision should be made with properly informed consent from the patient concerned. If i.v. lidocaine is used, we recommend an initial dose of no more than 1.5 mg.kg^-1 , calculated using the patient's ideal body weight and given as an infusion over 10 min. Thereafter, an infusion of no more than 1.5 mg.kg^-1 .h^-1 for no longer than 24 h is recommended, subject to review and re-assessment. Intravenous lidocaine should not be used at the same time as, or within the period of action of, other local anaesthetic interventions. This includes not starting i.v. lidocaine within 4 h after any nerve block, and not performing any nerve block until 4 h after discontinuing an i.v. lidocaine infusion.

Intravenous Lidocaine Infusion for the Management of Early Postoperative Pain: A Comprehensive Review of Controlled Trials

Previously used as anti-arrhythmic, intravenous lidocaine infusion is becoming popular for use in management of acute pain. There is still much to be understood about its pharmacokinetics and pharmacodynamics, especially with regard to optimal dosing to avoid side effects. In this article, we selected and reviewed randomized controlled trials to summarize the pharmacokinetics, antinociceptive effects, anti-hyperalgesic effects, anti-inflammatory effects, side effects, and role of intravenous lidocaine in the management of early postoperative pain. The mechanisms of action of lidocaine are still unclear but there are many theories postulated. Optimal dosing of lidocaine is not known but general consensus indicates that a loading dose of 1-2 mg/kg, followed by 1-2 mg/kg/hr continuous infusion during early postoperative pain control while recovering from anesthesia to achieve therapeutic levels of 0.5-5 mcg/kg clearly improves analgesia in the immediate postoperative period. Although lidocaine was initially studied and proven to have clear analgesic effects following laparoscopic and open abdominal surgeries, it has now been shown to be applicable in different clinical settings perioperatively including following spinal, breast, ENT and other surgeries. It is generally safe, with hypotension, headache and vomiting being the more common side effects. Serious adverse effects include cardiovascular block and arrhythmias, neuro-excitability and hypersensitivity, although the frequency of these are not known.

Perioperative bleeding and non-steroidal anti-inflammatory drugs: An evidence-based literature review, and current clinical appraisal

Patient satisfaction measures and the opioid epidemic have highlighted the need for effective perioperative pain management. Multimodal analgesia, including non-steroidal anti-inflammatory drugs (NSAIDs), have been shown to maximize pain relief and reduce opioid consumption, but are also associated with potential perioperative bleeding risks.A multidisciplinary panel conducted a clinical appraisal of bleeding risks associated with perioperative NSAID use. The appraisal consisted of review and assessment of the current published evidence related to the statement "In procedures with high bleeding risk, NSAIDs should always be avoided perioperatively." We report the presented literature and proceedings of the subsequent panel discussion and national pilot survey results. The authors' assessment of the statement based on current evidence was compared to the attempted national survey data, which revealed a wide range of opinions reflecting the ongoing debate around this issue in a small number of respondents.The appraisal concluded that caution is warranted with respect to perioperative use of NSAIDs. However, summarily excluding NSAIDs from perioperative use based on potential bleeding risks would be imprudent. It is recommended that NSAID use be guided by known patient- and procedure-specific factors to minimize bleeding risks while providing effective pain relief.

Preventive skin analgesia with lidocaine patch for management of post-thoracotomy pain: Results of a randomized, double blind, placebo controlled study

Background

To evaluate whether pre‐emptive skin analgesia using a lidocaine patch 5% would improve the effects of systemic morphine analgesia for controlling acute post‐thoracotomy pain.

Methods

This was a double‐blind, placebo controlled, prospective study. Patients were randomly assigned to receive lidocaine 5% patch (lidocaine group) or a placebo (placebo group) three days before thoracotomy. Postoperative analgesia was induced in all cases with intravenous morphine analgesia. The intergroup differences were assessed in order to evaluate whether the lidocaine patch 5% would have effects on pain intensity when at rest and after coughing (primary end‐point) on morphine consumption, on the recovery of respiratory function, and on peripheral painful pathways measured with N2 and P2 laser‐evoked potential (secondary end‐points).

Results

A total of 90 patients were randomized, of whom 45 were allocated to the lidocaine group and 45 to the placebo group. Lidocaine compared with the placebo group showed a significant reduction in pain intensity both at rest (P = 0.013) and after coughing (P = 0.015), and in total morphine consumption (P = 0.001); and also showed a better recovery of flow expiratory volume in one second (P = 0.025) and of forced vital capacity (P = 0.037). The placebo group compared with the lidocaine group presented a reduction in amplitude of N2 (P = 0.001) and P2 (P = 0.03), and an increase in the latency of N2 (P = 0.023) and P2 (P = 0.025) laser‐evoked potential.

Conclusions

The preventive skin analgesia with lidocaine patch 5% seems to be a valid adjunct to intravenous morphine analgesia for controlling post‐thoracotomy pain. However, our initial results should be corroborated/confirmed by larger studies.

Evaluation of lignocaine infusion on recovery profile, quality of recovery, and postoperative analgesia in patients undergoing total abdominal hysterectomy

Background and Aims:

Multimodal analgesia entrains the use of drugs in perioperative period producing adequate pain relief without affecting the quality of recovery by decreasing drug-related adverse effects. Systemic lignocaine has effective analgesic, anti-inflammatory, and anti-hyperalgesic properties and improves the quality of recovery after surgery.

Material and Methods:

Ninety women scheduled for elective transabdominal hysterectomy under general anesthesia were randomized to receive infusion of lignocaine (1.5 mg/kg over 15 min followed by a 2 mg/kg/h infusion until the end of surgery) (Group 1) or normal saline (10 mL over 15 min followed by infusion 1 mL/kg/h till end of surgery) (Group 2). Standard anesthesia techniques were used in both the groups. The patients received inj. tramadol for postoperative analgesia. Perioperative hemodynamics, extubation variables, postoperative analgesic requirement, and quality of recovery score were evaluated.

Results:

Hemodynamics were maintained in both the groups. Time for extubation was also similar. Demand for first postoperative analgesic was after 70.8 ± 70.4 min (Group 1) and 40.7 ± 30.0 min (Group 2) (P = 0.006). Total tramadol usage was 477.0 ± 133.2 mg (Group 1) and 560.0 ± 115.0 mg (Group 2) (P < 0.001). Return of bowel function was faster in Group 2 compared with Group 1 (37.1 ± 5 vs 41.8 ± 7.4 h, P < 0.001). The median (interquartile range) recovery score (QoR-40) was 184 (178–191) in Group 1 and 178 (171–180) in Group 2 (P < 0.001).

Conclusion:

Perioperative use of intravenous infusion of lignocaine is associated with decreased analgesic requirement postoperatively, and improved quality of recovery score signifying greater patient satisfaction.

Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery in adults

BACKGROUND

The management of postoperative pain and recovery is still unsatisfactory in a number of cases in clinical practice. Opioids used for postoperative analgesia are frequently associated with adverse effects, including nausea and constipation, preventing smooth postoperative recovery. Not all patients are suitable for, and benefit from, epidural analgesia that is used to improve postoperative recovery. The non-opioid, lidocaine, was investigated in several studies for its use in multimodal management strategies to reduce postoperative pain and enhance recovery. This review was published in 2015 and updated in January 2017.

OBJECTIVES

To assess the effects (benefits and risks) of perioperative intravenous (IV) lidocaine infusion compared to placebo/no treatment or compared to epidural analgesia on postoperative pain and recovery in adults undergoing various surgical procedures.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and reference lists of articles in January 2017. We searched one trial registry contacted researchers in the field, and handsearched journals and congress proceedings. We updated this search in February 2018, but have not yet incorporated these results into the review.

SELECTION CRITERIA

We included randomized controlled trials comparing the effect of continuous perioperative IV lidocaine infusion either with placebo, or no treatment, or with thoracic epidural analgesia (TEA) in adults undergoing elective or urgent surgery under general anaesthesia. The IV lidocaine infusion must have been started intraoperatively, prior to incision, and continued at least until the end of surgery.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures. Our primary outcomes were: pain score at rest; gastrointestinal recovery and adverse events. Secondary outcomes included: postoperative nausea and postoperative opioid consumption. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included 23 new trials in the update. In total, the review included 68 trials (4525 randomized participants). Two trials compared IV lidocaine with TEA. In all remaining trials, placebo or no treatment was used as a comparator. Trials involved participants undergoing open abdominal (22), laparoscopic abdominal (20), or various other surgical procedures (26). The application scheme of systemic lidocaine strongly varies between the studies related to both dose (1 mg/kg/h to 5 mg/kg/h) and termination of the infusion (from the end of surgery until several days after).The risk of bias was low with respect to selection bias (random sequence generation), performance bias, attrition bias, and detection bias in more than 50% of the included studies. For allocation concealment and selective reporting, the quality assessment yielded low risk of bias for only approximately 20% of the included studies.IV Lidocaine compared to placebo or no treatment We are uncertain whether IV lidocaine improves postoperative pain compared to placebo or no treatment at early time points (1 to 4 hours) (standardized mean difference (SMD) -0.50, 95% confidence interval (CI) -0.72 to -0.28; 29 studies, 1656 participants; very low-quality evidence) after surgery. Due to variation in the standard deviation (SD) in the studies, this would equate to an average pain reduction of between 0.37 cm and 2.48 cm on a 0 to 10 cm visual analogue scale . Assuming approximately 1 cm on a 0 to 10 cm pain scale is clinically meaningful, we ruled out a clinically relevant reduction in pain with lidocaine at intermediate (24 hours) (SMD -0.14, 95% CI -0.25 to -0.04; 33 studies, 1847 participants; moderate-quality evidence), and at late time points (48 hours) (SMD -0.11, 95% CI -0.25 to 0.04; 24 studies, 1404 participants; moderate-quality evidence). Due to variation in the SD in the studies, this would equate to an average pain reduction of between 0.10 cm to 0.48 cm at 24 hours and 0.08 cm to 0.42 cm at 48 hours. In contrast to the original review in 2015, we did not find any significant subgroup differences for different surgical procedures.We are uncertain whether lidocaine reduces the risk of ileus (risk ratio (RR) 0.37, 95% CI 0.15 to 0.87; 4 studies, 273 participants), time to first defaecation/bowel movement (mean difference (MD) -7.92 hours, 95% CI -12.71 to -3.13; 12 studies, 684 participants), risk of postoperative nausea (overall, i.e. 0 up to 72 hours) (RR 0.78, 95% CI 0.67 to 0.91; 35 studies, 1903 participants), and opioid consumption (overall) (MD -4.52 mg morphine equivalents , 95% CI -6.25 to -2.79; 40 studies, 2201 participants); quality of evidence was very low for all these outcomes.The effect of IV lidocaine on adverse effects compared to placebo treatment is uncertain, as only a small number of studies systematically analysed the occurrence of adverse effects (very low-quality evidence).IV Lidocaine compared to TEAThe effects of IV lidocaine compared with TEA are unclear (pain at 24 hours (MD 1.51, 95% CI -0.29 to 3.32; 2 studies, 102 participants), pain at 48 hours (MD 0.98, 95% CI -1.19 to 3.16; 2 studies, 102 participants), time to first bowel movement (MD -1.66, 95% CI -10.88 to 7.56; 2 studies, 102 participants); all very low-quality evidence). The risk for ileus and for postoperative nausea (overall) is also unclear, as only one small trial assessed these outcomes (very low-quality evidence). No trial assessed the outcomes, 'pain at early time points' and 'opioid consumption (overall)'. The effect of IV lidocaine on adverse effects compared to TEA is uncertain (very low-quality evidence).

AUTHORS' CONCLUSIONS

We are uncertain whether IV perioperative lidocaine, when compared to placebo or no treatment, has a beneficial impact on pain scores in the early postoperative phase, and on gastrointestinal recovery, postoperative nausea, and opioid consumption. The quality of evidence was limited due to inconsistency, imprecision, and study quality. Lidocaine probably has no clinically relevant effect on pain scores later than 24 hours. Few studies have systematically assessed the incidence of adverse effects. There is a lack of evidence about the effects of IV lidocaine compared with epidural anaesthesia in terms of the optimal dose and timing (including the duration) of the administration. We identified three ongoing studies, and 18 studies are awaiting classification; the results of the review may change when these studies are published and included in the review.

Effect of intravenous lidocaine infusion on long-term postoperative pain after spinal fusion surgery

BACKGROUND

Intravenous lidocaine infusion is known to reduce postoperative pain for days or weeks beyond the infusion time, and plasma half-life in several types of surgical procedures.

OBJECTIVES

To evaluate the effect of intravenous (IV) lidocaine infusion on long term postoperative pain intensity for 3 months in patients undergoing spinal fusion surgery.

STUDY DESIGN

Prospective randomized, double-blinded study.

SETTING

Assiut University Hospital, Assiut, Egypt.

METHODS

Forty patients undergoing spinal fusion surgery were randomized into 2 equal groups (n = 20 in each). Patients in the lidocaine group received IV lidocaine at a dosage of 2.0 mg/kg slowly before induction of anesthesia, followed by lidocaine IV infusion at a rate of 3.0 mg/kg/h until the end of surgery. Patients in the control group received an equal volume of normal saline. The following data were assessed: pain by Visual Analog Score (VAS) at 1 hour, 6 hours, 12 hours, 24 hours, 48 hours, at discharge time, and at 1 month, 2 months, and 3 months post-operation, time to first request for additional analgesia, and total morphine consumption in 24 hours.

RESULTS

Lidocaine significantly reduced the postoperative pain score (VAS) for up to 3 months (P < .05), and significantly reduced morphine consumption (4.5 mg vs. 19.85 mg) in the 1st 24 hours postoperative. Lidocaine also significantly, prolonged (P < .05) the time to first request for additional analgesia (9.56 ± 2.06 hours vs 1.82 ± 0.91 hours).

CONCLUSION

Intra-operative lidocaine, when given intravenously as a bolus followed by an infusion, significantly decreased long term postoperative back pain intensity in patients undergoing spinal fusion surgery.

Evaluating the Effect of Lidocaine on the Interactions of C-reactive Protein with Its Aptamer and Antibody by Dynamic Force Spectroscopy

Effects of medicine on the biomolecular interaction have been given extensive attention in biochemistry and biomedicine because of the complexity of the environment in vivo and the increasing opportunity of exposure to medicine. Herein, the effect of lidocaine on the interactions of C-reactive protein (CRP) with its aptamer and antibody under different temperature was investigated through dynamic force spectroscopy (DFS). The results revealed that lidocaine could reduce the binding probabilities and binding affinities of the CRP-aptamer and the CRP-antibody. An interesting discovery was that lidocaine had differential influences on the dynamic force spectra of the CRP-aptamer and the CRP-antibody. The energy landscape of the CRP-aptamer turned from two activation barriers to one after the treatment of lidocaine, while the one activation barrier in energy landscape of the CRP-antibody almost remained unchanged. In addition, similar results were obtained for 25 and 37 °C. In accordance with the result of molecular docking, the reduction of binding probabilities might be due to the binding of lidocaine on CRP. Additionally, the alteration of the dissociation pathway of the CRP-aptamer and the change of binding affinities might be caused by the conformational change of CRP, which was verified through synchronous fluorescence spectroscopy. Furthermore, differential effects of lidocaine on the interactions of CRP-aptamer and CRP-antibody might be attributed to the different dissociation processes and binding sites of the CRP-aptamer and the CRP-antibody and different structures of the aptamer and the antibody. This work indicated that DFS provided information for further research and comprehensive applications of biomolecular interaction, especially in the design of biosensors in complex systems.

Estimated Maximal Safe Dosages of Tumescent Lidocaine

Supplemental Digital Content is available in the text.

Published ahead of print February 18, 2016

BACKGROUND:

Tumescent lidocaine anesthesia consists of subcutaneous injection of relatively large volumes (up to 4 L or more) of dilute lidocaine (≤1 g/L) and epinephrine (≤1 mg/L). Although tumescent lidocaine anesthesia is used for an increasing variety of surgical procedures, the maximum safe dosage is unknown. Our primary aim in this study was to measure serum lidocaine concentrations after subcutaneous administration of tumescent lidocaine with and without liposuction. Our hypotheses were that even with large doses (i.e., >30 mg/kg), serum lidocaine concentrations would be below levels associated with mild toxicity and that the concentration-time profile would be lower after liposuction than without liposuction.

METHODS:

Volunteers participated in 1 to 2 infiltration studies without liposuction and then one study with tumescent liposuction totally by local anesthesia. Serum lidocaine concentrations were measured at 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, and 24 hours after each tumescent lidocaine infiltration. Area under the curve (AUC∞) of the serum lidocaine concentration-time profiles and peak serum lidocaine concentrations (Cmax) were determined with and without liposuction. For any given milligram per kilogram dosage, the probability that Cmax >6 μg/mL, the threshold for mild lidocaine toxicity was estimated using tolerance interval analysis.

RESULTS:

In 41 tumescent infiltration procedures among 14 volunteer subjects, tumescent lidocaine dosages ranged from 19.2 to 52 mg/kg. Measured serum lidocaine concentrations were all <6 μg/mL over the 24-hour study period. AUC∞s with liposuction were significantly less than those without liposuction (P = 0.001). The estimated risk of lidocaine toxicity without liposuction at a dose of 28 mg/kg and with liposuction at a dose of 45 mg/kg was ≤1 per 2000.

CONCLUSIONS:

Preliminary estimates for maximum safe dosages of tumescent lidocaine are 28 mg/kg without liposuction and 45 mg/kg with liposuction. As a result of delayed systemic absorption, these dosages yield serum lidocaine concentrations below levels associated with mild toxicity and are a nonsignificant risk of harm to patients.

The in vitro mechanisms and in vivo efficacy of intravenous lidocaine on the neuroinflammatory response in acute and chronic pain

INTRODUCTION

The neuroinflammatory response plays a key role in several pain syndromes. Intravenous (iv) lidocaine is beneficial in acute and chronic pain. This review delineates the current literature concerning in vitro mechanisms and in vivo efficacy of iv lidocaine on the neuroinflammatory response in acute and chronic pain.

DATABASES AND DATA TREATMENT

We searched PUBMED and the Cochrane Library for in vitro and in vivo studies from July 1975 to August 2014. In vitro articles providing an explanation for the mechanisms of action of lidocaine on the neuroinflammatory response in pain were included. Animal or clinical studies were included concerning iv lidocaine for acute or chronic pain or during inflammation.

RESULTS

Eighty-eight articles regarding iv lidocaine were included: 36 in vitro studies evaluating the effect on ion channels and receptors; 31 animal studies concerning acute and chronic pain and inflammatory models; 21 clinical studies concerning acute and chronic pain. Low-dose lidocaine inhibits in vitro voltage-gated sodium channels, the glycinergic system, some potassium channels and Gαq-coupled protein receptors. Higher lidocaine concentrations block potassium and calcium channels, and NMDA receptors. Animal studies demonstrate lidocaine to have analgesic effects in acute and neuropathic pain syndromes and anti-inflammatory effects early in the inflammatory response. Clinical studies demonstrate lidocaine to have advantage in abdominal surgery and in some neuropathic pain syndromes.

CONCLUSIONS

Intravenous lidocaine has analgesic, anti-inflammatory and antihyperalgesic properties mediated by an inhibitory effect on ion channels and receptors. It attenuates the neuroinflammatory response in perioperative pain and chronic neuropathic pain.

Intraoperative intravenous lidocaine exerts a protective effect on cell-mediated immunity in patients undergoing radical hysterectomy

Surgical procedures cause a decrease in lymphocyte proliferation rate, an increase in apoptosis and shifts the balance of T‑helper (Th)1/Th2 cells towards anti‑cell‑mediated immunity (CMI) Th2 dominance, which is relevant to the immunosuppressive effects of CMI, postoperative septic complications and the formation of tumor metastasis. Previous studies have revealed that lidocaine exhibits antibacterial actions; regulating inflammatory responses, reducing postoperative pain and affecting the duration spent in hospital. Thus, the present study hypothesized that lidocaine may exert a protective effect on the CMI of patients undergoing surgery for the removal of a primary tumor. A total of 30 adult female patients diagnosed with cervical cancer were recruited to the present study and were randomized into two groups. The lidocaine group received an intravenous bolus dose of 1.5 mg/kg lidocaine, followed by continuous infusion at 1.5 mg/kg/h until discharge from the operating room. The control group received the same volume of normal saline. A 10 ml sample of venous blood was drawn, and the lymphocytes were isolated using Ficoll‑paque 1 day prior to surgery, at discharge from the operating room and 48 h post‑surgery. The proliferation rate of the lymphocytes was assessed using a Cell Counting Kit‑8 assay and was found to be higher in the lidocaine group. The early apoptosis of lymphocytes was attenuated following lidocaine treatment at 48 h post‑surgery, as detected using flow cytometry with Annexin V‑fluorescein isothiocyanate/propidium iodide staining. The level of interferon (IFN)‑γ in the serum at 48 h was significantly decreased following surgery in the control group, compared with the pre‑surgical values (3.782 ± 0.282, vs. 4.089 ± 0.339 pg/ml, respectively) and the ratio of IFN‑γ to interleukin‑4 was well preserved in the lidocaine group. In conclusion, the present study demonstrated that the intraoperative systemic administration of lidocaine exerted a protective effect on CMI in patients with cervical cancer undergoing radical hysterectomy. This may be beneficial in reducing the occurrence of postoperative septic complications and tumor metastasis formation.

Comparison Between Intraperitoneal and Intravenous Lidocaine for Postoperative Analgesia After Elective Abdominal Hysterectomy, a Double-Blind Placebo Controlled Study

OBJECTIVE

To compare the efficacy of intravenous and intraperitoneal injection of lidocaine and normal saline in relieving postoperative pain after elective abdominal hysterectomy.

MATERIALS AND METHODS

For this double-blind randomized controlled study 109 patients undergoing elective abdominal hysterectomy were randomly allocated to three groups :1) IV group (intravenous injection group) received intravenous lidocaine %2 bolus 1.5mg/kg 30 min before incision and then a continuous lidocaine infusion of 2mg/kg and before the wound closure an intraperitoneal injection of N/S , 2) IP group (intraperitoneal group) received intravenous N/S and intraperitoneal lidocaine 3mg/kg , 3) P group (placebo, N/S) received both intravenous and intraperitoneal N/S. The pain scores (VAS) at rest, total morphine consumption , the time to first need for rescue analgesic ,incidence of lidocaine related adverse effects and nausea and vomiting were recorded at 0,2,4,8,12 and 24 hrs postoperatively.

RESULTS

The VAS scores were significantly lower in IP and IV groups compared with placebo (p = 0.001). Total consumption of morphine (p = 0.001) and time to firs request of recue analgesic (p = 0.001) were lower too in IP and IV groups.Incidence of vomiting was comparable between groups (p < 0.05) but nausea was higher in control group (p > 0.05).There were not notable lidocaine-related adverse effects. IP and IV groups were not statistically different for all investigated variables.

CONCLUSION

This study showed lidocaine administration both intravenously and intraperitoneally are effective in reducing the postoperative pain and also have opioid sparing effect and can be safely used in elective abdominal hysterectomy without any major adverse effects.

Best practice in the administration of analgesia in postoncological surgery

The rationale for using multimodal analgesia after any major surgery is achievement of adequate analgesia while avoiding the unwanted effects of large doses of any analgesic, in particular opioids. There are two reasons why we can hypothesize that multimodal analgesia might have a significant impact on cancer-related outcomes in the context of oncological orthopedic surgery. First, because multimodal analgesia is a key component of enhanced-recovery pathways and can accelerate return to intended oncological therapy. And second, because some of the analgesic used in multimodal analgesia (i.e., COX inhibitors, local analgesics and dexamethasone) can induce apoptosis in cancer cells and/or diminish the inflammatory response during surgery which itself can facilitate tumor growth.