Anesthetic Gases Research Articles

Comparison of ease of endotracheal intubation with fixed height pillow versus pillow height attained by alignment of external auditory meatus to sternal notch

Background: Endotracheal intubation is considered to be the “Gold Standard” for airway management during the administration of general anesthesia and in critical care setting because of its advantages, which allows delivery of anesthetic gases and oxygen through positive pressure ventilation without inflation of stomach, permits access to tracheobronchial tree for pulmonary hence minimizing the risk of gastric content aspiration, and improves surgical access to head and neck. The major determinants of easy tracheal intubation are optimal laryngoscopy and a good visualization of the glottis. Aims and Objectives: The aims and objectives of the study are to seek the optimal pillow height that gives the best direct laryngoscopic view and can be recommended as the starting head position before direct laryngoscopy in adults. Materials and Methods: The present study was conducted in a prospective randomized comparative manner in the Department of Anaesthesiology and Critical Care, Pt. B.D. Sharma University of Health Sciences, Rohtak after obtaining approval from the institutional ethical committee (approval number: No. BREC/Th/20/Anaesth.../034). Patients included were scheduled for elective surgery under general anesthesia requiring endotracheal intubation. The inclusion criteria were patients aged 18–50 years of either sex of ASA I and II. Results: A total of 50 subjects, 25 in each group, were included in the final analysis. Following observations and results were drawn from the present prospective and randomized study using appropriate statistical tests. The various observations were out of 50 patients in the study population, and the mean age in years of patients in Group 1 was 38.48±11.77 years and 39.36±11.64 years in Group 2. Conclusion: To conclude, alignment of external auditory meatus to sternal notch offers better conditions for endotracheal intubation than conventionally used sniffing position when assessed in terms of Cormack–Lehane grading and time taken for laryngoscopy and intubation.

Anesthetic Gases: Environmental Impacts and Mitigation Strategies for Fluranes and Nitrous Oxide

Anesthetic gases represent a small but significant portion of the environmental impact of health care in many countries. These compounds include several fluorocarbons commonly referred to as “fluranes”. The fluranes are greenhouse gases (GHG) with global warming potentials in the hundreds to thousands and are also PFAS compounds (per- and polyfluorinated alkyl substances) according to at least one definition. Nitrous oxide (N2O) is sometimes used as an adjunct in anesthesia, or for sedation, but has a significant stratospheric ozone depletion potential as well as GHG effects. Reducing emissions of these compounds into the environment is, therefore, a growing priority in the health care sector. Elimination or substitution of the highest impact fluranes with alternatives has been pursued with some success but limitations remain. Several emission control strategies have been developed for fluranes including adsorption onto solids, which has shown commercial promise. Catalytic decomposition methods have been pursued for N2O emission control, although mixtures of fluranes and N2O are potentially problematic for this technology. All such emission control technologies require the effective scavenging and containment of the anesthetics during use, but the limited available information suggests that fugitive emissions into the operating room may be a significant route for unmitigated losses of approximately 50% of the used fluranes into the environment. A better understanding and quantification of such fugitive emissions is needed to help minimize these releases. Further cost–benefit and techno-economic analyses are also needed to identify strategies and best practices for the future.

Evaluation of a protocol to reduce the environmental impact of anaesthetic gases

Evaluation of a protocol to reduce the environmental impact of anaesthetic gases

Study of electron interaction with halogenated anaesthetic molecules in gas phase at 50 eV electron energy

Abstract This study addresses the environmental concerns associated with halogenated anesthetic gases, specifically halothane, sevoflurane, and isoflurane, due to their contributions to global warming and ozone depletion. Using a combination of experimental and theoretical approaches, we analyzed elastic electron scattering properties of these compounds in the gaseous phase at an electron energy of 50 eV. The experimental data were gathered using a crossed-beam setup equipped with an electron gun and channeltron detection, with argon serving as the reference gas in a relative-flow method to calibrate the absolute cross-section measurements. Theoretical calculations were performed using the Independent Atom Model with Screening Corrected Additivity Rule (IAM-SCAR+I), which includes interference effects to compare with experimental results effectively. These findings enhance understanding of the scattering dynamics of these anesthetics, highlighting their atmospheric implications and potential environmental impacts.

Efficacy of Nebulized Dexmedetomidine and Lignocaine Inhalation versus Lignocaine Alone as Premedication for Flexible Fiber-optic Bronchoscopy under Sedation: A Randomized Comparative Study.

Airway management is an integral part of general anesthesia, allowing ventilation and oxygenation and working as a mode for delivering anesthetic gases. Awake fiber-optic-guided intubation is an essential component of airway management in difficult cases. We aim to study the benefits of nebulized dexmedetomidine with lignocaine over lignocaine alone for anesthetizing the airway for flexible fiber-optic bronchoscopy. In the study, after written informed consent, 50 patients were randomly allocated into two equal groups of 25 each. The intervention group received dexmedetomidine with lignocaine nebulization, while the control group received lignocaine nebulization alone. Baseline pulse rate, blood pressure, and, at regular intervals, cough, sedation, and pain scores were recorded along with the patient satisfaction score. Parametric data were analyzed by the Student's t-test, while nonparametric data were analyzed by the Wilcoxon Mann-Whitney U test. Out of a total of 54 patients, 4 patients did not give consent to participate in the study. The demographic profile was comparable in both groups. The pulse rate was comparable in both groups throughout the procedure; however, 10 min after the procedure, the pulse rate in the lignocaine group was (mean ± standard deviation) 114.2 ± 11.52, while in the intervention group, it was 87.32 ± 7.24 with a P = 0.027. The mean blood pressure was comparable throughout the procedure. The cough score yielded a Z-score of -5.12 and a P < 0.00001 favoring the dexmedetomidine group. Similarly, Richmond agitation-sedation score and Visual Analog Scale (VAS) also favored the intervention group, with P < 0.00054 and P < 0.00001 in RASS and VAS, respectively. Patient satisfaction score analysis found a Z-score of -5.29 and a P < 0.00001. The overall results favored dexmedetomidine with lignocaine nebulization over lignocaine alone for anesthetizing airways for flexible fiber-optic bronchoscopy.

Maternity protection in pneumology: considerations for a positive list

It seems difficult to continue to employ expectant/breastfeeding mothers in interventional medical fields due to numerous risks involved, such as in handling infectious agents or anaesthetic gases. Pregnancy for female doctors is thus often associated with a ban on employment and is therefore synonymous with a delay in their professional career. The aim of this article was to develop a positive list that allows pregnant women to continue working during their pregnancy at low risk and provides employers with a guide for drawing up risk assessment for specific occasions. The brief narrative overview is based on the recommendations drawn up by both professional associations and the Maternity Protection Committee. It is intended to provide assistance for the preparation of an event-related risk assessment after notification of a pregnancy in the speciality of pneumology in order to be able to continue to employ female doctors working in interventional medicine at low risk.

Assessment of waste anesthetic gas concentrations in the operating theaters and DNA damage in exposed female nurse anesthetists

BackgroundPersonnel that work in operation theaters are at risk of exposure to waste anesthetic gases (WAGs) that can cause deoxyribonucleic acid (DNA) damage. To assess the potential impacts of single strand break levels of nurse anesthetists, WAGs levels, and other factors were investigated. MethodsNon-smoker nurse anesthetists (exposure group) and registered nurses (control group) that have never worked in operating theaters (OT) were matched by age. The WAG concentrations in OT were measured via a direct reading instrument. A blood sample of 2 mL from each volunteer nurse was used to determine the single strand break of DNA damage by comet assay; between July 2014 and January 2016. ResultsIn total 77 nurses participated in this study. Even if the average 8-h TWA of the WAG concentrations were low, N2O peaked at 951 ppm and sevoflurane peaked at 88.3 ppm during the induction phrase of pediatric patients. Multivariate analysis showed that ln (% of DNA) in the tail and ln (tail moment) were positively, significantly associated with N2O and cancer in family history, while ln (tail length) was not. However, dietary consumption of fish, meat and cruciferous vegetable had influence on DNA damage and shift work should not be neglected. ConclusionNurse anesthetists were potentially exposed to very high WAG concentrations; especially in pediatric cases. There were multi-factors associated with DNA damage score. To decrease the DNA damage score, lifestyle and dietary consumption should be of more concern.

Anesthetic Gas Scavenging System for Gas Evacuation in the ICU.

Inhaled sedation is increasing in ICUs, with active carbon filters (ACFs) commonly used for evacuating halogenated gases. However, the potential benefits of a waste anesthetic gas system (WAGS) similar to the ones used in operating rooms should be explored. To limit the suction over the flow sensor where the WAGS is connected on ICU ventilators, an anesthetic gas receiving system (AGRS) is required, constituting with the WAGS an active gas receiving and scavenging system (AGRSS). Ensuring that this whole device does not compromise the flow sensor reliability is crucial. The aim of this study was to compare various gas evacuation devices and assess the reliability of AGRSS on ICU ventilators. In this experimental study, pressures and flows were recorded during the ventilation of a test lung using various ventilator settings and gas evacuation methods: no device (reference condition), ACF, the WAGS alone, AGRSS (WAGS and AGRS together), and the expiratory valve connected to the medical vacuum system with the AGRS in between. Visual comparisons of the pressure and flow curves followed by a statistical analysis comparing median pressures and flows of each device to the reference were performed. The test lung model demonstrated consistent comparability in pressures and flows among all devices, except for the WAGS alone, which exhibited discordance through significant overestimation or underestimation. These findings indicate that using a WAGS with the AGRS system appeared to be reliable for managing gas evacuation in ICUs without compromising pressure or flow delivery. The data from this experimental trial should be confirmed with clinical studies involving human subjects. Given the increasing use of inhaled sedation in ICUs, these results support the daily application of the WAGS with the AGRS for gas evacuation, similar to its established use in anesthesiology.

Minimising Carbon Footprint in Anaesthesia Practice

Carbon footprint refers to the total amount of greenhouse gas emitted in the atmosphere by an individual or by an organization causing global warming. There are various causes of greenhouse gas emissions and anaesthetic gases are one amongst them. Greenhouse gases warm the earth by absorbing infrared energy and slowing the rate at which the energy escapes into space. Each greenhouse gas has two important properties. One is the amount of infrared energy that a gas can absorb and the other is the lifetime of that gas in the atmosphere. Anaesthesia as a speciality contributes to carbon footprinting in three ways: direct emission, energy use, and operating room wastes and supplies. Direct emission of Waste Anaesthetic Gases (WAG) from anaesthesia workstations can either be scavenged and thrown out into the environment causing a green greenhouse gas effect or can pollute the operating room due to poor scavenging. Various techniques such as reducing direct emissions, energy use optimisation, and waste management have been tried in minimising carbon footprint in anaesthesia practice but providing safety to the patient is considered of utmost importance.

Strategies and tactics to reduce the impact of healthcare on climate change: systematic review

ObjectiveTo review the international literature and assess the ways healthcare systems are mitigating and can mitigate their carbon footprint, which is currently estimated to be more than 4.4% of global...

Bibliometric analysis of occupational exposure in operating room from 1973 to 2022

ObjectiveThe purpose of this study is to identify and visualize from different perspectives the topic on occupational exposure in operating room (OEOR).MethodsIn the Web of Science Core Collection (WoSCC), all the half-century data were retrieved from January 1st, 1973 to December 31st, 2022. CiteSpace, VOSviewer and Excel 2019 were employed to analyze and visualize data, based on publications, countries, institutions, journals, authors, keywords.ResultA total of 336 journal papers were found. The increase of publications virtually started in 1991, peaked in 2020 and has been slowing down ever since. USA played most significant part among all the 49 countries/regions, while Universidade Estadual Paulista out of 499 institutions published the most papers. International Archives of Occupational and Environmental Health bears the most documents and citations in all the 219 retrieved journals. There are 1847 authors found, among whom Hoerauf K is the most influential one. "Occupational exposure”, “nitrous oxide” and “operating room personnel” are the top 3 co-occurrences keywords.ConclusionThe trend in the field lies in “anaesthetic gas”, “blood borne pathogen”, “radiation” and “aerosol”, while “surgical smoke” and “occupational safety” are the recently researching hot spots in this study. Accurate recognize and effective protection are always essential subjects for researchers.

A comparative randomized study on effect of bispectral index versus end-tidal anesthetic gas concentration-guided protocol on time to tracheal extubation for isoflurane based general anesthesia

A comparative randomized study on effect of bispectral index versus end-tidal anesthetic gas concentration-guided protocol on time to tracheal extubation for isoflurane based general anesthesia

Trends in volatile anesthetic sevoflurane and desflurane usage and its impact on carbon emissions: A six-year audit at National Taiwan University Hospital (2018–2023)

This short communication presents an audit of anesthetic gas usage at National Taiwan University Hospital from 2018 to 2023. Using descriptive statistics and trend analysis, the data reveals trends in the consumption of sevoflurane and desflurane, associated costs, and their corresponding carbon emissions. A significant decrease in desflurane usage contributed to a 42.4% reduction in carbon dioxide equivalent (CO2e) emissions per general anesthesia case from 2018 to 2023. The findings underscore the importance of sustainable practices in anesthesia to align with global efforts to reduce carbon emissions.

Caudal analgesia application with bupivacaine in a pediatric patient with glucose-6-phosphate dehydrogenase enzyme deficiency; case report

Glucose-6-phosphate dehydrogenase enzyme has a cells protecting feature from oxidative damage. Glucose-6-phosphate Dehydrogenase Enzyme Deficiency is a hereditary disease that causes hemolysis in cases of deficiency due to mutation in the X chromosome, due to oxidative stresses such as some drugs, chemicals or infection. The preoperative Hb of a 4-year-old patient who was to undergo circumcision surgery was determined as 8.9 g/dL. Since increased bleeding was not expected during this procedure, no attempt was made to increase the hemoglobin value. After the induction of general anesthesia with sevoflurane 8%, 1 ml/kg of 0.25% bupivacaine was administered caudally to the patient. The hemodynamic findings remained within normal limits during the surgical procedure. In the follow-up, it was determined that the pain score was low and that no additional analgesic drugs were required. Afterwards, no additional hematological abnormalities were detected and the patient was discharged two days later. We believe that during surgery, when routine monitoring measures are taken and conditions that may cause stress to the patient such as hypotension, hypoxemia, and dehydration are avoided, the patient's anesthesia and postoperative pain can be controlled with a general anesthetic gas such as sevoflurane and a local anesthetic such as bupivacaine, with attention to toxic doses.

Waste not want not: the story of surgical trash.

Our escalating reliance on disposable products in the operating room has generated a large amount of waste, cost, and environmental pollution. Heath damages from the pollution caused by the US healthcare industry cause as much harm, as measured by disability-adjusted life years, as total medical errors. Our response to our own environmental impact should be proportional to that harm. Understanding the waste streams we create and the factors that contribute to our large waste generation in the operating room can help us target solutions to our most harmful practices. Recent studies within the field of medical waste in ObGyn have included a systematic review analyzing most effective practices for waste reduction and environmental life cycle analyses of specific medical procedures. Operating room waste includes regulated medical waste, pathologic waste/chemotherapy, sharps, general municipal waste, recycling, linens, and anesthetic gases. The most effective way to reduce the environmental impact from medical waste is to reduce our use of disposable supplies in favor of durable reusable materials. Other important interventions include eliminating 'overage' of unused supplies, optimizing use of anesthetic gas, custom pack scale backs, and proper waste segregation. This review of operative waste is intended to aid healthcare facilities in understanding and addressing their own environmental impact.

FP8.2 - Sustainability Within the Abscess Pathway

Abstract Background Global warming and the current climate crisis remain a threat to global health. It is estimated that 5% of the total carbon footprint of an acute NHS organisation was attributable to general anaesthetic (GA) gases, which contributes to ongoing ozone depletion. Aims To review current practices in managing abscesses and improve sustainability within the abscess pathway in our trust. Methods Retrospective data on all patients who underwent incision and drainages (I&amp;D) between January – July 2022 were collected and analysed. A new abscess pathway was introduced in June 2023 and departmental teaching provided to junior doctors on incision and drainage of abscesses under local anaesthetic (LA). Data on patients who underwent I&amp;D between June – September 2023 were collected and analysed to assess the impact of the new abscess pathway. Results In the first-cycle audit, 162 patients underwent I&amp;D, of which 119 (92%) were done under GA. Of these, 71 (60%) were suitable for LA I&amp;Ds, 91% were admitted for their procedures. The estimated carbon footprint was 4525kg CO2e/year. In the second-cycle audit, 68 patients underwent I&amp;D, of which 37 (76%) were done under GA. Of these, 31 (46%) were suitable for LA I&amp;Ds, 41% were admitted for their procedures. The estimated carbon footprint was 3735kg CO2e/year. Conclusions Following implementation of the new abscess pathway, we reduced the number of patients having general anaesthetic procedures and inpatient admission. This not only improves the sustainability of our practice, but makes treatment and recovery quicker for patients, and has a lower financial burden.

Scoping review for the SAGES EAES joint collaborative on sustainability in surgical practice.

Surgical care in the operating room (OR) contributes one-third of the greenhouse gas (GHG) emissions in healthcare. The European Association of Endoscopic Surgery (EAES) and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) initiated a joint Task Force to promote sustainability within minimally invasive gastrointestinal surgery. A scoping review was conducted by searching MEDLINE via Ovid, Embase via Elsevier, Cochrane Central Register of Controlled Trials, and Scopus on August 25th, 2023 to identify articles reporting on the impact of gastrointestinal surgical care on the environment. The objectives were to establish the terminology, outcome measures, and scope associated with sustainable surgical practice. Quantitative data were summarized using descriptive statistics. We screened 22,439 articles to identify 85 articles relevant to anesthesia, general surgical practice, and gastrointestinal surgery. There were 58/85 (68.2%) cohort studies and 12/85 (14.1%) Life Cycle Assessment (LCA) studies. The most commonly measured outcomes were kilograms of carbon dioxide equivalents (kg CO2eq), cost of resource consumption in US dollars or euros, surgical waste in kg, water consumption in liters, and energy consumption in kilowatt-hours. Surgical waste production and the use of anesthetic gases were among the largest contributors to the climate impact of surgical practice. Educational initiatives to educate surgical staff on the climate impact of surgery, recycling programs, and strategies to restrict the use of noxious anesthetic gases had the highest impact in reducing the carbon footprint of surgical care. Establishing green teams with multidisciplinary champions is an effective strategy to initiate a sustainability program in gastrointestinal surgery. This review establishes standard terminology and outcome measures used to define the environmental footprint of surgical practices. Impactful initiatives to achieve sustainability in surgical practice will require education and multidisciplinary collaborations among key stakeholders including surgeons, researchers, operating room staff, hospital managers, industry partners, and policymakers.

Exhaled Anesthetic Xenon Regeneration by Gas Separation Using a Metal-Organic Framework with Sorbent-Sorbate Induced-Fit.

Noble gas xenon (Xe) is an excellent anesthetic gas, but its rarity, high cost and constrained production prohibits wide use in medicine. Here, we have developed a closed-circuit anesthetic Xe recovery and reusage process with highly effective CO2-specific adsorbent CUPMOF-5 that is promising to solve the anesthetic Xe supply problem. CUPMOF-5 possesses spacious cage cavities interconnected in four directions by confinement throat apertures of ~3.4 Å, which makes it an ideal molecular sieving of CO2 from Xe, O2, N2 with the benchmark selectivity and high uptake capacity of CO2. In situ single-crystal X-ray diffraction (SCXRD) and computational simulation solidly revealed the vital sieving role of the confined throat and the sorbent-sorbate induced-fit strengthening binding interaction to CO2. CUPMOF-5 can remove 5 % CO2 even from actual moist exhaled anesthetic gases, and achieves the highest Xe recovery rate (99.8 %) so far, as verified by breakthrough experiments. This endows CUPMOF-5 great potential for the on-line CO2 removal and Xe recovery from anesthetic closed-circuits.

Exhaled Anesthetic Xenon Regeneration by Gas Separation Using a Metal–Organic Framework with Sorbent‐Sorbate Induced‐Fit

AbstractNoble gas xenon (Xe) is an excellent anesthetic gas, but its rarity, high cost and constrained production prohibits wide use in medicine. Here, we have developed a closed‐circuit anesthetic Xe recovery and reusage process with highly effective CO2‐specific adsorbent CUPMOF‐5 that is promising to solve the anesthetic Xe supply problem. CUPMOF‐5 possesses spacious cage cavities interconnected in four directions by confinement throat apertures of ~3.4 Å, which makes it an ideal molecular sieving of CO2 from Xe, O2, N2 with the benchmark selectivity and high uptake capacity of CO2. In situ single‐crystal X‐ray diffraction (SCXRD) and computational simulation solidly revealed the vital sieving role of the confined throat and the sorbent‐sorbate induced‐fit strengthening binding interaction to CO2. CUPMOF‐5 can remove 5 % CO2 even from actual moist exhaled anesthetic gases, and achieves the highest Xe recovery rate (99.8 %) so far, as verified by breakthrough experiments. This endows CUPMOF‐5 great potential for the on‐line CO2 removal and Xe recovery from anesthetic closed‐circuits.

Intraocular Pressure and Safety of Vitrectomy with Vitreous Gas Replacement using Low-concentration Nitrous Oxide Gas Anesthesia.

This study aims to evaluate the efficacy and safety of vitrectomy with vitreous gas replacement using low-concentration nitrous oxide (N2O) gas anesthesia, focusing on intraocular pressure (IOP) changes, pain, anxiety, and safety outcomes. This retrospective study analyzed 133 patients undergoing fluid-air exchange without use of such as SF6 or C3F8, at Saneikai Tsukazaki Hospital, Japan, from April 2019 to March 2022. Participants were divided into two groups: those receiving low-concentration nitrous oxide gas anesthesia (N2O group) and those receiving local anesthesia with room air inhalation (Air group). IOP, pain, anxiety levels, and intraoperative complications were assessed. No significant differences were found in IOP changes postoperatively between the N2O and Air groups. The N2O group reported significantly lower pain scores and had lower intraoperative systolic blood pressure and heart rate changes compared with the Air group. No significant intraoperative or postoperative complications were observed in either group. Vitrectomy with fluid-air exchange using low-concentration nitrous oxide gas anesthesia is safe, does not increase IOP, and may offer benefits in reducing intraoperative pain and stabilizing vital signs compared with traditional local anesthesia methods. This approach could be considered a viable option for vitreous surgery requiring fluid-air exchange.