Low-dose lidocaine reduces secondary hyperalgesia by a central mode of action

[Opioid-free anesthesia : Wrong track or meaningful exit from the era of opioid-based analgesia?]

The limitations and disadvantages of opioids in anesthesia are very well known but the advantages combined with a lack of effective alternatives even now still prevents refraining from using opioids as part of an adequate pain therapy. For decades, pain research has had the declared goal of replacing opioids with new substances which have no serious side effects; however, currently this goal seems to be a long way off. Due to the media coverage of the "opioid crisis" in North America, the use of opioids for pain management is also increasingly being questioned by the patients. Measures to contain this crisis are only slowly taking effect in view of the increasing number of deaths, which is why the triggers are still being sought. The perioperative administration of opioids is not only a possible gateway to addiction and abuse but it can also cause outcome-relevant complications, such as respiratory depression, postoperative nausea and vomiting and an increase in postoperative pain. Therefore, these considerations gave rise to the idea of an opioid-free anesthesia (OFA), i.e., opioids are not administered as part of anesthesia to carry out surgical procedures. Although this idea may make sense at first glance, a rapid introduction of this concept appears to be risky as it entails significant changes for the entire anesthesiological management. Based on relatively robust data from clinical studies, this concept can now be evaluated and discussed not only emotionally but also objectively. This review article presents arguments for or against the complete avoidance of intraoperative or even perioperative opioids. The current conditions in Germany are primarily taken into account, so that the perioperative pain therapy is transferable to the established standards. The results from current clinical studies on the implementation of an opioid-free anesthesia are summarized and discussed.

Analgesic effect of the mint terpenoid L-carvone in sheep

OBJECTIVE

To determine whether L-carvone increases the voltage threshold response to a noxious electrical stimulus in sheep.

STUDY DESIGN

Prospective, blinded, randomized, crossover experimental study.

ANIMALS

A group of six healthy adult sheep.

METHODS

Sheep were instrumented with cranial dorsothoracic subcutaneous copper electrodes. A stimulator delivered a 10 ms square-wave stimulus at 50 pps starting at 0.1 V with a 0.2 V second-1 ramp. The stimulus stopped once two observers who were blinded to treatment noted a behavioral pain response or when a 15 V cut-off was reached. Next, 0.15 mL kg-1 of either a 50% L-carvone solution or a saline-vehicle control was administered intramuscularly, and electrical threshold responses were measured every 5-15 minutes over a 6 hour period using methods identical to the baseline. One week following the first treatment (L-carvone or control), sheep were studied using identical methods with the second treatment (control or L-carvone). Drug and time effects were evaluated using a two-way repeated measures analysis of variance, and pairwise comparisons were evaluated with Holm-Sidák tests with values of p < 0.05 considered significant.

RESULTS

L-carvone significantly increased voltage threshold responses for most time points up to 75 minutes compared with baseline and with saline control. The last time point with a significantly different response between L-carvone and saline treatments was 5 hours after drug administration. The saline-vehicle control decreased voltage threshold responses at several time points after 3 hours.

CONCLUSIONS AND CLINICAL RELEVANCE

Intramuscular L-carvone is analgesic in sheep, although the ethanol-propylene glycol vehicle may cause mild hyperalgesia. This study demonstrates that a food-derived compound can be used to relieve pain in a food-producing animal.

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.

A case report of an 18-year-old receiving nebulized lidocaine for treatment of COVID-19 cough

An 18-year-old girl presenting with respiratory and gastrointestinal symptoms was found to have COVID-19 pneumonia and severe acute respiratory distress syndrome (ARDS). She was transferred to our pediatric intensive care unit (PICU) for ongoing mechanical ventilation and initiation of venovenous extracorporeal membrane oxygenation (VV-ECMO) for management of progressive hypoxic respiratory failure. She developed a worsening cough with associated life-threatening desaturation events that impaired ECMO flow and required deep sedation. Despite multiple sedative agents, our patient continued to have frequent coughing episodes with associated tachycardia, hypertension, and hypoxemia. The PICU team started nebulized lidocaine 1% 4 mL (40 mg) every 6 hours with albuterol pretreatment, gabapentin, and scheduled ipratropium. Lidocaine levels were <1 mcg/mL throughout the treatment duration. Nebulized lidocaine was stopped after 18 days given improvement in coughing episode severity. Our patient is one of the first reports of an adolescent patient receiving nebulized lidocaine for COVID-19 associated cough. Administration of nebulized lidocaine was well tolerated in this patient without adverse effects and was associated with decreased sedation needs. Given the widespread impact of the COVID-19 pandemic and its sequelae in pediatric, adolescent, and adult patients, additional research is warranted to explore options for management of COVID-19 associated cough.

Effect of perioperative lignocaine infusion on postoperative pain relief for laparoscopic intraperitoneal onlay mesh repair: A randomized controlled study

INTRODUCTION

The focus on enhanced recovery after surgery (ERAS) and opioid-free anesthesia has renewed interest in use of lignocaine. We evaluated postoperative pain relief following intravenous (IV) lignocaine administration in patients undergoing laparoscopic intraperitoneal onlay mesh repair (IPOM).

METHODS

Seventy patients were randomized into two groups. Group L patients were administered IV lignocaine infusion (1.5 mg/kg) at induction of anesthesia followed by infusion (1.5 mg/kg/h), until 1 hour in the post-anesthesia care unit (PACU). Group P patients received equal volumes of normal saline IV infusion. We recorded hemodynamics, perioperative analgesic consumption, postoperative visual analog scores (VAS), incidence of postoperative nausea and vomiting (PONV), bowel function, patient satisfaction and length of hospital stay (LOS).

RESULTS

The hemodynamics in both groups were maintained. Group L had lower VAS scores as compared to Group P (P < .05). Intraoperative fentanyl consumption in Group L was significantly less than Group P (P = .029). Group L patients scored lower on the Likert scale in comparison to the patients of Group P at 0 hour (P = .013). Recovery of bowel function as assessed by time to pass first flatus was significantly shortened by IV lignocaine (P = .001). The perioperative administration of IV lignocaine resulted in decreased postoperative analgesic requirement and greater patient satisfaction scores.

CONCLUSIONS

Perioperative IV lignocaine infusion provided good pain relief, hemodynamic stability and decreased perioperative analgesic consumption. PONV incidence decreased along with an early return of bowel function, reduced LOS and improved patient satisfaction in patients undergoing laparoscopic IPOM surgery.

The effects of target-controlled infusion of lidocaine undergoing vocal cord polypectomy: A randomized controlled trial (CONSORT compliant)

BACKGROUND

The present study aimed to assess the efficacy and safety of general anesthesia-assisted target-controlled plasma infusion of lidocaine in patients with vocal cord polypectomy using a supporting laryngoscope.

METHODS

In total, 80 patients undergoing vocal cord polypectomy using a supporting laryngoscope were randomly divided into an intervention group and a control group; each group contained 40 subjects: both groups received general anesthesia; subjects in the intervention also received an additional 3 mg/L of lidocaine by target-controlled plasma infusion during induction and maintenance of anesthesia; heart rate (HR) mean arterial pressure (MAP), propofol and urapidil consumption (Uradil, which is a blood pressure drug that blocks alpha-1, is called Urapidi Hydrochloride Injection. It is produced by Germany, the enterprise name is Nycomed Deutschland GmbH, the import drug registration number is H20090715, and it is widely used in China), recovery time, and cough score (measured by Minogue et al's 5-grade scoring method) during extubation, and throat pain score (measured by visual analogue scale,[VAS]) after extubation and adverse events were recorded.

RESULTS

Significant differences were observed in HR (P < .05) and MAP (P < .05) immediately after intubation (T2), immediately after the operation starting to support laryngoscope exposure (T3), immediately after operation field adrenergic tampon hemostasis (T4), and 5 minutes after hemostasis (T5) between the 2 groups, and significant differences were also observed in HR (P < .05) before intubation (T1). Moreover, significant differences were observed in propofol consumption (P < .05), urapidil consumption (P < .05), cough score during extubation (P < .05), and throat pain score after extubation (P < .05). However, no significant difference was observed in the recovery time (P > .05). Furthermore, no adverse events were detected in either group.

CONCLUSION

The results of this study showed that target-controlled plasma infusion of lidocaine can reduce propofol consumption in patients undergoing vocal cord polypectomy by supporting laryngoscopy, and the hemodynamics are more stable and reduce the coughing reaction in the wake period and throat pain after extubation without adverse events.

Use of intravenous lignocaine in the perioperative and chronic pain setting

Intravenous lignocaine has an emerging role in the treatment of acute pain within the perioperative setting, as recent consensus guidelines from the Association of Anaesthetists have shown. It has played a role in chronic pain management in recent decades, and continues to be a useful tool for pain specialists.

Role of Mechanoinsensitive Nociceptors in Painful Diabetic Peripheral Neuropathy

The cutaneous mechanisms that trigger spontaneous neuropathic pain in diabetic peripheral neuropathy (PDPN) are far from clear. Two types of nociceptors are found within the epidermal and dermal skin layers. Small-diameter lightly myelinated Aδ and unmyelinated C cutaneous mechano and heat-sensitive (AMH and CMH) and C mechanoinsensitive (CMi) nociceptors transmit pain from the periphery to central nervous system. AMH and CMH fibers are mainly located in the epidermis, and CMi fibers are distributed in the dermis. In DPN, dying back intra-epidermal AMH and CMH fibers leads to reduced pain sensitivity, and the patients exhibit significantly increased pain thresholds to acute pain when tested using traditional methods. The role of CMi fibers in painful neuropathies has not been fully explored. Microneurography has been the only tool to access CMi fibers and differentiate AMH, CMH, and CMi fiber types. Due to the complexity, its use is impractical in clinical settings. In contrast, a newly developed diode laser fiber selective stimulation (DLss) technique allows to safely and selectively stimulate Aδ and C fibers in the superficial and deep skin layers. DLss data demonstrate that patients with painful DPN have increased Aδ fiber pain thresholds, while C-fiber thresholds are intact because, in these patients, CMi fibers are abnormally spontaneously active. It is also possible to determine the involvement of CMi fibers by measuring the area of DLss-induced neurogenic axon reflex flare. The differences in AMH, CMH, and CMi fibers identify patients with painful and painless neuropathy. In this review, we will discuss the role of CMi fibers in PDPN.

"Post Mastectomy Pain Syndrome: A Systematic Review of Prevention Modalities"

Background

Post-mastectomy pain syndrome (PMPS) is a surgical complication of breast surgery characterized by chronic neuropathic pain. The development of PMPS is multifactorial and research on its prevention is limited. The objective of this systematic review is to synthesize the existing evidence on interventions for lowering the incidence of persistent neuropathic pain after breast surgery.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a comprehensive search of the electronic databases of MEDLINE, Cochrane Library, Embase, CINAHL, PsycINFO, Web of Science, and ClinicalTrials.gov using a combination of database-specific controlled vocabulary and keyword searches. Two reviewers independently screened all unique records. Publications on chronic (>3-month duration) pain after breast cancer-related surgery were included. Studies were classified by modality.

Results

Our literature search yielded 7092 articles after deduplication. We identified 45 studies that met final inclusion criteria for analysis, including 37 randomized-controlled trials. These studies revealed seven major intervention modalities for prevention of PMPS: physical therapy, mindfulness-based cognitive therapy, oral medications, surgical intervention, anesthesia, nerve blocks, and topical medication therapy.

Conclusion

High-quality data on preventative techniques for PMPS are required to inform decisions for breast cancer survivors. We present a comprehensive assessment of the modalities available that can help guide breast and reconstructive surgeons employ effective strategies to lower the incidence and severity of PMPS. Our review supports the use of multimodal care involving both a peripherally targeted treatment and centrally acting medication to prevent the development of PMPS.

Acute Visceral Pain in Rats: Vagal Nerve Block Compared to Bupivacaine Administered Intramuscularly

BACKGROUND

Visceral and parietal peritoneum layers have different sensory innervations. Most visceral peritoneum sensory information is conveyed via the vagus nerve to the nucleus of the solitary tract (NTS). We already showed in animal models that intramuscular (i.m.) injection of local anesthetics decreases acute somatic and visceral pain and general inflammation induced by aseptic peritonitis. The goal of the study was to compare the effects of parietal block, i.m. bupivacaine, and vagotomy on spinal cord and NTS stimulation induced by a chemical peritonitis.

METHODS

We induced peritonitis in rats using carrageenan and measured cellular activation in spinal cord and NTS under the following conditions, that is, a parietal nerve block with bupivacaine, a chemical right vagotomy, and i.m. microspheres loaded with bupivacaine. Proto-oncogene c-Fos (c-Fos), cluster of differentiation protein 11b (CD11b), and tumor necrosis factor alpha (TNF-α) expression in cord and NTS were studied.

RESULTS

c-Fos activation in the cord was inhibited by nerve block 2 hours after peritoneal insult. Vagotomy and i.m. bupivacaine similarly inhibited c-Fos activation in NTS. Forty-eight hours after peritoneal insult, the number of cells expressing CD11b significantly increased in the cord (P = .010). The median difference in the effect of peritonitis compared to control was 30 cells (CI95, 13.5-55). TNF-α colocalized with CD11b. Vagotomy inhibited this microglial activation in the NTS, but not in the cord. This activation was inhibited by i.m. bupivacaine both in cord and in NTS. The median difference in the effect of i.m. bupivacaine added to peritonitis was 29 cells (80% increase) in the cord and 18 cells (75% increase) in the NTS. Our study underlines the role of the vagus nerve in the transmission of an acute visceral pain message and confirmed that systemic bupivacaine prevents noxious stimuli by inhibiting c-Fos and microglia activation.

CONCLUSIONS

In rats receiving intraperitoneal carrageenan, i.m. bupivacaine similarly inhibited c-Fos and microglial activation both in cord and in the NTS. Vagal block inhibited activation only in the NTS. Our study underlines the role of the vagus nerve in the transmission of an acute visceral pain message and confirmed that systemic bupivacaine prevents noxious stimuli. This emphasizes the effects of systemic local anesthetics on inflammation and visceral pain.

Lidocaine infusions and reduced opioid consumption-Retrospective experience in pediatric hematology and oncology patients with refractory pain

BACKGROUND

Despite a more robust experience with lidocaine infusions for pain management in adults and general pediatric population, there is limited evidence of efficacy of lidocaine infusions for pain management in patients with pediatric hematology and oncology diagnoses.

METHODS

Data pertaining to continuous intravenous lidocaine infusions prescribed between January 2009 and June 2019 were reviewed, including patients' demographic characteristics, hematology/oncology and pain diagnoses, concurrent pain medications, and lidocaine infusion dose regimens and duration. Pain scores and opioid consumption calculations based on morphine equivalent doses (mg/kg/day) of patient-controlled analgesia were collected 1 day before infusion (D1), during infusion (D2), and 1 day after infusion (D3).

RESULTS

The mean opioid consumption on D3 was significantly lower than that on D2 (p = .01). The pain scores on D3 were significantly lower than those on D1 when measured as average pain scores per 24 hours (p < .001) or as single pain scores immediately before and after infusions (p < .001). No significant associations were found between cumulative doses of lidocaine (loading dose plus total infusion dose) and either a decrease in the opioid consumption or a decrease in pain scores.

CONCLUSIONS

In this retrospective series of pediatric hematology and oncology cases, we report positive outcomes in reducing opioid consumption and pain scores after lidocaine infusions. Prospective investigations designed in a collaborative, multi-institutional fashion, including a variety of pediatric populations are needed to further investigate the efficacy of lidocaine infusions.

Mechanisms of action of fascial plane blocks: a narrative review

BACKGROUND

Fascial plane blocks (FPBs) target the space between two fasciae, rather than discrete peripheral nerves. Despite their popularity, their mechanisms of action remain controversial, particularly for erector spinae plane and quadratus lumborum blocks.

OBJECTIVES

This narrative review describes the scientific evidence underpinning proposed mechanisms of action, highlights existing knowledge gaps, and discusses implications for clinical practice and research.

FINDINGS

There are currently two plausible mechanisms of analgesia. The first is a local effect on nociceptors and neurons within the plane itself or within adjacent muscle and tissue compartments. Dispersion of local anesthetic occurs through bulk flow and diffusion, and the resulting conduction block is dictated by the mass of local anesthetic reaching these targets. The extent of spread, analgesia, and cutaneous sensory loss is variable and imperfectly correlated. Explanations include anatomical variation, factors governing fluid dispersion, and local anesthetic pharmacodynamics. The second is vascular absorption of local anesthetic and a systemic analgesic effect at distant sites. Direct evidence is presently lacking but preliminary data indicate that FPBs can produce transient elevations in plasma concentrations similar to intravenous lidocaine infusion. The relative contributions of these local and systemic effects remain uncertain.

CONCLUSION

Our current understanding of FPB mechanisms supports their demonstrated analgesic efficacy, but also highlights the unpredictability and variability that result from myriad factors at play. Potential strategies to improve efficacy include accurate deposition close to targets of interest, injections of sufficient volume to encourage physical spread by bulk flow, and manipulation of concentration to promote diffusion.

Human surrogate models of central sensitization: A critical review and practical guide

Background

As in other fields of medicine, development of new medications for management of neuropathic pain has been difficult since preclinical rodent models do not necessarily translate to the clinics. Aside from ongoing pain with burning or shock‐like qualities, neuropathic pain is often characterized by pain hypersensitivity (hyperalgesia and allodynia), most often towards mechanical stimuli, reflecting sensitization of neural transmission.

Data treatment

We therefore performed a systematic literature review (PubMed‐Medline, Cochrane, WoS, ClinicalTrials) and semi‐quantitative meta‐analysis of human pain models that aim to induce central sensitization, and generate hyperalgesia surrounding a real or simulated injury.

Results

From an initial set of 1569 reports, we identified and analysed 269 studies using more than a dozen human models of sensitization. Five of these models (intradermal or topical capsaicin, low‐ or high‐frequency electrical stimulation, thermode‐induced heat‐injury) were found to reliably induce secondary hyperalgesia to pinprick and have been implemented in multiple laboratories. The ability of these models to induce dynamic mechanical allodynia was however substantially lower. The proportion of subjects who developed hypersensitivity was rarely provided, giving rise to significant reporting bias. In four of these models pharmacological profiles allowed to verify similarity to some clinical conditions, and therefore may inform basic research for new drug development.

Conclusions

While there is no single “optimal” model of central sensitization, the range of validated and easy‐to‐use procedures in humans should be able to inform preclinical researchers on helpful potential biomarkers, thereby narrowing the translation gap between basic and clinical data.

Significance

Being able to mimic aspects of pathological pain directly in humans has a huge potential to understand pathophysiology and provide animal research with translatable biomarkers for drug development. One group of human surrogate models has proven to have excellent predictive validity: they respond to clinically active medications and do not respond to clinically inactive medications, including some that worked in animals but failed in the clinics. They should therefore inform basic research for new drug development.

Wide Awake Open Carpal Tunnel Release: The Effect of Local Anesthetics in the Postoperative Outcome

Introduction  Wide awake open carpal tunnel decompression is a procedure performed under local anesthesia. This study aimed to present the effect of various local anesthetics in peri and postoperative analgesia in patients undergoing this procedure. Materials and Methods  A total of 140 patients, with 150 hands involved, underwent carpal tunnel release under local anesthesia. Patients were divided in five groups according to local anesthetic administered: lidocaine 2%, ropivacaine 0.75%, ropivacaine 0.375%, chirocaine 0.5%, and chirocaine 0.25%. Total 400 mg of gabapentin were administered to a subgroup of 10 cases from each group (50 cases totally), 12 hours before surgery. Patients were evaluated immediately, 2 weeks and 2 months after surgery according to VAS pain score, grip strength, and two-point discrimination. Results  In all patients, pain and paresthesia improved significantly postoperatively, while the use of gabapentin did not affect outcomes. Grip strength recovered and exceeded the preoperative value 2 months after surgery, without any difference between the groups. No case of infection, hematoma, or revision surgery was reported. Conclusion  Recovery after open carpal tunnel release appears to be irrelevant of the type of local anesthetic used during the procedure. Solutions of low local anesthetic concentration (lidocaine 2%, ropivacaine 0.375%, and chirocaine 0.25%) provide adequate intraoperative analgesia without affecting the postoperative course.

The analgesic effect of intravenous lidocaine versus intrawound or epidural bupivacaine for postoperative opioid reduction in spine surgery: A systematic review and meta-analysis

BACKGROUND

Pain management following spine surgery remains a challenge. The significant use of opioids may lead to opioid-related adverse events. These complications can increase perioperative morbidity and rapidly expend health care resources by developing chronic pain. Although intraoperative pain control for surgery has been studied in the literature, a thorough assessment of the effect in spine surgery is rarely reported. The objective of the present study was to examine the outcomes of intraoperative intravenous lidocaine and intrawound or epidural bupivacaine use in spine surgery.

METHODS

An electronic literature search was conducted for studies on the use of lidocaine and bupivacaine in spine surgery for all years available. Only articles in English language were included. Postoperative opioid consumption, VAS score, nausea/vomiting, and length of hospital stay comprised the outcomes of interest. Pooled descriptive statistics with Risk Ratios (RR), Mean Differences (MD) and 95 % confidence interval were used to synthesize the outcomes for each medication.

RESULTS

A total of 10 studies (n = 579) were included in the analysis. Comparison of the opioid consumption revealed a significant mean difference between lidocaine and bupivacaine (MD: -12.25, and MD: -0.4, respectively, p = 0.01), favoring lidocaine. With regard to postoperative VAS, the pooled effect of both groups decreased postoperative pain (MD: -0.61 (95 % CI: -1.14, -0.08)), with a more significant effect in the lidocaine group (MD: -0.84, (95 % CI: -1.21, -0.48)). There was no significant effect in length of stay, and postoperative nausea/vomiting.

CONCLUSIONS

The results of the present meta-analysis indicate that lidocaine and bupivacaine use may decrease postoperative pain and opioid consumption. Lidocaine had a stronger effect on the reduction of opioid consumption compared to bupivacaine.

Perioperative intravenous lignocaine infusion for postoperative pain control in patients undergoing surgery of the spine: protocol for a systematic review and meta-analysis

INTRODUCTION

Intravenous lignocaine is an amide local anaesthetic known for its analgesic, antihyperalgesic and anti-inflammatory properties. Administration of intravenous lignocaine has been shown to enhance perioperative recovery parameters. This is the protocol for a systematic review which intends to summarise the evidence base for perioperative intravenous lignocaine administration in patients undergoing spinal surgery.

METHODS AND ANALYSIS

Our primary outcomes include: postoperative pain scores at rest and movement at predefined early, intermediate and late time points and adverse events. Other outcomes of interest include perioperative opioid consumption, composite morbidity, surgical complications and hospital length of stay. We will include randomised controlled trials, which compared intravenous lignocaine infusion vs standard treatment for perioperative analgesia. We will search electronic databases from inception to present; MEDLINE, EMBASE and Cochrane Library (Cochrane Database of Systematic Reviews and CENTRAL). Two team members will independently screen all citations, full-text articles and abstract data. The individual study risk of bias will be appraised using the Cochrane risk of bias tool. We will obtain a risk ratio or mean difference (MD) from the intervention and control group event rates based on the nature of data. We will correct for the variable measurement tools by using the standardised MD (SMD). We will use a random-effects model to synthesise data. We will conduct five subgroup analysis: major versus minor surgery, emergency versus elective surgery, patients with chronic pain conditions versus patients without, duration of lignocaine infusion and adult versus paediatric. Confidence in cumulative evidence for will be classified according to the Grading of Recommendations, Assessment, Development and Evaluation system. We will construct summary of findings tables supported detailed evidence profile tables for predefined outcomes.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication.

PROSPERO REGISTRATION NUMBER

CRD420201963314.

Ketamine and lidocaine infusions decrease opioid consumption during vaso-occlusive crisis in adolescents with sickle cell disease

PURPOSE OF REVIEW

Recurrent exposure to opioids can lead to development of opioid tolerance and opioid-induced hyperalgesia through activation of N-methyl-D-aspartate receptors. N-methyl-D-aspartate receptor antagonists ketamine and lidocaine can modulate development of opioid tolerance and OIH. This study evaluated the utility of ketamine and/or lidocaine in decreasing opioid consumption during acute pain episodes in adolescents with sickle cell disease. There has been an increased effort to promote opioid-sparing pain relieving methods given the ongoing opioid epidemic.

RECENT FINDINGS

There have been six studies published over the past decade that highlight the ability of ketamine to reduce opioid consumption in the management of sickle cell disease-related pain, primarily in adult patients. There has been one study (2015) that demonstrated a similar benefit with lidocaine, however this was also in adult patients.

SUMMARY

We retrospectively evaluated treatment with ketamine and/or lidocaine infusions in adolescents hospitalized for vaso-occlusive crisis (VOC). Patients served as self-controls using a comparison with a previous control admission for VOC. The use of ketamine and/or lidocaine as adjuncts to opioids resulted in lower daily opioid consumption in three of four patients. Our study suggests that ketamine and/or lidocaine infusions may be useful adjuncts in reducing opioid exposure during VOC pain.

Application of Intravenous Lidocaine in Obese Patients Undergoing Painless Colonoscopy: A Prospective, Randomized, Double-Blind, Controlled Study

OBJECTIVE

Propofol for procedural sedation and analgesia (PSA) for colonoscopy can result in a high prevalence of severe respiratory depression. Studies have shown that intravenous (IV) infusion of lidocaine can reduce propofol requirements significantly and increase the ventilatory response to carbon dioxide in humans. We tested the hypothesis that IV lidocaine could improve propofol-induced respiratory depression in obese patients during colonoscopy.

METHODS

Ninety obese patients scheduled for painless colonoscopy were randomized to receive lidocaine (1.5 mg/kg, then 2 mg/kg/h, IV) or the same volume of 0.9% saline. Intraoperative sedation was provided by propofol. The primary outcome was the number of oxygen-desaturation episodes. Secondary outcomes were: the number of apnea episodes; total propofol consumption; time to the first hypoxia episode; time to consciousness loss; intraoperative hemodynamic parameters; awakening time; adverse events; duration of post-anesthesia care unit (PACU) stay; satisfaction of endoscopists and patients.

RESULTS

Demographic characteristics between the two groups were comparable. The number of oxygen-desaturation episodes in group L (1.49±1.12) decreased by 0.622 (P=0.018) compared with that in group N (2.11±1.32), and the number of apnea episodes in group L decreased by 0.533 (P<0.001). Kaplan-Meier curves showed that the median time to the first hypoxia episode was longer in group L (86.78 s) than that in group N (63.83 s) (Log rank P=0.0008). The total propofol consumption, awakening time, and duration of PACU stay were reduced in group L. There was no significant difference in the prevalence of adverse events (P>0.05 for all). Satisfaction scores for endoscopists and patients in group L were higher than that in group N (P<0.001).

CONCLUSION

Intravenous infusion of lidocaine could significantly reduce the number of oxygen-desaturation and apnea episodes in obese patients during painless colonoscopy. This method is worthy of clinical promotion.

CLINICAL TRIALS REGISTRATION

ChiCTR2000028937.

The Efficacy of Lidocaine in Disrupting Cocaine Cue-Induced Memory Reconsolidation

RATIONAL

Cue-induced craving memories, linked to drug-seeking behaviors, require key molecular processes for memory reconsolidation. Lidocaine, a sodium channel blocker, inhibits NMDA receptor activation and suppresses nitric oxide and ERK production. These processes are required for memory re-consolidation; inhibiting them may reduce cue-related craving memories in cocaine dependent subjects.

OBJECTIVES

To assess the efficacy of lidocaine in decreasing cue-induced cocaine craving and cocaine use.

METHODS

Treatment-seeking cocaine-dependent participants (n = 33, 25 men) were recruited. Personalized craving and relaxation scripts were developed. Participants were then randomly assigned in a double-blind design to either receive intravenous lidocaine immediately following a cocaine craving script (lidocaine/craving), saline following a craving script (saline/craving), or lidocaine following a relaxation script (lidocaine/relax). One week following the infusion, cue-induced craving was assessed in the same paradigm without an infusion. Cocaine use and craving were assessed for 4 weeks following infusion.

RESULTS

The administration of lidocaine during craving induction (lidocaine/craving) did not decrease cue-induced craving during craving reactivation one week later or craving and cocaine use over the 4-week follow-up period compared to the saline/craving group. There were no significant differences in craving and cocaine use between the lidocaine/relax and saline/craving groups.

CONCLUSION

Lidocaine administered following craving induction did not decrease subsequent cue-induced craving or cocaine use. Blocking the reconsolidation of craving-related memories with pharmacological agents remains an important area of investigation.

Intravenous lidocaine affects oxaliplatin pharmacokinetics in simultaneous infusion

BACKGROUND

Oxaliplatin is a chemotherapeutic agent used to treat malignancies of the gastrointestinal tract. Neuropathy is a frequent dose-limiting side-effect of oxaliplatin therapy, without preventive or curative strategies. Concomitant administration of intravenous lidocaine could be a promising treatment. However, the effect of intravenous lidocaine on oxaliplatin pharmacokinetics was never studied before. We evaluated the effect of lidocaine on the area under the curve and C_max of oxaliplatin as a part of a larger study addressing the prevention and treatment of oxaliplatin induced peripheral neuropathy with lidocaine.

METHODS

In this prospective cross-over trial, patients received an oxaliplatin cycle with and without lidocaine (bolus 1.5 mg kg^-1 followed by 1.5 mg kg^-1 h^-1 in 3 h). Levels of oxaliplatin, measured as ultrafiltrable platinum were determined at 10 min after cessation of oxaliplatin infusion and hourly thereafter. Outcomes are the difference in area under the curve of oxaliplatin (primary) and the difference in the C_max of oxaliplatin (secondary).

RESULTS

No difference in the %Δ area under the curve of oxaliplatin (-2.40 ± 7.66, 90% CI +10.50 to -15.31) was found. However, %Δ C_max of oxaliplatin (-28.72 ± 6.01, 90% CI -18.59 to -38.85) was lower to a statistically significant extent in the chemotherapy cycle with lidocaine. No (serious) adverse events were reported.

CONCLUSIONS

Lidocaine does not affect the area under the curve of oxaliplatin, which is the most important parameter in drug interaction studies and for oxaliplatin treatment effect. The lower C_max in the chemotherapeutic cycle with lidocaine is significant and remarkable, but with an unknown exact mechanism or clinical significance, making further research desirable.

Impact of perioperative pain management on cancer recurrence: an ASRA/ESRA special article

Cancer causes considerable suffering and 80% of advanced cancer patients experience moderate to severe pain. Surgical tumor excision remains a cornerstone of primary cancer treatment, but is also recognized as one of the greatest risk factors for metastatic spread. The perioperative period, characterized by the surgical stress response, pharmacologic-induced angiogenesis, and immunomodulation results in a physiologic environment that supports tumor spread and distant reimplantation.In the perioperative period, anesthesiologists may have a brief and uniquewindow of opportunity to modulate the unwanted consequences of the stressresponse on the immune system and minimize residual disease. This reviewdiscusses the current research on analgesic therapies and their impact ondisease progression, followed by an evidence-based evaluation of perioperativepain interventions and medications.

Acute Pain in Older Adults: Recommendations for Assessment and Treatment

The management of acute pain in older adults (age 65 or greater) requires special attention due to various physiologic, cognitive, functional, and social issues that may change with aging. Especially in the postoperative setting, there are significant complications that can occur if pain is not treated adequately for elderly patients. In this article, the authors describe these changes in detail and discuss how pain should be assessed appropriately in older patients. In addition, the authors detail the unique risks and benefits of several mainstream analgesic medications as well as interventional treatments for elderly patients. The authors' goal is to provide recommendations for health care providers on appropriately recognizing and treating pain in a safe, effective manner for aging patients.

Intravenous Lidocaine for Chronic Neuropathic Pain A Systematic Review Addressing Nursing Care

BACKGROUND

The intravenous administration of lidocaine for patients with chronic neuropathic pain is well documented in the literature. However, little is known about the role of the nurse caring for patients receiving the infusion.

AIM

The purpose of this systematic review was to examine and describe common side effects associated with the intravenous administration of lidocaine to patients with chronic neuropathic pain and outline nursing care described in an effort to develop evidence-based protocols for care.

METHOD

A comprehensive search of databases was completed and yielded eleven (n = 11) articles and one care protocol for analysis.

RESULTS

Evidence was appraised and findings suggest intravenous lidocaine has a low risk of causing adverse events, however patients should be monitored closely.

CONCLUSIONS

Nursing care focuses on pain assessment, close observation and intervention if neurological changes occur.

Effects of intravenous infusion of lidocaine and dexmedetomidine on inhibiting cough during the tracheal extubation period after thyroid surgery

Background

Intravenous lidocaine and dexmedetomidine treatments have been proposed as methods for inhibiting cough. We compared the efficacy of intravenous lidocaine and dexmedetomidine treatments on inhibiting cough during the tracheal extubation period after thyroid surgery.

Methods

One hundred eighty patients undergoing thyroid surgeries were randomly allocated to the LIDO group (received lidocaine 1.5 mg/kg loading, 1.5 mg/kg/h infusion), the DEX group (received dexmedetomidine 0.5 μg/kg loading, 0.4 μg/kg/h infusion) and the CON group (received saline), with 60 cases in each group. The primary outcomes of cough were recorded. Secondary outcomes included hemodynamic variables, awareness time, volume of drainage, the postoperative visual analogue scale and adverse effects were recorded.

Results

The incidence of cough were significantly lower in the LIDO group (28.3%) and the DEX group (31.7%) than that in the CON group (66.7%) (P = 0.000). Additionally, both moderate and severe cough were significantly lower in the LIDO group (13.3%) and the DEX group (13.4%) than these in the CON group (43.4%) (P < 0.05). Compared with the two treatment groups, both mean arterial blood pressure and heart rate were significantly increased in the CON group during tracheal extubation (P < 0.05). Compared with the CON group, the volume of drainage was significantly reduced in the two treatment groups within 48 h after surgery (P < 0.05). compared with the CON group, the postoperative visual analogue scale was significantly lower in groups LIDO and DEX after surgery(P < 0.05). Compared with the LIDO group and the CON group, the time to awareness was longer in the DEX group (P < 0.05). In the DEX group, bradycardia was noted in 35 patients, while no bradycardia was noted in LIDO group and CON group.

Conclusion

Compared with intravenous infusions of normal saline, both lidocaine and dexmedetomidine had equal effectiveness in attenuating cough and hemodynamic changes during the tracheal extubation period after thyroid surgery, and both of these treatments were able to reduce the volume of postoperative bleeding and provide better analgesic effect after surgery. But intravenous infusions of dexmedetomidine resulted in bradycardia and delayed the time to awareness when compared with lidocaine and normal saline.

Trial registration

ChiCTR1800017482. (Prospective registered). Initial registration date was 01/08/2018.

Lidocaine inhibits proliferation and induces apoptosis in colorectal cancer cells by upregulating mir-520a-3p and targeting EGFR

Lidocaine is a conventional local anesthetic which is shown antiproliferative of colorectal cancer (CRC) in patients. MicroRNAs (miRNAs) have been consistently demonstrated to be involved in CRC, and miR-520a-3p could suppress CRC migration, promote apoptosis by targeting epidermal growth factor receptor (EGFR). However, the mechanism by which lidocaine regulated CRC proliferation and apoptosis remains unknown. In this study, quantitative RT-PCR were used to measure miR-520a-3p and EGFR expression levels, and western blotting assays ware performed to measure EGFR expression in CRC cells. Luciferase reporter assay was employed to validate the direct targeting of EGFR by miR-520a-3p. Cell proliferation and apoptosis assays ware utilized to analyze the role of lidocaine in CRC cells. The results indicated that 500 and 1000 μM lidocaine over 24 h inhibited proliferation and induced apoptosis of CRC cells. Compared with the control group, the expression of EGFR was suppressed by lidocaine (500 μM) in CRC cells. Furthermore, miR-520a-3p could directly targets EGFR in CRC cells. Lidocaine (500 μM) increased the expression of miR-520a-3p and rescued the reduction of miR-520a-3p caused by miR-520a-3p inhibitor. The results suggested that lidocaine could suppress the expression of EGFR by upregulating miR-520a-3p, and it could induce apoptosis and inhibit proliferation in CRC cells. Lidocaine may serve as potential therapeutic regimen for colorectal cancer.

A randomized crossover study of the effects of lidocaine on motor- and sensory-evoked potentials during spinal surgery

BACKGROUND CONTEXT

Lidocaine has emerged as a useful adjuvant anesthetic agent for cases requiring intraoperative monitoring of motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SSEPs). A previous retrospective study suggested that lidocaine could be used as a component of propofol-based intravenous anesthesia without adversely affecting MEP or SSEP monitoring, but did not address the effect of the addition of lidocaine on the MEP and SSEP signals of individual patients.

PURPOSE

The purpose of this study was to examine the intrapatient effects of the addition of lidocaine to balanced anesthesia on MEPs and SSEPs during multilevel posterior spinal fusion.

STUDY DESIGN

This is a prospective, two-treatment, two-period crossover randomized controlled trial with a blinded primary outcome assessment.

PATIENT SAMPLE

Forty patients undergoing multilevel posterior spinal fusion were studied.

OUTCOME MEASURES

The primary outcome measures were MEP voltage thresholds and SSEP amplitudes. Secondary outcome measures included isoflurane concentrations and hemodynamic parameters.

METHODS

Each participant received two anesthetic treatments (propofol 50 mcg/kg/h and propofol 25 mcg/kg/h+lidocaine 1 mg/kg/h) along with isoflurane, ketamine, and diazepam. In this manner, each patient served as his or her own control. The order of administration of the two treatments was determined randomly.

RESULTS

There were no significant within-patient differences between MEP threshold voltages or SSEP amplitudes during the two anesthetic treatments.

CONCLUSIONS

Lidocaine may be used as a component of balanced anesthesia during multilevel spinal fusions without adversely affecting the monitoring of SSEPs or MEPs in individual patients.

Clinical Efficacy of Intravenous Lidocaine for Thyroidectomy: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Systemic lidocaine has analgesic and anti-inflammatory effects. The purpose of this prospective, randomized, double-blind study was to evaluate the effects of intravenous lidocaine on pain following thyroidectomy.

METHODS

Fifty-eight adult patients scheduled for total thyroidectomy were randomly allocated to receive a 1.5 mg/kg lidocaine bolus followed by a 2 mg/kg/h infusion during surgery, or the same volume of normal saline (control). After thyroidectomy, we evaluated postoperative pain, nausea, fentanyl consumption, frequency of pushing the button (FPB) for patient-controlled analgesia (PCA), High-sensitivity C-reactive protein (hs-CRP) in serum, and patient satisfaction scores regarding the recovery process.

RESULTS

Postoperative pain and nausea scores were significantly lower in the lidocaine group for the first 4 h following thyroidectomy, compared to the control group. Fentanyl consumption and FPB for the PCA were also significantly reduced in the lidocaine group for 4 h following thyroidectomy, and hs-CRP was significantly less in the lidocaine group at postoperative days 1 and 3. Furthermore, satisfaction scores were significantly higher in the lidocaine group compared to the control group.

CONCLUSIONS

Intravenous lidocaine effectively reduced postoperative pain and nausea following thyroidectomy as well as improved the quality of recovery.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT01608360.

Effect of perioperative intravenous lidocaine infusion on postoperative recovery following laparoscopic Cholecystectomy-A randomized controlled trial

BACKGROUND AND OBJECTIVE

Intravenous lidocaine infusion has been shown to facilitate postoperative recovery after major abdominal surgery. The current randomized controlled study was performed to assess the effect of perioperative intravenous lidocaine infusion on pain intensity, bowel function and cytokine response after larparoscopic cholecystectomy.

METHODS

Eighty patients undergoing laparoscopic cholecystectomy were randomly allocated to receive intravenous lidocaine (bolus injection of 1.5 mg/kg lidocaine at induction of anesthesia, then a continuous infusion of 2 mg/kg/h until the end of surgery) or an equal volume of saline. Patients, anesthesiologists, and study personnel were blinded, and anesthesia and multimodal perioperative analgesia were standardized. Blood cytokines were measured at scheduled times within 48 h. Pain scores, opioid consumption, time to first flatus and time to first bowel movement were also measured after surgery.

RESULTS

Seventy-one of the 80 patients who were recruited completed the study protocol. Patient demographics were similar in the two groups. Lidocaine significantly reduced pain intensity [visual analogue scale (VAS), 0-10 cm] at 2 h (lidocaine 3.01 ± 0.65 cm vs. placebo 4.27 ± 0.58 cm, p = 0.01) and 6 h (lidocaine 3.38 ± 0.42 cm vs. placebo 4.22 ± 0.67 cm, p = 0.01) and total fentanyl consumption 24 h after surgery (lidocaine 98.27 ± 16.33 μg vs. placebo 187.49 ± 19.76 μg, p = 0.005). Time to first flatus passage (lidocaine 20 ± 11 h vs. placebo 29 ± 10 h, p = 0.01) and time to first bowel movement (lidocaine 41 ± 16 h vs. placebo 57 ± 14 h, p = 0.01) were also significantly shorter in patients who received lidocaine. Intravenous lidocaine infusion experienced less cytokine release than the control group.

CONCLUSIONS

This study indicates that perioperative systemic lidocaine improves postoperative recovery and attenuates the initiation of excessive inflammatory response following laparoscopic cholecystectomy.

A Review of Adjunctive CNS Medications Used for the Treatment of Post-Surgical Pain

Inadequate post-operative pain management can have significant impacts on patients' quality of life. Effective management of acute pain after surgery is important for early mobilization and discharge from hospital, patient satisfaction, and overall well-being. Utilizing multimodal analgesic strategies has become the mainstay of acute post-operative pain management. A comprehensive search was performed, assessing the published or otherwise publically available literature on different central nervous system (CNS) drugs [excluding opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and acetaminophen] and their uses to treat acute post-surgical pain. Included among the drugs evaluated in this review are anticonvulsants, N-methyl-D-aspartic acid (NMDA) agonists, local anesthetics, α₂-agonists, cannabinoids, serotonin-noradrenaline reuptake inhibitors (SNRIs), and serotonin-noradrenaline-dopamine reuptake inhibitors (SNDRIs). Timing, dosing, routes of administration, as well as mechanisms of action are discussed for these CNS drugs.

Perioperative Use of Intravenous Lidocaine

Perioperative lidocaine infusion improves analgesia and recovery after some surgical procedures, possibly through systemic antiinflammatory effects. This commentary provides the clinician with evidence for rational use of perioperative lidocaine infusion in procedures where it is of demonstrated benefit.

Effects of systemic lidocaine versus magnesium administration on postoperative functional recovery and chronic pain in patients undergoing breast cancer surgery: A prospective, randomized, double-blind, comparative clinical trial

Introduction

We aimed to compare the effects of intraoperative lidocaine and magnesium on postoperative functional recovery and chronic pain after mastectomy due to breast cancer. Systemic lidocaine and magnesium reduce pain hypersensitivity to surgical stimuli; however, their effects after mastectomy have not been evaluated clearly.

Methods

In this prospective, double-blind, clinical trial, 126 female patients undergoing mastectomy were randomly assigned to lidocaine (L), magnesium (M), and control (C) groups. Lidocaine and magnesium were administered at 2 mg/kg and 20 mg/kg for 15 minutes immediately after induction, followed by infusions of 2 mg/kg/h and 20 mg/kg/h, respectively. The control group received the same volume of saline. Patient characteristics, perioperative parameters, and postoperative recovery profiles, including the Quality of Recovery 40 (QoR-40) survey, pain scales, length of hospital stay, and the short-form McGill pain questionnaire (SF-MPQ) at postoperative 1 month and 3 months were evaluated.

Results

The global QoR-40 scores on postoperative day 1 were significantly higher in group L than in group C (P = 0.003). Moreover, in sub-scores of the QoR-40 dimensions, emotional state and pain scores were significantly higher in group L than those in groups M and C (P = 0.027 and 0.023, respectively). At postoperative 3 months, SF-MPQ and SF-MPQ-sensitive scores were significantly lower in group L than in group C (P = 0.046 and 0.036, respectively).

Conclusions

Intraoperative infusion of lidocaine improved the quality of recovery and attenuated the intensity of chronic pain in patients undergoing breast cancer surgery.

Intravenous lidocaine for effective pain relief after bimaxillary surgery

OBJECTIVES

The aim of this prospective, randomized, double-blind, placebo-controlled study was to evaluate the analgesic effect of intravenous lidocaine on postoperative pain in bimaxillary surgery.

MATERIALS AND METHODS

Between July 2015 and November 2015, 52 consecutive patients that underwent bimaxillary surgery were recruited to the present study. The patients were randomly divided into two groups: group L (1.5 mg/kg bolus and 2 mg/kg/h continuous infusion during the operation) and group C (normal saline). To measure pain intensity, a visual analog scale (VAS) was used at 2, 4, 8, 12, 24, and 48 h after surgery. Rescue ketorolac use was measured in the first 4, 4-8, 8-24, and 24-48 h after surgery. Total ketorolac consumption (the sum of rescue and eight-hourly fixed schedule ketorolac injection), WBC count, neutrophil count, and postoperative swelling were recorded.

RESULTS

There were no significant differences between the two groups with respect to demographics. VAS pain scores were significantly lower in group L compared with group C up to 8 h after surgery. Rescue ketorolac use up to 8 h after surgery and total ketorolac consumption were significantly lower in group L than in group C. Postoperative WBC and neutrophil counts were significantly decreased in group L. Compared with group C, the amount of calibrated postoperative swelling was lower in group L.

CONCLUSIONS

Systemic lidocaine infusion during bimaxillary surgery reduces postoperative pain, analgesic consumption, and facial swelling.

CLINICAL RELEVANCE

Systemic lidocaine is simple, economic, and a safe procedure reducing pain and soft tissue swelling after bimaxillary surgery.

Lidocaine Infusion: A Promising Therapeutic Approach for Chronic Pain

Opioid abuse is a national epidemic in the United States, where it is estimated that a prescription drug overdose death occurs every 19 minutes. While opioids are highly effective in acute and subacute pain control, their use for treatment of chronic pain is controversial. Chronic opioids use is associated with tolerance, dependency, hyperalgesia. Although there are new strategies and practice guidelines to reduce opioid dependence and opioid prescription drug overdose, there has been little focus on development of opioid-sparing therapeutic approaches. Lidocaine infusion has been shown to be successful in controlling pain where other agents have failed. The opioid sparing properties of lidocaine infusion added to its analgesic and antihyperalgesic properties make lidocaine infusion a viable option for pain control in opioid dependent patients. In this review, we provide an overview of the opioid abuse epidemic, and we outline current evidence supporting the potential use of lidocaine infusion as an adjuvant therapeutic approach for management of chronic pain.