Polycyclic aromatic hydrocarbons in estuarine sediments as a consequence of the mine tailings remobilization and transport in the Rio Doce basin.

The Fundão dam failure in 2015 severely impaired the economy, the lives of riverine communities, and the aquatic ecosystems of the Rio Doce basin in southeast Brazil. Several contaminants, including polycyclic aromatic hydrocarbons (PAHs), were transported downstream, deposited in the estuary, and released into the Atlantic Ocean. The high concentration of PAHs in estuarine sediments may pose ecological risks and deleterious effects to benthic organisms, so here we aimed at determining the source and fate of these compounds before and after the tailings' arrival. The mean concentration of the analyzed Σ16PAHs increased from 34.05 µg kg-1 in the prefailure period to 751.77 µg kg-1 one year after the arrival of the tailing. The classification of the sediment quality changed from low to moderate contamination. Our results suggest that there was PAHs remobilization by mine tailings along the Rio Doce basin. The target analytes exhibited mostly a pyrolytic profile from fossil fuel and biomass burning. In addition to other contaminants deposited in the estuary after the arrival of the tailings, this study revealed that the profile change of PAHs in the estuary region is a consequence of the mud's erosive power. Integr Environ Assess Manag 2024;20:169-178. © 2023 SETAC.

Rare earth elements as tracers of iron ore tailings on the Brazilian eastern continental shelf.

Iron ore tailings are stored in large dams and pose risks to the environment around the world. In Brazil, the rupture of these dams has become frequent and has generated environmental and social concern. Rare earth elements are good tracers of sediment sources and our results indicated chronic contamination of the seabed sediment from the marine region affected by the Fundão Dam tailings since 2015, including areas of environmental protection. This research, carried out between November 2018 and September 2021, with a database of 575 samples, showed a greater amount of contaminated material in the marine region adjacent to the Doce River mouth. Although data suggest prior mining contamination of the Doce River basin, the Fundão episode was an empirical and massive example of the environmental damage caused by these human activities over the centuries, showing that the impact remains in the shallow marine environments for years. Integr Environ Assess Manag 2024;20:179-188. © 2023 SETAC.

Os rejeitos de minério de ferro são armazenados em grandes barragens que trazem riscos ao meio ambiente em todo o mundo. No Brasil, o rompimento dessas barragens tem se tornado frequente e gerado preocupação ambiental e social. Elementos terras raras são bons marcadores de fontes sedimentares e nossos resultados indicaram uma contaminação crônica da região marinha afetada pelos rejeitos da barragem de Fundão, incluindo áreas de proteção ambiental. Esta pesquisa teve com 575 amostras analisadas entre os meses de novembro de 2018 e outubro de 2021, com a região marinha adjacente a foz do Rio Doce apresentando o maior grau de impacto. Embora os dados ressaltem a contaminação histórica da mineração na bacia do Rio Doce, o episódio do Fundão foi um exemplo empírico e massivo dos danos ambientais causados por essas atividades ao longo dos séculos, mostrando que o impacto permanece nos ambientes marinhos rasos por anos. Integr Environ Assess Manag 2024;20:179-188.

Historical contamination with a current problem: Can mining tailings enhance coastal arsenic pollution?

The coast of Espírito Santo state (Southeast Brazil) is recognized for its environmental arsenic (As) enrichment and, over the years, mining operations have potentialized it. We aimed to evaluate the effect of Rio Doce discharge on As inputs and the role of iron ore tailings from the Fundão dam disaster in enhancing As contamination in the marine sediment. Two scenarios were evaluated: Predisaster and Postdisaster; dry and wet conditions were considered in each period. High As concentrations were found in the Predisaster (28.44 ± 13.53 µg g-1 ), but a significant increase in As was remarkable during the Postdisaster in the wet season, one year after the disaster (maximum of 58.39 µg g-1 ; geoaccumulation index (Igeo ) Class 3, moderately severe pollution). On that occasion, iron (Fe) oxy-hydroxides from tailings were remobilized from the Rio Doce channel and deposited on the continental shelf bottom. Therefore, chemical interactions among Fe, As, and carbonates were enhanced, resulting in As and Fe coprecipitation and the trapping by carbonate adsorption. Rio Doce discharge seems to be the main factor in As inputs to the inner continental shelf when flooding do not occur previously in samplings, which allows further dispersion of contaminants, although this hypothesis should be tested further. Integr Environ Assess Manag 2024;20:159-168. © 2023 SETAC.

The Cost-Benefit of Aging: Financial Capability and Well-Being across Age Groups in Brazil.

A large proportion of older persons in developing countries do not have access to pension, which also constrains their ability to afford healthcare services and entails extensive challenges to the well-being of older people. This study aimed to analyze the financial preparedness of different age groups for retirement in Brazil. Data were derived from a survey to empirically validate the proposed relationships between preparedness for retirement and resilience for the future (financial well-being (FWB) outcomes) on the one hand and among demographic and socioeconomic aspects, behaviors and attitudes, knowledge and experience, and "key" psychological factors on the other hand. The sample consisted of 412 individuals aged between 22 and 79 years. FWB was measured using the financial capability and well-being model and regressed on a number of sociodemographic and psychological variables using linear regression analyses. The results demonstrated that preparedness for retirement was strongly related to older age. Additionally, age was correlated with resilience for the future close to zero, which indicates no relationship. Knowledge and the psychological factors of self-control and confidence were positively and strongly related to better financial behavior for all age groups. In addition, grit and resilience for the future were positively related to better financial behavior in the older age group. Furthermore, the variables of retirement contribution were seemingly not viewed as important to the older group compared with their young and mature counterparts. Multidimensional interventions, especially targeting behaviors and psychological patterns, could, therefore, be recommended in advance to young and mature groups to prepare them to secure their old age and achieve FWB.

Effect of dexamethasone on experimental enteritis produced by Giardia lamblia in a Meriones unguiculatus model.

Our aim was to evaluate the impact of immunosuppression on the development of giardiasis. Thirty-six gerbils (4-6 weeks old) were distributed in four groups containing nine animals each: Control (CT); Control-Infected by Giardia lamblia (CTIn), Immunosuppressed (IS), and Immunosuppressed-Infected by G. lamblia (ISIn). Animals in the IS and ISIn groups received intramuscular dexamethasone solution for 25 days. On the 11th day, the animals in the CTIn and ISIn groups were inoculated with G. lamblia. After 14 days of infection, the 25th day of the experiment, all groups were euthanized. Four hours after euthanasia, the intestinal permeability was evaluated and sections of the duodenum and spleen were harvested for morphometric and histopathological analyses. Immunosuppressed groups showed a significant increase in intestinal permeability compared to control and infected groups. Considering that the infection can become chronic in immunosuppressed groups, we should be alert to the possibilities of chronic inflammatory changes, both locally and systemically, due to the loss of the intestinal barrier. Lesions were observed in the duodenal mucosa of the gerbils of the CTIn group, with reduced villi size, crypt hyperplasia, edema, and the presence of inflammatory infiltrate in the lamina propria. In the ISIn group, we observed no inflammation, long and intact villi, and a significant increase in the area of intestinal mucins, despite the large number of trophozoites identified. Our results suggest that exacerbation of the immune response has a direct relationship with the appearance of lesions during enteritis produced by G. lamblia in the assessed model.

Depression and anxiety in patients with multiple sclerosis treated with interferon-beta or fingolimod: Role of indoleamine 2,3-dioxygenase and pro-inflammatory cytokines.

Depression/anxiety (D/A) occurs in up to 50% of multiple sclerosis (MS) patients. Proinflammatory cytokines induce classical symptoms of depression. Activation of the inflammatory response also triggers production of indoleamine 2,3-dioxygenase (IDO), which catabolizes tryptophan, the amino acid precursor of serotonin and melatonin. It has been suggested that IDO is the link between the immune and serotonergic systems. This study aimed to quantify the levels of IDO and pro-inflammatory and anti-inflammatory cytokines in patients with MS and depression, according to treatment with interferon-beta (IFN-ß) or fingolimod. The study inclusion criteria were age 18-60 years and a clinical and radiological diagnosis of MS. One hundred and thirty-two patients diagnosed by McDonald's criteria and followed up at Brasília District Hospital, Brazil, with relapsing-remitting MS were identified as potential study participants. Thirty-five of these patients were identified to be receiving treatment with fingolimod or IFN-ß and to have a diagnosis of D/A. IDO and pro-inflammatory and anti-inflammatory cytokine levels were compared between these 35 patients and 18 healthy controls. The level of IL-10 (an anti-inflammatory cytokine) was lower in both the fingolimod-treated (P â€‹< â€‹0.001) and IFN-ß-treated (P â€‹< â€‹0.01) patient groups than in the control group. IFN-ß-treated patients showed increased IDO expression and decreased inflammatory cytokine levels. In contrast, fingolimod-treated patients showed significantly decreased expression of IDO and significantly increased levels of proinflammatory cytokines produced by innate immune cells, including tumor necrosis factor-alpha and interleukin-6. The agents used to treat MS maintain symptoms of D/A in patients with MS via different mechanisms.

Cognitive and Neural Effects of a Brief Nonsymbolic Approximate Arithmetic Training in Healthy First Grade Children.

Recent studies with children and adults have shown that the abilities of the Approximate Number System (ANS), which operates from early infancy and allows estimating the number of elements in a set without symbols, are trainable and transferable to symbolic arithmetic abilities. Here we investigated the brain correlates of these training effects, which are currently unknown. We trained two Groups of first grade children, one in performing nonsymbolic additions with dot arrays (Addition-Group) and another one in performing color comparisons of the same arrays (Color-Group). The training program was computerized, throughout seven sessions and had a pretest-posttest design. To evaluate cognitive gains, we measured math skills before and after the training. To measure the brain changes, we used electroencephalogram (EEG) recordings in the first and the last training sessions. We explored the changes in N1 and P2p, which are two electrophysiological components sensitive to nonsymbolic numeric computations. A passive Control-Group receiving no intervention also had their math skills evaluated. We found that the two training Groups had similarly gain in math skills, suggesting no specific transfer of the nonsymbolic addition training to math skills at the behavioral level. In contrast, at the brain level, we found that only in the Addition-Group the P2p amplitude significantly increased across sessions. Notably, the gain in P2p amplitude positively correlated with the gain in math abilities. Together, our results showed that first graders rapidly gained in math skills by different interventions. However, number-related brain networks seem to be particularly sensitive to nonsymbolic arithmetic training.

Indigofera suffruticosa Mill. (Anil): Plant Profile, Phytochemistry, and Pharmacology Review.

Indigoferasuffruticosa Mill. (Fabaceae) is known as anil or anileira and also with other names, due to the production of a blue pigment, which is commonly used for yarn dyeing. It is distributed in some states of Brazil (Pernambuco, Paraíba, Mato Grosso, São Paulo, Bahia, Pará, and others) and is used in the popular medicine as a febrifuge, antispasmodic, diuretic, abortive, analgesic, purgative, or soothing agent against stomach and urinary problems, jaundice, and ulcers and also as an insecticide. In addition, I. suffruticosa can be used as animal feed. This review aimed at providing important data on the botanical, distribution, ethnopharmacology, phytochemical, pharmacological, and toxicity of I. suffruticosa based on the scientific literature. Information on I. suffruticosa was gathered via the Internet (from Elsevier, NCBI, and Sci-Hub) and libraries in the period from February to March 2016. More than 40 chemical compounds have been identified and a few compounds isolated, and the main origins are the essential oils, organic extracts, and aqueous extracts of different parts of the plant. I. suffruticosa and its active compounds possess wide pharmacological actions in the literature, such as anti-inflammatory, antibacterial, antifungal, antioxidative, antitumor, antimutagenic, anticonvulsant, gastroprotective, and hepatoprotective activities. Therefore, as an important traditional popular medicine, further studies on I. suffruticosa are required for the development of new drugs and therapeutics for various diseases.

Diaphragm and genioglossus corticomotor excitability in patients with obstructive sleep apnea and control subjects.

Corticomotor excitability of peripheral muscles appears to be altered in patients with obstructive sleep apnea. However, there is no evidence of such alteration for upper airway/respiratory muscles that are involved in the pathophysiology of this disease. The aim of this study was to compare the effects of hypercapnic stimulation on diaphragm and genioglossus corticomotor excitability in awake healthy subjects versus patients with obstructive sleep apnea. Corticomotor excitability was assessed by transcranial magnetic stimulation in 12 untreated apneic men (48 ± 10 years; body mass index = 28.9 ± 4.7 kg m(-2); apnea-hypopnoea index = 41 ± 23 events per hour) and nine control men (45 ± 10 years; body mass index = 27.3 ± 3.3 kg m(-2); apnea-hypopnoea index = 7 ± 4 events per hour). Assessments included diaphragm and genioglossus expiratory motor thresholds, and transcranial magnetic stimulation-induced motor-evoked potential characteristics obtained while breathing room air or 5% CO2 (random order) and then 7% CO2 both balanced with pure O2. Transcranial magnetic stimulation twitches were applied during early inspiration and end expiration. Diaphragm motor-evoked potential amplitudes increased and expiratory diaphragm motor-evoked potential latencies decreased during CO2-induced increase in ventilatory drive, with no difference in these responses between patients with obstructive sleep apnea and control subjects. Expiratory genioglossus motor-evoked potential amplitudes were significantly lower in patients with obstructive sleep apnea than in control subjects. Baseline activity of the genioglossus increased with increasing FiCO2, this effect being significantly higher in patients with obstructive sleep apnea than in control subjects. However, neither genioglossus motor-evoked potential amplitudes nor latencies were significantly modified with increasing FiCO2 both in patients with obstructive sleep apnea and in control subjects. Corticomotor excitability of genioglossus and diaphragm are not altered during CO2-induced increase in ventilatory drive in patients with obstructive sleep apnea.

Effects of anti-inflammatory drugs in primary kidney cell culture of a freshwater fish.

The non-steroidal anti-inflammatory drugs are emerging contaminants in aquatic ecosystems. This study aimed to evaluate toxic effects of some representative drugs of this pharmaceutical group on primary culture of monocytic lineage of Hoplias malabaricus anterior kidney. The effects of diclofenac, acetaminophen and ibuprofen in cell viability, lipopolysaccharide (LPS)-induced NO production and genotoxicity were evaluated. Cytometry analysis CD11b(+) cells showed 71.5% of stem cells, 19.5% of macrophages and 9% of monocytes. Cell viability was lower in the ficoll compared to percoll separation. LPS-induced NO production by these cells was blocked after treatment with dexamethasone and NG-Methyl-L-Arginine (L-NMMA). Exposure of the cells to diclofenac (0.2-200 ng/mL), acetaminophen (0.025-250 ng/mL) ibuprofen (10-1000 ng/mL) reduced basal NO production and inhibited LPS-induced NO production at all concentrations after 24 h of exposure. Genotoxicity occurred at the highest concentration of diclofenac and at the intermediary concentration of acetaminophen. Genotoxicity was also observed by ibuprofen. In summary, the pharmaceuticals influenced NO production and caused DNA damage in monocytic cells suggesting that these drugs can induce immunosuppression and genotoxicity in fish.

TNF-α mediates PKR-dependent memory impairment and brain IRS-1 inhibition induced by Alzheimer's ß-amyloid oligomers in mice and monkeys.

Alzheimer's disease (AD) and type 2 diabetes appear to share similar pathogenic mechanisms. dsRNA-dependent protein kinase (PKR) underlies peripheral insulin resistance in metabolic disorders. PKR phosphorylates eukaryotic translation initiation factor 2α (eIF2α-P), and AD brains exhibit elevated phospho-PKR and eIF2α-P levels. Whether and how PKR and eIF2α-P participate in defective brain insulin signaling and cognitive impairment in AD are unknown. We report that ß-amyloid oligomers, AD-associated toxins, activate PKR in a tumor necrosis factor α (TNF-α)-dependent manner, resulting in eIF2α-P, neuronal insulin receptor substrate (IRS-1) inhibition, synapse loss, and memory impairment. Brain phospho-PKR and eIF2α-P were elevated in AD animal models, including monkeys given intracerebroventricular oligomer infusions. Oligomers failed to trigger eIF2α-P and cognitive impairment in PKR(-/-) and TNFR1(-/-) mice. Bolstering insulin signaling rescued phospho-PKR and eIF2α-P. Results reveal pathogenic mechanisms shared by AD and diabetes and establish that proinflammatory signaling mediates oligomer-induced IRS-1 inhibition and PKR-dependent synapse and memory loss.

Hematologic and hepatic responses of the freshwater fish Hoplias malabaricus after saxitoxin exposure.

The bioaccumulation of saxitoxins (STX) in the trophic chain, mainly in freshwater, are not completely known. This work aimed to elucidate the effects of STX on Hoplias malabaricus through trophic bioassay. The fish were fed once every five days with Astyanax sp. before being subjected to an intraperitoneal inoculation with the lysate of Cylindrospermopsis raciborskii culture containing 97% STX and 3% by neosaxitoxin and gonyautoxin during 20 days. The animal's liver was assessed using biomarkers as activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx), and concentrations of reduced glutathione (GSH) and lipoperoxidation (LPO) and protein carbonylation (PCO). In the blood was analyzed the genotoxic and hematological parameters. The hepatosomatic index and the relative condition factor did not show a significant difference between the exposed and control groups. The values of mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin increased in the STX group. The hepatic tissue from both groups exhibited a typical pattern that have been already described for most teleost fish. The results suggested the generation of reactive oxygen species, with increased activity of GPx and concentrations of LPO and GSH; whereas the specific activity of SOD decreased. However, no changes were observed in the CAT, PCO, and DNA damage. Although the STX effects are known as neurotoxic, this cyanotoxin caused liver biochemical alterations that can be considered ecologically relevant.

Source correlation of biomarkers in a mangrove ecosystem on Santa Catarina Island in southern Brazil.

The relative distribution of several compounds identified in four samples of recently deposited sediments of the Itacorubi Mangrove located on the Santa Catarina Island, southern Brazil, was compared with similar data on compounds extracted from fresh leaves of three mangrove species (Avicennia schaueriana, the dominant species in the area, Rhizophora mangle and Laguncularia racemosa) and the Gramineae Spartinna alterniflora. Terpenols, previously identified in mangrove species in northern Brazil, were also found. A. schaueriana mainly contains ß-amyrin (90.6 µg g(-1) of extractable organic matter); low amounts of friedelin, betulin and germanicol were detected only in the leaf extract of this species. R. mangle also contained a significant amount of ß-amyrin and it was the only species where taraxerol was detected. In contrast to the leaves, sediment extracts were dominated by germanicol, α-amyrin and campesterol. Despite its chemical lability, betulin was also detected. Two homologous series of α and ω-hydroxy fatty acids were detected in the acid-alkaline fraction. In spite of being reported in the literature as components of terrigenous plants, saturated ω-hydroxy acids were not identified. Our results indicate that although triterpenols may be used as biomarkers for mangrove-derived organic matter, their relative distribution can change according to the region.

First report about saxitoxins in freshwater fish Hoplias malabaricus through trophic exposure.

Cyanobacterial waterblooms, such as the saxitoxin (STX) producer Cylindrospermopsis raciborskii, have been a worldwide concern in environmental health. However, the bioaccumulation of this neurotoxin in the trophic chain is not completely known. The aim of the present work was to evaluate STX bioaccumulation through chemical analyses and the toxic and trophic effects using biomarkers in the tropical freshwater fish Hoplias malabaricus. They were fed once every five days with Astyanax sp. before being subjected to intraperitoneal inoculation with STX extract (0.08 µg/100 g) obtained by lysis of toxic C. raciborskii strain (T3). After 20 days the brain was collected for acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH), lipoperoxidation (LPO), protein carbonylation (PCO), and comet assay analysis. The muscle was collected for STX chemical analysis. The activities of SOD and concentrations of PCO and LPO increased. The CAT, GST, and GPx activities decreased. Genotoxicity was observed in the experimental group. STX was not detected in muscle samples. Thus, an oxidative stress was observed in the brain, leading to the damage of lipids, proteins, and DNA. The mechanism of action of the neurotoxin in this subchronic exposure suggests an apoptotic cellular process.

Glargine vs. NPH insulin therapy in pregnancies complicated by diabetes: an observational cohort study.

AIMS: The effects of glargine insulin therapy in pregnancies are not well established. We compared maternal and neonatal outcomes of women with pregestational and gestational diabetes treated with glargine or NPH insulin. METHODS: A prospective cohort study was conducted analyzing outcomes from 56 women with pregestational and 82 with gestational diabetes treated with either insulin regimen. RESULTS: Comparisons were performed among 138 women: 56 with pregestational and 82 with gestational diabetes. In relation to maternal complications, worsening of retinopathy and nephropathy, preeclampsia, micro and macroalbuminuria, and all kinds of hypoglycemia were found higher in women with pregestational diabetes NPH-treated vs. glargine-treated. In women with gestational diabetes NPH-treated, it was observed increased incidence of prepregnancy and new-onset pregnancy hypertension, micro and macroalbuminuria, as well as mild and frequent hypoglycemia, compared to glargine-treated. Among the neonatal outcomes, 1-min Apgar score <7, necessity of intensive care unit and fetal death in pregestational, while jaundice and congenital malformations in gestational diabetes, respectively, were more frequently observed in infants born to NPH-treated, compared to glargine-treated. CONCLUSIONS: Glargine use during pregnancy from preconception through delivery, showed to be safe since it is associated with decreased maternal and neonatal adverse outcomes compared with NPH insulin-treated patients.

Partitioning of caseinomacropeptide in aqueous two-phase systems.

This study evaluates the influence of type of salt and temperature on the partition coefficient of caseinomacropetide (CMP) to determine the best conditions for the recovery of CMP in aqueous two-phase systems (ATPS) composed by poly(ethylene glycol) (PEG) 1500 and an inorganic salt (potassium phosphate, sodium citrate, lithium sulfate or sodium sulfate). In all systems, CMP presented affinity for the PEG-rich phase. The PEG1500+lithium sulfate showed the highest values of partitioning coefficient. In addition, thermodynamic parameters (DeltaH degrees , DeltaS degrees , DeltaG degrees) as a function of temperature, were calculated for the system PEG1500-sodium citrate at different PEG concentrations and the results imply thermodynamic differences between partitioning of CMP in this system.

Avaliação do pico de pressão e da freqüência respiratória durante o uso de balão auto-inflável em um modelo de pulmão neonatal / Evaluation of peak inspiratory pressure and respiratory rate during ventilation of an infant lung model with a self-inflating bag

OBJETIVO: Avaliar o pico de pressão inspiratória e a freqüência ventilatória obtidos por médicos quando da utilização de balão auto-inflável neonatal em modelo de pulmão. MÉTODOS: Quinze médicos ventilaram simuladores de pulmão de recém-nascidos a termo e pré-termo, sendo os desfechos captados através de um monitor de ventilação. RESULTADOS: As medianas dos picos de pressão foram 23 (intervalo interquartil, 15-47) e 26 (intervalo interquartil, 14-51) cmH2O, sendo menor que 20 em 41,2 e 35,8 por cento das vezes; maior que 40 em 29,7 e 33,6 por cento das vezes e entre 27 e 33 cmH2O em 8,2 e 6,5 por cento das vezes, para o pulmão de termo e de pré-termo, respectivamente. As medianas das freqüências ventilatórias foram de 45 (intervalo interquartil, 36-57) e 48 (intervalo interquartil, 39-55,5) ciclos por minuto, sendo menor que 30 em 9,3 e 6,7 por cento das vezes e maior que 60 em 12 e 13,3 por cento das vezes, respectivamente, para o pulmão de termo e de pré-termo. As diferenças nas medianas não foram estatisticamente significantes. CONCLUSÃO: A ventilação utilizando o balão auto-inflável promoveu adequação para a freqüência ventilatória em aproximadamente 80 por cento das vezes, e os médicos não conseguiram promover ventilação com mínima variabilidade na pressão, alcançando níveis diferentes daqueles definidos no curso de reanimação neonatal em 70 por cento das vezes. Essa situação independeu da ventilação do pulmão-teste análogo ao sistema respiratório de recém-nascidos a termo ou pré-termo.

OBJECTIVE: To evaluate the peak inspiratory pressure and ventilation rate achieved by physicians when using a neonatal self-inflating bag on a lung model. METHODS: Fifteen physicians ventilated full term and preterm infant lung simulators while the outcomes were captured by a ventilation monitor. RESULTS: Median peak pressures in cmH2O for full term and preterm lungs were 23 (interquartile range: 15-47) and 26 (interquartile range: 14-51), being less than 20 in 41.2 and 35.8 percent of the pressure curves analyzed, more than 40 in 29.7 and 33.6 percent, and between 27 and 33 cmH2O in 8.2 and 6.5 percent of the curves, respectively. Median ventilation rates were 45 (interquartile range: 36-57) and 48 (interquartile range: 39-55.5) cycles per minute, being more than 30 in 9.3 and 6.7 percent of pressure curves and more than 60 in 12 and 13.3 percent of pressure curves, for the full term and preterm lungs, respectively. The differences between these medians were not statistically significant. CONCLUSIONS: Ventilation rates achieved with the self-inflating bag were adequate in approximately 80 percent of pressure curves analyzed, but the physicians were unable to provide ventilation with minimal pressure variation, producing pressures that diverged from those defined by the neonatal resuscitation training course in 70 percent of the curves. This was irrespective of whether they were ventilating the lung model analogous to preterm or full term infant lungs.

Evaluation of peak inspiratory pressure and respiratory rate during ventilation of an infant lung model with a self-inflating bag.

OBJECTIVE: To evaluate the peak inspiratory pressure and ventilation rate achieved by physicians when using a neonatal self-inflating bag on a lung model. METHODS: Fifteen physicians ventilated full term and preterm infant lung simulators while the outcomes were captured by a ventilation monitor. RESULTS: Median peak pressures in cmH(2)O for full term and preterm lungs were 23 (interquartile range: 15-47) and 26 (interquartile range: 14-51), being less than 20 in 41.2 and 35.8% of the pressure curves analyzed, more than 40 in 29.7 and 33.6%, and between 27 and 33 cmH(2)O in 8.2 and 6.5% of the curves, respectively. Median ventilation rates were 45 (interquartile range: 36-57) and 48 (interquartile range: 39-55.5) cycles per minute, being more than 30 in 9.3 and 6.7% of pressure curves and more than 60 in 12 and 13.3% of pressure curves, for the full term and preterm lungs, respectively. The differences between these medians were not statistically significant. CONCLUSIONS: Ventilation rates achieved with the self-inflating bag were adequate in approximately 80% of pressure curves analyzed, but the physicians were unable to provide ventilation with minimal pressure variation, producing pressures that diverged from those defined by the neonatal resuscitation training course in 70% of the curves. This was irrespective of whether they were ventilating the lung model analogous to preterm or full term infant lungs.

Evaluation of peak inspiratory pressure, tidal volume and respiratory rate during ventilation of premature lambs using a self-inflating bag.

OBJECTIVE: To evaluate the peak inspiratory pressure, tidal volume and respiratory rate achieved during manual ventilation of premature lambs, using a self-inflating bag. METHODS: In this descriptive, experimental study, five pairs of physicians, selected at random among 35 neonatologists working at a neonatal intensive care unit and with experience in the resuscitation of newborn infants, ventilated five intubated premature lambs using a self-inflating bag. Pressure and flow monitor signals were passed through a transducer and digitized for recording and analysis. Tidal volume and pressure curves were obtained from the integral of flow rate, at peak, during the last 50 seconds of every fifth minute, and analyzed. RESULTS: Median pressure was 39.8 (IQ(25-75%) 30.2-47.2) cmH(2)O; being below 20 in 1.1% of cases and above 40 in 49.1%. Seven out of 10 physicians produced more than six pressure peaks of over 40 cmH(2)O. Median tidal volume/kg was 17.8 (IQ(25-75%) 14.1-22.4) mL, being below 5 mL in 0.1% of cases and greater than or equal to 20 mL in 37.7%. All of the physicians propelled five or more ventilation cycles with tidal volume/kg of 20 mL or more. Respiratory rate was between 30 and 60 cycles/minute in 65.9% of cases, being below 30 in 6.8% of cases and over 60 in 27.3% of cases. CONCLUSIONS: There was major variation in peak inspiratory pressure and tidal volume/kg values, which were in many cases elevated, attaining levels that habitually cause biotrauma, while respiratory rates were adequate in the majority of cases.

Evaluation of peak inspiratory pressure, tidal volume and respiratory rate during ventilation of premature lambs using a self-inflating bag

OBJETIVO: Avaliar o pico de pressão inspiratória, o volume corrente e a freqüência respiratória obtidos durante ventilação manual de carneiros prematuros, utilizando balão auto-inflável. MÉTODOS: Estudo experimental descritivo em que cinco duplas de médicos selecionados aleatoriamente entre 35 neonatologistas que trabalham em unidade de terapia intensiva neonatal e experientes em reanimação de recém-nascidos ventilaram cinco carneiros prematuros intubados, utilizando balão auto-inflável. Os sinais de pressão e fluxo eram captados, convertidos por meio de transdutores e digitalizados para armazenamento e análise. Foram avaliadas curvas de pressão e de volume corrente, este a partir da integral do fluxo, em suas medidas de pico, nos 50 segundos finais de cada 5 minutos. RESULTADOS: A mediana da pressão foi de 39,8 (IQ25-75 por cento 30,2-47,2) cmH2O; foi menor que 20 em 1,1 por cento das vezes e maior que 40 em 49,1 por cento. Sete em 10 médicos propiciaram mais de seis picos de pressão maiores que 40 cmH2O. A mediana do volume corrente/kg foi de 17,8 (IQ25-75 por cento 14,1-22,4) mL, sendo menor que 5 mL em 0,1 por cento das vezes e igual ou maior que 20 mL em 37,7 por cento. Todos os médicos impuseram cinco ou mais ciclos ventilatórios com volume corrente/kg de 20 mL ou mais. A freqüência situou-se entre 30 e 60 ciclos/minuto em 65,9 por cento das vezes, sendo menor que 30 em 6,8 por cento e maior que 60 em 27,3 por cento das vezes. CONCLUSÃO: Ocorreu grande variabilidade nos valores do pico de pressão inspiratória e do volume corrente/kg, sendo muitas vezes elevados e alcançando níveis indutores de biotrauma; para a freqüência respiratória, os valores foram adequados na maioria das vezes.

OBJECTIVE: To evaluate the peak inspiratory pressure, tidal volume and respiratory rate achieved during manual ventilation of premature lambs, using a self-inflating bag. METHODS: In this descriptive, experimental study, five pairs of physicians, selected at random among 35 neonatologists working at a neonatal intensive care unit and with experience in the resuscitation of newborn infants, ventilated five intubated premature lambs using a self-inflating bag. Pressure and flow monitor signals were passed through a transducer and digitized for recording and analysis. Tidal volume and pressure curves were obtained from the integral of flow rate, at peak, during the last 50 seconds of every fifth minute, and analyzed. RESULTS: Median pressure was 39.8 (IQ25-75 percent 30.2-47.2) cmH2O; being below 20 in 1.1 percent of cases and above 40 in 49.1 percent. Seven out of 10 physicians produced more than six pressure peaks of over 40 cmH2O. Median tidal volume/kg was 17.8 (IQ25-75 percent 14.1-22.4) mL, being below 5 mL in 0.1 percent of cases and greater than or equal to 20 mL in 37.7 percent. All of the physicians propelled five or more ventilation cycles with tidal volume/kg of 20 mL or more. Respiratory rate was between 30 and 60 cycles/minute in 65.9 percent of cases, being below 30 in 6.8 percent of cases and over 60 in 27.3 percent of cases. CONCLUSIONS: There was major variation in peak inspiratory pressure and tidal volume/kg values, which were in many cases elevated, attaining levels that habitually cause biotrauma, while respiratory rates were adequate in the majority of cases.