Topical Anesthetics for Analgesia in Acute Corneal Abrasion: Eye Care Providers Survey.

STUDY OBJECTIVES: To evaluate the current attitudes of ophthalmologists and optometrists regarding topical anesthetic (TA) use in the emergency department (ED) for analgesia in corneal abrasions. METHODS: A survey was distributed through email to ophthalmologists and optometrists, and their responses were deidentified. Three scenarios were presented involving the addition of tetracaine in addition to usual care in the setting of uncomplicated corneal abrasion. A 250-character space for comments and demographic questionnaire followed. A chi-square test, Fisher exact test, or sign test, at a significance level of 0.05, was used. RESULTS: Of the 978 individuals surveyed, 486 responded (MD/DOs: 47.1% and ODs: 52.9%). Topical anesthetic favorability significantly decreased with shorter practice length when the patient was only examined by an ED provider. Topical anesthetic favorability was significantly impacted by respondents' degree type. When respondents were posed with using TAs if the respondents were the patient, the respondents were 22.6% more likely to use TA when compared with their answers in the scenario where the ED provider examined the patient and 20.0% more likely when compared with the scenario where a MD/OD examined the patient. Most did not support tetracaine use. CONCLUSIONS: Although treating pain is associated with improved quality of life, most respondents did not support TA use in the ED. Practice length and degree type significantly impacted responses. Respondents were more inclined to use TAs when the respondents were the patient. Results suggest that eye care providers need additional research data supporting safety before routine use in the ED, given the potential for adverse events with TAs.

Real-life experience of a lidocaine/tetracaine self-occluding topical anesthetic for dermatological procedures.

BACKGROUND: Pliaglis® is a self-occluding topical anesthetic containing a eutectic mixture of 7% lidocaine and 7% tetracaine, with proven efficacy and safety in several trials. AIMS: To evaluate the effectiveness and safety of Pliaglis® for different dermatological procedures in real-life clinical practice. METHODS: This retrospective, multicenter study included 35 patients treated with Pliaglis® prior to five dermatological procedures (pulsed dyed laser, picosecond laser, non-ablative fractional laser, radiofrequency microneedling, and photodynamic therapy). The primary endpoint was to assess the pain during the procedure with a visual analogue score (VAS) from 0 (no pain) to 10 (most severe pain). Secondary endpoints were the global effectiveness and tolerability (from 0 = very low to 10 = excellent), and the adverse events (AEs) after Pliaglis® removal, classified according to intensity (1-3). RESULTS: The median and mean pain VAS reported by patients was 2 (range 0-9) and 2.9 (±2.3), respectively. More than 65% of the patients had a VAS score ≤3. The effectiveness reported by investigators was "very good" (median 8 [range 2-10], mean 7.5 [±1.9]), which was strongly correlated with the pain VAS reported by patients (Spearman coefficient = - 0.9; p < 0.001). Forty-five percent of patients reported AEs and they were transient and mostly mild, with a mean intensity score of 1.5 (range 1-3). Tolerability of Pliaglis® was reported by investigators as "excellent" (median 10 [range 1-10], mean 9 [±1.8]). CONCLUSIONS: Pliaglis® is an effective topical anesthetic for several dermatological procedures, with an excellent safety and tolerability profile.

An Observational Study to Determine Whether Routinely Sending Patients Home With a 24-Hour Supply of Topical Tetracaine From the Emergency Department for Simple Corneal Abrasion Pain Is Potentially Safe.

STUDY OBJECTIVE: To determine if the number of emergency department (ED) rechecks, persistent fluorescein uptake, ophthalmology referrals, or complications would be affected by the prescription of topical tetracaine for pain relief from simple corneal abrasions (SCAs). METHODS: This retrospective cohort study was conducted in an ED where policy change allowed physicians to use topical tetracaine hydrochloride 1% eye drops for 24 hours for pain treatment for patients with corneal abrasions. Outcomes were compared between patients who did or did not received tetracaine (adjusting for the propensity for treatment). RESULTS: Of 1,576 initial ED presentations, 532 were SCAs, with 1,044 deemed nonsimple corneal abrasions (NSCAs). Tetracaine was dispensed at the initial visit for 303 SCA presentations (57%) and inappropriately for 141 NSCA presentations (14%). There were no serious complications or uncommon adverse events attributed to tetracaine for all SCAs and NSCAs combined (0/459; upper 95% confidence interval [CI] 0.80%). The relative risks (RRs) of ED recheck and fluorescein staining were increased overall among patients who received tetracaine (RR 1.67, 95% CI 1.25 to 2.23; and RR 1.65, 95% CI 1.07 to 2.53 for recheck and staining, respectively). However, the relative risks for only SCAs receiving tetracaine was 1.16 (95% CI 0.69 to 1.93) and 0.77 (95% CI 0.37 to 1.62), respectively. Referrals to ophthalmology were significantly decreased for all patients (SCAs and NSCAs) dispensed tetracaine (relative risk 0.33; 95% CI 0.19 to 0.59). The number of complications was too small to permit modeling. CONCLUSION: There was no evidence that up to 24-hour topical tetracaine for the treatment of pain caused by SCA was unsafe; however, CIs were wide and some increased risks were observed for NSCAs.

Subarachnoid Block-Induced Deafferentation Pain Successfully Treated with Pentazocine.

Deafferentation pain induced by subarachnoid block (SAB) is rare, but it can appear in the form of recurrent phantom lower limb pain, new acute-onset stump pain in amputees, lower limb pain in patients with tabes dorsalis, and neuropathic pain. We have previously reported that thiopental is an effective treatment for deafferentation pain induced by therapeutic SAB applied to treat neuropathic pain of central origin. Here, we report the case of an amputee who developed new stump pain in his lower limb immediately after subarachnoid tetracaine was administered prior to appendectomy. A 51-year-old man who had previously undergone right below-knee amputation for acute arterial thrombosis, and who had not previously experienced chronic phantom limb or stump pain, was scheduled for emergency open appendectomy. For anesthesia, we induced SAB with a hyperbaric tetracaine solution. No paresthesia occurred during administration. However, the patient immediately complained of severe, lightning-bolt pain in the right lower limb stump after the SAB was established. He was given intravenous pentazocine, which promptly resolved the pain. Appendectomy was then performed under sedation using intravenous midazolam. The patient did not experience further deafferentation pain during his hospital stay and has reported no stump pain since discharge from the hospital. This case report suggests that SAB induces deafferentation pain in some patients and that this unusual pain can be treated with pentazocine.

Fibrinous Anterior Uveitis Following Topical Tetracaine Abuse.

BACKGROUND: A 54-year-old man presented complaining of severe pain and blurred vision in his left eye. Slit-lamp biomicroscopy revealed a large epithelial defect with an underlying prominent ring infiltrate and severe anterior uveitis with fibrinous exudates and hypopyon. Patient admitted abuse of topical tetracaine, which was discontinued and topical treatment with a non-steroidal antiinflammatory agent, an antibiotic, a cycloplegic agent were instituted while a therapeutic contact lens was applied. Response to treatment was favorable with a rapid resolution of anterior uveitis within days while the epithelial defect fully healed within a month. Four months later the patient returned with a new subtotal epithelial defect with no previous history of trauma or topical anesthetic abuse. CONCLUSION: In conclusion, while a common complication of topical tetracaine abuse is toxic keratopathy, we describe a case where tetracaine abuse was also complicated with a severe fibrinous anterior uveitis. Interestingly, in our case, anaesthetic abuse was complicated in the mid-term with a spontaneous corneal epithelial defect attributed to possible anaesthetic-induced anatomical changes, such as poor adhesion between the stroma and the epithelium.

Topical anaesthetics for pain control during repair of dermal laceration.

BACKGROUND: Topical local anaesthetics provide effective analgesia for patients undergoing numerous superficial procedures, including repair of dermal lacerations. The need for cocaine in topical anaesthetic formulations has been questioned because of concern about adverse effects, thus novel preparations of cocaine-free anaesthetics have been developed. This review was originally published in 2011 and has been updated in 2017. OBJECTIVES: To assess whether benefits of non-invasive topical anaesthetic application occur at the expense of decreased analgesic efficacy. To compare the efficacy of various single-component or multi-component topical anaesthetic agents for repair of dermal lacerations. To determine the clinical necessity for topical application of the ester anaesthetic, cocaine. SEARCH METHODS: For this updated review, we searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 11), Cumulative Index to Nursing and Allied Health Literature (CINAHL; 2010 to December 2016), Embase (2010 to December 2016) and MEDLINE (2010 to December 2016). We did not limit this search by language or format of publication. We contacted manufacturers, international scientific societies and researchers in the field. Weemailed selected journalsand reviewed meta-registers of ongoing trials. For the previous version of this review, we searched these databases to November 2010. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that evaluated the efficacy and safety of topical anaesthetics for repair of dermal laceration in adult and paediatric participants. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information when needed. We collected adverse event information from trial reports. We assessed methodological risk of bias for each included study and employed the GRADE approach to assess the overall quality of the evidence. MAIN RESULTS: The present updated review included 25 RCTs involving 3278 participants. The small number of trials in each comparison group and the heterogeneity of outcome measures precluded quantitative analysis of data for all but one outcome: pain intensity. In two pooled studies, the mean self-reported visual analogue scale (VAS; 0 to 100 mm) score for topical prilocaine-phenylephrine (PP) was higher than the mean self-reported VAS (0 to 100 mm) score for topical tetracaine-epinephrine-cocaine (TAC) by 5.59 points (95% confidence interval (CI) 2.16 to 13.35). Most trials that compared infiltrated and topical anaesthetics were at high risk of bias, which is likely to have affected their results. Researchers found that several cocaine-free topical anaesthetics provided effective analgesic efficacy. However, data regarding the efficacy of each topical agent are based mostly on single comparisons in trials with unclear or high risk of bias. Mild, self-limited erythematous skin induration occurred in one of 1042 participants who had undergone application of TAC. Investigators reported no serious complications among any of the participants treated with cocaine-based or cocaine-free topical anaesthetics. The overall quality of the evidence according to the GRADE system is low owing to limitations in design and implementation, imprecision of results and high probability of publication bias (selective reporting of data). Additional well-designed RCTs with low risk of bias are necessary before definitive conclusions can be reached. AUTHORS' CONCLUSIONS: We have found two new studies published since the last version of this review was prepared. We have added these studies to those previously included and have conducted an updated analysis, which resulted in the same review conclusions as were presented previously.Mostly descriptive analysis indicates that topical anaesthetics may offer an efficacious, non-invasive means of providing analgesia before suturing of dermal lacerations. Use of cocaine-based topical anaesthetics might be hard to justify, given the availability of other effective topical anaesthetics without cocaine. However, the overall quality of the evidence according to the GRADE system is low owing to limitations in design and implementation, imprecision of results and high probability of publication bias (selective reporting of data). Additional well-designed RCTs with low risk of bias are necessary before definitive conclusions can be reached.

Embutramide, a Component of Tanax(®) (T-61) as a New Drug of Abuse?

Tanax(®) (T-61) is a euthanasia solution commonly used in veterinary medicine in Europe. It consists of three active components: embutramide, mebezonium iodide, and tetracaine hydrochloride. Human consumption of Tanax(®) (T-61) is usually associated with suicide attempts. In our 15-year-long practice, embutramide was detected only three times but within a short period. First, it was found in the urine of a 42-year-old veterinarian, and the other two observations were made in a 16-year-old young man. Urine samples were analyzed using Shimadzu Prominence TOX.I.S.II. HPLC-DAD system with online SPE extraction system. Both of the two patients denied any intention to die. These cases show that this veterinary drug may also be considered as potential drugs of abuse.

A randomized controlled trial comparing Ametop™ with placebo for reducing pain associated with local anesthetic skin infiltration before neuraxial anesthesia in parturients.

BACKGROUND: Between 10-22% of the general population experience needle phobia. Needle phobic parturients are at increased risk of adverse outcomes. We assessed the efficacy of topical Ametop™ (tetracaine 4%) gel in reducing the pain associated with local anesthetic skin infiltration before neuraxial block in non-laboring women. METHODS: This was a prospective, randomized, double-blind, placebo-controlled study. Ametop™ or placebo was applied to the skin of the lower back at least 20min before neuraxial block using a standardized technique with 1% lidocaine skin infiltration. The primary outcome was numeric pain score (0-10) 30s after lidocaine infiltration. Groups were compared using Welch's t-test. RESULTS: Thirty-six subjects in each group were analyzed. There was a statistically significant difference in the mean (standard deviation) pain score between the Ametop™ and the placebo groups: 2.36±1.80 and 3.51±2.22, respectively (P=0.019). There were no significant adverse events. CONCLUSION: The mean numeric pain score in the Ametop™ group was 33% lower compared to the placebo group. Topical Ametop™ gel applied at least 20min before local anesthetic infiltration of the skin prior to neuraxial block in elective cesarean delivery may be a useful adjunct in needle phobic women.

Dorsal penile nerve block for rigid cystoscopy in men: study protocol for a randomized controlled trial.

BACKGROUND: Pain is common in men undergoing rigid cystoscopy. Even with the application of a lubricant containing 2 % lidocaine, about 76 % of men suffer from mild to severe pain when undergoing rigid cystoscopy. The most painful part of the procedure for men is when the cystoscope passes through the membranous urethra. Song et al. (Neurourol Urodyn 29:592-5, 2010) did autopsies on males and found that the dorsal nerve of the penis (DNP), the terminal branch of the pudendal nerve, innervates the membranous urethra in 53.3 % of specimens. In addition, the urethral mucosa has branches of innervated DNP. Dorsal penile nerve block (DPNB) is usually used for circumcision in children, and it has been shown to provide effective analgesia for penile surgeries. In this study, we hypothesized that DPNB could reduce the overall pain level in men during rigid cystoscopy. METHODS/DESIGN: The trial is a prospective, randomized, double-blind, placebo-controlled, single-center trial to evaluate the effectiveness and safety of DPNB in analgesia for men undergoing rigid cystoscopy. Participants will be enrolled and randomly allocated into one of three groups according to the different analgesia regimens: 1) tetracaine gel group (DPNB with saline), 2) DPNB group (DPNB with ropivacaine plus plain lubricant), 3) combination group (DPNB with ropivacaine plus tetracaine gel). The primary outcome of this study is the visual analog scale (VAS, 0-10) for pain at cystoscopic inspection of the external sphincter. VAS scores evaluated at other time points serve as secondary outcomes. Vital signs are secondary outcomes that address the discomfort and pain during the procedure. Furthermore, the incidence of adverse events as secondary outcomes will also be recorded for evaluation of the safety of DPNB in rigid cystoscopy. Clinical assessments will be evaluated prior to DPNB, at administration of the lubricant gel, at cystoscopic inspection of the penile and bulbar urethra, external sphincter, prostate, and bladder, as well as at withdrawal of the cystoscope. DISCUSSION: This research will determine the effectiveness and safety of DPNB in men undergoing rigid cystoscopy. The results of this trial may have important implications for exploring the role of DPNB in analgesia for cystoscopy in men. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02502487 (6 Jul 2015).

Double-masked, randomized, placebo-controlled study to evaluate the efficacy and tolerability of intranasal K305 (3% tetracaine plus 0.05% oxymetazoline) in anesthetizing maxillary teeth.

BACKGROUND: The authors compared the local anesthetic efficacy and safety of an intranasally administered formulation of tetracaine and oxymetazoline (K305) with placebo in adult participants undergoing single dental restorative procedures in teeth nos. 4 through 13. METHODS: The authors screened and allocated 150 participants in a double-masked, randomized fashion to either K305 or placebo nasal spray. The authors delivered the study drug as two 0.2-milliliter sprays separated by 4 minutes inside the nostril on the side ipsilateral to the tooth being treated. The authors administered a third 0.2-mL spray, if necessary, and administered 4% articaine with 1:200,000 epinephrine by means of injection if anesthesia was inadequate. Safety evaluations included participant reports of adverse events, vital signs, and alcohol sniff tests during the 2-hour study period and at a 1-day follow-up visit. The primary efficacy end point was anesthetic success defined as the completion of the dental procedure without the need for rescue injectable local anesthetic. The authors evaluated differences in success rates observed between K305 and placebo by using a 1-sided Fisher exact test. RESULTS: The overall success rates were 88.0% (95% confidence interval, 80.0-93.6) and 28% (95% confidence interval, 16.2-42.5) for K305 and placebo, respectively (P < .0001). The most frequent adverse effects in the K305 group were rhinorrhea (57.0%) and nasal congestion (26.0%). No serious adverse events occurred during this study. CONCLUSIONS: K305 was effective and well tolerated during restorative procedures in adult participants. PRACTICAL IMPLICATIONS: K305 provides a needleless alternative for obtaining maxillary pulpal anesthesia on premolars, canines, and incisors.

The Safety of Topical Anesthetics in the Treatment of Corneal Abrasions: A Review.

BACKGROUND: Despite the fact that topical anesthetics provide superb analgesia to the painful eye, they are not prescribed routinely to patients when they are discharged from the emergency department because of concerns for delayed healing and corneal erosion. OBJECTIVE: To summarize the evidence for the safety of topical proparacaine and tetracaine for pain relief in patients with corneal abrasions. METHODS: This is a systematic review looking at the use of topical anesthetic agents in the treatment of corneal abrasions in the emergency department. RESULTS: Our literature search produced two emergency department-based, randomized, double blind, placebo-controlled studies on human patients with corneal abrasions. Additionally, we found four studies that investigated the application of topical anesthetics in patients who underwent photorefractive keratectomy. All six studies demonstrated that a short course of dilute topical anesthetic provided efficacious analgesia without adverse effects or delayed epithelial healing. CONCLUSION: Limited available data suggests that the use of dilute topical ophthalmologic proparacaine or tetracaine for a short duration of time is effective, though their safety for outpatient use is inconclusive.

Systemic contact dermatitis due to amethocaine following digital rectal examination.

Systemic contact dermatitis is a dermatitis that may occur in previously sensitized individuals when they are re-exposed to the allergen. Although many drugs have been implicated as a cause of systemic contact dermatitis, local anesthetics derived from caines have been rarely reported. We present a case of systemic contact dermatitis after a digital rectal examination with a urological lubricant containing amethocaine.

The effect of oral topical anesthesia on the characteristics of voice.

OBJECTIVES/HYPOTHESIS: Although oral topical anesthesia is used routinely before rigid laryngeal endoscopy, no study has determined whether oral topical anesthesia changes voice quality. Our goal was to determine the effects of topical anesthesia on voice. STUDY DESIGN: Prospective cohort study. METHODS: Adult patients presenting to a laryngology practice who required rigid laryngeal endoscopy as part of the routine clinical visit were eligible for the study. Voices were recorded before and after oral topical benzocaine (14%)/butamben (2%)/tetracaine (2%) (ie, cetacaine) spray. Consensus auditory perceptual evaluation of voice (CAPE-V) protocol was used for the voice recordings and was the primary outcome measure. Recordings were presented randomly to two blinded speech-language pathologists specialized in voice. Secondary outcome measures were fundamental frequency (F0), jitter, shimmer, and noise-to-harmonics ratio (N/H) on sustained /i/ and speaking F0. RESULTS: One hundred two patients participated in the study. There was no significant difference in CAPE-V measurements before and after topical anesthesia for all six attributes: overall severity (P = 0.145), roughness (P = 0.214), breathiness (P = 0.761), strain (P = 0.053), pitch (P = 0.301), and loudness (P = 0.320). There was no significant difference in jitter (P = 0.315), shimmer (P = 0.942), N/H (P = 0.128), and speaking F0 (P = 0.320). F0 /i/ decreased by a mean of 4.8Hz, which was statistically significant (P = 0.003), but probably not clinically significant. CONCLUSION: There was no clinically significant voice change after oral topical anesthesia.

Cetacaine induced methemoglobinemia: overview of analysis and treatment strategies.

Methemoglobin is formed upon iron oxidation of the heme molecule from ferrous (Fe2+) to its ferric (Fe3+) state. Normal methemoglobin levels in the body vary between 1-2% of the total hemoglobin. Cause of methemoglobinemia can be inherited or acquired. Inherited causes include an enzymatic deficiency in the enzyme cytochrome b5 reductase where as acquired causes are most commonly from routinely used medications. Herein, we present to you a case of methemoglobinemia after Cetacaine (a benzocaine based topical anesthetic) utilization during a transesophageal echocardiography. Some of the other common potential inciting agents are also discussed here along with an overview of treatment strategies.