Assessment of the Pharmacokinetics and Pharmacodynamics of Injectable Lidocaine and a Lidocaine-Impregnated Latex Band for Castration and Tail Docking in Lambs.

The objectives of this study were to assess the pharmacokinetics and pharmacodynamics of the current standard-of-care for pain mitigation in lambs during castration and tail docking (injectable lidocaine) and assess the ability of Lidocaine-Loaded Bands (LLBs) to deliver therapeutic concentrations into the contacted tissues over time. The study was comprised of four different trials: (1) investigation of in vitro release of lidocaine from LLBs; (2) pharmacokinetics and pharmacodynamics of injectable lidocaine in scrotal and tail tissue; (3) pharmacokinetics and pharmacodynamics of in vivo delivery of lidocaine with LLBs placed on the tail and scrotum of lambs; and (4) a "proof-of-concept" study comparing the sensation of control- versus LLB-banded tail tissue over time. The use of injectable lidocaine provides effective short-term anesthesia for 120 to 180 min following the injection; however, additional strategies are needed to manage long-term pain. The use of an LLB could provide an alternative where tissue lidocaine concentrations meet or exceed the EC50 for at least 21-28 days and, based on electrostimulation data, provides local anesthesia for at least 3 days when compared to a control band. Further studies are needed to compare the use of an injectable local anesthetic to the LLBs.

Comparative Evaluation of Electronic Acupuncture Pen and 2% Lignocaine Gel as an Intraoral Topical Anesthetic Agent in Children.

Background The most exasperating aspect for pediatric patients in a dental setup is the fear and anxiety caused by injections, called "blenophobia". There are numerous local anesthetic agents available to reduce the needle prick pain. Taking into consideration the paradigm shift, there is always a possibility for alternate treatment options. This study aimed to evaluate and compare the effectiveness of transcutaneous electrical nerve stimulation (TENS) application through an electronic acupuncture pen (Meridian Energy Acupuncture Pen W-912 GENERIC) and 2% lignocaine gel as an intraoral topical anesthetic agent in children. Method Patients aged 6 to 12 years were eligible for inclusion. The topical anesthetic agents were administered to the patients in a bilateral split-mouth technique. In Group A, 2% topical anesthetic gel was administered on the first visit on one side of the mandible and topical anesthesia through the electronic acupuncture pen was administered on the next visit, on the opposite side of the mandible. The electronic acupuncture pen was applied on one side of the mandible on the first visit, and on the next appointment, 2% topical anesthetic gel on the other side was administered in Group B. Sound, eye, motor scale (SEM) and faces pain scale-Revised (FPS) were used as tools of evaluation after local anesthesia was administered.  Results  The comparison between electronic acupuncture pen and 2% lignocaine gel using the SEM scale shows a statistically insignificant difference (p-value = 0.082). Similarly, a comparison of FPS values between both groups indicates no significant difference (p-value = 0.582). However, results show a reduced pain perception in both groups. Conclusion Topical anesthetic agents are commonly used to reduce needle prick pain in children. TENS through the electronic acupuncture pen, a revisited aid in scientific research, has proved its efficacy as a topical pain reduction measure during dental treatment. This device overcomes the shortcomings of the anesthetic gels and also nullifies the chances of overdosage, hypersensitivity, and disagreeable taste. Thus, this tool can be used in dental practice for the management of pain in children.

Local Anesthetic Systemic Toxicity During Transversus Abdominis Plane Block With Liposomal Bupivacaine.

Local anesthetic systemic toxicity (LAST) is a rare but potentially fatal outcome associated with local anesthetic administration. Liposomal bupivacaine (LB; EXPAREL®) is a widely used local anesthetic with extended-release and liposomal formulation that carries an improved cardiac and central nervous system safety profile. However, there is limited data regarding LAST associated with liposomal bupivacaine. Here is described a case of local anesthetic systemic toxicity in a 68-year-old male who presented with obstructing sigmoid adenocarcinoma and underwent open sigmoidectomy with end descending colostomy. The operation was complicated by LAST following transversus abdominis plane block injection with liposomal bupivacaine resulting in cardiac arrest. Return of spontaneous circulation was achieved following advanced cardiac life support and infusion of 20% I.V. fat emulsion. Given the widespread use of local anesthetics, providers must be aware of the pathophysiology, diagnosis, and immediate treatment of LAST.

Assessing CRNA Knowledge of Local Anesthetic Systemic Toxicity Treatment.

Local anesthetic systemic toxicity (LAST) is a rare life-threatening adverse event. Due to the potential for devastating patient outcomes, it is crucial for anesthesia providers to understand appropriate LAST management. The primary aim of this study was to assess certified registered nurse anesthetist (CRNA) knowledge of the 2020 American Society of Regional Anesthesia and Pain Medicine (ASRA) LAST treatment guidelines. The secondary aim was to determine whether there was a relationship between the frequency of CRNAs' exposure to perioperative local anesthetic use and their knowledge level. A quantitative descriptive study and national American Association of Nurse Anesthetists electronic survey solicited practicing CRNAs. Survey findings revealed knowledge scores averaging 47.3% among 184 respondents. Almost all (97.8%) recognized the importance of early lipid emulsion administration. Over half (54.3%) were unaware of the recommended epinephrine dosing during LAST. No relationship was found between knowledge level and CRNAs' exposure to local anesthetics. Those who reported having immediate access to written or electronic guidelines in the event of LAST had significantly higher knowledge scores than those without access (P = .049). Implementing cognitive aids may help bridge knowledge gaps identified in this study and ensure critical steps are not missed. Further studies examining the use of cognitive aids to improve CRNA knowledge of LAST management may be beneficial in the future.

Standing sedation management of a domesticated reindeer for third eyelid removal.

Background: Reindeer are becoming popular animals within petting farms. Few case reports describe the sedation of domesticated reindeer, but none describe the use of ocular local anesthetic blocks in this species. Case Description: A 9-year-old, female, Svalbard reindeer (Rangifer tarandus platyrhynchus) presenting for removal of a squamous cell carcinoma involving the third eyelid. Standing sedation was performed using initial boluses of medetomidine and butorphanol via intramuscular injection before catheter placement and maintenance with a variable rate infusion of medetomidine. Supraorbital, auriculopalpebral, infratrochlear blocks and local infiltration of the base of the third eyelid were performed using mepivacaine. Following the surgical removal of the third eyelid, atipamazole was administered intramuscularly to antagonize the effects of medetomidine. The patient recovered without complications. Conclusion: Medetomidine-butorphanol in combination with local anesthetic blocks provided a sufficient plane of sedation and analgesia for extra ocular surgery in a domesticated reindeer.

Sustained release of levobupivacaine from temperature-sensitive injectable hydrogel for long-term local anesthesia in postoperative pain management.

Postoperative pain is a major concern for most of the surgical patients, and an inadequate postoperative pain control may cause a series of complications. With an effective pain control and lesser side effects, local anesthetics are preferred for use in postoperative pain management. However, the action duration of current local anesthetics is too short to meet the requirements of postoperative analgesia. In this study, an injectable levobupivacaine (LB)-loaded thermo-sensitive hydrogel system based on biodegradable poly(D,L-lactide)-poly(ethylene glycol)-poly(D,L-lactide) (PLEL) was developed for long-acting local anesthetic, in which the soluble charged cation form of LB (LB HCl) was partly alkalified to the poorly soluble base form (LB base). This hybrid LB loaded PLEL system (hLB/PLEL) is a free flowable liquid at room temperature and changes into a semi-solid hydrogel once injection in response to the physiological temperature. Then, the dissolved LB HCl could release firstly from the hydrogel contributing to a quick work, and the insoluble LB base dissolved and released gradually as the decrease of the pH during the biodegradation of PLEL hydrogel, resulting in a long-term LB release in local. The drug release behavior, pharmacokinetic, and biocompatibility of the thermo-sensitive hLB/PLEL were studied in vitro and in vivo. The anesthetic effects of hLB/PLEL system were evaluated in the rat models of sciatic nerve block, subcutaneous infiltration anesthesia and postoperative pain as well. This hLB/PLEL system generated a significantly prolonged analgesic effect in rat models, which produced approximately 7 times longer duration than 0.75% LB HCl and effectively relieved the spontaneous pain for 3 days. In general, the presented hLB/PLEL system can not only achieve a fast-acting but also sustainably release LB to block the nerve and significantly extend the effect of local analgesia, which means a promising candidate for long-acting postoperative pain management.

A Patient with Known Allergy to Local Anesthesia Presenting for a Dental Restoration.

Dentists should be equipped to treat an allergic reaction in a dental office, and in this scenario, the potential allergic reaction is noted after administration of a common local anesthetic lidocaine with epinephrine. The allergic reaction quickly escalates to a full-blown anaphylaxis, and the management of such an episode is detailed in this article.

Comparative study of two different computer-controlled local anesthesia injection systems in children: a randomized clinical trial.

PURPOSE: To compare pain perception associated with two computer-controlled local anesthesia devices, the WAND™ STA (Milestone Scientific Inc., Livingston, NJ, USA) and the Calaject (Rønvig dental MFG, Daugaard, Denmark) in young children. METHODS: A split-mouth randomized clinical trial comprising 30 patients, aged 6-12 years, received randomly, in two separate sessions, a local anesthesia injection in the maxillary using either the wand STA or the Calaject. Pain perception was evaluated using the patient's heart rate, an 11-point numerical scale (NRS), and the Sound, Eye, and Motor (SEM) body movements. Statistical difference was set at p = 0.05. Repeated measures analysis of variance were conducted to compare the mean pulse for Calaject and STA at different times. It was followed by univariate analysis and Bonferroni multiple comparisons tests. Wilcoxon tests were performed to compare NRS, SEM, and injection duration between Calaject and STA. RESULTS: There was no significant statistical difference between Calaject and STA in pulse rate before injection (p = 0.720), during injection (p = 0.767), and after injection (p = 0.757). The mean NRS score was significantly greater with STA in comparison with Calaject (p = 0.017). The mean SEM score was also significantly greater with STA in comparison with Calaject (p = 0.002). However, the mean duration was significantly longer with Calaject (p = 0.001). CONCLUSIONS: Calaject was more effective than STA in reducing pain perception associated with periapical injection in young children.

Evaluation of the Local Anesthetic Activity, Acute Toxicity, and Structure-Toxicity Relationship in Series of Synthesized 1-Aryltetrahydroisoquinoline Alkaloid Derivatives In Vivo and In Silico.

Isoquinoline alkaloids constitute one of the most common classes of alkaloids that have shown a pronounced role in curing various diseases. Finding ways to reduce the toxicity of these molecules and to increase their therapeutic margin is an urgent matter. Here, a one-step method for the synthesis of a series of 1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines was performed in 85-98% yield by the Pictet-Spengler reaction. This was accomplished using the reaction between 3,4-dimethoxyphenylethylamine and substituted benzaldehydes boiling in trifluoroacetic acid. Furthermore, 1-(3'-amino-, 4'-aminophenyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines were obtained in 94% and 97% yield by reduction in 1-(3'-nitro-, 4'-nitrophenyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines with SnCl2 × 2H2O. The structures of the substances obtained were confirmed by infrared (IR) and nuclear magnetic resonance (1H and 13C NMR) spectra. ADMET/TOPKAT in silico study concluded that the synthesized compounds exhibited acceptable pharmacodynamic and pharmacokinetic properties without carcinogenic or mutagenic potential but with variable hepatotoxicity. The acute toxicity and structure-toxicity relationship (STR) in the series of 20 derivatives of 1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (3a-r, 4a, b) was studied via determination of acute toxicity and resorptive action in white mice employing intragastric step-by-step administration. The first compound, 1-phenyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (3a), showed the highest toxicity with LD50 of 280 mg/kg in contrast to 1-(3'-bromo -4'-hydroxyphenyl)-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (3e) which proved to be the safest of the compounds studied. Its toxicity was 13.75 times lower than that of the parent compound 3a. All compounds investigated showed high local anesthetic activity on rabbit eyes in the concentrations studied. Only 3r, 3n, and 4a caused eye irritation and redness. All investigated derivatives (except 4b) in 1% concentration were more active than lidocaine, providing longer duration of complete anesthesia. Therefore, based on the obtained results of in silico tests, local anesthesia, and acute toxicity, a conclusion can be drawn that the experimental compounds need further extensive future investigations and possible modifications so that they can act as promising drug candidates.

The Benefits of Local Anesthesia Used in Mastectomy Without Reconstruction.

BACKGROUND: The opioid epidemic has driven renewed interest in local anesthesia to reduce postoperative opioid use. Our objective was to determine if local anesthesia decreased hospital pain scores, oral morphine equivalents (OME), length of stay (LOS), and nausea/vomiting. METHODS: Single institution retrospective study of females who underwent mastectomy without reconstruction. RESULTS: Overall, 712 patients were included; 63 (8.8%) received bupivacaine (B), 512 (72%) liposomal bupivacaine (LB), and 137 (19%) no local. 95% were discharged on POD1. Liposomal bupivacaine use increased from 2014 to 2019. Additional factors associated with use of local regimen were surgeon and extent of axillary surgery. Fewer patients used postop opioids during their hospital stay if any local was used compared to none (76 vs 88%; 0.003). Compared to none, local had shorter mean PACU LOS (95 vs 87 min; P = .02), lower mean intraoperative-OME (96 vs 106; P < .001), and lower mean postoperative OME/hr (1.4 vs 1.8 P = .001). Multivariable analysis (MVA) showed lower OME/hr with LB compared to B and none (P = .002); this translates to 22 mg and 30 mg of oxycodone in a 24-hr period, respectively. MVA showed lower POD1 pain scores with LB relative to none (P = .049). Local did not impact nausea/emesis. CONCLUSION: Local anesthesia was superior to no local in several measures. However, a consistent benefit of a specific local anesthetic agent was not demonstrated (LB vs B). A prospective study is warranted to determine the optimal local regimen for this cohort and further inform clinical relevance.

Complications After Dental Sedation: A Myotonic Mystery Case Report.

Myotonic dystrophy (dystrophia myotonica; DM) is an uncommon progressive hereditary muscle disorder that can present with variable severity at birth, in early childhood, or most commonly as an adult. Patients with DM, especially type 1 (DM1), are extremely sensitive to the respiratory depressant effects of sedative-hypnotics, anxiolytics, and opioid agonists. This case report describes a 37-year-old male patient with previously undiagnosed DM1 who received dental care under minimal sedation using intravenous midazolam. During the case, the patient experienced 2 brief episodes of hypoxemia, the second of which required emergency intubation after propofol and succinylcholine and resulted in extended hospital admission. A lipid emulsion (Liposyn II 20%) infusion was given approximately 2 hours after the last local anesthetic injection due to slight ST elevation and suspicion of local anesthetic toxicity (LAST). Months after treatment, the patient suffered a fall resulting in a fatal traumatic brain injury. Complications noted in this case report were primarily attributed to the unknown diagnosis of DM1, although additional precipitating factors were likely present. This report also provides a basic review of the literature and clinical guidelines for managing myotonic dystrophy patients for dental care with local anesthesia, sedation, or general anesthesia.

Comparison of pain perception between computer-controlled local anesthetic delivery and the conventional syringe for inferior alveolar nerve block in children.

BACKGROUND: Local anesthesia (LA) is commonly used for pain control in clinical dental practice. However, it is often perceived as the most painful part of the treatment and the factor leading to the avoidance of dental care. Hence, research on better means of pain management is being conducted. OBJECTIVES: The aim of the study was to evaluate and compare pain perception using the No Pain III™ computer-controlled local anesthesia delivery (CCLAD) system and the conventional syringe, for inferior alveolar nerve block (IANB) in children. MATERIAL AND METHODS: Thirty children aged 6-12 years were included in the study. Children were randomly allocated into 2 groups by the flip of a coin. Group A received LA by conventional syringe and group B received LA by No Pain III™, on the contralateral side. Physiological parameters including blood pressure (BP), heart rate (HR) and respiratory rate (RR) were assessed at baseline, during the deposition and after the deposition of LA. A subjective evaluation of pain perception was assessed using the Wong-Baker FACES Pain Rating Scale (WBS). The measured values were subjected to statistical analysis. RESULTS: A statistically significant difference was observed between group A and group B for pain perception using the WBS, systolic BP and RR. CONCLUSIONS: The use of the No Pain III™ CCLAD system resulted in reduced pain perception and better acceptance when compared to the use of the conventional syringe, for IANB in children.

[Aspiration test as dental anesthesia safety criterion]. / Aspiratsionnyi test kak kriterii bezopasnosti obezbolivaniya v stomatologii.

Intravascular anesthetic injection can lead to acute toxic reaction even the minimal dose of the drug was administered. The aspiration test is a generally accepted standard for local anesthesia in medicine, specially designed to reduce the risk of emergency conditions. Medical instruments should be adapted for aspiration test, the local anesthetic carpule should have a retention notch, and the dental syringe plunger need to have retention elements. The aspiration test protocol may vary. For legal protection of the doctor the aspiration test result should be described in the patient's medical record.

Effectiveness Of Local Anaesthetic In Reducing Postoperative Pain At Port Site After Laparoscopic Cholecystectomy.

Background: Laparoscopy has become the highest quality level way to deal with cholecystectomy since its inception 30 years preceding, and is perhaps the most normally performed general surgeries. Pain being a significant issue after laparoscopic cholecystectomy bringing about extended admissions or readmissions. With significant varieties in pain relieving conventions an integrated approach is important to diminish pain. The aim of this study is to assess the effectiveness of Bupivacaine as local anesthetic agent at port sites after laparoscopic cholecystectomy. Method: Study population of 84 patients was divided into control group (receiving no local anesthetic) and study group (receiving Bupivacaine as local anesthetic). Visual analogue scale was used to quantify and compare pain perceived by each group; at fixed intervals of 6, 12 and 24 hours after shifting of the patients back to the ward. Results: Each group comprised 42 patients. At 6 hours post operative pain score in study group, 4.5±0.32 was significantly lower than in control group, 7.6±0.41 (p<0.05). Though pain assessments at 12 and 24 hours didn't reveal any significant differences among the two groups; postoperative requirement of Tramadol was significantly (p<0.05) lower in study group (92±0.064mg) in comparison to control group (158±0.21mg). Conclusion: Use of long-acting local anesthetic injections at port sites after laparoscopic cholecystectomy significantly lowers pain during first 6 hours post operatively and also lowers narcotic analgesics requirements during post operative period.

Minimal anesthetic manual small-incision cataract surgery (MSICS): A novel technique in use for anesthesia in MSICS.

Ever-evolving modern day cataract extraction techniques have been accompanied by the use of smaller quantities and less invasive methods of anesthesia. Topical anesthesia is routinely used for phacoemulsification. However, peribulbar block or some modification of it is used for anesthesia in manual small-incision cataract surgery (MSICS) by most practitioners. The authors describe a technique using a combination of 1.5-2 milliliters of anesthetic mixture given subconjunctivally and supplemented with commercially available intracameral anesthetic and mydriatic for MSICS. It is possible to get high level of anesthetic effect and ease of surgery with this technique though there is a small learning curve. Several modifications from topical phacoemulsification like two side ports six o'clock hours apart make this surgery easy to adapt to. No special instrumentation is required. It gives adequate analgesia and anesthesia to complete the surgery. a minimalistic anesthetic approach in MSICS can be used with enhanced safety and by avoiding usual complications of traditional peribulbar and retrobulbar anesthesia.

The clinical efficacy of minocycline mouth rinse on recurrent aphthous stomatitis-A randomized controlled trial.

Introduction: Recurrent aphthous stomatitis (RAS) is one of the most common ulcerative diseases affecting the general population. The present study aimed to evaluate the clinical efficiency of 0.5% minocycline mouth rinse prescribed along with the topical anesthetic gel and vitamin supplement over the topical anesthetic gel and vitamin supplement prescribed alone for treating RAS. Materials and Methods: A total of 60 participants were randomly divided into two groups-experimental group: 0.5% minocycline mouth rinse prescribed along with vitamin supplement and topical anesthetic gel; and control group: vitamin supplement and topical anesthetic gel alone. The pain symptoms were evaluated using the VAS scores at baseline and first follow-up visits. The data were analyzed using Student's t test. Results: A significant reduction in the pain scores was observed in participants using the 0.5% minocycline mouth rinse prescribed along with vitamin supplement and topical anesthetic gel on the first follow-up visit (P = < 0.001). Conclusion: The 0.5% minocycline mouth rinse prescribed along with vitamin supplement and topical anesthetic gel had shown more reduction in the pain symptoms when compared to topical anesthetic gel and vitamin supplement prescribed alone for the treatment of RAS.

Physiological Response of Atlantic Salmon (Salmo salar) to Long-Term Exposure to an Anesthetic Obtained from Heterosigma akashiwo.

Despite the invaluable role of anesthetics as a tool for ensuring animal welfare in stressful situations, there is currently a lack of anesthetic drugs that meet the requirements of intensive aquaculture. In response to the growing interest in anesthetic substances of natural origin, this study evaluated the physiological and health impact of an anesthetic based on an extract of the microalga Heterosigma akashiwo on juvenile salmon (Salmo salar) exposed for a period of 72 h. To simulate a condition closer to reality where fish are subjected to stimuli (e.g., transport), the animals were exposed to 50 mg L-1 of algal extract and to physical stress. Functional, physiological, and histological parameters were evaluated in blood and tissues at different sampling periods (0, 24, and 72 h). There was no mortality and the induction and recovery times observed were within the established criteria for anesthetic efficacy. The anesthetic extract did not induce any side effects, such as stress or metabolic damage, indicating that this extract is a viable option for supporting fish welfare during deleterious events. This study provides information to support that the anesthetic extract tested, derived from H. akashiwo, is a promising candidate drug for operations requiring sedation (e.g., Salmonid transport).

Local anesthetic systemic toxicity: A narrative review for emergency clinicians.

INTRODUCTION: Emergency clinicians utilize local anesthetics for a variety of procedures in the emergency department (ED) setting. Local anesthetic systemic toxicity (LAST) is a potentially deadly complication. OBJECTIVE: This narrative review provides emergency clinicians with the most current evidence regarding the pathophysiology, evaluation, and management of patients with LAST. DISCUSSION: LAST is an uncommon but potentially life-threatening complication of local anesthetic use that may be encountered in the ED. Patients at extremes of age or with organ dysfunction are at higher risk. Inadvertent intra-arterial or intravenous injection, as well as repeated doses and higher doses of local anesthetics are associated with greater risk of developing LAST. Neurologic and cardiovascular manifestations can occur. Early recognition and intervention, including supportive care and intravenous lipid emulsion 20%, are the mainstays of treatment. Using ultrasound guidance, aspirating prior to injection, and utilizing the minimal local anesthetic dose needed are techniques that can reduce the risk of LAST. CONCLUSIONS: This focused review provides an update for the emergency clinician to manage patients with LAST.

Neuronal Nitric Oxide Synthase Suppression Confers the Prolonged Analgesic Effect of Sciatic Nerve Block With Perineural Dexamethasone in Postoperative Pain Model Mice.

Dexamethasone supplementation to local anesthetics prolongs its action, yet the underlying mechanism is unclear. Previous studies have reported that increased p-p38 mitogen-activated protein kinase (MAPK) in the dorsal root ganglia (DRG) is associated with pain-associated behavior and that nitric oxide (NO), which is known to be a pronociceptive substance, directly inhibits sciatic nerve conduction. Here, we investigated the temporal changes in the hyperalgesic effect and p-p38 MAPK and NO synthase (NOS) expression levels in the DRG when dexamethasone was added to ropivacaine used for a sciatic nerve block (SNB) in postoperative pain model mice. Dexamethasone supplementation to ropivacaine significantly prolonged the analgesic effect of SNB via glucocorticoid receptor activation. Histological examination revealed that ropivacaine suppressed p-p38 MAPK expression in the DRG regardless of dexamethasone supplementation, suggesting that p-p38 MAPK was not involved in the prolonging effect of dexamethasone on nerve block. Contrastingly, plantar incision markedly increased the expression of neuronal NOS (nNOS) in DRG, and dexamethasone supplementation to ropivacaine significantly suppressed nNOS expression. Supplementation of L-NAME, an inhibitor of NOS, to ropivacaine markedly prolonged the effect of SNB, similar to dexamethasone. These results suggest that dexamethasone supplementation to local anesthetics prolongs the analgesic effect by inhibiting nNOS activity. PERSPECTIVE: The current study revealed that dexamethasone supplementation to local anesthetics prolongs the analgesic effect by inhibiting the activity of neuronal NOS and that p-p38 MAPK may not be involved in this phenomenon. Our findings offer a new target for the discovery of long-acting local anesthetics.

Reducing tumescent anesthetic injection pain by topical anesthesia pretreatment among patients undergoing endovenous radiofrequency ablation of varicose veins: A double-blind randomized controlled trial.

OBJECTIVES: Tumescent anesthesia frequently causes the intraoperative and postoperative pain during radiofrequency ablation (RFA) of varicose veins. We have to find a way to reduce pain caused by these injections. This randomized controlled trial investigated the effectiveness of topical anesthesia pretreatment (TAP) on relieving needle puncture pain during administration of tumescent anesthesia among patients undergoing RFA of varicose veins. METHODS: Eligible patients treated with RFA were recruited and randomized to either application of TAP with lidocaine-prilocaine cream (EMLA) or water-based cream (placebo). The primary outcome was patient described pain scores on the visual analogue scale (VAS) at different time points during the procedure. Secondary outcomes were technical success rate, complications, satisfaction level, expense, and extra analgesia use. RESULTS: Sixty-two patients were randomized: 32 to EMLA and 30 to placebo. Both groups had comparable baseline demographics, CEAP classification, and Venous Clinical Severity Score (VCSS). Less tumescent anesthetic needle puncture pain was found in the EMLA group (22 ± 7 vs 42 ± 8, p < .01). Pain scores of other time points were equivalent. There was less pain in EMLA pretreated area compared to non-pretreated area in the same patient during needle puncture (22 ± 7 vs 45 ± 7, p < .01), and similar phenomena did not appear in the placebo group. There was no statistical difference in complications, satisfaction level, expense, and technical success between the two groups. And no extra analgesia was used in all patients. CONCLUSION: We recommend the routine use of TAP to reduce the needle puncture pain during tumescent anesthesia in RFA of lower extremity varicose veins.