RESUMO
Obesity is a multifactorial disease with genetic, social, and environmental influences. This study aims at analyzing the effects of the combination of a refined carbohydrate diet and exposure to hyperoxia on the pulmonary oxidative and inflammatory response in mice. Twenty-four mice were divided into four groups: control group (CG), hyperoxia group (HG), refined carbohydrate diet group (RCDG), and refined carbohydrate diet + hyperoxia group (RCDHG). The experimental diet was composed of 10% sugar, 45% standard diet, and 45% sweet condensed milk. For 24 hours, the HG and RCDHG were exposed to hyperoxia and the CG and RCDG to ambient air. After the exposures were completed, the animals were euthanized, and blood, bronchoalveolar lavage fluid, and lungs were collected for analyses. The HG showed higher levels of interferon-γ in adipose tissue as compared to other groups and higher levels of interleukin-10 and tumor necrosis factor-α compared to the CG and RCDHG. SOD and CAT activities in the pulmonary parenchyma decreased in the RCDHG as compared to the CG. There was an increase of lipid peroxidation in the HG, RCDG, and RCDHG as compared to the CG. A refined carbohydrate diet combined with hyperoxia promoted inflammation and redox imbalance in adult mice.
Assuntos
Carboidratos da Dieta/efeitos adversos , Hiperóxia/patologia , Adipócitos/patologia , Adiposidade/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Glicemia/metabolismo , Líquido da Lavagem Broncoalveolar/citologia , Contagem de Células , Colesterol/metabolismo , Epididimo/efeitos dos fármacos , Epididimo/patologia , Comportamento Alimentar , Hiperóxia/sangue , Imunoensaio , Inflamação/patologia , Leptina/sangue , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Camundongos Endogâmicos BALB C , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacosRESUMO
BACKGROUND: Donor smoking history and higher fraction of inspired oxygen (FIO2) at reperfusion are associated with primary graft dysfunction (PGD) after lung transplantation. We hypothesized that oxidative injury biomarkers would be elevated in PGD, with higher levels associated with donor exposure to cigarette smoke and recipient hyperoxia at reperfusion. METHODS: We performed a nested case-control study of 72 lung transplant recipients from the Lung Transplant Outcomes Group cohort. Using mass spectroscopy, F2-isoprostanes and isofurans were measured in plasma collected after transplantation. Cases were defined in 2 ways: grade 3 PGD present at day 2 or day 3 after reperfusion (severe PGD) or any grade 3 PGD (any PGD). RESULTS: There were 31 severe PGD cases with 41 controls and 35 any PGD cases with 37 controls. Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (28.6 pg/ml vs 19.8 pg/ml, p = 0.03). Plasma F2-isoprostane levels were higher in severe PGD cases compared with controls (29.6 pg/ml vs 19.0 pg/ml, p = 0.03) among patients reperfused with FIO2 >40%. Among recipients of lungs from donors with smoke exposure, plasma F2-isoprostane (38.2 pg/ml vs 22.5 pg/ml, p = 0.046) and isofuran (66.9 pg/ml vs 34.6 pg/ml, p = 0.046) levels were higher in severe PGD compared with control subjects. CONCLUSIONS: Plasma levels of lipid peroxidation products are higher in patients with severe PGD, in recipients of lungs from donors with smoke exposure, and in recipients exposed to higher Fio2 at reperfusion. Oxidative injury is an important mechanism of PGD and may be magnified by donor exposure to cigarette smoke and hyperoxia at reperfusion.
Assuntos
Hiperóxia/sangue , Transplante de Pulmão/efeitos adversos , Complicações Pós-Operatórias , Disfunção Primária do Enxerto/sangue , Traumatismo por Reperfusão/complicações , Fumar/efeitos adversos , Adulto , Biomarcadores/sangue , Feminino , Seguimentos , Humanos , Hiperóxia/etiologia , Peroxidação de Lipídeos , Masculino , Disfunção Primária do Enxerto/etiologia , Traumatismo por Reperfusão/sangue , Estudos Retrospectivos , Fatores de Tempo , Doadores de TecidosRESUMO
OBJECTIVE: To assess if monitoring of cerebral regional tissue oxygen saturation (crSO2) using near-infrared spectroscopy (NIRS) to guide respiratory and supplemental oxygen support reduces burden of cerebral hypoxia and hyperoxia in preterm neonates during resuscitation after birth. STUDY DESIGN: Preterm neonates <34(+0) weeks of gestation were included in a prospective randomized controlled pilot feasibility study at 2 tertiary level neonatal intensive care units. In a NIRS-visible group, crSO2 monitoring in addition to pulse oximetry was used to guide respiratory and supplemental oxygen support during the first 15 minutes after birth. In a NIRS-not-visible group, only pulse oximetry was used. The primary outcomes were burden of cerebral hypoxia (<10th percentile) or hyperoxia (>90th percentile) measured in %minutes crSO2 during the first 15 minutes after birth. Secondary outcomes were all cause of mortality and/or cerebral injury and neurologic outcome at term age. Allocation sequence was 1:1 with block-randomization of 30 preterm neonates at each site. RESULTS: In the NIRS-visible group burden of cerebral hypoxia in %minutes, crSO2 was halved, and the relative reduction was 55.4% (95% CI 37.6-73.2%; P = .028). Cerebral hyperoxia was observed in NIRS-visible group in 3 neonates with supplemental oxygen and in NIRS-not-visible group in 2. Cerebral injury rate and neurologic outcome at term age was similar in both groups. Two neonates died in the NIRS-not-visible group and none in the NIRS-visible group. No severe adverse reactions were observed. CONCLUSIONS: Reduction of burden of cerebral hypoxia during immediate transition and resuscitation after birth is feasible by crSO2 monitoring to guide respiratory and supplemental oxygen support. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02017691.
Assuntos
Circulação Cerebrovascular/fisiologia , Hiperóxia/prevenção & controle , Hipóxia Encefálica/prevenção & controle , Recém-Nascido Prematuro , Monitorização Fisiológica/métodos , Oxigenoterapia , Estudos de Viabilidade , Feminino , Humanos , Hiperóxia/sangue , Hipóxia Encefálica/sangue , Lactente , Mortalidade Infantil , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Oximetria/métodos , Oxigênio/sangue , Projetos Piloto , Estudos Prospectivos , Ressuscitação , Espectroscopia de Luz Próxima ao Infravermelho , Fatores de TempoRESUMO
Although assist ventilation with FIO2 0.21 is the preferable mode of ventilation in the intensive care unit, sometimes controlled ventilation with hyperoxia is needed. But the impact of this setting has not been extensively studied in elderly subjects. We hypothesized that a high fraction of inspired oxygen (FiO(2)) and controlled mechanical ventilation (CMV) is associated with greater deleterious effects in old compared to adult subjects. Adult and old rats were submitted to CMV with low tidal volume (6 ml/kg) and FiO(2) 1 during 3 or 6 h. Arterial blood gas samples were measured at 0, 60 and 180 min (four groups: old and adult rats, 3 or 6 h of CMV), and additionally at 360 min (two groups: old and adult rats, 6 h of CMV). Furthermore, total protein content (TPC) and tumor necrosis factor-alpha (TNF-α) in bronchoalveolar lavage were assessed; lung tissue was used for malondialdehyde and histological analyses, and the diaphragm for measurement of contractile function. Arterial blood gas analysis showed an initial (60 min) greater PaO(2) in elderly versus adult animals; after that time, elderly animals had lowers pH and PaO(2), and greater PaCO(2). After 3 h of CMV, TPC and TNF-α levels were higher in the old compared with the adult group (P < 0.05). After 6 h of MV, malondialdehyde was significantly higher in elderly compared with the adult animals (P < 0.05). Histological analysis showed leukocyte infiltration and edema, greater in old animals. In diaphragm, twitch contraction with caffeine significantly declined after 6 h of CMV only for the elderly group. These data support the hypothesis that relatively short-term CMV with low tidal volume and hyperoxia has greatest impact in elderly rats, decreasing diaphragmatic contractile function and increasing lung inflammation.
Assuntos
Diafragma/fisiopatologia , Hiperóxia/complicações , Pulmão/fisiopatologia , Pneumonia Associada à Ventilação Mecânica/etiologia , Respiração Artificial/efeitos adversos , Fatores Etários , Animais , Gasometria , Líquido da Lavagem Broncoalveolar/química , Modelos Animais de Doenças , Hiperóxia/sangue , Hiperóxia/imunologia , Hiperóxia/patologia , Hiperóxia/fisiopatologia , Mediadores da Inflamação/metabolismo , Pulmão/imunologia , Pulmão/patologia , Masculino , Malondialdeído/metabolismo , Contração Muscular , Pneumonia Associada à Ventilação Mecânica/sangue , Pneumonia Associada à Ventilação Mecânica/imunologia , Pneumonia Associada à Ventilação Mecânica/patologia , Pneumonia Associada à Ventilação Mecânica/fisiopatologia , Ratos , Ratos Wistar , Fatores de Risco , Volume de Ventilação Pulmonar , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
As complicações neurológicas representam importante causa de morbidade no período pós-operatório de cirurgia cardíaca e sua incidência alcança até 75% dos pacientes. Uma importante causa desses eventos é a formação de microbolhas na corrente sanguínea durante a circulação extracorpórea. Realizou-se revisão integrativa sobre microembolia gasosa na circulação extracorpórea. Esse trabalho analisou estudos com abordagens metodológicas diferentes, mas que contemplam o tema. O resultado sugere que a desnitrogenação do sangue causada pela hiperoxia dissolve microbolhas formadas no sangue e o shunt venoarterial pode equilibrar os parâmetros respiratórios alterados pela hiperoxia.
Neurological complications are an important cause of morbidity in the postoperative period of cardiac surgery and its incidence reaches up to 75% of patients. An important cause of these events is the formation of microbubbles in the bloodstream during cardiopulmonary bypass. Integrative review was carried out on gaseous microemboli in cardiopulmonary bypass. This study analyzed studies with different methodological approaches, but that address the issue. The result suggests the denitrogenation of blood by hyperoxia dissolved microbubbles in the blood and venoarterial shunt can balance the respiratory parameters changed with hyperoxia.
Assuntos
Humanos , Derivação Arteriovenosa Cirúrgica/métodos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Embolia Aérea/prevenção & controle , Oxigenação por Membrana Extracorpórea/métodos , Embolia Aérea/etiologia , Hemodinâmica , Hiperóxia/sangueRESUMO
BACKGROUND: The rate of change (Δ) in cerebral oxygenation (COx) during exercise is influenced by blood flow and arterial O(2) content (CaO(2)). It is currently unclear whether ΔCOx would (i) be impaired during exercise in patients with chronic obstructive pulmonary disease (COPD) who do not fulfil the current criteria for long-term O(2) therapy but present with exercise-induced hypoxaemia and (ii) improve with hyperoxia (FIO(2) = 0·4) in this specific sub-population. METHODS: A total of 20 non-hypercapnic men (FEV(1) = 47·2 ± 11·5% pred) underwent incremental cycle ergometer exercise tests under normoxia and hyperoxia with ΔCOx (fold-changes from unloaded exercise in O(2)Hb) being determined by near-infrared spectroscopy. Pulse oximetry assessed oxyhaemoglobin saturation (SpO(2)), and impedance cardiography estimated changes in cardiac output (ΔQT). RESULTS: Peak work rate and ΔCOx in normoxia were lower in eight O(2) 'desaturators' compared with 12 'non-desaturators' (P < 0·05). Area under ΔCOx during sub-maximal exercise was closely related to SpO(2) decrements in 'desaturators' (r = 0·92, P < 0·01). These patients showed the largest improvement in peak exercise capacity with hyperoxia (P < 0·05). Despite a trend to lower sub-maximal ΔQT and mean arterial pressure with active intervention, ΔCOx was significantly improved only in this group (0·57 ± 0·20 versus 2·09 ± 0·42 for 'non-desaturators' and 'desaturators', respectively; P < 0·05). CONCLUSIONS: ΔCOx was impaired in non-hypoxaemic patients with COPD who desaturated during exercise. Hyperoxic breathing was able to correct for these abnormalities, an effect related to enhanced CaO(2) rather than improved central haemodynamics. This indicates that O(2) supplementation ameliorates exercise COx in patients with COPD who are not currently entitled to ambulatory O(2) therapy.
Assuntos
Encéfalo/metabolismo , Exercício Físico , Hiperóxia/terapia , Consumo de Oxigênio , Oxigenoterapia/métodos , Oxigênio/sangue , Doença Pulmonar Obstrutiva Crônica/terapia , Idoso , Análise de Variância , Ciclismo , Encéfalo/irrigação sanguínea , Brasil , Cardiografia de Impedância , Circulação Cerebrovascular , Método Duplo-Cego , Teste de Esforço , Volume Expiratório Forçado , Hemodinâmica , Humanos , Hiperóxia/sangue , Hiperóxia/fisiopatologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Oximetria , Oxiemoglobinas/metabolismo , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Espectroscopia de Luz Próxima ao Infravermelho , Espirometria , Resultado do TratamentoRESUMO
Neurological complications are an important cause of morbidity in the postoperative period of cardiac surgery and its incidence reaches up to 75% of patients. An important cause of these events is the formation of microbubbles in the bloodstream during cardiopulmonary bypass. Integrative review was carried out on gaseous microemboli in cardiopulmonary bypass. This study analyzed studies with different methodological approaches, but that address the issue. The result suggests the denitrogenation of blood by hyperoxia dissolved microbubbles in the blood and venoarterial shunt can balance the respiratory parameters changed with hyperoxia.
Assuntos
Derivação Arteriovenosa Cirúrgica/métodos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Embolia Aérea/prevenção & controle , Oxigenação por Membrana Extracorpórea/métodos , Embolia Aérea/etiologia , Hemodinâmica , Humanos , Hiperóxia/sangueRESUMO
The South American lungfish (Lepidosiren paradoxa) has an arterial P(O(2)) (Pa(O(2))) as high as 70-100 mmHg, corresponding to Hb-O(2) saturations from 90% to 95%, which indicates a moderate cardiovascular right to left (R-L) shunt. In hyperoxia (50% O(2)), we studied animals in: (1) aerated water combined with aerial hyperoxia, which increased Pa(O(2)) from 78+/-2 to 114+/-3 mmHg and (2) and aquatic hyperoxia (50% O(2)) combined room air, which gradually increased Pa(O(2)) from 75+/-4 mmHg to as much as 146+/-10 mmHg. Further, the hyperoxia (50%) depressed pulmonary ventilation from 58+/-13 to 5.5+/-3.0 mLBTPSkgh(-1), and Pa(CO(2)) increased from 20+/-2 to 31+/-4 mmHg, while pHa became reduced from 7.56+/-0.03 to 7.31+/-0.09. At the same time, venous P(O(2)) (Pv(O(2))) rose from 40.0+/-2.3 to 46.4+/-1.2 mmHg and, concomitantly, Pv(CO(2)) increased from 23.2+/-1.1 to 32.2+/-0.5 mmHg. R-L shunts were estimated to about 19%, which is moderate when compared to most amphibians.