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.

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.

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.

Veterinarians exposed to inhaled anesthetic present chromosome damage, apoptosis and cell cycle changes

This cross-sectional study evaluated, for the first time, DNA damage, viability, and cell death of lymphocytes and cell cycle phases of mononuclear and polymorphonuclear cells in veterinarians exposed to the volatile anesthetic isoflurane. Veterinarians who were occupationally exposed to isoflurane (exposed group; n = 20) and matched-unexposed individuals (volunteers without occupational exposure; n = 20) were enrolled in the study. DNA damage was assessed in lymphocytes by micronucleus (MN) and phosphorylated histone gamma-H2AX (γ-H2AX). Cell viability, cytotoxicity, and the cell cycle were evaluated by flow cytometry. Isoflurane was detected in urine samples by headspace gas chromatography-mass spectrometry. Compared with unexposed subjects, veterinarians occupationally exposed to isoflurane (25.7 ± 23.7 μg/L urine) presented statistically higher MN frequencies, lymphocytic apoptosis rates, and numbers of polymorphonuclear cells in the G0/G1 stage. Additionally, the exposed group presented statistically lower proportions of viable lymphocytes and G2/M polymorphonuclear cells. Our findings indicate that veterinarians who are frequently exposed to inhaled anesthetic exhibit chromosomal and cell damage in addition to changes in peripheral blood cell proliferation.

Global anaesthesia-related cardiac arrest rates in children: a systematic review and meta-analysis

BACKGROUND

Neonates and infants have a higher perioperative risk of cardiac arrest and mortality than adults. The Human Development Index (HDI) ranges from 0 to 1, representing the lowest and highest levels of development, respectively. The relation between anaesthesia safety and country HDI has been described previously. We examined the relationship among the anaesthesia-related cardiac arrest rate (ARCAR), country HDI, and time in a mixed paediatric patient population.

METHODS

Electronic databases were searched up to July 2022 for studies reporting 24-h postoperative ARCARs in children. ARCARs (per 10,000 anaesthetic procedures) were analysed in low-HDI (HDI<0.8) vs high-HDI countries (HDI≥0.8) and over time (pre-2001 vs 2001-22). The magnitude of these associations was studied using systematic review methods with meta-regression analysis and meta-analysis.

RESULTS

We included 38 studies with 5,493,489 anaesthetic procedures and 1001 anaesthesia-related cardiac arrests. ARCARs were inversely correlated with country HDI (P<0.0001) but were not correlated with time (P=0.82). ARCARs did not change between the periods in either high-HDI or low-HDI countries (P=0.71 and P=0.62, respectively), but were higher in low-HDI countries than in high-HDI countries (9.6 vs 2.0; P<0.0001) in 2001-22. ARCARs were higher in children aged <1 yr than in those ≥1 yr in high-HDI (10.69 vs 1.48; odds ratio [OR] 8.03, 95% confidence interval [CI] 5.96-10.81; P<0.0001) and low-HDI countries (36.02 vs 2.86; OR 7.32, 95% CI 3.48-15.39; P<0.0001) in 2001-22.

CONCLUSIONS

The high and alarming anaesthesia-related cardiac arrest rates among children younger than 1 yr of age in high-HDI and low-HDI countries, respectively, reflect an ongoing challenge for anaesthesiologists.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021229919.

High anesthetic exposure leads to oxidative damage and gene expression changes in physicians during medical residency: a cohort study

Evaluation of the possible toxic effects of occupational exposure to anesthetics is of great importance, and the literature is limited in assessing the possible association between occupational exposure to anesthetics and oxidative stress and genetic damage. To contribute to the gap of knowledge in relation to cause-effect, this cohort study was the first to monitor exposure assessment and to evaluate oxidative stress, DNA damage, and gene expression (OGG1, NRF2, HO-1, and TP53) in young adult physicians occupationally exposed to the most modern halogenated anesthetics (currently the commonly used inhalational anesthetics worldwide) in addition to nitrous oxide gas during the medical residency period. Therefore, the physicians were evaluated before the beginning of the medical residency (before the exposure to anesthetics-baseline), during (1 1/2 year) and at the end (2 1/2 years) of the medical residency. Anesthetic air monitoring was performed in operating rooms without adequate ventilation/scavenging systems, and biological samples were analyzed for lipid peroxidation, protein carbonyl content, primary and oxidative DNA damage, antioxidant enzymes and plasma antioxidant capacity, and expression of some key genes. The results showed induction of lipid peroxidation, DNA damage, glutathione peroxidase activity, and NRF2 and OGG1 expression up to the end of medical residency. Plasma antioxidant capacity progressively increased throughout medical residency; oxidative DNA damage levels started to increase during medical residency and were higher at the end of residency than at baseline. Protein carbonyls increased during but not at the end of medical residency compared to baseline. The antioxidant enzyme superoxide dismutase activity remained lower than baseline during and at the end of medical residency, and HO-1 (related to antioxidant defense) expression was downregulated at the end of medical residency. Additionally, anesthetic concentrations were above international recommendations. In conclusion, high concentrations of anesthetic in the workplace induce oxidative stress, gene expression modulation, and genotoxicity in physicians during their specialization period.

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.

Evaluation of genetic instability, oxidative stress, and metabolism-related gene polymorphisms in workers exposed to waste anesthetic gases

Professionals who work in operating rooms (ORs) may be exposed daily to waste anesthetic gases (WAGs) due to the use of inhalational anesthetics. Considering the controversial findings related to genetic damage and redox status in addition to a lack of knowledge about the effect of polymorphisms in genes related to phase I and II detoxification upon occupational exposure to WAGs, this cross-sectional study is the first to jointly evaluate biomarkers of genetic instability, oxidative stress, and susceptibility genes in professionals occupationally exposed to high trace amounts of halogenated (≥ 7 ppm) and nitrous oxide (165 ppm) anesthetics in ORs and in individuals not exposed to WAGs (control group). Elevated rates of buccal micronucleus (MN) and nuclear bud (NBUD) were observed in the exposure group and in professionals exposed aged more than 30 years. Exposed males showed a higher antioxidant capacity, as determined by the ferric reducing antioxidant power (FRAP), than exposed females; exposed females had higher frequencies of MN and NBUD than nonexposed females. Genetic instability (MN) was observed in professionals with greater weekly WAG exposure, and those exposed for longer durations (years) exhibited oxidative stress (increased lipid peroxidation and decreased FRAP). Polymorphisms in metabolic genes (cytochrome P450 2E1 (CYP2E1) and glutathione S-transferases (GSTs)) did not exert an effect, except for the effects of the GSTP1 (rs1695) AG/GG polymorphism on FRAP (both groups) and GSTP1 AG/GG and GSTT1 null polymorphisms, which were associated with greater FRAP values in exposed males. Minimizing WAG exposure is necessary to reduce impacts on healthcare workers.

High anesthetic (isoflurane) indoor pollution is associated with genetic instability, cytotoxicity, and proliferative alterations in professionals working in a veterinary hospital

This is the first study to monitor anesthetic pollution in veterinary operating rooms (VOR) and assess the toxicological impact of the inhalational anesthetic isoflurane (exposed group) compared to matched volunteers (control group). DNA damage was evaluated in mononuclear cells by the comet assay while genetic instability (including micronucleus-MN), cell proliferation, and cell death markers were assessed by the buccal MN cytome assay. Residual isoflurane concentrations in VOR (air monitoring) lacking the scavenging system were assessed by infrared spectrophotometry; the mean concentration was 11 ppm (≥ 5 times above the international recommended threshold). Comet assay results did not differ between groups; however, both younger exposed professionals (with higher week workload) compared to older individuals exposed for the same period and older professionals with greater time of exposure (years) compared to those in the same age group with fewer years of exposure presented higher DNA damage. The exposed group had a higher frequency of MN, nuclear buds, binucleated cells, karyorrhexis, and karyolysis and a lower frequency of basal cells than the control group. Exposed women were more vulnerable to genetic instability and proliferative index; exposed men presented more cytotoxicity. High WAG exposure has deleterious effects on exposed professionals.

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.

Spontaneous abortion in women occupationally exposed to inhalational anesthetics: a critical systematic review

Occupational exposure to inhalational anesthetics has been associated with health problems, including reproductive issues. Considering the scarcity and outdated nature of reviews concerning this relevant topic, which has implications for indoor pollution/environmental science/public health, this critical review aimed to systematically evaluate whether exposure to inhalational anesthetics is associated with abortion. Seven databases were searched with no language or year restrictions. Of the 3881 search results, 18 observational studies were included. Some studies demonstrated a significant association between occupational exposure to inhalational anesthetics and spontaneous abortion, especially among professionals who work for longer periods and/or in an environment without gas scavenging/ventilation systems, which may favor the occurrence of abortion in this population. Due to considerable heterogeneity and limitations, it cannot be concluded whether an association exists between occupational exposure to anesthetics and the occurrence of abortion. However, more well-designed studies should be performed, especially in less economically developed countries that do not have access to quality anesthetic gas scavenging/ventilation systems, thereby bringing this issue into sharp focus. This review highlights the need for scientific knowledge in this area and the extensive use of scavenging equipment and in the workplace to minimize exposure and reduce the risk of abortion.

Association between intra-operative cardiac arrest and country Human Development Index status: a systematic review with meta-regression analysis and meta-analysis of observational studies. Anaesthesia 2021;76:1259-1273. [PMID: 33512708 DOI: 10.1111/anae.15374]

Intra-operative cardiac arrests differ from most in-hospital cardiac arrests because they reflect not only the patient's condition but also the quality of surgery and anaesthesia care provided. We assessed the relationship between intra-operative cardiac arrest rates and country Human Development Index (HDI), and the changes occurring in these rates over time. We searched PubMed, EMBASE, Scopus, LILACS, Web of Science, CINAHL and SciELO from inception to 29 January 2020. For the global population, rates of intra-operative cardiac arrest and baseline ASA physical status were extracted. Intra-operative cardiac arrest rates were analysed by time, country HDI status and ASA physical status using meta-regression analysis. Proportional meta-analysis was performed to compare intra-operative cardiac arrest rates and ASA physical status in low- vs. high-HDI countries and in two time periods. Eighty-two studies from 25 countries with more than 29 million anaesthetic procedures were included. Intra-operative cardiac arrest rates were inversely correlated with country HDI (p = 0.0001); they decreased over time only in high-HDI countries (p = 0.040) and increased with increasing ASA physical status (p < 0.0001). Baseline ASA physical status did not change in high-HDI countries (p = 0.106), while it decreased over time in low-HDI countries (p = 0.040). In high-HDI countries, intra-operative cardiac arrest rates (per 10,000 anaesthetic procedures) decreased from 9.59 (95%CI 6.59-13.16) pre-1990 to 5.17 (95%CI 4.42-5.97) in 1990-2020 (p = 0.013). During the same time periods, no improvement was observed in the intra-operative cardiac arrest rates in low-HDI countries (p = 0.498). Odds ratios of intra-operative cardiac arrest rates in ASA 3-5 patients were 8.48 (95%CI 1.67-42.99) times higher in low-HDI countries than in high-HDI countries (p = 0.0098). Intra-operative cardiac arrest rates are related to country-HDI and decreased over time only in high-HDI countries. The widening gap in these rates between low- and high-HDI countries needs to be addressed globally.

Hepatotoxic and neuroendocrine effects in physicians occupationally exposed to most modern halogenated anesthetics and nitrous oxide

The lack of data on hepatic and hormonal markers for occupational exposure to most modern halogenated anesthetics has stimulated our research, which assessed liver enzymes, high-sensitivity C-reactive protein (hs-CRP) and neuroendocrine response. The study investigated 106 physicians who were categorized in an exposed group (primarily exposed to isoflurane and sevoflurane and less to desflurane and nitrous oxide) as well as as a control group. Anesthetic air monitoring was performed, and biological samples were analyzed for the most important liver enzymes, hs-CRP, adrenocorticotrophic hormone, cortisol and prolactin. No biomarkers were significantly different between the groups. Exposed males showed significant increases in cortisol and prolactin compared to unexposed males. However, values were within the reference ranges, and 22 % of exposed males versus 5 % of unexposed males exhibited higher prolactin values above the reference range. This study suggests that occupational exposure to the most commonly used inhalational anesthetics is not associated with hepatotoxicity or neurohormonal changes.

Perioperative mortality in older patients: a systematic review with a meta-regression analysis and meta-analysis of observational studies

STUDY OBJECTIVE

Older patients have a higher probability of developing major complications during the perioperative period than other adult patients. Perioperative mortality depends on not only on a patient condition but also on the quality of perioperative care provided. We tested the hypothesis that the perioperative mortality rate among older patients has decreased over time and is related to a country's Human Development Index (HDI) status.

DESIGN

A systematic review with a meta-regression and meta-analysis of observational studies that reported perioperative mortality rates in patients aged ≥60 years was performed. We searched the PubMed, EMBASE, LILACS and SciELO databases from inception to December 30, 2019.

SETTING

Mortality rates up to the seventh postoperative day were evaluated.

MEASUREMENTS

We evaluated the quality of the included studies. Perioperative mortality rates were analysed by time, country HDI status and baseline American Society of Anesthesiologists (ASA) physical status using meta-regression. Perioperative mortality and ASA status were analysed in low- and high-HDI countries during two time periods using proportion meta-analysis.

MAIN RESULTS

We included 25 studies, which reported 4,412,100 anaesthesia procedures and 3568 perioperative deaths from 12 countries. Perioperative mortality rates in high-HDI countries decreased over time (P = 0.042). When comparing pre-1990 to 1990-2019, in high-HDI countries, the perioperative mortality rates per 10,000 anaesthesia procedures decreased 7.8-fold from 100.85 (95% CI 43.36 to 181.72) in pre-1990 to 12.98 (95% CI 6.47 to 21.70) in 1990-2019 (P < 0.0001). There were no studies from low-HDI countries pre-1990. In the period from 1990 to 2019, perioperative mortality rates did not differ between low- and high-HDI countries (P = 0.395) but the limited number of patients in low-HDI countries impaired the result. Perioperative mortality rates increased with increasing ASA status (P < 0.0001). There were more ASA III-V patients in high-HDI countries than in low-HDI countries (P < 0.0001), and the perioperative mortality rate increased 24-fold in ASA III-V patients compared with ASA I-II patients (P < 0.0001).

CONCLUSION

The perioperative mortality rates in older patients have declined over the past 60 years in high-DHI countries, highlighting that perioperative safety in this population is increasing in these countries. Since data prior to 1990 were lacking in low-HDI countries, the evolution of their mortality rates could not be analysed. The perioperative mortality rate was similar in low- and high-HDI countries in the post-1990 period, but the low number of patients in the low-HDI countries does not allow a definitive conclusion.

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-1β, 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.

Perioperative and anesthesia-related cardiac arrest and mortality rates in Brazil: A systematic review and proportion meta-analysis

INTRODUCTION

Studies have shown that both perioperative and anesthesia-related cardiac arrest (CA) and mortality rates are much higher in developing countries than in developed countries. This review aimed to compare the rates of perioperative and anesthesia-related CA and mortality during 2 time periods in Brazil.

METHODS

A systematic review with meta-analysis of full-text Brazilian observational studies was conducted by searching the Medline, EMBASE, LILACS and SciELO databases up to January 29, 2020. The primary outcomes were perioperative CA and mortality rates and the secondary outcomes included anesthesia-related CA and mortality events rates up to 48 postoperative hours.

RESULTS

Eleven studies including 719,273 anesthetic procedures, 962 perioperative CAs, 134 anesthesia-related CAs, 1,239 perioperative deaths and 29 anesthesia-related deaths were included. The event rates were evaluated in 2 time periods: pre-1990 and 1990-2020. Perioperative CA rates (per 10,000 anesthetics) decreased from 39.87 (95% confidence interval [CI]: 34.60-45.50) before 1990 to 17.61 (95% CI: 9.21-28.68) in 1990-2020 (P < 0.0001), while the perioperative mortality rate did not alter (from 19.25 [95% CI: 15.64-23.24] pre-1990 to 25.40 [95% CI: 13.01-41.86] in 1990-2020; P = 0.1984). Simultaneously, the anesthesia-related CA rate decreased from 14.39 (95% CI: 11.29-17.86) to 3.90 (95% CI: 2.93-5.01; P < 0.0001), while there was no significant difference in the anesthesia-related mortality rate (from 1.75 [95% CI: 0.76-3.11] to 0.67 [95% CI: 0.09-1.66; P = 0.5404).

CONCLUSIONS

This review demonstrates an important reduction in the perioperative CA rate over time in Brazil, with a large and consistent decrease in the anesthesia-related CA rate; however, there were no significant differences in perioperative and anesthesia-related mortality rates between the assessed time periods.

Genetic instability assessed by telomere length and micronucleus in physicians exposed to anesthetics

This study evaluated both telomere length (TL) and micronucleus (MN) as indicators of genome instability in 40 anesthesiologists occupationally exposed to anesthetics and in 40 physicians without occupational exposure to anesthetics who were matched by age, sex, and lifestyle. Blood and buccal samples were collected from both groups at the same period. Anesthetic exposure assessment was performed. The studied groups were assessed regarding relative TL by quantitative polymerase chain reaction and MN by buccal MN assay. Mean trace concentrations of anesthetics were below two parts per million. No significant differences between groups were found for both biomarkers. However, MN frequency was slightly increased (1.9-fold; p = .094) in the exposed group compared to the control group and in the exposed males (2.4-fold; p = .090) compared to unexposed males. TL and age showed a significant negative correlation. Anesthetic occupational exposure below recommended levels is not associated with changes in TL and MN in anesthesiologists.

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.

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.

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.

Small-for-pregnancy-age rats submitted to exercise: DNA damage in mothers and newborns, measured by the comet assay

BACKGROUND

Fetal impairment caused by a deleterious intrauterine environment may have long-term consequences, such as oxidative stress and genetic damage. Rats born as small-for-gestational-age (SPA) were submitted to exercise (swimming) before and during pregnancy. The animals exhibited glucose intolerance, reduced general adiposity, and increased maternal and offspring organ weight, showing the benefit of exercise for these rats. We hypothesised that regular exercise in SPA during gestation could prevent DNA damage in these animals and in their offspring, contributing to altered fetal programming of metabolism in the offspring. Severe diabetes was induced by streptozotocin treatment, to obtain SPA newborns. At adulthood, pregnant SPA rats were randomly distributed into two groups: exercised (SPAex - submitted to swimming program) or not-exercised (SPA - sedentary rats). Post-partum, blood was collected for analysis of DNA damage (comet assay) and oxidative stress. SPAex rats presented lower DNA damage levels, decreased lipid peroxidation, and a lower rate of newborns classified as large-for-pregnancy-age. DNA damage was also lower in SPAex newborns. We conclude that swimming applied to SPA pregnant rats contributes to decreased DNA damage and lipid peroxidation in the dams, and decreased DNA damage and macrosomia in their offspring.

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.

Occupational hazards, DNA damage, and oxidative stress on exposure to waste anesthetic gases

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.

Perioperative and anesthesia-related cardiac arrests in geriatric patients: a systematic review using meta-regression analysis

The worldwide population is aging, and the number of surgeries performed in geriatric patients is increasing. This systematic review evaluated anesthetic procedures to assess global data on perioperative and anesthesia-related cardiac arrest (CA) rates in geriatric surgical patients. Available data on perioperative and anesthesia-related CA rates over time and by the country's Human Development Index (HDI) were evaluated by meta-regression, and a pooled analysis of proportions was used to compare perioperative and anesthesia-related CA rates by HDI and time period. The meta-regression showed that perioperative CA rates did not change significantly over time or by HDI, whereas anesthesia-related CA rates decreased over time (P = 0.04) and in high-HDI (P = 0.015). Perioperative and anesthesia-related CA rates per 10,000 anesthetic procedures declined in high-HDI, from 38.6 before the 1990s to 7.7 from 1990-2017 (P < 0.001) and from 9.2 before the 1990s to 1.3 from 1990-2017 (P < 0.001), respectively. The perioperative CA rate from 1990-2017 was higher in low-HDI than in high-HDI countries (P < 0.001). Hence, a reduction in anesthesia-related CA rates over time was observed. Both perioperative and anesthesia-related CA rates only decreased with a high-HDI between time periods, and perioperative CA rates during 1990-2017 were 4-fold higher with low- compared to high-HDI in geriatric patients.

Genotoxicity assessment of fipronil (frontline plus®) in Canis familiaris

ABSTRACT: Fipronil is a pesticide widely used for controlling fleas and ticks in domestic animals, and its short-term exposure can lead to serious effects on animals. However, the possible genotoxic effect of this compound has not been investigated in target animals. Based on the hypothesis that fipronil can induce genotoxicity, this study evaluated the effect of fipronil on DNA damage in peripheral blood cells. For that purpose, ten dogs of both sexes were used in the study. The product (6.7mg/kg) was applied on the dorsal neck region of each animal. Peripheral blood samples were collected immediately prior to application of the product, and at 3, 8 and 24 hours after the application. Samples were processed for comet assay. No statistically significant differences were found among the four time points. The current study suggests for the first time that a single exposure to this pesticide does not induce systemic genotoxic effect in dogs.

The Humidity in a Low-Flow Dräger Fabius Anesthesia Workstation with or without Thermal Insulation or a Heat and Moisture Exchanger: A Prospective Randomized Clinical Trial

Background

During anesthesia, as compared with intensive care, the time of the tracheal intubation is much shorter. An inhaled gas minimum humidity of 20 mgH₂O.L^-1 is recommended to reduce the deleterious effects of dry gas on the airways during anesthesia with tracheal intubation. The Fabius GS Premium® anesthesia workstation (Dräger Medical, Lübeck, Germany) has a built-in hotplate to heat gases in the breathing circuit. A heat and moisture exchanger (HME) is used to further heat and humidify the inhaled gas. The humidity of the gases in the breathing circuit is influenced by the ambient temperature. We compared the humidity of the inhaled gases from a low-flow Fabius anesthesia workstation with or without thermal insulation (TI) of the breathing circuit and with or without an HME.

Methods

We conducted a prospective randomized trial in 41 adult female patients who underwent elective abdominal surgery. The patients were allocated into four groups according to the devices used to ventilate their lungs using a Dräger Fabius anesthesia workstation with a low gas flow (1 L.min^-1): control, with TI, with an HME or with TI and an HME (TIHME). The mean temperature and humidity of the inhaled gases were measured during 2-h after connecting the patients to the breathing circuit.

Results

The mean inhaled gas temperature and absolute humidity were higher in the HME (29.2±1.3°C; 28.1±2.3 mgH₂O·L^-1) and TIHME (30.1±1.2°C; 29.4±2.0 mgH₂O·L^-1) groups compared with the control (27.5±1.0°C; 25.0±1.8 mgH₂O·L^-1) and TI (27.2±1.1°C; 24.9±1.8 mgH₂O·L^-1) groups (P = 0.003 and P<0.001, respectively).

Conclusions

The low-flow Fabius GS Premium breathing circuit provides the minimum humidity level of inhaled gases to avoid damage to the tracheobronchial epithelia during anesthesia. TI of the breathing circuit does not increase the humidity of the inhaled gases, whereas inserting an HME increases the moisture of the inhaled gases closer to physiological values.

Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide - N₂O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N₂O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170ppm for N₂O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and pyknosis, and a lower frequency of basal cells compared with the control group. In conclusion, exposure to modern waste anesthetic gases did not induce systemic DNA damage, but it did result in genomic instability, cytotoxicity and proliferative changes, which were detected in the EBC of anesthesiologists. Thus, these professionals can be considered at risk for developing genetic alterations resulting from occupational exposure to these gases, suggesting the need to minimize this exposure.

Evaluation of genotoxicity of general anesthesia maintained with desflurane in patients under minor surgery

There is controversy over the genotoxic effects of volatile anesthetics. The available literature on the genotoxicity of desflurane, one of the newest volatile halogenated agents used for general anesthesia maintenance, is scarce. This study aimed to evaluate the genotoxic potential of desflurane in 15 patients without comorbidities, of both sexes, who underwent minor surgeries lasting at least 90 min. Patients enrolled in the study received desflurane anesthesia (6%); blood samples were collected before anesthesia induction (T0), 90 min after the beginning of anesthesia (T1), and on the day following surgery (T2). DNA damage was evaluated in lymphocytes using the alkaline comet assay. We found statistically significant increases in DNA damage in T2 samples compared to T0. The findings suggest that desflurane anesthesia induces DNA strand breaks/alkali-labile sites on the day after minimally invasive surgery in healthy patients.

Perioperative and Anesthesia-Related Mortality: An 8-Year Observational Survey From a Tertiary Teaching Hospital

In 2006, a previous study at our institution reported high perioperative and anesthesia-related mortality rates of 21.97 and 1.12 per 10,000 anesthetics, respectively. Since then, changes in surgical practices may have decreased these rates. However, the actual perioperative and anesthesia-related mortality rates in Brazil remains unknown. The study aimed to reexamine perioperative and anesthesia-related mortality rates in one Brazilian tertiary teaching hospital.In this observational study, deaths occurring in the operation room and postanesthesia care unit between April 2005 and December 2012 were identified from an anesthesia database. The data included patient characteristics, surgical procedures, American Society of Anesthesiologists (ASA) physical status, and medical specialty teams, as well as the types of surgery and anesthesia. All deaths were reviewed and grouped by into 1 of 4 triggering factors groups: totally anesthesia-related, partially anesthesia-related, surgery-related, or disease/condition-related. The mortality rates are expressed per 10,000 anesthetics with 95% confidence intervals (CIs).A total of 55,002 anesthetics and 88 deaths were reviewed, representing an overall mortality rate of 16.0 per 10,000 anesthetics (95% CI: 13.0-19.7). There were no anesthesia-related deaths. The major causes of mortality were patient disease/condition-related (13.8, 95% CI: 10.7-16.9) followed by surgery-related (2.2, 95% CI: 1.0-3.4). The major risks of perioperative mortality were children younger than 1-year-old, older patients, patients with poor ASA physical status (III-V), emergency, cardiac or vascular surgeries, and multiple surgeries performed under the same anesthetic technique (P < 0.0001).There were no anesthesia-related deaths. However, the high mortality rate caused by the poor physical conditions of some patients suggests that primary prevention might be the key to reducing perioperative mortality. These findings demonstrate the need to improve medical perioperative practices for high-risk patients in under-resourced settings.

Anesthesia-Related and Perioperative Cardiac Arrest in Low- and High-Income Countries: A Systematic Review With Meta-Regression and Proportional Meta-Analysis

The anesthesia-related cardiac arrest (CA) rate is a quality indicator to improve patient safety in the perioperative period. A systematic review with meta-analysis of the worldwide literature related to anesthesia-related CA rate has not yet been performed.This study aimed to analyze global data on anesthesia-related and perioperative CA rates according to country's Human Development Index (HDI) and by time. In addition, we compared the anesthesia-related and perioperative CA rates in low- and high-income countries in 2 time periods.A systematic review was performed using electronic databases to identify studies in which patients underwent anesthesia with anesthesia-related and/or perioperative CA rates. Meta-regression and proportional meta-analysis were performed with 95% confidence intervals (CIs) to evaluate global data on anesthesia-related and perioperative CA rates according to country's HDI and by time, and to compare the anesthesia-related and perioperative CA rates by country's HDI status (low HDI vs high HDI) and by time period (pre-1990s vs 1990s-2010s), respectively.Fifty-three studies from 21 countries assessing 11.9 million anesthetic administrations were included. Meta-regression showed that anesthesia-related (slope: -3.5729; 95% CI: -6.6306 to -0.5152; P = 0.024) and perioperative (slope: -2.4071; 95% CI: -4.0482 to -0.7659; P = 0.005) CA rates decreased with increasing HDI, but not with time. Meta-analysis showed per 10,000 anesthetics that anesthesia-related and perioperative CA rates declined in high HDI (2.3 [95% CI: 1.2-3.7] before the 1990s to 0.7 [95% CI: 0.5-1.0] in the 1990s-2010s, P < 0.001; and 8.1 [95% CI: 5.1-11.9] before the 1990s to 6.2 [95% CI: 5.1-7.4] in the 1990s-2010s, P < 0.001, respectively). In low-HDI countries, anesthesia-related CA rates did not alter significantly (9.2 [95% CI: 2.0-21.7] before the 1990s to 4.5 [95% CI: 2.4-7.2] in the 1990s-2010s, P = 0.14), whereas perioperative CA rates increased significantly (16.4 [95% CI: 1.5-47.1] before the 1990s to 19.9 [95% CI: 10.9-31.7] in the 1990s-2010s, P = 0.03).Both anesthesia-related and perioperative CA rates decrease with increasing HDI but not with time. There is a clear and consistent reduction in anesthesia-related and perioperative CA rates in high-HDI countries, but an increase in perioperative CA rates without significant alteration in the anesthesia-related CA rates in low-HDI countries comparing the 2 time periods.

Isoflurane and Propofol Contribute to Increasing the Antioxidant Status of Patients During Minor Elective Surgery: A Randomized Clinical Study

Isoflurane is a volatile halogenated anesthetic used especially for anesthesia maintenance whereas propofol is a venous anesthetic utilized for anesthesia induction and maintenance, and reportedly an antioxidant. However, there are still controversies related to isoflurane-induced oxidative stress and it remains unanswered whether the antioxidant effects occur in patients under propofol anesthesia.Taking into account the importance of better understanding the role of anesthetics on oxidative stress in anesthetized patients, the present study was designed to evaluate general anesthesia maintained with isoflurane or propofol on antioxidant status in patients who underwent minimally invasive surgeries.We conducted a prospective randomized trial in 30 adult patients without comorbidities who underwent elective minor surgery (septoplasty) lasting at least 2 h admitted to a Brazilian tertiary hospital.The patients were randomly allocated into 2 groups, according to anesthesia maintenance (isoflurane, n = 15 or propofol, n = 15). Peripheral blood samples were drawn before anesthesia (baseline) and 2-h after anesthesia induction.The primary outcomes were to investigate the effect of either isoflurane or propofol anesthesia on aqueous plasma oxidizability and total antioxidant performance (TAP) by fluorometry as well as several individual antioxidants by high-performance liquid chromatography. As secondary outcome, oxidized genetic damage (7,8-dihydro-8-oxoguanine, known as 8-oxo-Gua) was investigated by the comet assay.Both anesthesia techniques (isoflurane or propofol) for a 2-h period resulted in a significant decrease of plasma α-tocopherol, but not other antioxidants including uric acid, carotenoids, and retinol (P > 0.05). Propofol, in contrast to isoflurane anesthesia, significantly increased (P < 0.001) anti-inflammatory/antioxidant plasma γ-tocopherol concentration in patients. Both anesthesia types significantly enhanced hydrophilic antioxidant capacity and TAP, with no significant difference between them, and 8-oxo-Gua remained unchanged during anesthesia in both groups. In addition, both anesthetics showed antioxidant capacity in vitro.This study shows that anesthesia maintained with either propofol or isoflurane increase both hydrophilic and total antioxidant capacity in plasma, but only propofol anesthesia increases plasma γ-tocopherol concentration. Additionally, both types of anesthetics do not lead to oxidative DNA damage in patients without comorbidities undergoing minimally invasive surgery.

Oxidative stress on cardiotoxicity after treatment with single and multiple doses of doxorubicin

The mechanism of doxorubicin (DOX)-induced cardiotoxicity remains controversial. Wistar rats ( n = 66) received DOX injections intraperitoneally and were randomly assigned to 2 experimental protocols: (1) rats were killed before (−24 h, n = 8) and 24 h after (+24 h, n = 8) a single dose of DOX (4 mg/kg body weight) to determine the DOX acute effect and (2) rats ( n = 58) received 4 injections of DOX (4 mg/kg body weight/week) and were killed before the first injection (M0) and 1 week after each injection (M1, M2, M3, and M4) to determine the chronological effects. Animals used at M0 ( n = 8) were also used at moment −24 h of acute study. Cardiac total antioxidant performance (TAP), DNA damage, and morphology analyses were carried out at each time point. Single dose of DOX was associated with increased cardiac disarrangement, necrosis, and DNA damage (strand breaks (SBs) and oxidized pyrimidines) and decreased TAP. The chronological study showed an effect of a cumulative dose on body weight ( R = −0.99, p = 0.011), necrosis ( R = 1.00, p = 0.004), TAP ( R = 0.95, p = 0.049), and DNA SBs ( R = −0.95, p = 0.049). DNA SBs damage was negatively associated with TAP ( R = −0.98, p = 0.018), and necrosis ( R = −0.97, p = 0.027). Our results suggest that oxidative damage is associated with acute cardiotoxicity induced by a single dose of DOX only. Increased resistance to the oxidative stress is plausible for the multiple dose of DOX. Thus, different mechanisms may be involved in acute toxicity versus chronic toxicity.

Comparison of oxidative stress in ASA physical status I patients scheduled for minimally invasive surgery under balanced or intravenous anesthesia

BACKGROUND

The effects of anesthetics on inflammation and oxidative parameters, evaluated in patients without comorbidities undergoing minor surgery, remain unknown. The present study aimed to investigate the inflammatory and oxidative stress status in adult patients undergoing elective minimally invasive surgery, using different anesthetic techniques.

METHODS

Thirty patients classified as ASA physical status I, who were scheduled for minor surgeries (tympanoplasty or septoplasty), were randomly allocated into two groups: balanced (BAL) anesthesia maintained with isoflurane or total intravenous anesthesia (TIVA) with propofol. Blood samples were drawn prior to the induction of anesthesia (baseline), 120 min after the beginning of anesthesia and one day after surgery. The proinflammatory cytokine IL-6 was determined by flow cytometry; DNA oxidation was evaluated by the single cell gel electrophoresis assay, and plasma malondialdehyde (lipid peroxidation biomarker) and antioxidant status were determined through fluorometry.

RESULTS

Increased IL-6 was observed one day after surgery in both groups (P=0.0001). Malondialdehyde levels did not change among the time points assessed or between the groups (P>0.05). Whereas BAL anesthesia had no effect on acid nucleic and antioxidant status, TIVA decreased oxidized/alkylated purines (P=0.03) and increased antioxidant status (P=0.002) during anesthesia. The two groups did not differ significantly in DNA oxidation or antioxidant status (P>0.05).

CONCLUSION

BAL anesthesia maintained with isoflurane and TIVA maintained with propofol are safe by virtue of not causing oxidative stress status in ASA physical status I patients undergoing minimally invasive surgeries. Moreover, even in minor surgeries, TIVA with propofol produces an antioxidant effect in patients.

Lower levels of oxidative DNA damage and apoptosis in lymphocytes from patients undergoing surgery with propofol anesthesia

Propofol, which is widely used as an intravenous anesthetic, has a phenolic structure similar to that of α-tocopherol with antioxidant properties that could prevent genotoxicity and cytotoxicity in lymphocytes of anesthetized patients. The aims of this study were to evaluate oxidative DNA damage and apoptosis in lymphocytes and the expression of DNA repair genes in blood cells from patients undergoing elective surgery under anesthesia with propofol. Twenty healthy adults of both genders (18-50 years old) who were scheduled for otorhinological surgery were enrolled in this study. Blood samples were collected before anesthesia induction (T₁-baseline), 120 min after anesthesia induction (T₂), and on the first postoperative day (T₃). Oxidative DNA damage in peripheral lymphocytes was assessed using the comet assay. Lymphocytes were phenotyped as T helper or cytotoxic T cells, and apoptosis was evaluated using flow cytometry. The expression of DNA repair genes (hOGG1 and XRCC1) was assessed by quantitative polymerase chain reaction. A reduction in the level of oxidized purines in DNA (P < 0.01) was observed 120 min after anesthesia induction, and reduced apoptosis of T helper cells was observed 120 min after anesthesia induction and on the first postoperative day. Down-regulation of hOGG1 and XRCC1 gene expression was observed on the first postoperative day. In conclusion, patients undergoing non-invasive surgery under propofol anesthesia presented lower levels of oxidized purines and apoptosis of T helper lymphocytes. Furthermore, anesthesia with propofol did not directly influence the expression of the DNA repair genes hOGG1 and XRCC1 in blood cells.

DNA damage in patients who underwent minimally invasive surgery under inhalation or intravenous anesthesia

Recent studies have demonstrated the genotoxicity of anesthetics in patients who have undergone surgery and in personnel who are occupationally exposed to anesthetics. However, these findings are controversial. Herein, we used the comet assay (single-cell gel electrophoresis) to investigate the genotoxic effects of two volatile compounds [isoflurane (ISF) and sevoflurane (SVF)] that are used in inhalation anesthesia, and of one intravenous (iv) anesthetic compound [propofol (PF)]. The groups consisted of 45 patients who underwent minimally invasive surgery that lasted at least 2h. Patients were classified as physical status I using the criteria of the American Society of Anesthesiologists (ASA) and were randomly allocated to receive ISF, SVF or PF anesthesia. Venous blood samples were collected at three time points as follows: before the premedication and the induction of anesthesia (T(0)); 2h after the beginning of anesthesia (T(1)); and on the day following surgery (T(2)). DNA damage (strand breaks and alkali-labile sites) was evaluated in peripheral blood lymphocytes. For each patient, one hundred nucleoids were analyzed per time point using a semi-automated image system. Patients did not differ with respect to their demographic characteristics, the duration of surgery, or the total doses of intraoperative drugs. The amount of DNA damage was not different among the three groups before anesthesia (T(0)). No statistically significant (p>0.05) increase in DNA damage was detected during (T(1)) or after anesthesia (T(2)) using three different protocols (ISF, SVF or PF). In conclusion, general anesthesia with inhaled ISF and SVF or iv PF did not induce DNA strand breaks or alkali-labile sites in peripheral lymphocytes. Therefore, our results show that the genotoxic risk of these anesthetics, for healthy patients undergoing minimally invasive otorhinological surgery, is low or even absent.

Genotoxicity in primary human peripheral lymphocytes after exposure to regular and white mineral trioxide aggregate

OBJECTIVE

Taking into consideration that DNA damage plays an important role in carcinogenesis, the purpose of this study was to evaluate whether regular and white mineral trioxide aggregate (MTA) are able to induce genetic damage in primary human cells.

STUDY DESIGN

Human peripheral lymphocytes obtained from 10 healthy volunteers were exposed to 2 presentation forms of MTA at final concentrations ranging from 1 to 1000 microg/mL for 1 hour at 37 degrees C. The negative control group was treated with vehicle control (phosphate buffer solution, PBS) for 1 hour at 37 degrees C and the positive control group was treated with hydrogen peroxide (at 100 microM) for 5 minutes on ice. Results were analyzed by the Friedman nonparametric test.

RESULTS

The results pointed out that either regular or white MTA in all concentrations tested did not induce DNA breakage in human peripheral lymphocytes as depicted by the mean tail moment.

CONCLUSION

In summary, our results indicate that exposure to MTA may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single cell gel (comet) assay.

Evaluation of genetic damage in human peripheral lymphocytes exposed to mineral trioxide aggregate and Portland cements

summary Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root-end-filling material for periapical surgery and for the sealing of communications between the root canal system and the surrounding tissues. However, genotoxicity tests for complete risk assessment of these compounds have not been conducted up to now. In the present study, the genotoxic effects of MTA and Portland cements were evaluated in peripheral lymphocytes from 10 volunteers by the alkaline single cell gel (comet) assay. The results pointed out that the single cell gel (comet) assay failed to detect the presence of DNA damage after a treatment of peripheral lymphocytes by MTA and Portland cements for concentrations up to 1000 mug mL(-1). In summary, our results indicate that exposure to MTA or Portland cements may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single cell gel (comet) assay.