Is ethyl chloride the new nitrous oxide? A case report.

BACKGROUND: Over the last decade, there has been an emerging trend of recreational misuse of several drugs and inhaled solvent including ethyl chloride. This case report follows CARE guidelines and highlights, with supporting video, the neurological features of ethyl chloride intoxication. CASE PRESENTATION: A 48-year-old man was seen for the sudden occurrence of an unsteady gait with dizziness. His only medical history was a chronic and treated HIV infection without any complications. Clinical examination revealed a cerebellar syndrome associated with impairment of short-term memory. Biological and radiological workups were normal. After several days, the patient recalled ethyl chloride inhalation. He fully recovered after being discharged from hospital. CONCLUSION: Clinicians should recognise the clinical features and neurological manifestations of ethyl chloride intoxication due to the potential fatal cardiovascular complications of this intoxication.

Temperature changes of CoolSticks during simulated use.

INTRODUCTION: Cold sensation is often used to check neuraxial anaesthesia and analgesia. One opportunity to reduce the carbon footprint of anaesthesia is to replace vapo-coolant sprays such as ethyl chloride with a reusable device called the CoolStick, which is cooled in a refrigerator between uses. We designed a study to investigate how long the CoolStick remains at its working temperature, which we defined as <15 °C. METHOD: Experiments were undertaken using a thermocouple and digital temperature sensor attached to the CoolStick. We conducted two experiments to assess temperature changes following removal from the refrigerator for 10 min; the first investigated passive re-warming in the ambient theatre environment and the second investigated re-warming in simulated use. In our third experiment, we investigated the time taken to cool the device in the refrigerator, following use. Each experiment was repeated three times. RESULTS: In the passive re-warming experiment, the mean CoolStick temperature was 7.3 °C at the start, and 14.3 °C after 10 min. In the simulated use experiment, the mean CoolStick temperature was 7.3 °C at the start, and 18.9 °C at 10 min. In the cooling experiment, the mean CoolStick temperature was 15 °C at the start and 7.6 °C at 40 min. CONCLUSION: Our study indicates that it is feasible to use the CoolStick for providing cold sensation in clinical practice. Further study would be required to directly compare the effectiveness of the device to existing methods such as coolant sprays or ice in the clinical setting.

Reversible Neurotoxicity Due To Excessive Use of Ethyl Chloride.

BACKGROUND: Ethyl chloride is commercially available as a DVD/VCR cleaner, and can be found as a gasoline additive and topical anesthetic. There is an emerging trend of recreational huffing to enhance sexual relations. Neurotoxicity from repeated abuse is uncommon. CASE REPORT: A 36-year-old man with a history of intermittent ethyl chloride use for 15 years presented to the Emergency Department with an inability to walk for 4 days after frequent use for 1 week. The patient reported a rapid titration of inhalation from zero to eight cans of 4.6 oz ethyl chloride aerosol per day over a 1-week period. Initial vital signs were heart rate 88 beats/min, blood pressure 147/60 mm Hg, temperature 37.2°C (99°F), and respiratory rate 16 breaths/min. Physical examination was notable for slurred speech, ptosis, a wide-based and ataxic gait with short strides, inability to stand without support, loss of toe/finger proprioception, horizontal and vertical nystagmus, and dysmetria on coordination testing. Strength and sensation were preserved. His work-up included computed tomography and magnetic resonance imaging of the brain, cervical, thoracic, and lumbar spine that demonstrated no acute abnormalities. On hospital day 9, the patient was able to ambulate with mild difficulty. WHY SHOULD AN EMERGENY PHYSICIAN BE AWARE OF THIS?: Toxicity from excessive ethyl chloride huffing has been rarely reported. The toxicity was characterized with cerebellar findings, no attributable laboratory abnormalities, and no radiographic abnormalities on computed tomography/magnetic resonance imaging. The neurotoxicity resolved with supportive care. This case of excessive huffing of ethyl chloride presenting with neurotoxicity and ataxia further characterizes a rare complication of ethyl chloride toxicity that is gaining popularity.

Risk factors for HCV transmission in HIV-positive men who have sex with men in México.

PURPOSE: In the last two decades transmission of hepatitis C virus (HCV) in HIV positive men who have sex with men (MSM) has been reported globally. Chemsex and specific sexual practices have been identified as risk factors. Our study aimed to identify risk factors for HCV transmission in MSM living with HIV attending in Mexico. METHODS: We conducted a case-control study from April to December 2019 at the Hospital de Infectología "La Raza" National Medical Center, in Mexico City. A case was defined as an HIV-infected MSM with positive HCV-antibody test. For each case, 3 controls were included, defined as HIV infected MSM with negative HCV-antibody test. A self-questionnaire covering sexual practices and other risk factors for HCV transmission was applied. Bivariate analysis was performed to obtain odds ratio (OR) using Chi-square test. Independent risk factors were identified in a subsequent analysis performing a logistic regression model. RESULTS: A total of 324 patients participated in the study, 81 cases and 243 controls. Median age was 30.5 years (IQR: 18-52) and 28.8 years (IQR: 21-45) in the case and control group, respectively. Most prevalent HCV genotype was 1a (79%). In the logistic regression model, sharing straw during cocaine inhalation (OR: 9.03; 95% CI; 1.35-13.52; P = 0.003), sharing sex toys (OR: 17.53, 95% CI; 6.85-44.86; P = 0.002), and ethyl chloride use for chemsex (OR: 2.26; 95% CI; 1.29-5.56; P = 0.037) were significant risk factors for HCV infection. CONCLUSION: This study identifies risk factors for HCV transmission in Mexico in HIV positive MSM in congruence with the findings of many studies performed worldwide. This is the first study that indicates a possible association between ethyl chloride use in chemsex and HCV infection. Assessment of local populations for risk factors for HCV transmission may help to develop specifically targeted behavioral interventions to reduce HCV transmission.

Ethyl chloride spray, a local anesthetic in arterial blood gas sampling: A randomized, controlled, double-blinded study.

AIM: Arterial blood gas sampling provides useful information on respiratory parameters and acid-base balance. However, this procedure is painful and uncomfortable for the patient. Therefore, this study aimed to examine the analgesic efficacy of ethyl chloride spray compared to a placebo during radial artery blood gas sampling. METHOD: This randomized, double-blind, placebo-controlled study was conducted at the emergency department of a tertiary hospital. A total of 202 patients were randomly divided into two groups: ethyl chloride spray (n = 101) and placebo (n = 101). The analgesic efficacy of ethyl chloride spray was compared with the placebo using the Visual Analog Scale (VAS). RESULTS: The VAS score was determined to be 4 [interquartile range (IQR): 1.0] for the ethyl chloride spray group and 5 (IQR: 1.0) for the placebo group. The analgesic efficacy of ethyl chloride spray in reducing pain was statistically significantly higher compared to the placebo (p = 0.000). CONCLUSION: Ethyl chloride spray has analgesic efficacy in arterial blood gas sampling. Therefore, the use of this spray provides an analgesic effect on patients during arterial blood gas sampling performed in the emergency department.

A novel platform based on CoMn2O4-rGO/1-ethyl-3-methylimidazolium chloride modified carbon paste electrode for voltammetric detection of pethidine in the presence morphine and olanzapine.

The present work focuses on the development of a new electrochemical platform based on CoMn2O4-rGO/1-ethyl-3-methylimidazolium chloride modified carbon paste electrode (CoMn2O4-rGO/IL/CPE) for electrochemical determination of pethidine in the presence of biological species. For the first time, the electrooxidation mechanism of pethidine in presences of morphine and olanzapine is investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) technologies. The as-synthesized CoMn2O4-rGO nanocomposites are characterized by physicochemical measurements such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared (FT-IR). The obtained results illustrated synergistic interactions between rGO and CoMn2O4 structures. Also, to investigate the electrode charge-transfer resistances, electrochemical features of the resulting nanocomposites are studied via electrochemical impedance spectroscopy (EIS) analysis. Based on the result, three segmented linear ranges are observed over the range 0.08-900 µM and detection limit of 0.024 µM. Over the 10.0-40.0 µM ranges of pethidine in phosphate buffer solution (PBS-pH 7.0), suitable diffusion coefficient of 5.67 × 10-7 cm2 s-1 is evaluated by chronoamperometry technique (CHA). Finally, the CoMn2O4-rGO/IL/CPE with high sensitivity, selectivity and repeatability is successfully used for determination of pethidine in real sample and drug formulation.

Two Cases of Fatal Inhalation of Easily Available "Recreational" Substances.

ABSTRACT: We present 2 cases of fatal inhalation of easily available highly volatile substances that occurred in a recreational context. Case 1 concerns an 18-year-old man who was found dead with a 25-L plastic bag pulled over his head and a whipped cream steel siphon connected to the bag. The deceased was known to previously have inhaled nitrous oxide. Autopsy results were unremarkable, toxicological analysis using static headspace gas chromatography coupled to mass spectrometry analysis proved the presence of nitrous oxide in lung tissue and blood. Asphyxiation was ascertained as the cause of death. Case 2 describes the death of a 54-year-old man found dead on his bed wearing a rubber gas mask. A bottle with ethyl chloride-containing cold spray was found beside him. Autopsy did not reveal relevant pathological findings; a subsequent toxicological analysis proved the presence of ethyl chloride. Respiratory arrest because of ethyl chloride inhalation was established as the cause of death. The 2 cases presented here demonstrate the danger of easily available, volatile substances with a high potential for abuse. A careful investigation of the death scene, proper specimen collection during the autopsy, and extensive toxicological tests, including headspace gas chromatography coupled to mass spectrometry analysis, are necessary to prove inhalation of these substances.

Machine learning-driven identification of early-life air toxic combinations associated with childhood asthma outcomes.

Air pollution is a well-known contributor to asthma. Air toxics are hazardous air pollutants that cause or may cause serious health effects. Although individual air toxics have been associated with asthma, only a limited number of studies have specifically examined combinations of air toxics associated with the disease. We geocoded air toxic levels from the US National Air Toxics Assessment (NATA) to residential locations for participants of our AiRway in Asthma (ARIA) study. We then applied Data-driven ExposurE Profile extraction (DEEP), a machine learning-based method, to discover combinations of early-life air toxics associated with current use of daily asthma controller medication, lifetime emergency department visit for asthma, and lifetime overnight hospitalization for asthma. We discovered 20 multi-air toxic combinations and 18 single air toxics associated with at least 1 outcome. The multi-air toxic combinations included those containing acrylic acid, ethylidene dichloride, and hydroquinone, and they were significantly associated with asthma outcomes. Several air toxic members of the combinations would not have been identified by single air toxic analyses, supporting the use of machine learning-based methods designed to detect combinatorial effects. Our findings provide knowledge about air toxic combinations associated with childhood asthma.

Inhalant Abuse of Ethyl Chloride Spray: A Case Report.

Ethyl chloride spray, which is usually used to relieve pain after injuries, is increasingly being used as a sniffing alternative. The number of people using this is rising due to its easy availability, cost-effectiveness and legality. The high lipid solubility of ethyl chloride leads to a rapid absorption of it in the lungs. However, data on the biotransformation of ethyl chloride in humans are sparse. We present the case of a 53-year-old male who had been inhaling ethyl chloride up to 3 times a week since 25 years, and describe his symptoms and the circumstances of abuse. This should help raise awareness of this issue so that abuse can be recognized early and rapid action taken.

Does The Use of Ethyl Chloride Improve Patient-Reported Pain Scores With Negative Pressure Wound Therapy Dressing Changes? A Prospective, Randomized Controlled Trial.

BACKGROUND: Negative pressure wound therapy (NPWT) is commonly used for surgical incisions and large wounds, particularly in the context of trauma. Research has shown that patients report that the most painful aspect of NPWT is related to foam dressing changes. This study aimed to determine whether topical use of the vapocoolant anesthetic ethyl chloride would impact patient-reported pain during these procedures. METHODS: This study was a single-blinded, placebo-controlled randomized trial in patients who were undergoing NPWT foam dressing change following surgery performed by the orthopedic trauma team. A total of 100 patients were randomized to receive ethyl chloride topical anesthetic spray or placebo (tissue culture grade water) during dressing change. The outcome measure specified prior to enrollment was a mean decrease in patient-reported pain of 1.7 points using a numeric rating scale. Baseline and procedural characteristics were collected to investigate contributions to patient-reported pain. We hypothesized that the use of ethyl chloride would decrease patient reported pain scores. RESULTS: Significantly more females were randomized to the receive vapocoolant; remaining baseline and procedural characteristics were similar between groups. The median time for NPWT drape removal was 2.0 minutes in both groups (p = 0.66). The postprocedural pain reported by patients was significantly lower in the experimental group compared with placebo (median, 5.0 vs. 7.0; p = 0.03). Multivariate analysis adjusting for potential confounders showed treatment group to be the strongest predictor of postprocedure pain (p = 0.002). Additionally, a generalized linear model suggests that treatment group was the strongest predictor of change in pain score as reported by patients prior to and immediately following dressing change. CONCLUSIONS: Use of vapocoolant spray during NPWT dressing change for orthopedic trauma wounds and surgical incisions was feasible and resulted in significant reduction in patient-reported pain associated with the procedure. LEVEL OF EVIDENCE: Therapeutic, Level I.

Sterility of Ethyl Chloride Spray After Use in the Clinic.

Background: Ethyl chloride spray is used frequently in the outpatient setting as a local anesthetic for injections and aspirations with varying consensus about the sterility of the spray. We hypothesize that ethyl chloride spray remains sterile and would show no bacterial growth during routine clinical use. Methods: Thirteen ethyl chloride bottles were collected for testing. Two unopened bottles were used as controls. Eleven unopened bottles were placed in orthopedic clinics and recollected after varying duration of use. The final volume and duration of use were recorded. Each bottle was sprayed in a separate test tube and allowed to evaporate. Trypticase soy broth was added to each tube and incubated for 48 hours. Control test tubes with broth alone were prepared and incubated under the same conditions. Cultures were evaluated at 24 and 48 hours. Results: The mean duration of ethyl chloride bottle use prior to culturing was 26 days. The average volume used per day was 1.9 mL. Each ethyl chloride bottle had an initial volume of 103.5 mL. Using the average daily volume usage, an extrapolated lifespan of each bottle was estimated at 7.7 weeks. None of the samples showed bacterial or fungal growth at 24 or 48 hours. Conclusion: Ethyl chloride bottles used in the clinical settings showed no bacterial or fungal contamination through their shelf life and routine use. The duration and amount of use did not affect sterility. Although the antimicrobial activity of ethyl chloride spray on skin is debated, ethyl chloride itself remains sterile through clinical use.

Pain perception during transabdominal chorionic villus sampling: a randomized trial comparing topical ethyl chloride anesthetic spray and lidocaine injection.

Background: Chorionic villus sampling is an important invasive procedure used for early antenatal genetic testing that can be associated with anxiety and fear of pain. Pain analgesia prior to chorionic villus sampling can be offered with subdermal lidocaine; however, lidocaine injection itself is associated with pain. Our objective was to determine whether administration of topical ethyl chloride anesthetic spray is associated with decreased pain perception during transabdominal chorionic villus sampling compared to 1% lidocaine subdermal injection.Study design: Women undergoing transabdominal chorionic villus sampling from 10 to 13 weeks and 6 days in an outpatient setting were randomized with equal allocation to either 1% lidocaine injection or topical ethyl chloride anesthetic spray prior to the procedure. Women were asked about their pain on a scale of 0-100 prior to, during, and after the procedure. The primary outcome was pain perception during time of transabdominal chorionic villus sampling as measured on a 100-mm visual analog scale. The secondary outcome was pain immediately after procedure.Results: From October 2016 to June 2017, a total of 120 women were enrolled (63 in the lidocaine injection group and 57 in the topical ethyl chloride anesthetic spray group). Baseline demographic characteristics were similar between groups. During the procedure, patients in the topical ethyl chloride arm demonstrated significantly higher pain scores compared to the lidocaine injection group (median score of 50 mm (interquartile range [IQR]: 40-65) versus 50 mm (IQR: 30-60); p = .03). There was no significant difference in pain scores before or after the procedure.Conclusion: During transabdominal chorionic villus sampling procedures, topical ethyl chloride anesthetic spray is associated with a higher distribution of pain scores as compared to 1% lidocaine subdermal injection, which suggests higher levels of pain.Clinical trial registration: This trial is registered with clinicaltrials.gov (NCT03140293). https://clinicaltrials.gov/ct2/show/NCT03140293?term=NCT03140293&rank=1.

Two distinct Dehalobacter strains sequentially dechlorinate 1,1,1-trichloroethane and 1,1-dichloroethane at a field site treated with granular zero valent iron and guar gum.

Chlorinated ethanes are environmental pollutants found frequently at many contaminated industrial sites. 1,1,1-Trichloroethane (1,1,1-TCA) can be dechlorinated and detoxified via abiotic transformation or biologically by the action of dechlorinating microorganisms such as Dehalobacter (Dhb). At a field site, it is challenging to distinguish abiotic vs. biotic mechanisms as both processes share common transformation products. In this study, we evaluated using the Dhb 16S rRNA gene and specific reductive dehalogenase genes as biomarkers for 1,1,1-TCA and 1,1-dichloroethane (1,1-DCA) dechlorination. We analyzed samples from laboratory groundwater microcosms and from an industrial site where a mixture of granular zero valent iron (ZVI) and guar gum was injected for 1,1,1-TCA remediation. Abiotic and biotic transformation products were monitored and the changes in dechlorinating organisms were tracked using quantitative PCR (qPCR) with primers targeting the Dhb 16S rRNA gene and two functional genes cfrA and dcrA encoding enzymes that dechlorinate 1,1,1-TCA to 1,1-DCA and 1,1-DCA to chloroethane (CA), respectively. The abundance of the cfrA- and dcrA-like genes confirmed that the two dechlorination steps were carried out by two distinct Dhb populations at the site. The biomarkers used in this study proved useful for monitoring different Dhb populations responsible for step-wise dechlorination and tracking biodegradation of 1,1,1-TCA and 1,1-DCA where both abiotic (e.g., with ZVI) and biotic processes co-occur.

Comparison of the Effects of Vapocoolant Spray and Topical Anesthetic Cream on Pain During Intraarticular Injection of the Shoulder: A Randomized Double-Blind Controlled Trial.

OBJECTIVE: This study was performed to compare the effects of a vapocoolant spray and a eutectic mixture of local anesthetics (EMLA) cream on reducing pain during intra-articular (IA) injection of the shoulder. DESIGN: Double-blind randomized placebo-controlled clinical trial. SETTING: University hospital. PARTICIPANTS: Patients (N=63) who underwent IA injection of the shoulder joint were randomized into the spray group, EMLA group, or placebo group. INTERVENTION: Placebo cream+vapocoolant spray (spray group), EMLA cream+placebo spray (EMLA group), or placebo cream+placebo spray (placebo group) before IA injection. MAIN OUTCOME MEASURES: A 100-mm visual analog scale (VAS) for injection pain and 5-point Likert scales for participant satisfaction and preference for repeated use were administered immediately after IA injection. RESULTS: The VAS scores for pain during IA injection were 30.0 (95% CI, 19.7-41.2) in the spray group, 50.0 (95% CI, 37.7-63.0) in the EMLA group, and 53.8 (95% CI, 41.6-65.0) in the placebo group (F=6.403, P<.01). The spray group showed significantly better Likert scale scores than the placebo group for participant satisfaction (P=.003) and preference for repeated use (P<.001). CONCLUSIONS: Vapocoolant spray was effective in reducing pain during IA injection of the shoulder.

A multi-path chain kinetic reaction model to predict the evolution of 1,1,1-trichloroethane and its daughter products contaminant-plume in permeable reactive bio-barriers.

Permeable reactive bio-barriers (Bio-PRBs) are a new and developing technique for in situ remediation of groundwater contamination. Some remediation technologies have often been impeded by insufficient understanding of contaminant transport and transformation in the subsurface environment. Therefore, advanced knowledge in contaminant transport and reactions in Bio-PRBs will be crucial to the successful practical application of this technique. A two-dimensional reaction model C1 was developed for predicting the multi-path chain kinetic reaction of 1,1,1-trichloroethane (1,1,1-TCA) in Bio-PRBs. This study demonstrates that model C1 is able to predict the 1,1,1-TCA breakthrough time and rapidly evaluate the Bio-PRBs retardation performance. The results show that microbial growth and immobilization are the key factors that affect the retardation and remediation performance of Bio-PRBs. The free growth of microorganisms had significant negative effects on hydraulic conductivity (K) in the zero-valent iron (ZVI) region of free microorganism Bio-PRBs (FM-PRBs). The total head loss in the FM-PRB was 9.0 cm, which was significantly greater than the head loss (6.5 cm) of immobilized microorganism Bio-PRBs (IM-PRBs). Compared to ZVI-PRBs and FM-PRBs, the numerical simulation results reveal that microbial immobilization significantly improves the remediation performance of IM-PRBs by 550.9% and 32.7%, respectively. The dual effect of microorganisms leads to significant differences in the 1,1,1-TCA and daughter products (1,1-dichloroethane, 1,1-dichloroethene, chloroethane and vinyl chloride) contaminant-plume evolution between FM-PRBs and IM-PRBs. In addition, model C1 can be utilized to design standard Bio-PRBs for real site of 1,1,1-TCA contanminated groundwater. To meet the safety standard of groundwater as potable water, the width of IM-PRBs needs to be increased by 24 cm. However, in FM-PRBs, the width needs to be increased by 42 cm. Therefore, IM-PRBs save costs significantly. This work has successfully used a model to optimize Bio-PRBs and to predict 1,1,1-TCA and daughter products contaminant-plume evolution in different Bio-PRBs.