Inhaled Anesthetics: Environmental Role, Occupational Risk, and Clinical Use

The impact of volatile anesthetics and propofol on phosphatidylinositol 4,5-bisphosphate signaling

Phosphatidylinositol 4,5-bisphosphate (PIP2), as well as other anionic phospholipids, play a pivotal role in various cellular processes, including ion channel regulation, receptor trafficking, and intracellular signaling pathways. The binding of volatile anesthetics and propofol to PIP2 leads to alterations in PIP2-mediated signaling causing modulation of ion channels such as ɣ-aminobutyric acid type A (GABAA) receptors, voltage-gated calcium channels, and potassium channels through various mechanisms. Additionally, the interaction between anionic phospholipids and G protein-coupled receptors plays a critical role in various anesthetic pathways, with these anesthetic-induced changes impacting PIP2 levels which cause cascading effects on receptor trafficking, including GABAA receptor internalization. This comprehensive review of various mechanisms of interaction provides insights into the intricate interplay between PIP2 signaling and anesthetic-induced changes, shedding light on the molecular mechanisms underlying anesthesia.

Plastic waste in major orthopaedic surgical procedures: descriptive and sources of improvement

PURPOSE

The healthcare industry is a significant contributor to single-use plastic waste, particularly in the operating room (OR). This study aims to assess the volume of plastic waste generated during total hip, knee, and shoulder arthroplasty in the OR and identify areas for improvement.

METHOD

A prospective transversal study at a tertiary hospital was conducted. All total knee arthroplasty (TKA), total hip arthroplasty (THA), and reverse shoulder arthroplasty (RSA) from April to July 2021 were included. The weight of plastic used during patient preparation, anaesthesia, and the surgical procedure was recorded. To calculate the environmental impact, a calculator generated by the United States Environmental Protection Agency (U.S. EPA) was used.

RESULTS

A total of 68 surgeries were included. The mean weight of plastic used in total was 7.3 kg (SD 0.48), with the highest yielding procedure being TKA. It generated a mean of 7.63 kg (SD 0.28), followed by THA at 7.28 kg (SD 0.43), and RSA at 6.87 kg (SD 0.47). Various scenarios were simulated to evaluate the potential impact of reducing plastic waste. Substituting plastic wrapping with recyclable materials could save 159.6 kg of CO2 emissions per 100 prostheses. Eliminating non-essential equipment and adopting reusable fabric drapes also showed a significant potential.

CONCLUSION

The findings highlight the need for environmentally sustainable practices in the OR. In this way, the healthcare sector can contribute to a cleaner and greener world without compromising patient safety.

The effect of preemptive retrolaminar block on lumbar spinal decompression surgery

PURPOSE

Spinal decompression surgery causes severe pain. Retrolaminar block (RLB) is block, which is done by infiltration of local anesthetic to block spinal nerves between the lamina and superior costotransversospinalis muscle. The primary aim of this study is to evaluate the effectiveness of RLB on postoperative analgesia in patients undergoing spinal surgery. Secondary aims are effects on additional anesthetic and analgesic consumption.

METHODS

The sixty (60) patients who underwent lumbar spinal surgery between May 2020 and May 2021 under general anesthesia with or without applied preemptive RLB for postoperative analgesia were included in this prospective observational study. Group I received ultrasound-guided preemptive RLB. In Group II, no intervention was performed. Postoperative VAS scores were compared in groups as primary outcome, perioperative additional anesthetic and analgesic needs were compared as secondary outcome.

RESULTS

There was a significant difference between the groups in favor of the RLB group in terms of postoperative VAS scores at rest [1.33 (0.33-3.509)] and movement [2.40 (1.20-4.00)] (p < 0.001). Perioperative sevoflurane consumption was significantly low in block group (p < 0.001). Postoperative tramadol consumption was lower in Group I compared with Group II [Group 1: 200 (100-300); Group 2: 37.5 (0-200); p < 0.001].

CONCLUSION

Preemptive RLB may be used to reduce patients' pain in lumbar decompression surgery as well as to be part of a multimodal analgesia and anesthesia regimen to reduce anesthetic and analgesic drug consumption. Trial registration numberClinicalTrials.gov (No. NCT04209907).

How we can reduce the environmental impact of our operating theatres: a narrative review

Climate change is projected to become the leading cause of adverse health outcomes globally, and the healthcare system is a key contributor. Surgical theatres are three to six times more pollutant than other hospital areas, and produce anywhere from a fifth to a third of total hospital waste. Hospitals are increasingly expected to make operating theatres more sustainable, however guidelines to improve environmental sustainability are lacking, and previous research takes a narrow approach to operative sustainability. This paper presents a narrative review that, following a 'review of reviews' approach, aims to summarize the key recommendations to improve the environmental sustainability of surgical theatres. Key domains of discussion identified across the literature included minimisation of volatile anaesthetics, reduction of operating theatre power consumption, optimisation of surgical approach, re-use and re-processing of surgical instruments, waste management, and research, education and leadership. Implementation of individual items in these domains has seen significant reductions in the environmental impact of operative practice. This comprehensive summary of recommendations lays the framework from which providers can assess the sustainability of their practice and for the development of encompassing guidelines to build an environmentally sustainable surgical service.

Similarity and dissimilarity in alterations of the gene expression profile associated with inhalational anesthesia between sevoflurane and desflurane

Although sevoflurane is one of the most commonly used inhalational anesthetic agents, the popularity of desflurane is increasing to a level similar to that of sevoflurane. Inhalational anesthesia generally activates and represses the expression of genes related to xenobiotic metabolism and immune response, respectively. However, there has been no comprehensive comparison of the effects of sevoflurane and desflurane on the expression of these genes. Thus, we used a next-generation sequencing method to compare alterations in the global gene expression profiles in the livers of rats subjected to inhalational anesthesia by sevoflurane or desflurane. Our bioinformatics analyses revealed that sevoflurane and, to a greater extent, desflurane significantly activated genes related to xenobiotic metabolism. Our analyses also revealed that both anesthetic agents, especially sevoflurane, downregulated many genes related to immune response.

Prospective Observational Study of Volatile Sedation with Sevoflurane After Aneurysmal Subarachnoid Hemorrhage Using the Sedaconda Anesthetic Conserving Device

BACKGROUND

Volatile sedation is still used with caution in patients with acute brain injury because of safety concerns. We analyzed the effects of sevoflurane sedation on systemic and cerebral parameters measured by multimodal neuromonitoring in patients after aneurysmal subarachnoid hemorrhage (aSAH) with normal baseline intracranial pressure (ICP).

METHODS

In this prospective observational study, we analyzed a 12-h period before and after the switch from intravenous to volatile sedation with sevoflurane using the Sedaconda Anesthetic Conserving Device with a target Richmond Agitation Sedation Scale score of - 5 to - 4. ICP, cerebral perfusion pressure (CPP), brain tissue oxygenation (PBrO2), metabolic values of cerebral microdialysis, systemic cardiopulmonary parameters, and the administered drugs before and after the sedation switch were analyzed.

RESULTS

We included 19 patients with a median age of 61 years (range 46-78 years), 74% of whom presented with World Federation of Neurosurgical Societies grade 4 or 5 aSAH. We observed no significant changes in the mean ICP (9.3 ± 4.2 vs. 9.7 ± 4.2 mm Hg), PBrO2 (31.0 ± 13.2 vs. 32.2 ± 12.4 mm Hg), cerebral lactate (5.0 ± 2.2 vs. 5.0 ± 1.9 mmol/L), pyruvate (136.6 ± 55.9 vs. 134.1 ± 53.6 µmol/L), and lactate/pyruvate ratio (37.4 ± 8.7 vs. 39.8 ± 9.2) after the sedation switch to sevoflurane. We found a significant decrease in mean arterial pressure (MAP) (88.6 ± 7.6 vs. 86.3 ± 5.8 mm Hg) and CPP (78.8 ± 8.5 vs. 76.6 ± 6.6 mm Hg) after the initiation of sevoflurane, but the decrease was still within the physiological range requiring no additional hemodynamic support.

CONCLUSIONS

Sevoflurane appears to be a feasible alternative to intravenous sedation in patients with aSAH without intracranial hypertension, as our study did not show negative effects on ICP, cerebral oxygenation, or brain metabolism. Nevertheless, the risk of a decrease of MAP leading to a consecutive CPP decrease should be considered.

Easy-to-implement educational interventions to bring climate-smart actions to daily anesthesiologic practice: a cross-sectional before and after study

BACKGROUND

Anesthesia contributes significantly to a hospital's carbon footprint. Climate-smart actions have the potential to reduce greenhouse gas emissions. Prerequisites for sustainable behavior of providers are knowledge and awareness. We aimed to assess the change in anesthesiologists' climate-friendly behavior before and after educational interventions in three areas that every anesthesiologist can address in their daily clinical routine: 1) energy use; 2) recycling opportunities; 3) consumption of volatile anesthetics.

METHODS

We performed a cross-sectional before-and-after single center sub-study within the multicenter "Provider Education and Evaluation Project" at the Department of Anesthesiology, RWTH Aachen University hospital from May3 2021 to May 1 2022. Educational interventions consisted of stickers, posters and a presentation on climate-smart actions in anesthesiologists' work routine between the first and the second assessment. For each cross-sectional assessment, all central 28 ORs were observed for one week. During the before-and-after comparison we analyzed: 1) energy wasted in unoccupied ORs because of running computers and turned-on lights at 9 p.m.; 2) feasibility of recycling preoperative anesthesia plastic packaging by determining the difference between calculated weight of unseparated preoperative plastic waste in the first assessment and the weight of actual separated waste in the second assessment; 3) fresh gas flow in balanced anesthesia cases in steady state at 9 a.m., and purchased hypnotics converted to bottles/1000 general anesthesia cases in 2018-2022.

RESULTS

We observed a reduction of wasted energy by 44% in unoccupied ORs. Usage of low fresh gas flow settings increased from 55% to 75%. The average of purchased desflurane in 2018-2020 decreased by 72% in 2022. We calculated 10.33 kg of preoperative plastic waste per week but were unable to implement waste separation for infrastructural and logistical reasons.

CONCLUSIONS

We found that environment-friendly working behaviors increased after the implementation of educational interventions. The causality between the interventions and the observed improvements remains to be proven.

Modulation of gene expression and influence of gene polymorphisms related to genotoxicity and redox status on occupational exposure to inhaled anesthetics

The extensive use of inhalational anesthetics contributes to both indoor and outdoor (environmental) pollution. The influence of genetic susceptibility on DNA damage and oxidative stress and the possible modulation of gene expression have not yet been investigated upon occupational exposure to waste anesthetic gases (WAGs). This study assessed 8-oxoguanine DNA glycosylase 1 (OGG1) and superoxide dismutase 2 (SOD2) gene expression, which are related to oxidized DNA repair and antioxidant capacity, respectively, and the influence of their polymorphisms (OGG1 rs1052133 and SOD2 rs4880) in 100 professionals highly exposed to WAGs and 93 unexposed volunteers (control group). Additionally, X-ray repair cross complementing 1 (XRCC1 rs25487 and rs1799782) and ataxia telangiectasia mutated (ATM rs600931) gene polymorphisms as well as genetic instability (micronucleus-MN and nuclear bud-NBUD) and oxidative stress (malondialdehyde-MDA and ferric reducing antioxidant power-FRAP) biomarkers were assessed in the groups (control and exposed) and in the subgroups of the exposed group according to job occupation (anesthesiologists versus surgeons/technicians). Except for the ATM TT controls (associated with increased FRAP), there were no influences of OGG1, XRCC1, ATM, and SOD2 polymorphisms on MN, NBUD, MDA, and FRAP values in exposed or control subjects. No significant difference in the expression of either gene evaluated (OGG1 and SOD2) was found between the exposed and control groups. Increased OGG1 expression was observed among OGG1 -/Cys individuals only in the control group. Among the exposed group, anesthesiologists had a greater duration of WAG exposure (both h/week and years) than surgeons/technicians, which was associated with increased MDA and decreased antioxidant capacity (FRAP) and SOD2 expression (redox status). Higher expression of OGG1 was found in -/Cys surgeons/technicians than in anesthesiologists with the same genotype. Increased antioxidant capacity was noted in the surgeons/technicians carrying the ATM T allele and in those carrying XRCC1 -/Gln. Increased MN was influenced by OGG1 -/Cys in surgeons/technicians. Anesthesiologists with ATM CC exhibited increased MN, and those carrying the C allele (CC/CT genotype) exhibited increased NBUD. SOD2 polymorphism did not seem to be relevant for WAG exposure. These findings contribute to advancing the knowledge on genetic susceptibility/gene expression/genetic instability/oxidative stress, including differences in job occupation considering the workload, in response to occupational exposure to WAGs.

Perception of environmental issues in the head-and-neck surgery room: A preliminary study

OBJECTIVES

To assess the perception of environmental issues in head-and-neck surgery rooms and to compare the perception of priority environmental issues according to health professionals' age-group, initial training and role in the operating room.

METHODS

A multicenter descriptive observational study was conducted in January 2023, contacting health professionals working in the operating rooms of 5 French centers. An anonymous online questionnaire explored the perception of environmental issues according to age, initial training and role in the operating room.

RESULTS

Sixty-nine percent of the 387 persons contacted (267/387) completed the entire questionnaire. Ninety-six percent of respondents (256/267) said that they felt concerned about climate change issues and 85% (226/267) felt well-informed. Ninety-three percent (251/267) were willing to make environmental efforts in the operating room. Priorities were to improve waste recycling and reduce the amount of waste for 95% (251/267) and 97% (259/267) of respondents respectively. Those under 40 years of age tended to feel better informed about climate issues (76% [75/99] versus 60% [100/168]; P=0.010).

CONCLUSION

Our study showed that the vast majority of health professionals working in head-and-neck surgery rooms in France felt concerned about climate issues and were ready to make an effort. Nevertheless, it seems important to carry out information campaigns dedicated to these environmental issues.

Nitrous oxide use in Canadian pediatric emergency departments: a survey of physician's knowledge, attitudes, and practices

OBJECTIVES

Nitrous oxide (N2O) is an inhaled analgesic/ anxiolytic gas with evidence supporting its safety and efficacy for distressing procedures in children. Despite this, its use is not consistent across Canadian pediatric emergency departments (EDs). We aimed to characterize a) physicians' knowledge and practices with N2O and b) site-specific N2O protocols in Canadian pediatric EDs to help optimize its use nationally.

METHODS

This cross-sectional survey was distributed to physician members of Pediatric Emergency Research Canada (PERC) in early 2021. Survey items addressed practice patterns, clinician comfort, and perceived barriers/ facilitators to use. Further, a representative from each ED completed a site-specific inventory of N2O policies and procedures.

RESULTS

N2O was available in 40.0% of 15 pediatric EDs, with 83.3% of these sites having written policies in place. Of 230 distributed surveys, 67.8% were completed with mean (SD) attending experience of 14.7 (8.6) years and 70.1% having pediatric emergency subspecialty training. Of the 156 respondents, 48.7% used N2O in their clinical practice. The most common indications for use were digit fracture/ dislocation reduction (69.7%), wound closure (60.5%), and incision & drainage (59.2%). Commonly perceived facilitators were N2O equipment availability (73.0% of 156) and previous clinical experience (71.7% of 156). Of the 51.3% of physicians who reported not using N2O, 93.7% did not have availability at their site; importantly, the majority indicated a desire to acquire access. They identified concerns about ventilation/ scavenging systems (71.2% of 80) and unfamiliarity with equipment (52.5% of 80) as the most common barriers to use.

CONCLUSIONS

Despite evidence to support its use, only half of Canadian pediatric ED physicians surveyed use N2O in their clinical practice for treating procedure-related pain and distress. Increased availability of N2O equipment, protocols, and training may improve clinicians' abilities to better manage pediatric acute pain and distress in the ED.

Parenthood and neurosurgery in Europe a white paper from the European Association of Neurosurgical Societies' Diversity in Neurosurgery Committee Part I - Family Planning and Practice during Pregnancy

Introduction

Family and work have immensely changed and become intertwined over the past half century for both men and women. Additionally, alongside to traditional family structures prevalent, other forms of families such as single parents, LGBTQ + parents, and bonus families are becoming more common. Previous studies have shown that surgical trainees regularly leave residency when considering becoming a parent due to the negative stigma associated with pregnancy during training, dissatisfaction with parental leave options, inadequate lactation and childcare support, and desire for greater mentorship on work-life integration. Indeed, parenthood is one of the factors contributing to attrition in surgical specialities, neurosurgery not being an exception.

Research question

The Diversity in Neurosurgery Committee (DC) of the European Association of Neurosurgical Societies (EANS) recognizes the challenges individuals face in parenthood with neurosurgery and wishes to address them in this white paper.

Materials and methods

In the following sections, the authors will focus on the issues pertaining to family planning and neurosurgical practice during pregnancy in itemized fashion based on an exhaustive literature search and will make recommendations to address the matters raised.

Results

Potential solutions would be to further improve the work-family time ration as well as improving working conditions in the hospital.

Discussion and conclusion

While many obstacles have been quoted in the literature pertaining to parenthood in medicine, and in neurosurgery specifically, initiatives can and should be undertaken to ensure not only retention of colleagues, but also to increase productivity and job satisfaction of those seeking to combine neurosurgery and a family life, regardless of their sexual identity and orientation.

Neuroprotection Is in the Air-Inhaled Gases on Their Way to the Neurons

Cerebral injury is a leading cause of long-term disability and mortality. Common causes include major cardiovascular events, such as cardiac arrest, ischemic stroke, and subarachnoid hemorrhage, traumatic brain injury, and neurodegenerative as well as neuroinflammatory disorders. Despite improvements in pharmacological and interventional treatment options, due to the brain's limited regeneration potential, survival is often associated with the impairment of crucial functions that lead to occupational inability and enormous economic burden. For decades, researchers have therefore been investigating adjuvant therapeutic options to alleviate neuronal cell death. Although promising in preclinical studies, a huge variety of drugs thought to provide neuroprotective effects failed in clinical trials. However, utilizing medical gases, noble gases, and gaseous molecules as supportive treatment options may offer new perspectives for patients suffering neuronal damage. This review provides an overview of current research, potentials and mechanisms of these substances as a promising therapeutic alternative for the treatment of cerebral injury.

General purpose models for intravenous anesthetics, the next generation for target-controlled infusion and total intravenous anesthesia?

PURPOSE OF REVIEW

There are various pharmacokinetic-dynamic models available, which describe the time course of drug concentration and effect and which can be incorporated into target-controlled infusion (TCI) systems. For anesthesia and sedation, most of these models are derived from narrow patient populations, which restricts applicability for the overall population, including (small) children, elderly, and obese patients. This forces clinicians to select specific models for specific populations.

RECENT FINDINGS

Recently, general purpose models have been developed for propofol and remifentanil using data from multiple studies and broad, diverse patient groups. General-purpose models might reduce the risks associated with extrapolation, incorrect usage, and unfamiliarity with a specific TCI-model, as they offer less restrictive boundaries (i.e., the patient "doesn't fit in the selected model") compared with the earlier, simpler models. Extrapolation of a model can lead to delayed recovery or inadequate anesthesia. If multiple models for the same drug are implemented in the pump, it is possible to select the wrong model for that specific case; this can be overcome with one general purpose model implemented in the pump.

SUMMARY

This article examines the usability of these general-purpose models in relation to the more traditional models.

Occupational Exposure during Pregnancy and Effects on Newborns: A Nested Case-Control Study

BACKGROUND

The protection of pregnant workers should be based on evidence regarding the risks to reproductive health from exposure to specific work environments and conditions. The objective of this study was to identify the effects on mothers and newborns resulting from environmental exposure to various occupational risks.

METHODS

The study cohort was composed of 399 women admitted to the Obstetrics/Postpartum ward at Hospital La Fe in Valencia, Spain. Face-to-face interviews were conducted to establish associations between workplace exposure during pregnancy and its effects on maternal and newborn health. Sex, anthropometric characteristics, and blood gas analysis in arterial and venous umbilical cord blood at delivery were collected.

RESULTS

A total of 138 women were exposed to biological and/or chemical risks, 122 to physical risks, and 139 at no risk of exposure. In the group with chemical and/or biological risks, the frequency of women who resorted to in vitro fertilization to achieve the studied pregnancy is less than half of the group exposed to physical risks, with statistically significant differences (p = 0.047). The mean values for the arterial analysis in both exposure groups were within average values, with similar pH values between them, but the mean values of PCO2 and PO2 were lower in the group of neonates of mothers exposed to physical risks, with a significant difference for arterial PO2 (p = 0.027).

CONCLUSION

Our analysis contributes evidence for planning and prioritizing preventive actions to protect women's reproductive health. The results suggest the continuation of a future project that would consider more factors and potentially increase the sample size.

Towards a green hospital approach in Oman: A case study of quantifying an environmental impact

INTRODUCTION

The environmental impact of hospitals and healthcare providers practices is substantial, although often unnoticed and infrequently tracked. A green and healthy hospital is one that promotes public health by continuously monitoring and reducing its environmental impact.

METHODS

We adopted a descriptive case study design with a multi-dimensional evaluation and monitoring of carbon emission equivalence (CO2e) using two examples from a tertiary care hospital practice in Oman. One example (1) was related to inhalation anaesthetic gases (IAG) consumption and the second example (2) was related to estimation of telemedicine clinics (TMCs) CO2e travel-related savings.

RESULTS

The cumulative consumption of three different (1) IAG over three years (2019, 2020, 2021) was generated with estimated CO2e for each year for sevoflurane, isoflurane and desflurane. Desflurane had the lowest consumption with a yearly cumulative consumption of 6000 mL, 1500 mL, and 3000 mL for the years 2019, 2020 and 2021. The (2) TMCs during the first two years of the COVID-19 pandemic travel related CO2e savings were in the range of 12.65-3483.1 tonnes. In the second year of launching this service it doubled to a range of 24-6610.5 tonnes of CO2e savings.

CONCLUSION

A green and healthy hospital approach of tracking and monitoring environmental impact of healthcare providers practices is critical for health planning and management of the environmental policy. This case study illustrated the importance of closely tracking hospital-based practices from an environmental perspective towards a green hospital approach.

Comparison of the effects of 5 and 10 L/minute fresh gas flow on emergence from sevoflurane anesthesia: A randomized clinical trial

BACKGROUND

A high fresh gas flow of >5 L/minute is commonly used for emergence from inhalation anesthesia. In addition, a high fresh gas flow may have detrimental effects on climate change. However, no study has determined the optimal fresh gas flow for emergence from inhalation anesthesia. Therefore, we compared the effect of fresh gas flows of 5 L/minute and 10 L/minute on emergence time from sevoflurane anesthesia.

METHODS

Patients who were scheduled for transurethral resection of bladder tumor were randomly assigned to receive fresh gas flows of 5 L/minute (group 5) or 10 L/minute (group 10) during emergence. Emergence time was defined as the time from discontinuation of sevoflurane to tracheal extubation. The primary outcome was the emergence time, and the secondary outcomes were the time to self-movement and the time to eye-opening.

RESULTS

A total of 54 patients were included. In groups 5 and 10, emergence time (12.1 ± 2.9 minutes vs 11.1 ± 2.7 minutes, respectively; P = .232), time to self-movement (9.4 ± 3.8 minutes vs 8.5 ± 4.6 minutes, respectively; P = .435), and time to eye-opening (11.5 ± 3.1 minute vs 10.6 ± 3.0 minutes, respectively; P = .252) were not significantly different.

CONCLUSIONS

Emergence time, time to self-movement, and time to eye opening were not significantly different between fresh gas flow rates of 5 L/minute and 10 L/minute in transurethral resection of bladder tumor, thus suggesting that fresh gas flow of 5 L/minute is sufficient for emergence from sevoflurane anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05376631).

MicroRNAs-Based Theranostics against Anesthetic-Induced Neurotoxicity

Various clinical reports indicate prolonged exposure to general anesthetic-induced neurotoxicity (in vitro and in vivo). Behavior changes (memory and cognition) are compilations commonly cited with general anesthetics. The ability of miRNAs to modulate gene expression, thereby selectively altering cellular functions, remains one of the emerging techniques in the recent decade. Importantly, engineered miRNAs (which are of the two categories, i.e., agomir and antagomir) to an extent found to mitigate neurotoxicity. Utilizing pre-designed synthetic miRNA oligos would be an ideal analeptic approach for intervention based on indicative parameters. This review demonstrates engineered miRNA's potential as prophylactics and/or therapeutics minimizing the general anesthetics-induced neurotoxicity. Furthermore, we share our thoughts regarding the current challenges and feasibility of using miRNAs as therapeutic agents to counteract the adverse neurological effects. Moreover, we discuss the scientific status and updates on the novel neuro-miRNAs related to therapy against neurotoxicity induced by amyloid beta (Aβ) and Parkinson's disease (PD).

[Children need sustainability]

The reduction of greenhouse gases such as CO2 emissions and their equivalents (CO2e) generally has three aspects: Fugitive direct emissions (anesthetic gases, exhaust gases), indirect emissions through the purchase of energy (electricity, heat) and emissions in the supply chain (supply of consumables, disposal). Since pediatric anesthesia has a traditional affinity with inhalation, the use of anesthetic gases should be repeatedly questioned and, if possible, avoided on the way to net zero emissions in addition to general measures to conserve resources. In children, analgosedation, total intravenous anesthesia (TIVA) and establishment of venous access prior to the induction of anesthesia are particularly suitable for this purpose. In addition to avoiding greenhouse gases, the methods mentioned offer other significant medical advantages and can also be profitable in terms of safety and comfort. Nevertheless, anesthetic gases are required in pediatric anesthesia in some situations. For this reason, it is important to save anesthetic gases through minimal fresh gas flow and a rational approach to inhalation induction. To facilitate implementation in clinical practice, this article provides recommendations for mask induction and choice of anesthetic procedure.

Occupational Exposure to Inhalational Anesthetics and Teratogenic Effects: A Systematic Review

(1) Background: In the current healthcare environment, there is a large proportion of female staff of childbearing age, so, according to existing conflicting studies, the teratogenic effects that inhalational anesthetics may have on exposed pregnant workers should be assessed. This investigation aims to analyze the teratogenic effects of inhalational anesthetics in conditions of actual use, determining any association with spontaneous abortion or congenital malformations. (2) Methods: A systematic review was carried out according to the PRISMA statement based on PICO (problem of interest–intervention to be considered–intervention compared–outcome) (Do inhalational anesthetics have teratogenic effects in current clinical practice?). The level of evidence of the selected articles was evaluated using the SIGN scale. The databases used were PubMed, Embase, Scopus, Web of Science, Google academic and Opengrey. Primary studies conducted in professionals exposed to inhalational anesthetics that evaluate spontaneous abortions or congenital malformations, conducted in any country and language and published within the last ten years were selected. (3) Results: Of the 541 studies identified, 6 met all inclusion criteria in answering the research question. Since many methodological differences were found in estimating exposure to inhalational anesthetics, a qualitative systematic review was performed. The selected studies have a retrospective cohort design and mostly present a low level of evidence and a low grade of recommendation. Studies with the highest level of evidence do not find an association between the use of inhalational anesthetics and the occurrence of miscarriage or congenital malformations. (4) Conclusions: The administration of inhalational anesthetics, especially with gas extraction systems (scavenging systems) and the adequate ventilation of operating rooms, is not associated with the occurrence of spontaneous abortions or congenital malformations.

Neurosurgical Anesthesia: Optimizing Outcomes with Agent Selection

Anesthesia in neurosurgery embodies a vital element in the development of neurosurgical intervention. This undisputed interest has offered surgeons and anesthesiologists an array of anesthetic selections to utilize, though with this allowance comes the equally essential requirement of implementing a maximally appropriate agent. To date, there remains a lack of consensus and official guidance on optimizing anesthetic choice based on operating priorities including hemodynamic parameters (e.g., CPP, ICP, MAP) in addition to the route of procedure and pathology. In this review, the authors detail the development of neuroanesthesia, summarize the advantages and drawbacks of various anesthetic classes and agents, while lastly cohesively organizing the current literature of randomized trials on neuroanesthesia across various procedures.

Association Between Anesthesia Provider Education and Carbon Footprint Related to the Use of Inhaled Halogenated Anesthetics

BACKGROUND

Inhaled halogenated anesthetics are responsible for half of operating room total greenhouse gas emissions. Sustainable anesthesia groups were set up in 4 Lyon, France, university hospitals (Hospices Civils de Lyon) in January 2018 and have supported a specific information campaign about the carbon footprint related to the use of inhaled halogenated anesthetics in June 2019. We aimed to assess whether implementing such information campaigns was associated with a decrease in the carbon footprint related to inhaled halogenated anesthetics.

METHODS

This retrospective cohort study was conducted from January 1, 2015, to February 29, 2020, in 4 hospitals of the Hospices Civils de Lyon in France. Information meetings on sustainable anesthesia practices were organized by sustainable anesthesia groups that were set up in January 2018. In addition, a specific information campaign about the carbon footprint related to inhaled halogenated anesthetics was conducted in June 2019; it was followed by a questionnaire to be completed online. The monthly purchase of sevoflurane, desflurane, and propofol was recorded, and the estimated monthly carbon footprint from desflurane- and sevoflurane-related perioperative emissions was calculated. The interrupted time-series data from January 2015 to February 2020 were analyzed by segmented regression, considering both interventions (setting up of the sustainable anesthesia groups and specific information campaign) in the analysis and adjusting for 2 confounding factors (seasonality of the data and number of general anesthesia uses).

RESULTS

Among the 641 anesthesia providers from the study hospitals, 121 (19%) attended the information meetings about the carbon footprint of inhaled halogenated anesthetics, and 180 (28%) completed the questionnaire. The anesthetic activity from all 641 providers was considered in the analysis. After the sustainable anesthesia groups were set up, the carbon footprint of sevoflurane and desflurane started decreasing: the slope significantly changed ( P < .01) and became significantly negative, from -0.27 (95% confidence interval [CI], -1.08 to 0.54) tons.month -1 to -14.16 (95% CI, -16.67 to -11.65) tons.month -1 . After the specific information campaign, the carbon footprint kept decreasing, with a slope of -7.58 (95% CI, -13.74 to -1.41) tons.month -1 ( P = .02), which was not significantly different from the previous period ( P = .07).

CONCLUSIONS

The setup of the sustainable anesthesia groups was associated with a dramatic reduction in the carbon footprint related to halogenated anesthetics. These results should encourage health care institutions to undertake information campaigns toward anesthesia providers so that they also take into account the environmental impact in the choice of anesthetic drugs, in addition to the benefits for the patient and economic concerns.

Occupational Exposure to Halogenated Anaesthetic Gases in Hospitals: A Systematic Review of Methods and Techniques to Assess Air Concentration Levels

Objective During the induction of gaseous anaesthesia, waste anaesthetic gases (WAGs) can be released into workplace air. Occupational exposure to high levels of halogenated WAGs may lead to adverse health effects; hence, it is important to measure WAGs concentration levels to perform risk assessment and for health protection purposes. Methods A systematic review of the scientific literature was conducted on two different scientific databases (Scopus and PubMed). A total of 101 studies, focused on sevoflurane, desflurane and isoflurane exposures in hospitals, were included in this review. Key information was extracted to provide (1) a description of the study designs (e.g., monitoring methods, investigated occupational settings, anaesthetic gases in use); (2) an evaluation of time trends in the measured concentrations of considered WAGs; (3) a critical evaluation of the sampling strategies, monitoring methods and instruments used. Results Environmental monitoring was prevalent (68%) and mainly used for occupational exposure assessment during adult anaesthesia (84% of cases). Real-time techniques such as photoacoustic spectroscopy and infrared spectrophotometry were used in 58% of the studies, while off-line approaches such as active or passive sampling followed by GC-MS analysis were used less frequently (39%). Conclusions The combination of different instrumental techniques allowing the collection of data with different time resolutions was quite scarce (3%) despite the fact that this would give the opportunity to obtain reliable data for testing the compliance with 8 h occupational exposure limit values and at the same time to evaluate short-term exposures.

Volatile sedation in sepsis: a promising therapeutic approach or a venture doomed to fail?

Preclinical strategies targeting sepsis often had a single target and could not be translated into the clinical setting. Volatile sedation modulates multiple aspects of inflammation and improves sepsis-related survival in animal models. Whether a similar effect can be achieved in humans is unclear. Only a prospective clinical trial will be able to answer this question. The implementation of such a study in times when volatile anaesthetics are the focus of attention because of their greenhouse effect and their carbon dioxide emission will be a challenge, even though the alternative, i.v. sedation, is still insufficiently investigated in this respect.

The use of nitrous oxide 'cracking' technology in the labour ward: a case report and patient account

Nitrous oxide is a common choice of labour analgesia in many countries. However, its use is associated with significant cost to the environment as well as potential risks of long-term occupational exposure. Our hospital is one of a small number of healthcare providers in the United Kingdom trialling technology which catalytically destroys ('cracks') nitrous oxide to reduce greenhouse gas emissions and occupational exposure. When used in the setting of inhaled analgesia, cracking technology relies on capturing the patient's exhaled breath via a facemask or mouthpiece, a technique which requires some user skill and may be challenging for patients. In this report, we present the case of a primiparous 35-year-old consultant anaesthetist, who used nitrous oxide cracking technology with inhaled nitrous oxide analgesia (via a facemask) during labour. We present the patient's experiences and discuss the implications of using such technology on ambient nitrous oxide levels in the delivery room. Notably, despite this patient's professional expertise and familiarity with facemask use, nitrous oxide remained detectable throughout her labour, although generally at low levels. This illustrates that whilst this technology has the potential to reduce ambient nitrous oxide levels, its efficacy may vary depending on how it is used, with implications for patient education and support.

Non-Cellular Layers of the Respiratory Tract: Protection against Pathogens and Target for Drug Delivery

Epithelial barriers separate the human body from the environment to maintain homeostasis. Compared to the skin and gastrointestinal tract, the respiratory barrier is the thinnest and least protective. The properties of the epithelial cells (height, number of layers, intercellular junctions) and non-cellular layers, mucus in the conducting airways and surfactant in the respiratory parts determine the permeability of the barrier. The review focuses on the non-cellular layers and describes the architecture of the mucus and surfactant followed by interaction with gases and pathogens. While the penetration of gases into the respiratory tract is mainly determined by their hydrophobicity, pathogens use different mechanisms to invade the respiratory tract. Often, the combination of mucus adhesion and subsequent permeation of the mucus mesh is used. Similar mechanisms are also employed to improve drug delivery across the respiratory barrier. Depending on the payload and target region, various mucus-targeting delivery systems have been developed. It appears that the mucus-targeting strategy has to be selected according to the planned application.

Cost of Total Intravenous Anesthesia Versus Inhalation Anesthesia in Obstructive Sleep Apnea Surgery

OBJECTIVES

To compare cost and time spent in surgical and postoperative courses in patients with obstructive sleep apnea (OSA) undergoing surgery with either total intravenous anesthesia (TIVA) or inhalational anesthesia.

STUDY DESIGN

Retrospective chart review.

METHODS

Retrospective review on patients undergoing surgery for OSA under general anesthesia from January 2019 to October 2020. Cost per service was acquired for the day of surgery.

RESULTS

A total of 230 patients were included: 95 received TIVA; 135 received inhalation anesthesia. Total cost was significantly higher in the TIVA nasal surgery group by $286 (P = .035). TIVA produced significantly higher pharmacy and operating room costs across all surgeries and OSA severities. These increased costs were offset by significantly lower supply costs in upper airway stimulator (UAS, -$419.50; P = .007) and uvulopalatopharyngoplasty (UPPP, -$115.16; P = .015) patients receiving TIVA. In the TIVA cohort, there was a trend toward lower recovery room costs after UAS (-$111.09; P = .063) and nasal surgery (-$64.45; P = .096) and anesthesia costs after nasal surgery (-$36.67; P = .054). Total recovery time was reduced by 18 minutes (P = .004) for nasal surgery, 25 minutes (P = .043) for UAS, and 27 minutes (P = .147) for UPPP patients receiving TIVA.

CONCLUSION

When used in an outpatient setting for patients with OSA, TIVA adds to pharmacy and operating room costs, but this is usually offset by lower supply, anesthesia, and recovery room costs. We found decreased recovery times in the TIVA cohort. TIVA has proven benefits in patient outcomes and can be cost-effective in OSA surgery.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

The Triple Bottom Line and Stabilization Wedges: A Framework for Perioperative Sustainability

We present a narrative review of environmental sustainability aimed at perioperative clinicians. The review will familiarize readers with the triple bottom line framework, which aims to align the goals of delivering high-quality patient care, promoting environmental sustainability, and improving the financial position of health care organizations. We introduce the stabilization wedges model for climate change action adopted for the perioperative setting and discuss areas in which perioperative leaders can make sustainable choices. The goal of this review is to increase awareness among perioperative physicians of the environmental impacts of surgical and anesthetic care, promote engagement with sustainability efforts as a topic of professional concern for our specialty, and inspire new research in perioperative environmental sustainability.

Absolute Differential Cross-Sections for Elastic Electron Scattering from Sevoflurane Molecule in the Energy Range from 50-300 eV

We report the results of the measurements and calculations of the absolute differential elastic electron scattering cross-sections (DCSs) from sevoflurane molecule (C4H3F7O). The experimental absolute DCSs for elastic electron scattering were obtained for the incident electron energies from 50 eV to 300 eV, and for scattering angles from 25° to 125° using a crossed electron/target beams setup and the relative flow technique for calibration to the absolute scale. For the calculations, we have used the IAM-SCAR+I method (independent atom model (IAM) applying the screened additivity rule (SCAR) with interference terms included (I)). The molecular cross-sections were obtained from the atomic data by using the SCAR procedure, incorporating interference term corrections, by summing all the relevant atomic amplitudes, including the phase coefficients. In this approach, we obtain the molecular differential scattering cross-section (DCS), which, integrated over the scattered electron angular range, gives the integral scattering cross-section (ICS). Calculated cross-sections agree very well with experimental results, in the whole energy and angular range.

Application of sevoflurane inhalation sedation in dental treatment: a mini review

Sevoflurane is familiar to anesthesiologists as an inhaled anesthetic to induce and maintain anesthesia; however, it has not been widely used for sedation. Recently, the use of sevoflurane for inhalational sedation has been increasing. Moreover, in Korea, the use of sevoflurane for conscious or deep sedation in dental care for children and the disabled is increasing, primarily by dental anesthesiologists. In this article, we reviewed a sedation method using sevoflurane.