Cytotoxicity of local anaesthetics and protective effects of platelet rich plasma on equine tenocytes: An in vitro study.

Local anaesthetics (LAs) can have detrimental effects on rat, bovine, canine, and human tendon tissues and cells. Currently, there has been no available data on the impact of these drugs on equine tenocytes. Even if LA injection for managing painful tendon conditions in horses is limited, it is usually used via intra-articular, intrasynovial, perineural, and intrathecal as well as for lameness examinations. In this in vitro study, the cytotoxic effects of LAs, including lidocaine, mepivacaine, and bupivacaine on equine tenocytes, in the presence and absence of platelet rich plasma (PRP), were investigated. PRP accelerates tissue healing and can exert cytoprotective effects on different cell types exposed to different stressful conditions, including drugs. Results indicated that the exposure to LAs significantly reduced tenocytes viability in dose- and time-dependent manners while PRP was able to counteract their cytotoxic effects. Furthermore, microscopy and flow cytometry analyses revealed apoptosis and necrosis in equine tenocytes exposed to these drugs, that were both reduced when PRP was in the medium. These findings highlight the importance of considering the tenocyte toxicity associated with intrathecal and intraneural LA injections, as they might affect tenocytes or reduce the efficacy of associated therapies. Moreover, this study also highlights the protective effects of PRP, which could make LA injections safer.

Lidocaine spray vs mepivacaine local infiltration for suturing 1st/2nd grade perineal lacerations: a randomised controlled non-inferiority trial.

BACKGROUND: Perineal lacerations are a very common complication of post-partum. Usually, the repair of 1st and 2nd-grade lacerations is performed after the administration of local anesthesia. Despite the great relevance of the problem, there are only a few studies about the best choice of local anesthetic to use during suturing. We performed a randomised controlled trial to evaluate the efficacy and safety of the use of a local anesthetic spray during the suturing of perineal lacerations in the post-partum. METHODS: We compared the spray with the standard technique, which involves the infiltration of lacerated tissues, using the NRS scale. 136 eligible women who had given birth at University Hospital of Udine were enrolled and randomly assigned to receive nebulization of Lidocaine hydrochloride 10% spray (experimental group) or subcutaneous/submucosal infiltration of mepivacaine hydrochloride (control group) during suturing of perineal laceration. RESULTS: The lacerations included 84 1st-grade perineal traumas (61.7%) and 52 2nd-grade perineal traumas (38.2%). All the procedures were successfully completed without severe complications or serious adverse reactions. There were no statistically significant differences between the two groups in terms of blood losses or total procedure time. Moreover, there were no statistically significant differences in terms of NRS to none of the intervals considered. Regarding the application of the spray in the B group, in 36 cases (52.9%) it was necessary to improve the number of puffs previously supposed to be sufficient (5 puffs). Just in 3 cases, an additional injection was necessary (4.4%). CONCLUSIONS: Our study demonstrates that lidocaine spray alone can be used as a first line of local anesthetic during the closure of I-II-grade perineal lacerations, as it has comparable efficacy to mepivacaine infiltration. TRIAL REGISTRATION: The trial was recorded on https://clinicaltrials.gov . Identification number: NCT05201313. First registration date: 21/01/2022. Unique Protocol ID: 0042698/P/GEN/ARCS.

Mepivacaine instillation for pain reduction during intrauterine device placement in nulliparous women: a double-blinded randomized trial.

BACKGROUND: Fear of pain associated with intrauterine device (IUD) placement has been identified as a significant barrier to the adoption of long-acting reversible contraception, contributing to lower utilization of the most effective reversible contraceptive methods. OBJECTIVE: To assess whether instillation of intrauterine mepivacaine before IUD placement alleviates pain more effectively than a placebo. STUDY DESIGN: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving nulliparous women undergoing IUD placement. An intrauterine instillation of 10 mL of 20 mg/mL mepivacaine or 0.9 mg/mL sodium chloride was administrated through a hydrosonography catheter 2 minutes prior to IUD placement. Pain scores were assessed using a 100 mm visual analog scale (VAS) at prespecified time points. Primary outcome measured the difference in VAS pain scores between the intervention group and the placebo group during IUD placement. Secondary outcomes included VAS pain scores at instillation and 10 minutes after placement, tolerability of the placement pain, as well as acceptability of the analgesia method. RESULTS: We enrolled 151 participants, with 76 assigned to the mepivacaine group and 75 to the placebo group. The mean VAS pain score during IUD placement showed a difference of 13.3 mm (95% confidence interval (CI) 5.75-20.87; P<.001): the mepivacaine group had a mean of 53.9 mm (standard deviation [SD] 22.8), while the placebo group had a mean of 67.2 mm (SD 22.4). After adjusting for each individual provider's impact, the difference in mean pain scores remained statistically significant (12.2 mm 95% CI 4.85-19.62; P<.001). A greater proportion of women in the intervention group reported tolerable pain during placement with 70/75 participants (93.3%) compared to 53/66 participants (80.3%) in the placebo group (P=.021). CONCLUSION: The intrauterine instillation of mepivacaine results in statistically significant reduction in pain score among nulliparous women during IUD placement. Although the precise clinical impact of this pain reduction method remains uncertain, the observed reduction in pain score result in a higher proportion of women reporting tolerable pain. This finding and the high acceptance as a pain reduction method thereby suggests clinical relevance. Intrauterine instillation of mepivacaine is a possible strategy to increase IUD utilization, particularly among nulliparous women who are at high risk of unintended pregnancy.

[Improving the effectiveness of local anesthesia in patients with arterial hypertension in the provision of emergency dental care]. / Povyshenie effektivnosti mestnogo obezbolivaniya u patsientov s arterial'noi gipertenziei pri okazanii neotlozhnoi stomatologicheskoi pomoshchi.

THE AIM OF THE STUDY: Was to evaluate the use of Ketorol Express as a preventive analgesia to increase the effectiveness of local anesthesia in providing emergency dental care to patients with arterial hypertension. MATERIALS AND METHODS: The study was conducted on the basis of the state autonomous healthcare institution of the Moscow region «Royal Dental Clinic¼ with the participation of 83 people. The patients were divided into two groups. In group 1, Ketorol Express was prescribed as a preventive analgesia in a dosage of 20 mg before local anesthesia. Patients of group 2 underwent dental interventions without the use of preventive analgesia. A 3% solution of mepivacaine was used as a local analgesic solution. For a subjective assessment of the effectiveness of anesthesia, use a visual analog scale. All patients had their blood pressure and heart rate measured before and after the interventions and hemodynamic parameters were continuously monitored during emergency dental care. RESULTS: In group 1, the effectiveness of combined anesthesia with the infiltration method of local anesthetic administration was 93±1.17%, according to the patient, 94±1.47%, according to the doctor, with the conductive method of anesthesia at the mandibular orifice - according to the patient it was 91±1.01%, according to the doctor 92± 1.36%. In group 2, when providing emergency dental care with the infiltration method of administration of 3% mepivacaine the anesthesia was effective in 80±1.97% of cases according to the patient and in 80±1.17% of cases according to the doctor, with the conductive method of anesthesia at the mandibular orifice, the effectiveness of anesthesia according to the patient was 82±1.11%, according to the doctor 85±1.23%. CONCLUSION: The results of the study demonstrated a statistically significant increase in the effectiveness of local anesthesia performed with a 3% solution of mepivacaine in patients with arterial hypertension due to the use of preventive analgesia with Ketorol Express at a dosage of 20 mg (2 tablets of 10 mg) in emergency dental care with registration and analysis of changes in hemodynamic parameters.

Effect of ropivacaine, mepivacaine or the combination of ropivacaine and mepivacaine for epidural anaesthesia on the postoperative recovery in patients undergoing caesarean section: a randomized, prospective, double-blind study.

BACKGROUND: Anaesthetic methods and drugs with rapid onset, rapid recovery and better postoperative analgesia are more suitable for rapid recovery in obstetric anaesthesia. We formulated the following hypothesis: a combination of mepivacaine and ropivacaine could provide a longer analgesic effect and have more advantages in terms of rapid-recovery indicators. METHODS: A total of 180 pregnant women scheduled to undergo elective caesarean sections were randomly assigned to three surgical groups, which received 2% mepivacaine (Group M), 2% mepivacaine + 0.75% ropivacaine (Group MR) (Volume 1:1) or 0.75% ropivacaine (Group R) through an epidural catheter. The situation of postoperative analgesia and other indicators of rapid recovery were recorded. RESULTS: One hundred and fifty patients were included in the final analysis. Their demographic data were similar. The visual analogue scale (VAS) scores of Group MR and Group R were lower than Group M at 1 and 2 h after surgery both at rest and with movement (P < 0.05), and the time to first ambulation in Group MR (17.38 ± 2.06 h) and Group M (17.20 ± 2.09 h) was shorter than that in Group R (22.18 ± 1.74 h) (P < 0.05). CONCLUSION: Application of 2% mepivacaine combined with 0.75% ropivacaine for epidural anaesthesia can provide longer postoperative analgesia and earlier ambulation, these effect may be more suitable than that of 2% mepivacaine or 0.75% ropivacaine alone for caesarean section. TRIAL REGISTRATION: This study was registered at Chinese Clinical Trial Registry (Registration number: ChiCTR 2300078288; date of registration: 04/12/2023).

Comparison of Lidocaine and Mepivacaine for Variation in Regional Tissue Oxygenation in Stellate Ganglion Block: A Randomized, Double-Blind, Crossover Trial.

Introduction This prospective, randomized, double-blind, crossover trial aimed to investigate the effect of different types of local anesthetics on regional tissue blood oxygenation on the stellate ganglion block (SGB). Methods Twenty eligible patients were recruited for this study; 16 of whom were allocated to the study protocol. Participants were randomized into one of the two crossover sequences: 1% lidocaine hydrochloride or 1% mepivacaine hydrochloride, and received SGBs with 6 mL of any one of the local anesthetics, followed by a washout period of more than 24 hours, and then received SGBs by substituting the two local anesthetics. The tissue oxygenation index (TOI) in the skin near the mental foramen on the blocked side was recorded using near-infrared spectroscopy at 15 minutes after the local anesthetic injection. Results One participant did not complete the study. As such, variation in regional tissue oxygenation was compared between the 15 participants. There was no difference in the increase in regional tissue blood flow or tissue oxygenation after SGB between the patients who were given lidocaine and the ones who were given mepivacaine; however, the kinetics of the increase in regional tissue oxygenation were significantly faster with mepivacaine than with lidocaine. Conclusions Different types of local anesthetics do not affect the intensity of the increase in regional tissue oxygenation after SGB, but they do affect the kinetics of the increase. These differences in local anesthetics may affect how patients feel after receiving SGB, the duration of SGB effects, and the frequency of adverse events associated with SGB.

Effect of local anesthetics on renal function: An animal study in Iran.

Background: Although most of the metabolism of local anesthetics (LAs) takes place in the liver, no study has investigated the effect of these anesthetics on the kidney function of single-kidney humans or animals. The present study was conducted to examine the effect of LAs on renal function in single-kidney rats. Materials and Methods: The present experimental animal study with two control groups was done in an animal laboratory. Forty-two rats were randomly assigned to seven groups of six rats, including two control groups and five experimental groups. The experimental groups underwent intraperitoneal anesthesia with 2% lidocaine, 2% lidocaine with 1:80,000 epinephrine, 4% articaine, 3% prilocaine with 0.03 IU Felypressin, and 3% mepivacaine, respectively. Unilateral nephrectomy was done. After 24 h, the rats' blood urea nitrogen (BUN), serum creatinine (Cr), and blood specific gravity (BSG) were measured. A standard dose of anesthetics was injected into the peritoneum for 4 days afterward. Then, these indices were measured again 24 h after the last injection. Data were analyzed using IBM SPSS (version 21.0). One-way analysis of variance, Tukey's honestly significant difference post hoc, and paired t-tests were used for statistical analysis. P < 0.05 was considered statistically significant. Results: The results indicated significant differences among groups in the rats' BUN and serum Cr 24 h after nephrectomy (P < 0.05). However, there were no significant differences in BUN, BSG, and Cr among groups after the interventions. Conclusion: LAs did not affect renal function in single-kidney rats. Therefore, dentists can use the anesthetics in single-kidney people.

Efficacy and safety of articaine in 3-year-old children for dental procedures: a protocol for a clinical randomised control trial in Saudi Arabia.

INTRODUCTION: Despite the wide use of articaine in paediatric dentistry owing to its proven effectiveness and safety, articaine application in children <4 years remains controversial due to a lack of data on the use of articaine in very young children. This trial aims to examine the efficacy and safety of 4% articaine compared with 2% mepivacaine in children 3-4 years old requiring dental extractions. We aim to assess local anaesthetic efficacy and safety through a local anaesthetic infiltration technique for primary teeth requiring dental extraction in children 3 years old. METHODS AND ANALYSIS: This prospective, double-blind, randomised clinical trial with two parallel arms aims to evaluate the safety and efficacy of 4% articaine compared with 2% mepivacaine in 3-year-old children. The trial's outcomes will be assessed by measuring the pain experienced during injection and treatment, evaluating the child's behaviour during the procedure, and monitoring postoperative pain and complications. A total of 200 children will be included in the study, with 100 children in each arm. ETHICS AND DISSEMINATION: The Institutional Review Board (IRB) approved the study protocol and informed consent documents before initiation of the study. The IRB approval was granted by the Qassim Health Cluster under protocol number 607/43/7809. This study was also approved by the Saudi Food and Drug Authority. The study report will be disseminated through scientific forums, including peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: Saudi Clinical Trial Registry (22071802) and ClinicalTrials.gov Registry (NCT05839548).

Allergic reactions to local anesthetic mepivacaine in dental procedures: a case report.

Local anesthetics are an essential part of pain control during dental treatment. Despite its effectiveness and safety, patients should constantly be aware of potential adverse effects, including allergic reactions. Allergic reactions to amide-type local anesthetics (LAs), such as lidocaine and mepivacaine, are rare compared to those to ester-type LAs. Herein, we report the case of a patient with a history of allergy to lidocaine and mepivacaine, with symptoms of itching, diffuse erythema of the wrists and hands, dizziness, and pectoralgia. This case report emphasizes the importance of collecting medical and dental histories of patients is necessary, and how an allergy test in the allergy and clinical immunology department helps select safe LAs for patients.

Comparison of the success of inferior alveolar nerve anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine: A randomized controlled clinical trial.

Background: This study aimed to compare the success rate of inferior alveolar nerve (IAN) anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine. Materials and Methods: The current randomized controlled clinical trial was conducted on 100 patients in two groups (n = 50). Standard injection of IAN block (IANB) was performed using two cartridges of 3% mepivacaine plain in the first group and using two cartridges of 3% prilocaine with 0.03 IU felypressin in the second group. Fifteen minutes after injection, the patients were asked about lip anesthesia. In case of a positive answer, the tooth was isolated with a rubber dam. Success was defined as no or mild pain on the basis of the visual analog scale recording upon access cavity preparation, entry into the pulp chamber, and initial instrumentation. Data were analyzed with SPSS 17 using the Chi-square test, and P < 0.05 was set as statistically significant. Results: The patients' pain severities during the three stages were significantly different (P = 0.001, 0.0001, and 0.001, respectively). The success rate of IANB during access cavity preparation was 88% with prilocaine and 68% with mepivacaine. This rate during entry into the pulp chamber was 78% and 24%, respectively, which was 3.25 times higher with prilocaine than mepivacaine. The success rates during instrumentation were 32% and 10%, respectively, which was 3.2 times higher with prilocaine than mepivacaine. Conclusion: The success rate of IANB in the teeth with symptomatic irreversible pulpitis was higher using 3% prilocaine with felypressin than using 3% mepivacaine.

Behavior of Piglets in an Observation Arena before and after Surgical Castration with Local Anesthesia.

Surgical castration of piglets is generally recognized as a painful procedure, but there is currently no gold standard for the assessment of pain behavior in piglets. However, pain assessment is essential for evaluating the effectiveness of local anesthetics. In this study, we investigated the efficacy of four local anesthetics in terms of pain relief during and after surgical castration in three sequential study parts. To do so, we filmed 178 piglets before the applied procedures, after injection of the local anesthetic, and up to 24 h after castration (five observation times in total) in an observation arena and compared their behavior before and after castration and between treatments and control groups. The results showed significant differences in the behavior of the piglets before and after castration and between the sham-castrated control group and the control group castrated without anesthesia. The different local anesthesia treatment groups showed diverging differences to the control groups. The most frequently shown pain-associated behaviors of the piglets were changes in tail position and hunched back posture. We observed a reduction but no complete elimination of the expressed pain-associated behaviors after local anesthesia. Several behavioral changes-such as changes in tail position, hunched back posture or tail wagging-persisted until the day after castration. Owing to the limited duration of the effects of the local anesthetics, local anesthesia did not influence long-term pain.

Injectable and topical local anesthetics for acute dental pain: 2 systematic reviews.

BACKGROUND: Local anesthesia is essential for pain control in dentistry. The authors assessed the comparative effect of local anesthetics on acute dental pain after tooth extraction and in patients with symptomatic irreversible pulpitis. TYPES OF STUDIES REVIEWED: The authors searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the US Clinical Trials registry through November 21, 2020. The authors included randomized controlled trials (RCTs) comparing long- vs short-acting injectable anesthetics to reduce pain after tooth extraction (systematic review 1) and evaluated the effect of topical anesthetics in patients with symptomatic pulpitis (systematic review 2). Pairs of reviewers screened articles, abstracted data, and assessed risk of bias using a modified version of the Cochrane risk of bias 2.0 tool. The authors assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Fourteen RCTs comparing long- vs short-acting local anesthetics suggest that bupivacaine may decrease the use of rescue analgesia and may not result in additional adverse effects (low certainty evidence). Bupivacaine probably reduces the amount of analgesic consumption compared with lidocaine with epinephrine (mean difference, -1.91 doses; 95% CI, -3.35 to -0.46; moderate certainty) and mepivacaine (mean difference, -1.58 doses; 95% CI, -2.21 to -0.95; moderate certainty). Five RCTs suggest that both benzocaine 10% and 20% may increase the number of people experiencing pain reduction compared with placebo when managing acute irreversible pulpitis (low certainty). PRACTICAL IMPLICATIONS: Bupivacaine may be superior to lidocaine with epinephrine and mepivacaine with regard to time to and amount of analgesic consumption. Benzocaine may be superior to placebo in reducing pain for 20 through 30 minutes after application.

Electrochemical Sensor Design Based on Silver Nanoparticles Modified Multiwalled Carbon Nanotubes Paste Electrode for the Sensitive Determination of Mepivacaine.

Mepivacaine, an amide-type local anesthetic drug widely used in regional anesthesia, was studied by some aspects such as electrochemical behavior, mechanism illumination, and analytical applications by cyclic voltammetry (CV) and different pulse voltammetry (DPV) methods. In this study, a novel, fast, simple, portable, and the inexpensive electrochemical sensor was developed for the determination of mepivacaine. This study was carried out by mepivacaine anodic direction detection for the first time. The modified sensor was fabricated with silver nanoparticles (AgNP) and multiwalled carbon nanotubes paste electrode (MWCNTPE) by using the drop-dry method. Different experimental parameters, such as pulse amplitude, step potential, and scanning rate in the DPV application module, were optimized. Under optimal operation conditions, the limit of detection (LOD) as low as 31 µg L-1 was found over the dynamic range (0.1-8.0 mg L-1). In contrast to its high response towards mepivacaine, the DPV exhibits negligible responses on modified AgNP/MWCNTPE when exposed to interfering species such as dopamine, uric acid, glucose, ascorbic acid, and some heavy metals. Exceptionally, the proposed DPV method on modified AgNP/MWCNTPE was successfully applied to pharmaceutical dosage form and synthetic human serum with a low relative standard deviation (RSD) of 1.35% and 2.02%, respectively.

Intra-Articular Local Anesthetics in Temporomandibular Disorders: A Systematic Review and Meta-Analysis.

This systematic review with meta-analysis was conducted to evaluate the effectiveness of local anesthetic administration into temporomandibular joint cavities in relieving pain and increasing mandibular mobility. Randomized controlled trials were included with no limitation on report publication dates. Final searches were performed on 15 October 2023, using engines provided by the US National Library, Bielefeld University, and Elsevier Publishing House. The risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Articular pain and mandible abduction values and their mean differences were summarized in tables and graphs. Eight studies on a total of 252 patients evaluating intra-articular administration of articaine, bupivacaine, lidocaine, and mepivacaine were included in the systematic review. None of the eligible studies presented a high risk of bias in any of the assessed domains. An analgesic effect of intra-articular bupivacaine was observed for up to 24 h. In the long-term follow-up, there were no statistically significant changes in quantified pain compared to both the baseline value and the placebo group, regardless of the anesthetic used (articaine, bupivacaine, and lidocaine). There is no scientific evidence on the effect of intra-articular administration of local anesthesia on the range of motion of the mandible. Therefore, in the current state of knowledge, the administration of local anesthetics into the temporomandibular joint cavities can only be considered as a short-term pain relief measure.

The concentration of lidocaine and mepivacaine measured in synovial fluid of different joints of horses after single intra-articular injection.

Objective: To determine the synovial fluid (SF) concentrations of lidocaine and mepivacaine after intra-articular injection with clinically relevant doses to the distal interphalangeal (DIP), metacarpophalangeal (MCP), middle carpal (MC), and tarsocrural (TC) joint at two different time points after injection in order to be able to compare concentrations with previously established concentrations associated with cytotoxicity and antimicrobial activity. Procedures: In the first of two experiments, 20 joints (5 MC, 5 MCP, 10 DIP joints) of five horses under general anesthesia were injected with clinically referenced doses of 2% lidocaine. Simultaneously, the horses had 19 joints (5 MC, 5 MCP, 9 DIP joints) injected with clinically referenced doses of 2% mepivacaine. Synovial fluid samples were collected ~7 min after injection. In experiment 2, 23 joints of seven horses under standing sedation were injected with clinically referenced doses of 2% lidocaine. Similarly, the horses had 21 joints injected with 2% mepivacaine. Synovial fluid samples were collected ~23 min after injection. The concentration of mepivacaine and lidocaine in the obtained SF samples was assessed using high-performance-liquid-chromatography with mass spectrometry detection (HPLC MS). Results: Synovial fluid was obtained 6.8 ± 1.5 (experiment 1) and 23 ± 4.3 (experiment 2) min following intra-articular injection of mepivacaine and lidocaine. Synovial fluid concentrations of experiment 1 for lidocaine and mepivaciane were 6.46-19.62 mg/mL (mean 11.96 ± SD 3.89 mg/mL) and 5.01-13.38 mg/mL (mean 8.18 ± SD 1.76 mg/mL), respectively. In experiment 2, concentrations were 2.94-10.40 mg/mL (mean 6.31± SD 2.23 mg/mL) for lidocaine and 2.10-8.70 mg/mL (mean 4.97 ± SD 1.77 mg/mL) for mepivacaine. Conclusions and clinical relevance: Intra-articular LA injections in horses resulted in SF concentrations above those previously associated with cytotoxic effects in vitro but also above those associated with beneficial antimicrobial activities. Local anesthetic concentration was 33-60% lower after 23 min (experiment 2) than after 7 min (experiment 1).

Comparative Study of Pain-Related Responses of Male Piglets up to Seven Days of Age to the Application of Different Local Anaesthetics and Subsequent Castration.

To evaluate pain responses to intratesticular and subscrotal injection of three local anaesthetics and their efficacy during castration a randomized controlled study was conducted. In groups of 20 piglets, procaine (2%), lidocaine (2%), or mepivacaine (2%) were administered subscrotal and intratesticularly in two different dosages: 0.5 mL of the original substances or the maximum recommended dosage according to body weight diluted with isotonic saline to a volume of 0.3 mL per each injection site. Two placebo groups received the equivalent volume of isotonic saline. A control group was injected intramuscularly with 0.5 mL isotonic saline for injection pain comparison. Electroencephalographic changes, respiratory rate, heart rate and its variability, blood pressure, and nocifensive movements were assessed in superficial isoflurane anaesthesia. While EEG-changes and linear measures of heart rate variability did not appear conclusive, the low frequency/high frequency (LF/HF) ratio corresponded best with the other pain indicators recorded. The injection of 0.3 mL diluted local anaesthetic per injection site elicited significant fewer signs of pain compared to intramuscular injection of saline. However, pain reduction, but not complete pain elimination, during castration could only be achieved with 0.5 mL of the 2% local anaesthetics per injection site, whereby lidocaine and mepivacaine were the most effective.

Nociception-Induced Changes in Electroencephalographic Activity and FOS Protein Expression in Piglets Undergoing Castration under Isoflurane Anaesthesia.

The objective of this study was to investigate the electroencephalographic reaction pattern and FOS protein expression in male piglets undergoing surgical castration under light isoflurane anaesthesia with or without local anaesthesia. The experiment was conducted under isoflurane anaesthesia to exclude the effect of the affective components of pain on the measurements. Changes in the oscillatory activity of the cerebral cortex over a 90 s period after noxious stimulation or simulated interventions were analysed. FOS expression was determined postmortem by performing immunohistochemistry in the dorsal horn of the spinal cord. The analysis of the response to an interdigital pinch revealed a biphasic reaction pattern in the electroencephalogram (EEG) that similarly was observed for the surgical stimuli during the castration procedure in the group without analgesia. This EEG response was attenuated or altered by the application of local anaesthetics. Immunohistochemical staining for FOS indicated a lower expression in the handling and in three local anaesthetic groups than in the animals castrated without pain relief. The findings indicate that EEG and FOS expression may serve as indicators for nociception in piglets under light isoflurane anaesthesia. A lower activation of nociceptive pathways occurs during castration after the application of local anaesthetics. However, EEG and FOS analyses should be combined with additional parameters to assess nociception, e.g., haemodynamic monitoring.

Inferior alveolar nerve block success of 2% mepivacaine versus 4% articaine in patients with symptomatic irreversible pulpitis in mandibular molars: A randomized double-blind single-centre clinical trial.

AIM: The aim of this study was to assess inferior alveolar nerve block (IANB) success of 2% mepivacaine (Scandonest 2%, Septodont, France) and 4% articaine (Septanest 4%, Septodont) in patients with symptomatic irreversible pulpitis (SIP) in mandibular molars during access cavity preparation and instrumentation. METHODOLOGY: Three hundred and thirty patients with moderate-to-severe pain in mandibular molars with SIP randomly received either 3.6 ml 2% mepivacaine hydrochloride with 1:100 000 adrenalin or 3.4 ml 4% articaine hydrochloride with 1:100 000 adrenalin (n = 165). Intraoperative pain (IOP) intensity was assessed during access cavity preparation and canal instrumentation using 11-point Numerical Rating Scale (NRS). Overall success was considered if the patient felt no-to-mild pain without the need for supplemental anaesthesia throughout treatment; the incidence of need for supplemental anaesthesia was also recorded. Data were statistically analysed using Mann-Whitney U- and Chi-squared (χ2 ) tests. Relative risk (RR) and 95% confidence interval (CI) of anaesthetic failure were calculated. The effect of pre-disposing factors on outcome variables was assessed using multivariable regression analyses. None of the participants reported any adverse effects. RESULTS: Baseline variables were balanced between groups (p > .05). The IOP intensity during access cavity preparation and canal instrumentation was similar for both groups (p > .05). IOP intensity was associated with preoperative pain intensity and tooth type (p < .05). Overall anaesthetic success rate was 35.8% for mepivacaine and 41.2% for articaine (p > .05) with a relative risk of failure [95% CI] 1.09 [0.92, 1.30]. The need for supplemental anaesthesia occurred 43.6% and 38.2% with mepivacaine and articaine respectively (p > .05; RR [95% CI]: 1.14 [0.88, 1.48]). Preoperative pain level and age were associated with the need for supplemental anaesthesia. CONCLUSIONS: 2% mepivacaine and 4% articaine demonstrate similar IANB success rates for mandibular molars with SIP. Intraoperative pain experience during endodontic treatment can be associated with preoperative pain, tooth type and age.

Optimizing Spinal Anesthesia in Same-Day Discharge Knee Arthroplasty Patients: Mepivacaine Versus Ropivacaine.

BACKGROUND: Short-acting spinal anesthetics are playing an increasing role in same-day discharge total joint arthroplasty though their direct comparison remains to be studied. Therefore, this study aims to compare two formulations of spinal anesthesia regarding time to discharge following knee arthroplasty surgery. METHODS: A retrospective study was performed on 207 patients who underwent unicompartmental knee arthroplasty (UKA, n = 172) and total knee arthroplasty (TKA, n = 35) from May 2018 to December 2020 at a single institution and were discharged the same day. Two formulations of the spinal anesthetic were routinely administered in this population: 1) mepivacaine 1.5% 3-4 mL (n = 184) and 2) ropivacaine 0.5% 2.3-2.7 mL (n = 23). Discharge times were subsequently compared between mepivacaine and ropivacaine spinal anesthesia for each surgical procedure and between surgical procedures. RESULTS: There was no significant difference in discharge times between patients receiving mepivacaine versus ropivacaine for UKA (202 minutes [range = 54-449] versus 218 minutes [range = 175-385], P = .45) or TKA (193 minutes [range = 68-384] versus 196 minutes [range = 68-412], P = .93). Similarly, no difference was found in discharge times between UKA and TKA patients receiving mepivacaine (P = .68) or ropivacaine (P = .51). CONCLUSION: There was no significant difference in discharge times between anesthetic agents among knee surgery patients. Therefore, either agent may be recommended for same-day discharge.