Lidocaine Hydrochloride Solution Research Articles

Comparing Efficacy and Safety Aspects of 2% Lidocaine Hydrochloride Combination with 1:80.000 Added Epinephrine Solution versus the Most Commonly Used 2% Lidocaine Hydrochloride Solution in Surgical Procedures on Human Fingers and Toes

The effective management of pain and hemostasis is a pivotal concern in surgical procedures performed on human fingers and toes. The anatomical intricacies and limited tissue volume demand a meticulous approach to ensure both the safety of the patient and the successful outcome of the surgery. The use of vasoconstrictor agents, such as epinephrine, to provide clear surgical field and better surgical outcome further complicates the landscape. While epinephrine is a valuable adjunct to local anesthesia due to its hemostatic properties and ability to prolong anesthetic effects, its application in procedures on fingers and toes necessitates a deep understanding of potential risks and complications. This literature review delves into the comparative analysis of two widely employed local anesthetic solutions which are the 2% lidocaine hydrochloride solution and the 2% lidocaine hydrochloride solution combined with 1:80,000 epinephrine, with specific aim to comprehensively evaluate the efficacy and safety aspects of both local anesthetic solutions. Lidocaine solution alone offers effective pain relief with minimal systemic risks but might lack the extended duration and hemostasis benefits of epinephrine. The lidocaine-epinephrine combination solution provides prolonged anesthesia and reduced bleeding, but clinicians must balance these advantages with the potential for ischemic events and delayed wound healing. Close monitoring, precise dosing, and careful patient selection are paramount in ensuring successful outcomes while minimizing complications.

СОЕДИНЕНИЕ N-АЦЕТИЛ-6-АМИНОГЕКСАНОВОЙ КИСЛОТЫ ПОДАВЛЯЕТ НЕРВНУЮ ПРОВОДИМОСТЬ

Local anesthetic effect of N-acetyl-6-aminohexanoate salt (compound LHT-9-17) in the form of a substance with a purity of 99.8% was studied and also assessed the effect of the substance on the conductivity of single sodium channels and the conductivity of the nerve conductor at normal pH values and against the background of acidosis. Experimental ligature periodontitis was modeled in 20 laboratories male Wistar rats weighing 200-220 g. Local anesthetic effects of 2% LHT-9-17 and 2% lidocaine hydrochloride solution induced by infraorbital administration was assessed at day 12 of the pathology development. Conduction of single Na-channels was assessed by patch-clamp method on isolated giant neurons of Limnea stagnalis. Registration of the action potential of Rana radibunda isolated sciatic nerve was carried out in perfusion chamber contained 0.00001 to 0.01 μM LCT-9-17. Experiments included increasing the force of stimulating incentives until the maximum response. Compound LHT-9-17 has local anesthetic activity, including during the inflammatory process. The analgesic effect is due to the suppression of the conductivity of Na-channels of nerve conductors. The activity kept under inflammatory conditions may be due to the action of substances against the inflammatory state.

The versatility of the transnasal sphenopalatine ganglion block.

Dear Editor, We read with great interest the article by Ferjani et al.1 on how a patient’s headache from a postoperative spinal dural tear was successfully relieved with a bilateral transnasal sphenopalatine ganglion block. This is a simple and valuable technique that was discovered in 1908, but few anesthesiology or pain physicians are familiar with the block and its versatility. Intranasal devices for the administration of the transnasal sphenopalatine ganglion block are available but are expensive and might not be readily available at all institutions. To safely and inexpensively perform the transnasal sphenopalatine ganglion block to treat headaches and also extend the treatment to other types of pain, we have created our own device from supplies that are readily accessible in most medical facilities. For our transnasal sphenopalatine ganglion block applicator, we attached a 3-mL syringe (filled with 4% lidocaine hydrochloride solution) to one side of intravenous extension tubing with a stopcock, and we attached a hollow cotton swab dipped into 5% lidocaine ointment to the other side of the tubing. The patients position themselves supine with neck extension and hemodynamic monitoring. The applicator is gently advanced perpendicular to the patient’s nostril until the tip reaches the back of the nasal pharynx and gentle resistance is met. Lidocaine 4% is administered slowly under low pressure through the cotton-tipped applicator until the medication is felt in the back of the throat. A second applicator is then inserted into the opposite nostril, and the medication is administered as before. Symptoms are evaluated 15 minutes after insertion. If the symptoms are not sufficiently relieved, this procedure is repeated up to 2 more times. In our experience, this transnasal sphenopalatine ganglion block has successfully relieved the pain amenable to sphenopalatine ganglion blockade; importantly, this approach has not had a technical failure.

Efficacy of fascia iliaca nerve block in daily routine for children with femoral fractures in a pediatric emergency department

ObjectivesWe aimed to evaluate the efficacy of fascia iliaca nerve block (FINB), routinely used for children with femoral fractures, in a pediatric emergency department (PED). MethodsThis retrospective, single-center, observational study examined FINB using ropivacaine and a 1% lidocaine hydrochloride solution, in all patients under 18 years of age admitted with a femoral fracture from January 2012 to December 2016. Pain was assessed using two validated pediatric pain scales: EVENDOL or a visual analog scale. A level of ≥ 4 on either scale indicates the need for an analgesic. The primary outcome was the percentage of patients who were pain free after the FINB procedure defined by a pain score of < 4. Secondary outcomes were the time spent between PED admission and FINB, the need of additional analgesics, side effects, and the success rate of FINB. ResultsOf 161 patients screened, 144 were included. The median age was 3.2 years (range 2 months to 16 years) and 74% were boys. The number of children determined to be pain free (pain score < 4) increased from 36 (25%) before the FINB to 123 (85%) after the FINB (absolute risk difference 60%, 95% CI: 51%–70%). Overall, 21 children (15%) required a second analgesic after the FINB. ConclusionThe routine use of FINB with ropivacaine and lidocaine by pediatric ED physicians provided effective pain relief for children admitted for a femoral fracture in the emergency department. Our data support the efficiency and feasibility of FINB for the antalgic management of children with femoral fracture.

Pilot Randomized Clinical Trial Study: Comparative Study of 10% Lidocaine Hydrochloride Solution with Lidocaine Prilocaine Emulsion Prior to Local Anesthetic Injection

Background: The pain caused by the injection of local anesthetic has been reported as one of the main complaints of dental patients. Topical anesthetics are widely used drugs in dentistry, mainly to control pain associated with the needle penetration in the administration of local anesthesia. Objective: The present study aimed to evaluate (5%,7.5% and 10%) concentrations of lidocaine/prilocaine agent, compared to the common 10% lidocaine hydrochloride spray in the oral cavity. Materials and Methods: This was a split-mouth double-blind, randomized clinical trial pilot study. We randomized 15 patients, ages 35 to 64 years, with American Society of Anesthesiologists I and II with severe chronic periodontitis who were referred to the dental clinic for surgery, to receive 4 topical anesthetics (5%, 7.5%, and 10%) lidocaine prilocaine emulsion and 10% lidocaine hydrochloride topical anesthetic agent before local infiltration. Primary outcomes were assessing drug safety and pain level that measured by assessment of visual analog scale (VAS) scores of pain during LA injection in the first premolar and second molar in each maxillary quadrant in 15 patients corresponding to the posterior superior alveolar nerve (PSA) and secondary outcome was the relationship between age and gender regarding pain perception, and a total of 60 regions were analyzed. Results: Results revealed that there was no statistically significant difference between lidocaine hydrochloride and (5%,7.5% and 10%) lidocaine prilocaine in terms of pain reduction when the 4 different compounds were compared. According to Spearman's rank correlation coefficient and Friedman test, the age and gender of the patients had an insignificant correlation with the anesthetic effects of the four studied solutions. Conclusion: Based on these results, age and gender have insignificant effects on the pain scores and it can be said that the four solutions do not have significant differences regarding their anesthetic effects; also, we did not find any adverse reactions by using 7.5% and 10% lidocaine/prilocaine agent.

Use of topical anaesthesia and peribulbar anaesthesia in Descemets membrane endothelial keratoplasty.

In instances where peribulbar anaesthesia (PBA) cannot be used, Descemet membrane endothelial keratoplasty (DMEK) surgery can be performed under topical anaesthesia (TA). We evaluated subjective pain and post-operative outcomes of DMEK surgeries performed under PBA and TA. Sixty pseudophakic patients without history of ocular comorbidities underwent DMEK surgery under either PBA or TA. PBA was performed with a single injection of 6 mL Prilocaine Hydrochloride 2% in combination with 1500 I.U. hyaluronidase. For TA, patients were given 0.4% Oxybuprocaine eye drops followed by a 2% Lidocain Hydrochloride-Gel and an intraoperative injection of a 2% Lidocaine Hydrochloride solution into the anterior chamber. All surgeries were performed by the same surgeon. Subjective pain was measured using a visual analog scale (VAS). Secondary outcomes (BCVA, duration of surgery, endothelial density, rebubbling rate) were recorded during a follow-up period of 3 months. The mean subjective pain of patients in the PBA group was 1.27 (95% CI 0.87-1.68) and 1.64 (95% CI 1.15-2.21) in the TA group. The mean duration of surgery was 402 s (95% CI 356-448) in the PBA group and 427 s (95% CI 371-483) in the TA group, p = 0.477. No major differences were observed in BCVA, endothelium density and rebubbling rate between the two groups. Anaesthesia-related side effects were more frequent in the PAB group than in the TA group. Although levels of subjective pain are lower under PBA than under TA, in selected patients without ocular comorbidities TA can achieve levels of pain acceptable for DMEK surgery.

Comprehensive treatment of dogs with chronic generalized periodontitis in remission

It is known that periodontal diseases are a significant part of dental diseases in dogs. Chronic generalized periodontitis deserves the most attention. The disease develops slowly, beginning without visible clinical signs, but later, a combination of certain favorable etiological factors can lead to the loss of the animal's teeth, indigestion, metabolism with serious consequences for the dog. Therefore, the search of the features of the disease and the development of tactics for effective treatment of periodontally ill animals is relevant for modern veterinary dentistry. The aim of the work was to study the features of the course of chronic generalized periodontitis in remission in dogs and to develop tactics for rational treatment of periodontally ill animals. For the study, two groups of animals with chronic generalized periodontitis were formed in remission with 5 dogs in each (control and experimental), selected on the principle of analogues in terms of age and nature of the pathological process. Searches have shown that in chronic generalized periodontitis in remission in dogs there is an increase in the number of pathogenic microflora in the biotopes of the oral cavity, increasing the activity of acid phosphatase, increasing the protein concentration by reducing the content of lysozyme in the oral fluid. It was found that the dogs of the experimental group, after removal of tartar and rehabilitation of the oral cavity, were treated by using to the gums of ceftriaxone, diluted in 1% lidocaine hydrochloride solution in combination with 30 % dimexid solution 1 time per day for 7 days, anfluron injecteed intramuscularly at the rate of 1 ml 1 time per day for 7 days and caforsen – 0.1 ml/kg per day for 4 weeks. The treatment contributed to the recovery of dogs for 10 days, which is 8 days faster than in the control group.

Effects of 2% lidocaine hydrochloride solution as a coinduction agent with propofol on cardiopulmonary variables and administered propofol doses in healthy dogs premedicated with hydromorphone hydrochloride and acepromazine maleate.

To evaluate the effects of lidocaine as a coinduction agent with propofol on cardiopulmonary variables and administered propofol doses in healthy dogs premedicated with hydromorphone hydrochloride and acepromazine maleate and anesthetized with isoflurane. 40 client-owned dogs (American Society of Anesthesiologists physical status classification I or II and age ≥ 6 months) scheduled to undergo anesthesia for elective procedures. In a randomized, blinded, controlled clinical trial, dogs received 2% lidocaine hydrochloride solution (2.0 mg/kg [0.9 mg/lb], IV; n = 20) or buffered crystalloid solution (0.1 mL/kg [0.05 mL/lb], IV; 20; control treatment) after premedication with acepromazine (0.005 mg/kg [0.002 mg/lb], IM) and hydromorphone (0.1 mg/kg, IM). Anesthesia was induced with propofol (1 mg/kg [0.45 mg/lb], IV, with additional doses administered as needed) and maintained with isoflurane. Sedation was assessed, and anesthetic and cardiopulmonary variables were measured at various points; values were compared between treatment groups. Propofol doses, total sedation scores, and anesthetic and most cardiopulmonary measurements did not differ significantly between treatment groups over the monitoring period; only oxygen saturation as measured by pulse oximetry differed significantly (lower in the lidocaine group). Mean ± SD propofol dose required for endotracheal intubation was 1.30 ± 0.68 mg/kg (0.59 ± 0.31 mg/lb) and 1.41 ± 0.40 mg/kg (0.64 ± 0.18 mg/lb) for the lidocaine and control groups, respectively. No propofol-sparing effect was observed with administration of lidocaine as a coinduction agent for the premedicated dogs of this study. Mean propofol doses required for endotracheal intubation were considerably lower than currently recommended doses for premedicated dogs. (J Am Vet Med Assoc 2020;256:93-101).

Plasma concentrations of lidocaine following laryngeal administration or laryngeal and intratesticular administration in cats.

OBJECTIVE To determine plasma concentrations of lidocaine after laryngeal administration or laryngeal and intratesticular administration in cats. ANIMALS 14 healthy adult sexually intact male cats (7 cats/treatment). PROCEDURES Cats were randomly allocated to receive 0.1 mL of 2% or 10% lidocaine hydrochloride solution (treatments L2 and L10, respectively) sprayed on the larynx for laryngeal desensitization, followed by endotracheal intubation and isoflurane anesthesia. After a 7-day washout period, cats were again randomly allocated to receive treatment L2 or L10, and castration was performed under isoflurane anesthesia following intratesticular administration of 2% lidocaine solution (0.1 mL/kg). In both experiments, a blood sample for measurement of plasma lidocaine concentration was obtained before (0 minutes) and 3, 5, 10, 15, 20, 30, 45, 60, and 75 minutes after laryngeal administration of lidocaine solution. Anesthesia was discontinued at 60 minutes. Plasma lidocaine concentrations were measured with high-performance liquid chromatography. RESULTS After treatments L2 and L10, median maximum plasma lidocaine concentrations were 34.1 ng/mL (range, 0 to 279.4 ng/mL) and 93.6 ng/mL (range, 79.3 to 182.2 ng/mL), respectively. Time to maximum plasma concentration was 10 minutes (range, 0 to 20 minutes) for each treatment. When cats received intratesticular lidocaine administration following L2 or L10 treatment, median maximum plasma concentration was 181.0 ng/mL (range, 103.7 to 600.2 ng/mL) and 301.2 ng/mL (range, 265.8 to 1,770.0 ng/mL), respectively. CONCLUSIONS AND CLINICAL RELEVANCE On the basis of these data, combined laryngeal and intratesticular administration of lidocaine solution at a total dose of approximately 5 mg/kg appears to be safe for use in healthy adult cats.

Abstract OT3-07-04: A randomized study comparing MoistHer to topical lidocaine for female breast cancer survivors with dyspareunia

Abstract BACKGROUND: Problems related to sexual function are known to affect quality of life in female breast cancer survivors (BCS). A leading symptom of sexual dysfunction reported by BCS is dyspareunia, defined as moderate to severe penetrative pain with intercourse that results in reduced frequency of intercourse or abstinence. Dyspareunia in females is most commonly caused by vaginal dryness and primarily treated with estrogen therapy, a contraindication for many BCS. A recent trial found that estrogen-deficient BCS with dyspareunia who applied topical lidocaine to the vulvar vestibule (VV) prior to penetrative intercourse (PI) reported decreased pain during PI and improvement of sexual distress (Goetsch MF, JCO 2015). Identification of additional non-hormonal therapies to target the VV prior to PI may therefore provide treatment options for the improvement of sexual dysfunction in BCS with dyspareunia. TRIAL DESIGN: This is a double-blind, randomized trial to evaluate the benefits of applying natural lubricant MoistHer (MH) to the VV prior to PI in female BCS with dyspareunia. Subjects must be female ≥18 years BCS without active treatment (except for hormonotherapy), in a stable heterosexual partnership for ≥5 years, and report ≥ 3 months of consistent pain with PI. Patients with a history of pelvic pain, pelvic floor myalgia, vulvar dermatoses, or vaginismus will be excluded. Subjects will be randomized 1:1 to blinded home therapies of either MH or Topical Lidocaine (TL) for application to VV. MH is a commercially available vaginal moisturizer made of emu oil, tocopherol, safflower oil, and aloe extract and will be supplied by manufacturer Dromeo Inc. TL will be a 4% aqueous lidocaine hydrochloride solution prepared by research pharmacist (RP). Both MH and TL will be dispensed by RP in identical unmarked bottles. Subjects will agree to apply study liquid to VV and attempt PI at least twice per week for 4 weeks while maintaining a study diary to record pain scores. Outcomes will be measured via Sexual Function Questionnaire (SFQ), Female Sexual Distress Score-Revised (FSDS-R), and a rating of pain during PI on a scale of zero (no pain) to 10 (worst pain) via Numerical Rating Scale (NRS), to be completed by subjects at baseline, 2 weeks, and 4 weeks. AIMS: Primary endpoint is pain with PI, to be reported as a score on the NRS. Secondary endpoints are improved quality of sexual life and resumption of PI, to be measured by the SFQ and FSDS-R. STATS/TARGET ACCRUAL: A total of 50 patients will be recruited and randomized to receive either MH or TL at a 1:1 ratio (25 per group) using the Pocock-Simon dynamic allocation method. This sample size will achieve 94% power to detect at least 1.5 points NRS mean difference between treatments. NRS change will be compared between the two arms using a two-sample t-test (Pooled Standard error or Satterthwaite approximation as appropriate). Secondary outcomes include the SFQ and FSDS-R for which a longitudinal analysis of subscale scores will be conducted using a generalized linear mixed-effects model with fixed effects for treatment group and time. All statistical analyses will be conducted using SAS 9.3 [SAS Institute Inc., Cary, NC, USA]. Statistical significance will be defined as p &amp;lt; 0.05. Citation Format: Bendinger GM, Baptist S, Alvarez Tapias C, McGuire E, Rados K, Nixon D, Randolph K, McNight JE, Pabbathi H, Panicker R, Johnson AT, Geisler JP, Manahan KJ, Lammersfeld C, Avarez RH. A randomized study comparing MoistHer to topical lidocaine for female breast cancer survivors with dyspareunia [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-07-04.

Intraperitoneal lidocaine hydrochloride for prevention of intraperitoneal adhesions following laparoscopic genitourinary tract surgery in ewes

Adhesion formation involving the genitourinary tract is common following laparoscopic procedures. To evaluate the effectiveness of intraperitoneal lidocaine hydrochloride 1% solution for the prevention of abdominal adhesions, twenty four Santa Ines ewes submitted to laparoscopic ovum pick-up, uterine puncture and local rinsing, were randomly distributed into two groups of 12 animals, according to rinsing solution: normal saline (SG) or 1% lidocaine hydrochloride solution (LG). Laparoscopy for manipulation of the reproductive tract (uterine puncture trauma model and ovum pick-up) was applied. A standard laparoscopic approach using three ports in triangulation was employed. The uterus and ovaries were rinsed at the end of the procedure (using either saline or lidocaine hydrochloride) for removal of blood clots from the ovaries and uterine horn surfaces. Inflammation was assessed postoperatively by plasma fibrinogen, and all animals underwent a second laparoscopic procedure 21days after surgery for macroscopic assessment of adhesion formation. Four cases of adhesion were observed in each group. The plasma fibrinogen did not differ between groups and among different time points, indicating an absence of systemic inflammation following laparoscopic procedures. There were no significant differences between treatments. Both normal saline and 1% lidocaine hydrochloride were similarly effective in the prevention of adhesion formation.

Bacteremia in the pedal circulation following regional intravenous perfusion of a 2% lidocaine solution in cattle with deep digital sepsis.

To evaluate whether pedal bacteremia develops following regional IV perfusion (RIVP) of a 2% lidocaine hydrochloride solution in cattle with deep digital sepsis (DDS) and to determine which bacterial pathogens are most commonly isolated from the pedal circulation. Prospective observational cohort study. 9 adult cattle with DDS in 10 limbs and 10 healthy adult cattle with no evidence of lameness or digital infection. Blood samples were obtained aseptically from the dorsal common digital vein immediately following tourniquet application and 30 to 60 minutes after aseptic RIVP with a 2% lidocaine solution. Aerobic and anaerobic bacterial cultures were performed on all samples collected. For cattle with DDS, clinical examination with or without debridement of digital lesions was performed after RIVP. Bacteria were isolated from pedal blood prior to RIVP in 1 cow with DDS and after RIVP and examination with or without debridement in that cow and 4 additional cattle with DDS. Bacteria were not isolated from any blood sample obtained from the healthy cattle. Of the 8 bacterial isolates identified, 5 were gram-positive facultative anaerobes. Cattle with DDS were significantly more likely to develop bacteremia in the pedal circulation than were healthy cattle following RIVP. Results indicated that bacteremia may be present in the pedal circulation before and following RIVP and examination with or without debridement in cattle with DDS. Thus, systemic or local antimicrobial treatment might be warranted prior to or concurrently with RIVP in cattle with DDS.

A New Method of Topical Anesthesia by Using Anesthetic Solution in a Patch

IntroductionWe investigated the effects of topical anesthesia of the oral mucosa by using an adhesive patch instilled with 2% lidocaine hydrochloride solution. MethodsThe subjects were 20 healthy adult volunteers who gave written informed consent. Each patient was treated in a randomized crossover fashion with a hemostatic adhesive patch instilled with one of the following agents: 2% lidocaine hydrochloride with 12.5 μg/mL epinephrine, 2% lidocaine hydrochloride, 20% ethyl aminobenzoate, or physiological saline solution. A cotton ball containing 20% ethyl aminobenzoate was also tested. The adhesive patch or cotton ball was placed on the gingivobuccal fold of the maxillary right canine for 2 or 5 minutes. Then, a 33-gauge or 30-gauge needle was inserted to a depth of 2 mm. Insertion pain was evaluated with a visual analog scale (VAS) and a 4-level verbal rating scale immediately after needle removal. Efficacy of analgesia was calculated from the verbal rating scale. ResultsThe VAS was lower and the efficacy of analgesia was higher on 33-gauge needle insertion than on 30-gauge needle insertion in all treatments. The VAS was also significantly lower and the efficacy of analgesia was higher in the lidocaine groups than in the other groups. Adding epinephrine did not enhance the anesthetic effect of lidocaine hydrochloride. ConclusionsTopical mucosal anesthesia with an adhesive patch containing 2% lidocaine hydrochloride solution is simple and may be more effective than conventional methods.

Effects of peribulbar anesthesia (sub-Tenon injection of a local anesthetic) on akinesia of extraocular muscles, mydriasis, and intraoperative and postoperative analgesia in dogs undergoing phacoemulsification

To evaluate the effects of peribulbar anesthesia (sub-Tenon injection of lidocaine hydrochloride) on akinesia of extraocular muscles, mydriasis, and intraoperative and postoperative analgesia in dogs undergoing phacoemulsification. 14 Beagles with ophthalmically normal eyes. A blinded randomized controlled trial was performed. Dogs were anesthetized and assigned to 2 treatments: concurrent sub-Tenon injection of 2% lidocaine hydrochloride solution (2 mL) and IV injection of saline (0.9% NaCl) solution (0.02 mL/kg; lidocaine group [n = 7]) or concurrent sub-Tenon injection of saline solution (2 mL) and IV injection of 0.2 mg of atracurium/kg (0.02 mL/kg; control group [7]). Pupils were dilated by topical application of a combined tropicamide and phenylephrine ophthalmic solution. Ten minutes after the injections, pupil diameter was measured and phacoemulsification was performed. End-tidal isoflurane concentration was used to evaluate intraoperative pain. Subjective pain scores were recorded during the postoperative period. Akinesia was induced and maintained throughout the surgery in all eyes. Mean ± SD pupil diameter was significantly greater in the lidocaine group (13.7 ± 0.7 mm) than in the control group (12.2 ± 0.8 mm). Isoflurane requirements were significantly lower in the lidocaine group than the control group. However, postoperative pain scores were not significantly different between the groups. Sub-Tenon injection of lidocaine was an effective method for inducing akinesia of extraocular muscles, mydriasis, and intraoperative analgesia for phacoemulsification in dogs. Therefore, this could be another option for surgical field exposure and pain management during phacoemulsification in dogs.

TCH-010 Development of a Topical Lidocaine Sterile Formulation 20% (W/V)

Background The topical use of concentrated solutions of lidocaine (4 to 20%), which are usually unavailable, has been reported for microvascular surgery. Vasospasm is known to have an adverse effect...

Preparation and evaluation of lidocaine hydrochloride-loaded TAT-conjugated polymeric liposomes for transdermal delivery

Transactivation transcriptional activator (TAT) peptides were conjugated on the octadecyl-quaternized, lysine-modified chitosan to form polymeric liposomes (TAT-PLs) with cholesterol for improving transdermal delivery of local anesthetic lidocaine hydrochloride (LID). In this study, the LID loaded TAT-conjugated polymeric liposomes (LID-TAT-PLs) have been successfully prepared. LID-TAT-PLs were characterized by determination of their particle size, polydispersity, morphology, drug encapsulation efficiency, drug release behavior in vitro, and storage-stability. The skin permeation of LID-TAT-PLs was examined using a Franz diffusion cell mounted with depilated mouse skin in vitro, and penetration of TAT-PLs was visualized by confocal laser scanning microscopy (CLSM). The results showed that LID-TAT-PLs were spherical in solution, with substantially smaller mean diameter (154.7±10.7 nm), higher encapsulation efficiency (80.05±2.64%) and better stability in contrast to conventional liposomes (CLs). From the in vitro skin permeation results, transdermal flux of LID-TAT-PLs was approximately 4.17 and 1.75 times higher than that of LID solution and LID CLs (P<0.05). CLSM studies also confirmed that TAT-PLs reached viable layers of the skin. Hence, the results indicate that LID-TAT-PLs are effective and potential alternative for the LID transdermal formulation.

Local Anesthesia and Hydro‐Distension to Facilitate Cystic Calculus Removal in Horses

To report a technique for improving surgical access to the bladder for removal of cystic calculi in male horses. Retrospective case series. Geldings (8) with cystic calculi. After catheterization of the bladder through the penis, 100 mL 2% lidocaine hydrochloride solution was instilled. After 10 minutes, the bladder was distended with sterile, warmed Hartmann's solution to a pressure of ≈ 40 cm H(2) O, using gravity feed. This was left in place until abdominal access was gained at surgery, then the fluid siphoned off via the catheter. Calculi were 3-11 cm in diameter (median, 6 cm). Bladder capacity ranged from 1.4 to 2.5 L (median, 1.8 L). Exteriorization time from placing a hand in the abdomen to having the bladder in a surgically accessible position was <5 minutes. The described technique facilitates exteriorization of the bladder for removal of cystic calculi.

Oral Mucosal Injection of a Local Anesthetic Solution Containing Epinephrine Enhances Muscle Relaxant Effects of Rocuronium

The purpose of this study was to examine how submucosal injection of a clinically relevant dose of a lidocaine hydrochloride solution containing epinephrine affects the muscle relaxant effects of rocuronium bromide. Sixteen patients scheduled for orthognathic surgery participated in this study. All patients were induced with fentanyl citrate, a target-controlled infusion of propofol and rocuronium bromide. Anesthesia was maintained by total intravenous anesthesia. After nasotracheal intubation, an infusion of rocuronium bromide was started at 7 µg/kg/min, and the infusion rate was then adjusted to maintain a train of four (TOF) ratio at 10 to 15%. The TOF ratio just prior to oral mucosal injection of a 1% lidocaine hydrochloride solution containing 10 µg/mL epinephrine (LE) was taken as the baseline. TOF ratio was observed for 20 minutes, with 1-minute intervals following the start of injection. Mean epinephrine dose was 85.6 ± 18.6 µg and mean infusion rate of rocuronium bromide was 6.3 ± 1.6 µg/kg/min. TOF ratio began to decrease 2 minutes after the injection of LE, reached the minimum value at 3.1 ± 3.6% 12 minutes after the injection, and then began to recover. We conclude that oral mucosal injection of LE enhances the muscle relaxant effects of rocuronium bromide.

Localization of 14C-Labeled 2% Lidocaine Hydrochloride after Intraosseous Anesthesia in the Rabbit

Objective The purpose of this study was to investigate the tissue distribution of lidocaine hydrochloride in mandibular bone marrow after intraosseous anesthesia (IOA) in rabbits. Methods We used macroautoradiography to examine the tissue distribution of a 14C-labeled 2% lidocaine hydrochloride solution containing 1:80,000 epinephrine ( 14C-lidocaine). Under general anesthesia, 14C-lidocaine was injected intraosseously or paraperiosteally. After IOA, animals were divided into three groups and observed at 1 (IOA-1), 5 (IOA-5), and 10 minutes (IOA-10) after injection. After infiltration anesthesia (IA), animals were observed at 1 minute after injection. Results The accumulation of 14C-lidocaine was observed around the injection site in both the IA and the IOA groups. Paraperiosteally injected 14C-lidocaine diffused to the surrounding tissues such as the lip, whereas IOA showed concentrated accumulation around the root apex throughout the experiment. The distribution area was significantly smaller in the IOA-1 group than in the IA group. The distribution area in the IOA-5 group was larger than those in the IOA-1 and IOA-10 groups. Conclusions The accumulation of 14C-lidocaine injected by IOA in rabbits was concentrated around the root apex. These results may explain the rapid onset time of IOA.

Evaluation of the analgesic effect of intracameral lidocaine hydrochloride injection on intraoperative and postoperative pain in healthy dogs undergoing phacoemulsification

To evaluate the intraoperative and postoperative analgesic effects of intracameral lidocaine hydrochloride injection in dogs undergoing phacoemulsification. 12 healthy Beagles with healthy eyes. Dogs were randomly assigned to receive 1 of 2 intracameral injections: 2% lidocaine hydrochloride solution (0.3 mL) or an equivalent amount of balanced salt solution (BSS). All dogs were treated with acepromazine (0.05 mg/kg, i.v.) and cefazolin (30 mg/kg, i.v.), and tropicamide drops were topically applied to the eyes. Anesthesia was induced with propofol and maintained with isoflurane. The initial end-tidal isoflurane concentration was maintained at 1.2%. Heart rate, respiratory rate, arterial blood pressure, esophageal temperature, inspired and end-tidal isoflurane concentrations, and oxygen saturation were recorded every 5 minutes. The allocated agent was injected intracamerally after aspiration of the same volume of aqueous humor. Ten minutes after injection, phacoemulsification was performed. After surgery began, the isoflurane concentration was adjusted according to heart rate and mean arterial blood pressure. Pain scores were recorded before surgery and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 16, and 24 hours after extubation. Isoflurane requirements were significantly higher in the BSS group than in the lidocaine group. Mean +/- SD time to administration of supplementary analgesia was significantly shorter in the BSS group (1.4 +/- 1.2 hours) than in the lidocaine group (4.9 +/- 1.2 hours). Intracameral lidocaine injection had significant analgesic effects in dogs undergoing cataract surgery. Results of this study suggest the value of intracameral lidocaine injection as an analgesic for intraocular surgery in dogs.