An update on the mechanisms and risk factors for anesthesia-related cardiac arrest in children: a narrative review.

The relation between surgery and anesthesia safety in children and a country's Human Development Index (HDI) value has been described previously. The aim of this narrative review was to provide an update on the mechanisms and risk factors of Anesthesia-Related Cardiac Arrest (ARCA) in pediatric surgical patients in countries with different HDI values and over time (pre-2001 vs. 2001‒2024). Electronic databases were searched up to March 2024 for studies reporting ARCA events in children. HDI values range from 0 to 1 (very-high-HDI countries: ≥ 0.800, high-HDI countries: 0.700‒0.799, medium-HDI countries: 0.550‒0.699, and low-HDI countries: < 0.550). Independent of time, the proportion of children who suffered perioperative Cardiac Arrest (CA) attributed to anesthesia-related causes was higher in very-high-HDI countries (50%) than in countries with HDI values less than 0.8 (15‒36%), but ARCA rates were higher in countries with HDI values less than 0.8 than in very-high-HDI countries. Regardless of the HDI value, medication-related factors were the most common mechanism causing ARCA before 2001, while cardiovascular-related factors, mainly hypovolemia, and respiratory-related factors, including difficulty maintaining patent airways and adequate ventilation, were the major mechanisms in the present century. Independent of HDI value and time, a higher number of ARCA events occurred in children with heart disease and/or a history of cardiac surgery, those aged younger than one year, those with ASA physical status III‒V, and those who underwent emergency surgery. Many ARCA events were determined to be preventable. The implementation of specialized pediatric anesthesiology and training programs is crucial for anesthesia safety in children.

Comparison between inhalational anesthetics in terms of DNA damage and immunological markers.

This study compared genetic damage and immunological markers between surgical patients who underwent inhalational anesthesia with isoflurane or sevoflurane. Blood samples were collected from surgical patients (n = 18 in the isoflurane group and n = 17 in the sevoflurane group) at baseline (before the anesthesia procedure) and the day after anesthesia. DNA damage was detected using an alkaline comet assay; proinflammatory interleukin (IL)-6 was detected by flow cytometry, and white blood cells were detected via an automatic hematology analyzer. The characteristics of both groups were similar, and neither of the two anesthetics induced DNA damage. Similarly, mild neutrophilia was observed after anesthesia in both groups. Increased IL-6 levels were observed 1 day after anesthesia regardless of the type of anesthetic, but this increase was greater in the isoflurane group. Our study suggested that isoflurane and sevoflurane administration may contribute to changes in the immune parameters measured, though no genotoxic hazard was identified, in healthy adult patients who undergo low-stress surgery.

Global neonatal perioperative mortality: A systematic review and meta-analysis.

STUDY OBJECTIVE: There are large differences in health care among countries. A higher perioperative mortality rate (POMR) in neonates than in older children and adults has been recognized worldwide. The aim of this study was to provide a systematic review of published 24-h and 30-day POMRs in neonates from 2011 to 2022 in countries with different Human Development Index (HDI) levels. DESIGN AND SETTING: A systematic review with a meta-analysis of studies that reported 24-h and 30-day POMRs in neonates was performed. We searched the databases from January 2011 to July 30, 2022. MEASUREMENTS: The POMRs (per 10,000 procedures under anesthesia) were analyzed according to country HDI. The HDI levels ranged from 0 to 1, representing the lowest and highest levels, respectively (very-high-HDI: ≥ 0.800, high-HDI: 0.700-0.799, medium-HDI: 0.550-0.699, and low-HDI: < 0.550). The magnitude of the POMRs by country HDI was studied using meta-analysis. MAIN RESULTS: Eighteen studies from 45 countries were included. The 24-h (n = 96 deaths) and 30-day (n = 459 deaths) POMRs were analyzed from 33,729 anesthetic procedures. The odds ratios (ORs) of the 24-h POMR in low-HDI countries were higher than those in very-high- (OR 8.4, 95% CI 1.7-40.4; p = 0.008), high- (OR 7.3, 95% CI 2.2-24.4; p = 0.001) and medium-HDI countries (OR 7.7, 95% CI 3.1-18.7; p < 0.0001) but with no odds differences between very-high- and high-HDI countries (p = 0.879), very-high- and medium-HDI countries (p = 0.915) and high- and medium-HDI countries (p = 0.689). The odds of a 30-day POMR in low-HDI countries were higher than those in very-high-HDI countries (OR 6.9, 95% CI 1.9-24.6; p = 0.002) but not in high-HDI countries (OR 1.4, 95% CI 0.6-3.0; p = 0.396). CONCLUSIONS: The review demonstrated very high global POMRs in a surgical population of neonates independent of the country HDI level. We identified differences in 24-h and 30-day POMRs between low-HDI countries and other countries with higher HDI levels.

Modulation of gene expression and inflammation but not DNA damage after sevoflurane anesthesia.

This study assessed, for the first time, the expression of the genes hOGG1, TP53, and IL-6 in leukocytes by real-time quantitative polymerase chain reaction in surgical patients before (baseline), during (2 h of anesthesia) and 1 day after sevoflurane anesthesia. Additionally, DNA damage was detected by the comet assay, serum interleukin (IL)-6 was detected by flow cytometry, and differential leukocyte counting was also performed. TP53 and hOGG1 expression was downregulated on the day after anesthesia compared to before anesthesia. However, IL-6 expression did not change, and no DNA damage induction was observed during or after anesthesia. At the systemic level, mild neutrophilia and an increase in IL-6 levels occurred after anesthesia. Our findings suggest that sevoflurane anesthesia downregulates gene expression (hOGG1 and TP53) and contributes to an inflammatory status (increased systemic IL-6 and mild neutrophilia) but is not associated with DNA damage in patients without comorbidities who undergo minor elective surgery.

A correlation between anaesthesia-related cardiac arrest outcomes and country human development index: A narrative review.

Studies have demonstrated gaps between developed and developing countries in the quality of surgical and anaesthesia care. The aim of this review was to provide a critical overview of documented outcomes from the 2010s of anaesthesia-related cardiac arrest events in countries with largely differing Human Development Indexes (HDIs). The HDI ranges from 0 to 1, representing the lowest and highest levels of development, respectively. Most related studies conducted between 2011 and 2020 showed low rates (from 0 to 215 per million anaesthetics) of anaesthesia-related mortality up to the 30th postoperative day in very high-HDI countries (HDI ≥ 0.800) and higher rates (from 0 to 915.4 per million anaesthetics) in high-HDI countries (HDI: 0.700-0.799). Low-HDI countries (HDI < 0.550) showed higher anaesthesia-related mortality rates, which were greater than 1500 per million anaesthetics. The anaesthesia-related mortality rates per quartile demonstrated a gap in the anaesthesia-related safety between very high- and high-HDI countries, and especially between very high- and low-HDI countries. Anaesthesia-related cardiac arrest showed similarly high survival proportions in very high-HDI countries (45.9% to 100%) and high-HDI countries (62.9% to 100%), while in a low-HDI country, the anaesthesia-related cardiac arrest survival was lower (22.2%). Our review demonstrates large gaps among countries with largely differing HDIs regarding anaesthesia-related cardiac arrest outcomes in the last decade. This finding highlights the need to improve patient safety care in low-HDI countries. Anaesthesia patient safety has improved in high-HDI countries, but there is still a persistent gap in the health care systems of these countries and those of very high-HDI countries. Our review also found a consistent improvement in anaesthesia patient safety in very high-HDI countries.

Oxidative stress, DNA damage, inflammation and gene expression in occupationally exposed university hospital anesthesia providers.

Considering the importance and lack of data of toxicogenomic approaches on occupational exposure to anesthetics, we evaluated possible associations between waste anesthetic gases (WAGs) exposure and biological effects including oxidative stress, DNA damage, inflammation, and transcriptional modulation. The exposed group was constituted by anesthesia providers who were mainly exposed to the anesthetics sevoflurane and isoflurane (10 ppm) and to a lesser degree to nitrous oxide (150 ppm), and the control group was constituted by physicians who had no exposure to WAGs. The oxidative stress markers included oxidized DNA bases (comet assay), malondialdehyde (high-performance liquid chromatography [HPLC]), nitric oxide metabolites (ozone-chemiluminescence), and antioxidative markers, including individual antioxidants (HPLC) and antioxidant defense marker (ferric reducing antioxidant power by spectrophotometry). The inflammatory markers included high-sensitivity C-reactive protein (chemiluminescent immunoassay) and the proinflammatory interleukins IL-6, IL-8 and IL-17A (flow cytometry). Telomere length and gene expression related to DNA repair (hOGG1 and XRCC1), antioxidant defense (NRF2) and inflammation (IL6, IL8 and IL17A) were evaluated by real-time quantitative polymerase chain reaction. No significant differences (p > .0025) between the groups were observed for any parameter evaluated. Thus, under the conditions of the study, the findings suggest that occupational exposure to WAGs is not associated with oxidative stress or inflammation when evaluated in serum/plasma, with DNA damage evaluated in lymphocytes and leucocytes or with molecular modulation assessed in peripheral blood cells in university anesthesia providers. However, it is prudent to reduce WAGs exposure and to increase biomonitoring of all occupationally exposed professionals.

Gene and systemic inflammatory effects and neuroendocrine response in surgical patients anesthetized with desflurane-nitrous oxide or desflurane-nitrous oxide-free: A randomized trial.

There is growing interest in assessing possible immunotoxicological effects in anesthetized patients. There are controversial findings concerning the effect of nitrous oxide (N2O) anesthetic gas effect on inflammatory response. We tested the hypothesis that N2O associated with desflurane (inhalational anesthetic) was likely to worsen neuro-immune-endocrine effects when compared with desflurane alone in this randomized trial. The primary endpoint of this study was to evaluate the systemic proinflammatory interleukin (IL)-6, and the secondary endpoints included other systemic (IL-1ß, TNF-α, IL-8, IL-10, IL-17A and high-sensitivity C-reactive protein - hs-CRP) and genetic inflammatory markers (NF-kB, IL-6 and COX-2) as well as hormones (adrenocorticotropic hormone, cortisol and prolactin) comparing patients undergoing minor surgery with or without N2O-desflurane. As a second aim, we assessed whether there were changes in the neuro-immune-endocrine profiles within each group. Blood samples were collected before anesthesia, 90 min after anesthesia induction, and the day after surgery. We assessed serum cytokines using a cytometric bead array and hs-CRP by chemiluminescent immunoassay. Expression of three proinflammatory transcripts was assessed by real-time quantitative polymerase chain reaction, and neuroendocrine hormones were detected by chemiluminescent microparticle immunoenzymatic assay. There were no significant between-group differences for any analyzed biomarkers. However, there was a significant increase in: (a) systemic IL-6 and hs-CRP values one day after surgery in both groups and (b) prolactin levels in the intraoperative period compared to baseline and postoperative period levels for both groups. In conclusion, N2O does not impair the inflammatory profile and neuroendocrine response compared to patients who receive only desflurane anesthesia.

[Epidemiology of perioperative cardiac arrest and mortality in Brazil: a systematic review]. / Epidemiologia de parada cardíaca e de mortalidade perioperatória no Brasil: revisão sistemática.

BACKGROUND AND OBJECTIVES: The perioperative cardiac arrest (CA) and mortality rates in Brazil, a developing country, are higher than in developed countries. The hypothesis of this review was that knowledge of the epidemiology of perioperative CA and mortality in Brazil enables the comparison with developed countries. The systematic review aimed to verify, in studies conducted in Brazil, the epidemiology of perioperative CA and mortality. METHOD AND RESULTS: A search strategy was carried out on different databases (PubMed, EMBASE, SciELO and LILACS) to identify observational studies that reported perioperative CA and/or mortality up to 48 hours postoperatively in Brazil. The primary outcomes were data on epidemiology of perioperative CA and mortality. In 8 Brazilian studies, there was a higher occurrence of perioperative CA and mortality in males; in extremes of age; in patients in worse physical status according to the American Society of Anesthesiologists (ASA); in emergency surgeries; in general anesthesia; and in cardiac, thoracic, vascular, abdominal and neurological surgeries. The patient's disease/condition was the main triggering factor, with sepsis and trauma as the main causes. CONCLUSIONS: The epidemiology of both perioperative CA and mortality events reported in Brazilian studies does not show important differences and, in general, is similar to studies in developed countries. However, sepsis represents one of the major causes of perioperative CA and mortality in Brazilian studies, contrasting with studies in developed countries in which sepsis is a secondary cause.

Perioperative cardiac arrest and mortality in trauma patients: A systematic review of observational studies.

STUDY OBJECTIVE: Factors that influence the occurrence of perioperative cardiac arrest (CA) and its outcomes in trauma patients are not well known. The novelty of our study lies in the performance of a systematic review conducted worldwide on the occurrence of perioperative CA and/or mortality in trauma patients. DESIGN: A systematic review was performed to identify observational studies that reported the occurrence of CA and/or mortality due to trauma and CA and/or mortality rates in trauma patients up to 24 h postoperatively. We searched the MEDLINE, EMBASE, LILACS and SciELO databases through January 29, 2020. SETTING: Perioperative period. MEASUREMENTS: The primary outcomes evaluated were data on the epidemiology of perioperative CA and/or mortality in trauma patients. MAIN RESULTS: Nine studies were selected, with the first study being published in 1994 and the most recent being published in 2019. Trauma was an important factor in perioperative CA and mortality, with rates of 168 and 74 per 10,000 anesthetic procedures, respectively. The studies reported a higher proportion of perioperative CA and mortality in trauma patients who were males, young adults and adults, patients with American Society of Anesthesiologists (ASA) physical status ≥ III, patients undergoing general anesthesia, and in abdominal or neurological surgeries. Uncontrolled hemorrhage was the main cause of perioperative CA and mortality after trauma. Survival rates after perioperative CA were low. CONCLUSIONS: Trauma is an important factor in perioperative CA and mortality, especially in young adult and adult males and in patients classified as having an ASA physical status ≥ III mainly due to uncontrollable bleeding after blunt and perforating injuries. Trauma is a global public health problem and has a strong impact on perioperative morbidity and mortality.

Epidemiology of perioperative cardiac arrest and mortality in Brazil: a systematic review / Epidemiologia de parada cardíaca e de mortalidade perioperatória no Brasil: revisão sistemática

Abstract Background and objectives: The perioperative cardiac arrest (CA) and mortality rates in Brazil, a developing country, are higher than in developed countries. The hypothesis of this review was that knowledge of the epidemiology of perioperative CA and mortality in Brazil enables the comparison with developed countries. The systematic review aimed to verify, in studies conducted in Brazil, the epidemiology of perioperative CA and mortality. Method and results: A search strategy was carried out on different databases (PubMed, EMBASE, SciELO and LILACS) to identify observational studies that reported perioperative CA and/or mortality up to 48 hours postoperatively in Brazil. The primary outcomes were data on epidemiology of perioperative CA and mortality. In 8 Brazilian studies, there was a higher occurrence of perioperative CA and mortality in males; in extremes of age; in patients in worse physical status according to the American Society of Anesthesiologists (ASA); in emergency surgeries; in general anesthesia; and in cardiac, thoracic, vascular, abdominal and neurological surgeries. The patient's disease/condition was the main triggering factor, with sepsis and trauma as the main causes. Conclusions: The epidemiology of both perioperative CA and mortality events reported in Brazilian studies does not show important differences and, in general, is similar to studies in developed countries. However, sepsis represents one of the major causes of perioperative CA and mortality in Brazilian studies, contrasting with studies in developed countries in which sepsis is a secondary cause.

Resumo Justificativa e objetivos: As incidências de parada cardíaca (PC) e de mortalidade perioperatória no Brasil, um país em desenvolvimento, são mais elevadas em relação às dos países desenvolvidos. A hipótese desta revisão é que o conhecimento da epidemiologia de PC e de mortalidade perioperatória no Brasil possibilita sua comparação com a dos países desenvolvidos. A revisão sistemática teve como objetivo verificar, em estudos realizados no Brasil, a epidemiologia de PC e de mortalidade perioperatória. Conteúdo: Realizou-se estratégia de busca em diferentes bases de dados (PubMed, EMBASE, SciELO e LILACS) para a identificação de estudos observacionais que reportaram PC e/ou mortalidade perioperatória até 48 horas pós-operatório no Brasil. Os desfechos primários foram dados de epidemiologia de PC e de mortalidade perioperatória. Em 8 estudos nacionais, identificou- se maior ocorrência de PC e de mortalidade perioperatória no sexo masculino, em extremos de idade, em pacientes em pior estado físico segundo a American Society of Anesthesiologists (ASA), em cirurgias de emergência, em anestesia geral, e em cirurgias cardíaca, torácica, vascular, abdominal e neurológica. A doença/condição do paciente foi o principal fator desencadeante, tendo como causas principais a sepse e o trauma. Conclusões: Nos estudos nacionais, a epidemiologia dos eventos tanto de PC como de mortalidade perioperatória não apresenta diferenças importantes, e de maneira geral, é semelhante à de estudos de países desenvolvidos. Entretanto, a sepse, nos estudos nacionais, representa uma das principais causas de PC e de mortalidade perioperatória, diferenciando-se dos estudos de países desenvolvidos nos quais a sepse é causa secundária.

High concentrations of waste anesthetic gases induce genetic damage and inflammation in physicians exposed for three years: A cross-sectional study.

This cross-sectional study analyzed the impact of occupational waste anesthetic gases on genetic material, oxidative stress, and inflammation status in young physicians exposed to inhalational anesthetics at the end of their medical residency. Concentrations of waste anesthetic gases were measured in the operating rooms to assess anesthetic pollution. The exposed group comprised individuals occupationally exposed to inhalational anesthetics, while the control group comprised individuals without anesthetic exposure. We quantified DNA damage; genetic instability (micronucleus-MN); protein, lipid, and DNA oxidation; antioxidant activities; and proinflammatory cytokine levels. Trace concentrations of anesthetics (isoflurane: 5.3 ± 2.5 ppm, sevoflurane: 9.7 ± 5.9 ppm, and nitrous oxide: 180 ± 150 ppm) were above international recommended thresholds. Basal DNA damage and IL-17A were significantly higher in the exposed group [27 ± 20 a.u. and 20.7(19.1;31.8) pg/mL, respectively] compared to the control group [17 ± 11 a.u. and 19.0(18.9;19.5) pg/mL, respectively], and MN frequency was slightly increased in the exposed physicians (2.3-fold). No significant difference was observed regarding oxidative stress biomarkers. The findings highlight the genetic and inflammatory risks in young physicians exposed to inhalational agents in operating rooms lacking adequate scavenging systems. This potential health hazard can accompany these subjects throughout their professional lives and reinforces the need to reduce ambient air pollution and consequently, occupational exposure.

Inflammation and DNA damage induction in surgical patients maintained with desflurane anesthesia.

The use of anesthetics during surgical interventions may contribute to disorders in the perioperative period. Desflurane is the newest volatile halogenated anesthetic to be introduced in clinical practice. Considering that inflammation and genotoxicity are linked events, and that little is known regarding possible genetic and inflammatory effects of desflurane in surgical patients, this study evaluated DNA damage, systemic inflammatory cytokines and related gene expression in adult patients without comorbidities who underwent minor otorhinological surgeries under general anesthesia maintained with the inhalational anesthetic desflurane. This study involved a self-controlled design in which venous blood samples were collected from subjects before anesthesia administration and after the surgical procedure. The comet assay was applied to assess DNA lesions, while the cytokines IL-1ß, IL-6, IL-8, IL-10, IL-17A and TNF-α were evaluated by flow cytometry. A genotoxic effect was observed (p = 0.027), and pro-inflammatory IL-6 and IL-8 levels were significantly increased after surgery (p = 0.001 and p = 0.02, respectively), whereas the levels of the other cytokines did not significantly change. Considering that serum IL-6 and IL-8 were increased, we further evaluated IL-6 and IL-8 gene expression by quantitative real-time polymerase chain reaction (qPCR). However, IL-6 and IL-8 gene expression was unaltered (p >  0.05). In conclusion, anesthetic maintenance with the modern agent desflurane during minor surgeries led to genotoxic and inflammatory effects without altering the expression of inflammation related-genes the day after surgery in patients without comorbidities.

Monitoring early cell damage in physicians who are occupationally exposed to inhalational anesthetics.

Worldwide, millions of professionals who work in operating rooms are occupationally exposed to inhalational anesthetics. Thus, the potential health effects of the continuous exposure to inhalational anesthetics on individuals in the operating room remain a subject of debate. Human biomonitoring is a potentially useful tool for assessing the health of exposed professionals. No report has yet evaluated the possible cytotoxic and genotoxic effects of the most commonly used inhalational anesthetics on young professionals who are occupationally exposed. Considering the importance of this issue, we monitored physicians who were exposed to inhalational anesthetics during their first year of a medical residency program to evaluate the possible early damage events. Twenty-six young physicians who had been occupationally exposed to the anesthetics isoflurane, sevoflurane, desflurane, and nitrous oxide and who worked in operating rooms using modern anesthesia workstations during their medical residency program, participated in this study. Blood samples were evaluated before the start of the program (before the exposure), and after 1/2 year and 1 year of exposure. We monitored the subjects by assessing the cytotoxicity (early apoptosis and loss of the mitochondrial membrane potential) using flow cytometry and genotoxicity using the comet assay. No significant changes were observed in the biomarkers of cytotoxicity or genotoxicity (p > 0.05). Thus, biomonitoring showed that short-term exposure to inhalational anesthetics did not induce early cell damage during the first year of medical residency. Based on the results, brief occupational exposure to anesthetics does not induce either cytotoxicity or genotoxicity in mononuclear cells under the conditions of this study. Thus, young physicians should undergo additional biomonitoring at the beginning of their careers to determine possible toxic effects on their cells and genetic material, and further investigations are warranted to determine whether a longer exposure to inhalational anesthetics results in mitochondrial depolarization, apoptosis and DNA breaks.

Detrimental effects detected in exfoliated buccal cells from anesthesiology medical residents occupationally exposed to inhalation anesthetics: An observational study.

Operating room professionals are scarcely aware of their individual occupational exposure to waste anesthetic gases (WAGs). Medical residents spend several hours per day in operating rooms and consequently experience occupational exposure to WAGs. Considering that no studies have yet evaluated the potential toxicity in medical residents exposed to WAGs using the buccal micronucleus cytome (BMCyt) assay, this pioneering study aimed to compare the BMCyt assay markers, including DNA damage, cell proliferation, and cell death in the exfoliated buccal cells of surgery and anesthesiology residents occupationally exposed to WAGs. The study enrolled a total of 60 physicians, including internal medicine residents (unexposed group), and residents from surgery and anesthesiology programs who were occupationally exposed to sevoflurane, isoflurane and nitrous oxide. WAGs were measured, and the mean values were higher than the international recommendation. The anesthesiology residents (high exposure) showed statistically significant lower frequencies of basal cells, and statistically significant higher frequencies of micronuclei, karyorrhexis, pyknosis, and differentiated cells than did the unexposed group; karyolysis frequencies were significantly higher in anesthesiology residents than were those in the unexposed group or in surgical residents (low exposure). The findings suggest a genetic risk for young professionals exposed to WAGs at the beginning of their careers. Thus, exposure to high WAGs concentrations leads to impairment of the buccal cell proliferative potential, genomic instability and cell death, especially in anesthesiology residents, demonstrating an early impact on their health.

Expression and promoter methylation status of two DNA repair genes in leukocytes from patients undergoing propofol or isoflurane anaesthesia.

Despite the widespread use of the anaesthetics propofol (PROP) and isoflurane (ISO), data about their toxicogenomic potential and interference in epigenetic events are unknown. This study evaluated the expression and methylation profile of two important DNA-repair genes (XRCC1 and hOGG1) in 40 patients undergoing elective and minimally invasive surgery (tympanoplasty and septoplasty) under ISO or PROP anaesthesia. The endpoints were examined at three sampling times: before anaesthesia (T0), 2 h after the beginning of anaesthesia (T2) and 24 h after the beginning of surgery (T24). Both gene expressions were assessed by quantitative real-time polymerase chain reaction (qRT-PCR), whereas methylation specific-PCR (MS-PCR) evaluated the DNA methylation patterns. Increased expression of XRCC1 was observed at T2 only in the PROP group. On the other hand, hOGG1 and XRCC1 expressions were decreased at T24 in both groups. There were no statistical significant differences between the two anaesthetics at the respective sampling times. The methylation status of XRCC1 (methylated at T0) and hOGG1 (unmethylated at T0) remained unchanged in the three sampling times. In conclusion, this study showed modulations of hOGG1 and XRCC1 expression especially 1 day after elective surgery in patients undergoing PROP and ISO anaesthesia. However, the data indicated that methylation was not the mechanism by which the genes were regulated. More studies are warranted to further investigate the possible epigenetic mechanisms involved after exposure to anaesthetics.

Occupational hazards, DNA damage, and oxidative stress on exposure to waste anesthetic gases / Riscos ocupacionais, danos no material genético e estresse oxidativo frente à exposição aos resíduos de gases anestésicos

Abstract Background and objectives The waste anesthetic gases (WAGs) present in the ambient air of operating rooms (OR), are associated with various occupational hazards. This paper intends to discuss occupational exposure to WAGs and its impact on exposed professionals, with emphasis on genetic damage and oxidative stress. Content Despite the emergence of safer inhaled anesthetics, occupational exposure to WAGs remains a current concern. Factors related to anesthetic techniques and anesthesia workstations, in addition to the absence of a scavenging system in the OR, contribute to anesthetic pollution. In order to minimize the health risks of exposed professionals, several countries have recommended legislation with maximum exposure limits. However, developing countries still require measurement of WAGs and regulation for occupational exposure to WAGs. WAGs are capable of inducing damage to the genetic material, such as DNA damage assessed using the comet assay and increased frequency of micronucleus in professionals with long-term exposure. Oxidative stress is also associated with WAGs exposure, as it induces lipid peroxidation, oxidative damage in DNA, and impairment of the antioxidant defense system in exposed professionals. Conclusions The occupational hazards related to WAGs including genotoxicity, mutagenicity and oxidative stress, stand as a public health issue and must be acknowledged by exposed personnel and responsible authorities, especially in developing countries. Thus, it is urgent to stablish maximum safe limits of concentration of WAGs in ORs and educational practices and protocols for exposed professionals.

Resumo Justificativa e objetivos Os Resíduos de Gases Anestésicos (RGA) presentes no ar ambiente das Salas de Operação (SO) são associados a riscos ocupacionais diversos. O presente artigo propõe-se a discorrer sobre exposição ocupacional aos RGA e seu impacto em profissionais expostos, com ênfase em danos genéticos e estresse oxidativo. Conteúdo Apesar do surgimento de anestésicos inalatórios mais seguros, a exposição ocupacional aos RGA ainda é preocupação atual. Fatores relacionados às técnicas anestésicas e estação de anestesia, além da ausência de sistema de exaustão de gases em SO, contribuem para poluição anestésica. Para minimizar os riscos à saúde em profissionais expostos, recomendam-se limites máximos de exposição. Entretanto, em países em desenvolvimento, ainda carece a mensuração de RGA e de regulamentação frente à exposição ocupacional aos RGA. Os RGA são capazes de induzir danos no material genético, como danos no DNA avaliados pelo teste do cometa e aumento na frequência de micronúcleos em profissionais com exposição prolongada. O estresse oxidativo também é associado à exposição aos RGA por induzir lipoperoxidação, danos oxidativos no DNA e comprometimento do sistema antioxidante em profissionais expostos. Conclusões Por tratar-se de questão de saúde pública, é imprescindível reconhecer os riscos ocupacionais relacionados aos RGA, inclusive genotoxicidade, mutagenicidade e estresse oxidativo. Urge a necessidade de mensuração dos RGA para conhecimento desses valores nas SO, especialmente em países em desenvolvimento, de normatização das concentrações máximas seguras de RGA nas SO, além de se adotarem práticas de educação com conscientização dos profissionais expostos.

Comparison of DNA Damage and Oxidative Stress in Patients Anesthetized With Desflurane Associated or Not With Nitrous Oxide: A Prospective Randomized Clinical Trial.

BACKGROUND: Little is known about the effects of desflurane associated or not with nitrous oxide (N2O) on oxidative stress and patient genetic material. The aim of this study was to compare the effects of anesthesia maintained with desflurane associated or not with N2O on DNA damage (as a primary outcome) and oxidative stress (as a secondary outcome) in patients who underwent an elective minimally invasive surgery. METHODS: This prospective randomized clinical trial analyzed 40 patients of both sexes with an American Society of Anesthesiologists physical status I who were 18-50 years of age and scheduled for septoplasty. The patients were randomly allocated into 2 groups according to anesthesia maintenance as follows: desflurane (n = 20) or desflurane/N2O (n = 20). Blood samples were collected before anesthesia (T1 = baseline), 1.5 hours after anesthesia induction (T2), and on the morning of the postoperative first day (T3). Basal and oxidative DNA damage (determined using formamidopyrimidine DNA glycosylase to detect oxidized purines and endonuclease III to detect oxidized pyrimidines) were evaluated using the comet assay. Oxidative stress markers were evaluated based on lipid peroxidation (by assessing 4-hydroxynonenal and 8-iso-prostaglandin F2α [8-isoprostane] using enzyme linked immunosorbent immunoassay), protein carbonyls (assessed by enzyme linked immunosorbent immunoassay), and antioxidant defense (ferric-reducing antioxidant power by spectrophotometry). The effect size was expressed as the mean differences between groups and the corresponding 95% confidence interval (CI). RESULTS: There was no significant mean difference between groups in relation to DNA damage (-1.7 [95% CI, -7.0 to 3.5]), oxidized DNA pyrimidines (-1.8 [95% CI, -12.5 to 8.9]) and purines (-1.9 [95% CI, -13.9 to 10.1]), 4-hydroxynonenal (-0.2 [95% CI, -2.8 to 2.4]), 8-isoprostane (549 [95% CI, -2378 to 3476]), protein carbonyls (0.2 [95% CI, -2.1 to 2.3]), or ferric-reducing antioxidant power (24 [95% CI, -52.0 to 117.2]). CONCLUSIONS: The coadministration of 60% N2O with desflurane did not seem to impair the effects on DNA or the redox status compared with desflurane anesthesia, suggesting that both studied anesthetic techniques can be suitable options for healthy individuals who undergo minimally invasive surgery lasting at least 1.5 hours. However, due to the low power of the study, more research is necessary to confirm our findings.

[Occupational hazards, DNA damage, and oxidative stress on exposure to waste anesthetic gases]. / Riscos ocupacionais, danos no material genético e estresse oxidativo frente à exposição aos resíduos de gases anestésicos.

BACKGROUND AND OBJECTIVES: The waste anesthetic gases (WAGs) present in the ambient air of operating rooms (OR), are associated with various occupational hazards. This paper intends to discuss occupational exposure to WAGs and its impact on exposed professionals, with emphasis on genetic damage and oxidative stress. CONTENT: Despite the emergence of safer inhaled anesthetics, occupational exposure to WAGs remains a current concern. Factors related to anesthetic techniques and anesthesia workstations, in addition to the absence of a scavenging system in the OR, contribute to anesthetic pollution. In order to minimize the health risks of exposed professionals, several countries have recommended legislation with maximum exposure limits. However, developing countries still require measurement of WAGs and regulation for occupational exposure to WAGs. WAGs are capable of inducing damage to the genetic material, such as DNA damage assessed using the comet assay and increased frequency of micronucleus in professionals with long-term exposure. Oxidative stress is also associated with WAGs exposure, as it induces lipid peroxidation, oxidative damage in DNA, and impairment of the antioxidant defense system in exposed professionals. CONCLUSIONS: The occupational hazards related to WAGs including genotoxicity, mutagenicity and oxidative stress, stand as a public health issue and must be acknowledged by exposed personnel and responsible authorities, especially in developing countries. Thus, it is urgent to stablish maximum safe limits of concentration of WAGs in ORs and educational practices and protocols for exposed professionals.

Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro

Abstract Background and objectives Occupational exposure to waste anesthetic gases in operating room without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhalational anesthetics isoflurane and sevoflurane in operating room with and without central scavenging system. Method Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120 min after the start of surgery) in both operating room types. Results All isoflurane and sevoflurane concentrations in unscavenged operating room were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged operating room, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. Conclusions The exposure to both anesthetics exceeded the international limit in unscavenged operating room. In scavenged operating room, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the operating room scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.

Resumo Justificativa e objetivos A exposição ocupacional aos resíduos de gases anestésicos em salas de operação (SO) sem sistema ativo de exaustão tem sido associada a efeitos adversos à saúde. Assim, o objetivo do estudo foi comparar os resíduos dos anestésicos inalatórios isoflurano e sevoflurano em SO com e sem sistema de exaustão. Método Concentrações residuais de isoflurano e sevoflurano foram mensuradas por analisador infravermelho em diferentes locais (próximo à área respiratória do auxiliar de enfermagem e do anestesiologista e próximo à estação de anestesia) e em dois momentos (30 e 120 min após o início da cirurgia) em ambos os tipos de SO. Resultados Todas as concentrações de isoflurano e sevoflurano nas SO sem sistema de exaustão foram mais elevadas em relação ao valor limite recomendado pelos EUA (2 partes por milhão), independentemente do local e momento avaliados. Nas SO com sistema de exaustão, as concentrações médias de isoflurano ficaram dentro do limite de exposição, exceto para as mensurações próximas à estação de anestesia, independentemente dos momentos avaliados. Para o sevoflurano, as concentrações excederam o valor limite em todos locais de medição e nos dois momentos. Conclusões A exposição a ambos os anestésicos excedeu o limite internacional nas SO sem sistema de exaustão. Nas SO com sistema de exaustão, as concentrações de sevoflurano, e em menor extensão, as de isoflurano excederam o valor limite recomendado. Dessa forma, o sistema de exaustão das SO analisado no presente estudo diminuiu as concentrações dos anestésicos, embora não tenha reduzido a valores internacionalmente recomendados.

[Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital]. / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro.

BACKGROUND AND OBJECTIVES: Occupational exposure to waste anesthetic gases in operating room (OR) without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhaled anesthetics isoflurane and sevoflurane in OR with and without central scavenging system. METHOD: Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120minutes after the start of surgery) in both OR types. RESULTS: All isoflurane and sevoflurane concentrations in unscavenged OR were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged OR, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. CONCLUSIONS: The exposure to both anesthetics exceeded the international limit in unscavenged OR. In scavenged OR, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the OR scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.