Influence of Pre- and Intraoperative Local Anaesthetic in Strabismus Surgery under General Anaesthesia in Adults.

BACKGROUND: As studies have shown a reduction in the occurrence of the oculocardiac reflex with the addition of local anaesthesia, we changed our care regime accordingly a few years ago. To promote and establish better patient care, we retrospectively analysed the files of our patients who underwent strabismus surgery from 2013 to 2021 in order to compare strabismus surgery under general anaesthesia with and without local anaesthetics in a routine clinical setting. PATIENTS AND METHODS: Data from 238 adult patients who had undergone strabismus surgery could be extracted from the files: G1: n = 102, only general anaesthesia; G2: n = 136, preoperative application of tetracaine eye drops and intraoperative subtenon lidocaine/levobupivacaine in addition to general anaesthesia. We compared the two groups in regard to the frequency of oculocardiac reflex, the amount of atropine needed to treat, as well as the amount of antiemetic and analgesic medication given, and time spent in the recovery room. RESULTS: Mean age of G1 was 50 years and 52 years in G2. There was no significant difference between the kind of surgeries (recessions/resections), the number of patients who had undergone a reoperation, or the duration of the operations. Adding local anaesthetics resulted in significantly less occurrence of oculocardiac reflex (p = 0.009), a reduction in the need for atropine, analgesic, or antiemetic medication, as well as reduced time in the recovery room. CONCLUSION: As this increases patient safety and comfort and is cost-effective (less time in the recovery room), we recommend adding perioperative local anaesthesia to strabismus surgery performed under general anaesthesia.

Chloroprocaine 3% Gel as a Novel Ocular Topical Anesthetic: Results from a Multicenter, Randomized Clinical Trial in Patients Undergoing Cataract Surgery.

Purpose: To compare the efficacy and safety of a novel ophthalmic anesthetic, chloroprocaine 3% gel to tetracaine 0.5% eye drops in patients undergoing cataract surgery with phacoemulsification. Methods: This was a prospective, randomized, multicenter, active-controlled, masked-observer, parallel group competitive equivalence study. The study comprised 338 patients having routine cataract extraction by clear corneal phacoemulsification, randomized to receive 3 drops of chloroprocaine gel (n = 166) or tetracaine eye drops (n = 172) before surgery. The primary objective of the study was to assess the equivalence of chloroprocaine gel to tetracaine eye drops as proportion of patients with successful ocular surface anesthesia, without any supplementation just before intraocular lens implantation. Safety measurements were pain, irritation, burning, stinging, photophobia, and foreign body sensation, graded by the patient and objective ocular signs. Results: Equivalence was demonstrated, with a somewhat higher success rate of chloroprocaine gel: 152/166 (92.0%) chloroprocaine versus 153/172 (90.5%) tetracaine patients achieved ocular surface anesthesia with no supplementation. Difference in proportions was 1.5% confidence interval [95% CI: (-3.6 to 6.6)] and 90% CI fell within (-10 to 10). Mean onset of anesthesia was 1.35 ± 0.87 min for chloroprocaine and 1.57 ± 1.85 for tetracaine (P = 0.083). Mean duration of anesthesia was 21.57 ± 12.26 min for chloroprocaine and 22.04 ± 12.58 for tetracaine (P = 0.574). No treatment emergent adverse events related to chloroprocaine were reported and no relevant findings related to local tolerance or vital signs were observed in both arms. Conclusions: Results obtained from the present cataract study demonstrated that chloroprocaine 3% ophthalmic gel is safe and effective, representing a valid alternative in ocular topical anesthesia. Clinical Trial Registration number: NCT04685538.

[Effects of topical anesthesia with 1% tetracaine on hemodynamic responses in microlaryngosurgery].

Objective: To observe the effects of topical anesthesia with 1% tetracaine on hemodynamic responses in general anesthesia patients undergoing microlaryngosurgery. Methods: From October 2021 to December 2021, 92 patients (46 males and 46 females) in Beijing Tongren Hospital, with a median age [M (Q1, Q3)] of 51 (42, 57) years who scheduled for microlaryngosurgery under general anesthesia, were divided into two groups (n=46 in each group) using the random number table method. Group T received topical anesthesia with 1% tetracaine at the root of the tongue and epiglottis and glottis on the basis of general intravenous anesthesia induction, with 0.5 ml at each position, while the control group (group C) received equal volume of normal saline. Heart rate (HR) and mean arterial pressure (MAP) were recorded at the time of patients entering the operating room (baseline), after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation. The recovery profiles, including time to recover breathing, time to open eyes, time to extubation and adverse reactions were evaluated during recovery period. Results: The MAP of patients in group T at baseline, after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation were (99.4±12.9), (78.5±8.8), (79.2±10.2), (100.6±17.0), (101.9±14.7), (100.8±13.9), (97.4±12.1), (107.3±16.8) mmHg (1 mmH=0.133 kPa), respectively, while in group C were (99.5±11.6), (80.9±12.8), (90.5±16.0), (109.5±20.4), (108.0±18.9), (103.7±15.5), (100.1±13.3), (114.2±17.3) mmHg, respectively. The two critical time points of MAP after intubation and immediately suspending laryngoscopy in group C were significantly higher than group T (P<0.05).The HR of patients in group T at baseline, after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation was (71.3±10.6), (66.0±10.1), (69.5±11.4), (61.3±14.2), (69.8±9.8), (71.0±10.6), (70.6±11.0), (78.8±11.6) bmp, respectively, while in group C were (73.1±10.9), (67.8±9.9), (79.5±12.9), (57.1±18.1), (69.2±12.8), (71.4±11.7), (70.7±11.5), (85.3±13.0) bmp, respectively. The two critical time points of HR after intubation and after extubation in group C were significantly higher than that of group T (P<0.05). The time to recover breathing in the two groups was (11.8±3.5) min and (11.3±4.6) min, respectively. The time to open eyes was (12.0±3.3) min and (11.5±5.0) min, respectively. The time to extubation was (13.2±3.7) min and (12.6±4.9) min, respectively. There were no statistically significant difference in time to recovery between the two groups (P>0.05). Likewise, there were no toxic reactions to local anesthetics, respiratory depression, hypoxemia, laryngospasm and cough occurred in either group. Conclusion: Topical anesthesia with 1% tetracaine can effectively reduce the hemodynamic changes without influencing patient's recovery, and does not increase the incidence of adverse reactions.

The Role of Topical Anesthetics in the Treatment of Pediatric Facial Lacerations.

PURPOSE: Pediatric facial lacerations (PLACS) are a common emergency, often requiring a general anesthetic (GA) or sedation if infiltration of local anesthetic (LA) cannot be tolerated. Topical anesthetics are a well-established and accepted alternative to infiltrations for facial lacerations which can reduce the need for general anesthesia. We report our experience following the introduction of topical 5% cocaine w/v and 1:2000 adrenaline gel (TCA) in a single center. METHODS: A secondary data analysis of 11 months attendances with PLACS following the introduction of TCA as part of a service improvement project. RESULTS: Fifty-three patients had wounds suitable for use of TCA. Twenty-three patients were treated with TCA, 14 with TCA alone and 9 with top-up local anesthetic infiltration (TCA + LA). Fourteen patients were treated using LA alone and 16 underwent GA. No adverse reactions were recorded. CONCLUSION: Topical anesthetics are a safe and effective alternative to infiltration of local anesthetic for PLACS and can be used to avoid the additional risks posed by sedation or GA. We recommend more departments introduce a topical anesthetic for this purpose.

[Primary wound care in children]. / Kleine Wundversorgung bei Kindern.

Primary wound care in children Abstract. Successful wound care of infants and children is facilitated by good preparation and a calm atmosphere. There is not only the child as a patient but also the parents, with their fears and concerns. The physician has to take care of both of them. Parent and child should be informed about the therapeutic intervention appropriately. Reassuring of the child and distraction from the procedure are as important as the treatment itself (e. g. wound stitching or application of wound dressing). Topical anesthesia with LET Gel (lidocain, epinephrine, tetracaine), non-stinging methods to clean the wound (NaCl 0,9 % / Polyhexanid (Prontosan®) soaked swabs) and intranasal application of fentanyl / dormicum can be used to avoid fear and pain. Sedation is used deliberately in small children for wound care. Laceration wounds, mainly those affecting the scalp, chin or forehead can be treated in the emergency room without general anesthesia. Extensive wounds, burns and animal bites often require wound care under anesthesia in children.

Neurotoxicity secondary to local tetracaine use.

INTRODUCTION: Systemic reactions from local tetracaine use are often an anomaly - not only is tetracaine short-acting and quickly metabolized by the pseudocholinesterase system leading to very limited systemic uptake, but most adverse reactions are usually associated with dental or spinal anesthesia. Furthermore, reactions to local anesthetics manifest in standard allergy-type reactions. When local anesthetics lead to nervous or cardiac system abnormalities, it is termed a local anesthetic systemic toxicity - an event with an incidence currently estimated to be 0.03%. CASE PRESENTATION: We present a case of a 56-year-old female who experienced a systemic reaction to tetracaine 1% while undergoing a fine needle biopsy of a thyroid nodule. The patient had previous allergic reactions to lidocaine. Upon conclusion of the procedure, the patient began convulsing and became rigid and non-verbal. She was able to move all extremities, had no respiratory distress, no swelling, hives, or redness, and was swallowing without difficulty. After about 5 min, the patient began to improve and experienced reversal of all previous symptoms. Her physical exam and labs were otherwise normal, she returned to her baseline functioning, and was discharged without any medical interventions. DISCUSSION: This case illustrates a case of LAST in a patient with previous Lidocaine allergy without any other obvious risk factors. There have been no cases of cross-reaction between lidocaine and tetracaine so it explores the possibility of patients having cross reaction to those two different kinds of local anesthetic.

The Efficacy of Pulsed Dye Laser Pretreated With or Without Local Anesthetic on Patients Presenting With Erythema of Face, Neck, Chest, and Extremities.

BACKGROUND AND OBJECTIVES: Erythema is one of the most common cosmetic concerns and usually responds well to pulsed dye laser (PDL) treatment. As this laser can cause significant discomfort, topical anesthesia is sometimes offered. However, it is still uncertain whether topical anesthetics can affect the outcome of the laser therapy. We performed a retrospective single site study to compare the efficacy of PDL for the treatment of erythema in patients with and without pretreatment with topical anesthetic. STUDY DESIGN/MATERIALS AND METHODS: A chart review was performed and patients who presented with erythema of face, neck, chest, and extremities pretreated with topical anesthesia (23% lidocaine/7% tetracaine ointment or 7% lidocaine/7% tetracaine ointment) undergoing PDL were reviewed and compared with another group without anesthesia. Two blinded dermatologists evaluated the postlaser procedure photographs and gave an assessment compared with baseline. RESULTS: A total of 69 patient charts were reviewed. The erythema resulted from various skin conditions including telangiectasia, cherry angioma, striae, and rosacea. The mean improvement was 2.2581 in the anesthesia group and 2.2632 in the nonanesthesia group. There was no significant difference between both groups as confirmed by a noninferiority test. CONCLUSIONS: Topical anesthesia with lidocaine and tetracaine ointment do not interfere with the efficacy of the PDL. Since pain management is essential for any cosmetic procedure, the application of a local anesthetic will enhance patient comfort and satisfaction during treatment with PDL. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Pentadecapeptide BPC 157 shortens duration of tetracaine- and oxybuprocaine-induced corneal anesthesia in rats.

We focused on the relationship of 0.5% tetracaine- and 0.4% oxybuprocaine-induced corneal anesthesia in rats, and pentadecapeptide BPC 157 (0.4 µg/eye), along with nitric oxide synthase (NOS) inhibitor N(gamma)-nitro-L-arginine methyl ester (L-NAME) (0.1 mg/eye) and/or NOS substrate L-arginine (2 mg/eye), applied in the form of eye drops. We assessed corneal sensitivity recovery (Cochet-Bonnet esthesiometer), corneal lesion elimination (staining with 10% fluorescein) and decrease in tear volume (Schirmer test). BPC 157 administration had a full counteracting effect. Recovery also occurred in the presence of NOS blockade and NOS substrate application. L-arginine eventually shortened duration of corneal insensitivity and exerted corneal lesion counteraction (and counteraction of tetracaine-induced decrease of tear volume) only in earlier but not in later period. L-NAME application led to longer duration of corneal insensitivity, increase in corneal lesions and decrease in tear volume. When L-NAME and L-arginine were applied together, they antagonized each other's effect. These distinctions may indicate particular NOS involvement (corneal insensitivity vs. corneal lesion along with tear production), distinctively affected by the administration of NO agents. However, additional BPC 157 co-administration would re-establish counteraction over topical ophthalmic anesthetic-induced effect, be it in its early or late course. We suggest BPC 157 as an antidote to topical ophthalmic anesthetics.

Reduction of oculocardiac reflex with Tetracaine eye drop in strabismus surgery.

INTRODUCTION: Recently, to reduce the incidence of oculocardiac reflex (OCR) in strabismus surgery, retrobulbar block and anticholinergic drugs or local anesthesia are also used. The present study evaluated the effects of Tetracaine eye drop as a topical nerve blocker on OCR during strabismus surgery. METHODS AND MATERIALS: In this randomized trial, 70 strabismus surgery candidates were randomly divided into placebo or synthetic teardrop (E) and Tetracaine eye drop (T) groups, so 3 drops of each solution were dropped in four directions of patients' eye immediately after applying anesthesia and before surgery. The incidence and severity of OCR during the stages of muscle release and incision (cutting), hemodynamic changes, the required time for OCR recovery and atropine dose were assessed. RESULTS: OCR was more seen in release phase compared to cutting phase. There were no significant differences between two group regarding the incidence and severity of OCR in the release phase (p > 0.05), but the incidence and severity of OCR in the cutting phase was more in group E than group T (p = 0.02, for both). The duration of OCR improvement (p-value = 0.74) and Atropine consumption (p-value = 0.92) did not differ between the groups. CONCLUSION: Tetracaine eye drop only reduces the incidence and severity of OCR during the incision stage of strabismus surgery.

Effect of four local anesthetics (tetracaine, proparacaine, lidocaine, and bupivacaine) on intraocular pressure in dogs.

PURPOSE: To measure IOP in animals, it is often necessary to use topical anesthetics. The use of these drugs may cause changes in IOP and interfere with the final results. To address this issue, the effects of four local anesthetics (tetracaine, proparacaine, lidocaine, and bupivacaine) on IOP were investigated in ten adult dogs. METHODS: One drop of tetracaine was instilled in the right eye of half of the dogs and in the left eye of the other dogs; normal saline was instilled in the fellow eyes. The IOP in each dog was measured before and at 0, 5, 10, 15, 20, 25, 30, and 35 min after drug instillation using an electronic rebound tonometer. The effects of the other anesthetics were studied in the same way at intervals of at least 1 week. RESULTS: After instillation of tetracaine, the IOP decreased gradually, such that after 15 min, the IOP was significantly lower than the baseline (p = 0.022) and control values (p = 0.048). Proparacaine also reduced IOP after 10 min compared to baseline values (p = 0.046), but the two other drugs, bupivacaine and lidocaine, had no significant effect on IOP. The duration of eye anesthesia was 16, 20, 22, and 34 min for tetracaine, lidocaine, bupivacaine, and proparacaine, respectively. CONCLUSION: We recommend using drugs that combine inducing longer anesthesia with producing the smallest change in IOP, such as bupivacaine and, subsequently, lidocaine. Tetracaine and proparacaine have a significant effect on IOP, and if these drugs are used, this effect should be considered.

Femtosecond laser-assisted cataract surgery in pediatric patients.

Pediatric cataract surgery poses a significant challenge for the cataract surgeon, in part because an elastic anterior capsule can make capsulorhexis difficult. With the use of femtosecond laser-assisted cataract surgery (FLACS), however, the continuous curvilinear capsulorhexis can be made with predictable size, circular shape, centration, and accuracy. In addition, topical anesthesia can be used for the FLACS docking procedure in cooperative children above 6 years of age, using transparent adhesive polyurethane film segments.

Topical anaesthesia for needle-related pain in newborn infants.

BACKGROUND: Hospitalised newborn neonates frequently undergo painful invasive procedures that involve penetration of the skin and other tissues by a needle. One intervention that can be used prior to a needle insertion procedure is application of a topical local anaesthetic. OBJECTIVES: To evaluate the efficacy and safety of topical anaesthetics such as amethocaine and EMLA in newborn term or preterm infants requiring an invasive procedure involving puncture of skin and other tissues with a needle. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase and CINAHL up to 15 May 2016; previous reviews including cross-references, abstracts, and conference proceedings. We contacted expert informants. We contacted authors directly to obtain additional data. We imposed no language restrictions. SELECTION CRITERIA: Randomised, quasi-randomised controlled trials, and cluster and cross-over randomised trials that compared the topical anaesthetics amethocaine and eutectic mixture of local anaesthetics (EMLA) in terms of anaesthetic efficacy and safety in newborn term or preterm infants requiring an invasive procedure involving puncture of skin and other tissues with a needle DATA COLLECTION AND ANALYSIS: From the reports of the clinical trials we extracted data regarding clinical outcomes including pain, number of infants with methaemoglobin level 5% and above, number of needle prick attempts prior to successful needle-related procedure, crying, time taken to complete the procedure, episodes of apnoea, episodes of bradycardia, episodes of oxygen desaturation, neurodevelopmental disability and other adverse events. MAIN RESULTS: Eight small randomised controlled trials met the inclusion criteria (n = 506). These studies compared either EMLA and placebo or amethocaine and placebo. No studies compared EMLA and amethocaine. We were unable to meta-analyse the outcome of pain due to differing outcome measures and methods of reporting. For EMLA, two individual studies reported a statistically significant reduction in pain compared to placebo during lumbar puncture and venepuncture. Three studies found no statistical difference between the groups during heel lancing. For amethocaine, three studies reported a statistically significant reduction in pain compared to placebo during venepuncture and one study reported a statistically significant reduction in pain compared to placebo during cannulation. One study reported no statistical difference between the two groups during intramuscular injection.One study reported no statistical difference between EMLA and the placebo group for successful venepuncture at first attempt. One study similarly reported no statistically significant difference between Amethocaine and the placebo group for successful cannulation at first attempt.Risk for local redness, swelling or blanching was significantly higher with EMLA (typical risk ratio (RR) 1.65, 95% confidence interval (CI) 1.24 to 2.19; typical risk difference (RD) 0.17, 95% CI 0.09 to 0.26; n = 272; number needed to treat for an additional harmful outcome (NNTH) 6, 95% CI 4 to 11; I2 = 92% indicating considerable heterogeneity) although not for amethocaine (typical RR 2.11, 95% CI 0.72 to 6.16; typical RD 0.05, 95% CI -0.02 to 0.11, n = 221). These local skin reactions for EMLA and amethocaine were reported as short-lasting. Two studies reported no methaemoglobinaemia with single application of EMLA. The quality of the evidence on outcomes assessed according to GRADE was low to moderate. AUTHORS' CONCLUSIONS: Overall, all the trials were small, and the effects of uncertain clinical significance. The evidence regarding the effectiveness or safety of the interventions studied is inadequate to support clinical recommendations. There has been no evaluation regarding any long-term effects of topical anaesthetics in newborn infants.High quality studies evaluating the efficacy and safety of topical anaesthetics such as amethocaine and EMLA for needle-related pain in newborn term or preterm infants are required. These studies should aim to determine efficacy of these topical anaesthetics and on homogenous groups of infants for gestational age. While there was no methaemoglobinaemia in the studies that reported methaemoglobin, the efficacy and safety of EMLA, especially in very preterm infants, and for repeated application, need to be further evaluated in future studies.

Exponential Decay Metrics of Topical Tetracaine Hydrochloride Administration Describe Corneal Anesthesia Properties Mechanistically.

PURPOSE: To identify pharmacodynamic (PD) and pharmacokinetic (PK) metrics that aid in mechanistic understanding of dosage considerations for prolonged corneal anesthesia. METHODS: A rabbit model using 0.5% tetracaine hydrochloride was used to induce corneal anesthesia in conjunction with Cochet-Bonnet anesthesiometry. Metrics were derived describing PD-PK parameters of the time-dependent domain of recovery in corneal sensitivity. Curve fitting used a 1-phase exponential dissociation paradigm assuming a 1-compartment PK model. Derivation of metrics including half-life and mean ligand residence time, tau (τ), was predicted by nonlinear regression. Bioavailability was determined by area under the curve of the dose-response relationship with varying drop volumes. RESULTS: Maximal corneal anesthesia maintained a plateau with a recovery inflection at the approximate time of predicted corneal drug half-life. PDs of recovery of corneal anesthesia were consistent with a first-order drug elimination rate. The mean ligand residence time (tau, τ) was 41.7 minutes, and half-life was 28.89 minutes. The mean estimated corneal elimination rate constant (ke) was 0.02402 minute. Duration of corneal anesthesia ranged from 55 to 58 minutes. There was no difference in time domain PD area under the curve between drop volumes. CONCLUSIONS: Use of a small drop volume of a topical anesthetic (as low as 11 µL) is bioequivalent to conventional drop size and seems to optimize dosing regiments with a little effect on ke. Prolongation of corneal anesthesia may therefore be best achieved with administration of small drop volumes at time intervals corresponding to the half-life of drug decay from the corneal compartment.

Corneal anesthetic effect and ocular tolerance of 3.5% lidocaine gel in comparison with 0.5% aqueous proparacaine and 0.5% viscous tetracaine in normal canines.

OBJECTIVE: To compare the degree and duration of corneal anesthesia of a novel viscous ophthalmic lidocaine hydrochloride preparation vs. two commonly used ophthalmic anesthetic preparations. METHODS: Each subject was randomly selected to receive 2 of 4 treatments at 2 different time periods separated by a 1 week washout: 3.5% lidocaine hydrochloride gel (Akten® ; Akorn Inc., Lake Forest, Illinois, USA), 0.5% aqueous proparacaine hydrochloride (Akorn Inc.), 0.5% viscous tetracaine hydrochloride (TetraVisc™; Ocusoft Inc., Richmond, Texas, USA), or 0.9% saline eyewash as a negative control. Corneal sensitivity was determined using a Cochet-Bonnet aesthesiometer (Luneau® , Chartres Cedex, France) prior to instillation of each treatment; at 1 and 5 min post treatment; and at 5-min intervals thereafter for 90 min total. Ocular side effects were recorded on a scale of 0-3. RESULTS: Twenty-four normal dogs (48 eyes) were entered into the study. Mean duration of maximal anesthesia was significantly greater at 34.2 min with tetracaine compared to 21.5 min and 19 min with proparacaine and lidocaine respectively. Corneal sensitivity was significantly decreased from baseline for up to 70 min with tetracaine and 55 min with both proparacaine and lidocaine. All lidocaine-treated eyes had transient blepharospasm and conjunctival hyperemia. Ten out of 24 tetracaine-treated eyes had conjunctival hyperemia with 4 of these having concurrent chemosis. CONCLUSIONS: Tetracaine provided a significantly longer duration of corneal anesthesia than proparacaine or lidocaine. Tetracaine and lidocaine were associated with more ocular side effects than proparacaine, although these were mild and transient. None.

Treatment of catecholaminergic polymorphic ventricular tachycardia in mice using novel RyR2-modifying drugs.

RATIONALE: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal arrhythmic disorder caused by mutations in the type-2 ryanodine receptor (RyR2). Mutant RyR2 cause abnormal Ca2+ leak from the sarcoplasmic reticulum (SR), which is associated with the development of arrhythmias. OBJECTIVE: To determine whether derivatives of tetracaine, a local anesthetic drug with known RyR2 inhibiting action, could prevent CPVT induction by suppression of RyR2-mediated SR Ca2+ leak. METHODS AND RESULTS: Confocal microscopy was used to assess the effects of tetracaine and 9 derivatives (EL1-EL9) on spontaneous Ca2+ sparks in ventricular myocytes isolated from RyR2-R176Q/+ mice with CPVT. Whereas each derivative suppressed the Ca2+ spark frequency, derivative EL9 was most effective at the screening dose of 500nmol/L. At this high dose, the Ca2+ transient amplitude was not affected in myocytes from WT or R176Q/+ mice. The IC50 of EL9 was determined to be 13nmol/L, which is about 400× time lower than known RyR2 stabilizer K201. EL9 prevented the induction of ventricular tachycardia observed in placebo-treated R176Q/+ mice, without affecting heart rate or cardiac contractility. CONCLUSIONS: Tetracaine derivatives represent a novel class of RyR2 stabilizing drugs that could be used for the treatment of the potentially fatal disorder catecholaminergic polymorphic ventricular tachycardia.

Comparison of Peribulbar with Posterior Sub-Tenon's Anesthesia in Cataract Surgery Among Nigerians.

PURPOSE: To compare the akinetic and the analgesic effects of peribulbar and posterior sub-Tenon's anesthesia in patients undergoing cataract surgery. METHODS: In a hospital-based randomized comparative interventional study, patients aged 50 years and above who underwent elective surgery for uncomplicated cataract were randomized to receive either peribulbar block or posterior sub-Tenon block. Pain during injection, surgery, and after surgery was assessed using numerical reporting scale (NRS). Limbal excursion was measured with a transparent meter rule. RESULT: A total of 152 eyes of 152 patients were studied. Peribulbar and sub-Tenon regional blocks provided comparable adequate akinesia (P = 0.06) and similar levels of analgesia (P = 0.10) during cataract surgery. Both techniques also provided similar levels of analgesia to the patient during injection and in the immediate postoperative period. Ninety-two percent of patients who had peribulbar and 97% of those who had sub-Tenon blocks reported either mild pain or no pain at all during surgery (P = 0.49). There was no report of severe pain in all patients during the stages of the surgery. Occurrence of chemosis and subconjunctival hemorrhage was more common in sub-Tenon than peribulbar anesthesia. CONCLUSIONS: This study shows that peribulbar and posterior sub-Tenon routes of administering anesthetic substances is comparable in providing adequate akinesia and analgesia for cataract surgery with minimal complications. Therefore, both techniques are effective and safe for cataract surgery among Nigerians.

Oral dyclonine hydrochloride mucilage versus tetracaine spray in electronic flexible laryngoscopy: A prospective, randomized controlled trial.

BACKGROUND: Topical anesthesia is important for electronic flexible laryngoscopy (EFL) utilization. We hypothesized that oral dyclonine hydrochloride mucilage (ODHM) is superior to tetracaine spray (TS) in patients undergoing EFL examination. METHODS: This study included 932 patients randomized into either an ODHM or TS group, in which patients received either a single utilization of ODHM or TS administered via spray in three intervals. A 4.9 mm diameter flexible PENTAX-VNL-1570STK insertion tube placed into a Naso-Pharyngo-Laryngoscope (PENTAX Medical, Japan) was used in the procedure. Visual analogue scale (VAS) (0-10) was used to evaluate patient tolerance and procedure success by the operator, independently. Procedure time was also recorded. RESULTS: Both patients' and doctors' VAS scores were significantly higher in the ODHM group compared to the TS group. When subgroup analysis was made according to the procedure length (100 s), there was no significant difference in VAS between ODHM and TS groups in the short time procedure (≤100 s), while VAS in the ODHM group was higher compared to the TS in the long time procedure (>100 s), as assessed by both patients and doctors. CONCLUSION: A single use of ODHM seems to be superior to three doses of TS in patients undergoing EFL, specifically in procedures longer than 100seconds.

History of T-cain: a local anesthetic developed and manufactured in Japan.

In many anesthesia textbooks written in English, lidocaine, tetracaine, bupivacaine, ropivacaine, and chloroprocaine are listed as useful local anesthetics for spinal anesthesia. In contrast, T-cain is not included in these lists, even though it has been reported to be suitable for spinal anesthesia in Japan. T-cain was developed as a local anesthetic in the early 1940s by Teikoku Kagaku Sangyo Inc. in Itami, Japan, by replacing a methyl group on tetracaine (Pantocaine(®)) with an ethyl group. T-cain was clinically approved for topical use in Japan in November 1949, and a mixture of dibucaine and T-cain (Neo-Percamin S(®)) was approved for spinal use in May 1950. Simply because of a lack of foreign marketing strategy, T-cain has never attracted global attention as a local anesthetic. However, in Japan, T-cain has been used topically or intrathecally (as Neo-Percamin S(®)) for more than 60 years. Other than the side effects generally known for all local anesthetics, serious side effects have not been reported for T-cain. In fact, several articles have reported that T-cain decreases the neurotoxicity of dibucaine. In this historical review, the characteristics of T-cain and its rise to become a major spinal anesthetic in Japan are discussed.