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1.
Clin Appl Thromb Hemost ; 25: 1076029619863495, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31298057

RESUMO

D-dimer might be correlated with prognosis in pulmonary embolism (PE). The predictive value of plasma D-dimer for disease severity and survival was investigated in the lowest and highest D-dimer quartile among 200 patients with PE. Patients with high D-dimers were significantly more often hypotensive (P = .001), tachycardic (P = .016), or hypoxemic (P = .001). Pulmonary arterial obstruction index (PAOI) values were significantly higher in the high D-dimer quartile (P < .001). Elevated troponin I (TNI) levels (P < .001), simplified PE severity indices ≥1 (P < .001), right-to-left ventricular (RV/LV) diameter ratios ≥1 (P < .001), and thrombolysis (P = .001) were more frequent in the high D-dimer quartile. D-dimer was associated with RV/LV ratios ≥1 (P = .021), elevated PAOI (P < .001) or TNI levels (P < .001), hypotension (P < .001), tachycardia (P = .003), and hypoxemia (P < .001), but not with long-term all-cause mortality. D-dimer predicts disease severity but not long-term prognosis in acute PE, possibly due to a more aggressive treatment strategy in severely affected patients.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Valor Preditivo dos Testes , Prognóstico , Embolia Pulmonar/diagnóstico , Doença Aguda , Idoso , Feminino , Humanos , Hipotensão/sangue , Hipóxia/sangue , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/sangue , Taquicardia/sangue
2.
Eur J Appl Physiol ; 119(9): 1959-1970, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31286240

RESUMO

PURPOSE: This study investigated the effects of repeated-sprint (RS) training in hypoxia induced by voluntary hypoventilation at low lung volume (RSH-VHL) on physiological adaptations, RS ability (RSA) and anaerobic performance. METHODS: Over a 3-week period, eighteen well-trained cyclists completed six RS sessions in cycling either with RSH-VHL or with normal conditions (RSN). Before (Pre) and after (Post) the training period, the subjects performed an RSA test (10 × 6-s all-out cycling sprints) during which oxygen uptake [Formula: see text] and the change in both muscle deoxyhaemoglobin (Δ[HHb]) and total haemoglobin (Δ[THb]) were measured. A 30-s Wingate test was also performed and maximal blood lactate concentration ([La]max) was assessed. RESULTS: At Post compared to Pre, the mean power output during both the RSA and the Wingate tests was improved in RSH-VHL (846 ± 98 vs 911 ± 117 W and 723 ± 112 vs 768 ± 123 W, p < 0.05) but not in RSN (834 ± 52 vs 852 ± 69 W, p = 0.2; 710 ± 63 vs 713 ± 72 W, p = 0.68). The average [Formula: see text] recorded during the RSA test was significantly higher in RSH-VHL at Post but did not change in RSN. No change occurred for Δ[THb] whereas Δ[HHb] increased to the same extent in both groups. [Lamax] after the Wingate test was higher in RSH-VHL at Post (13.9 ± 2.8 vs 16.1 ± 3.2 mmol L-1, p < 0.01) and tended to decrease in RSN (p = 0.1). CONCLUSIONS: This study showed that RSH-VHL could bring benefits to both RSA and anaerobic performance through increases in oxygen delivery and glycolytic contribution. On the other hand, no additional effect was observed for the indices of muscle blood volume and O2 extraction.


Assuntos
Adaptação Fisiológica/fisiologia , Hipoventilação/fisiopatologia , Hipóxia/fisiopatologia , Pulmão/fisiologia , Condicionamento Físico Humano/fisiologia , Adulto , Desempenho Atlético/fisiologia , Hemoglobinas/metabolismo , Humanos , Hipoventilação/sangue , Hipoventilação/metabolismo , Hipóxia/sangue , Hipóxia/metabolismo , Ácido Láctico/sangue , Pulmão/metabolismo , Masculino , Oxigênio/metabolismo , Consumo de Oxigênio/fisiologia
3.
Undersea Hyperb Med ; 46(1): 1-6, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31154680

RESUMO

Hypoxia is one of the main problems an underwater diver may have to face. The probability of experiencing hypoxia is related to the type of dive and the equipment used. Hypoxia in diving is a potentially fatal event for the diver, as it can lead to the loss of brain functions and consequently to the loss of breathing control, all in the absence of specific premonitory symptoms. It is a risk that may be encountered more frequently by divers who use a closed-circuit rebreather (CCR). For those who use this type of equipment, hypoxia is usually the most frequent cause of death [1]. Our study was aimed at the detection of peripheral oxygen saturation in order to identify, in the future, a preclinical hypoxic condition. We combined the use of pulse oximetry with two forehead sensors on an underwater diver subject who was using an electronic closed-circuit rebreather (ECCR). Despite the known limits of this method and the preliminary status of these findings [2], the recorded data show a clear validity in the use of pulse oximetry in immersion for the detection of peripheral oxygen saturation. In the future, the pulse oximeter could become part of the instrumentation of the diver who uses CCR gear. The device could easily be implemented in these rebreathers. The possibility of being able to perform a basic instrumental analysis means that the diver can become more quickly aware of imminent hypoxia, characterized by the absence of clearly identifiable warning symptoms, and can put in place all the correct procedures for an emergency ascent, avoiding serious consequences.


Assuntos
Mergulho/efeitos adversos , Desenho de Equipamento , Hipóxia/diagnóstico , Oximetria , Oxigênio/sangue , Adulto , Gasometria/instrumentação , Gasometria/métodos , Equipamentos para Diagnóstico , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Imersão , Masculino , Oximetria/instrumentação , Oximetria/métodos , Sintomas Prodrômicos , Água do Mar , Avaliação de Sintomas/instrumentação , Temperatura Ambiente
4.
Anim Reprod Sci ; 205: 88-93, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31047762

RESUMO

During sow parturition, there is need for an alternative uterotonic to oxytocin with less potency so piglets are not at risk of hypoxia and stillbirth. In this study, there was examination of carbetocin, a longer lasting analogue of oxytocin, and whether the lesser contractile force and duration resulting as a consequence of this treatment would improve piglet survivability. Following delivery of the first piglet, sows were serially assigned by parity to receive injections of 10 IU oxytocin (n = 35), 0.07 mg carbetocin (n = 36), or serve as a non-injected control (n = 30). The incidence of dystocia and stillbirths was recorded. To estimate liveborn piglet viability, umbilical cord blood samples were obtained from pigs 1, 2, 3 and 8, 9, 10, and lactate content was quantified to assess hypoxia during delivery. A blood sample collected at 24 h was assayed for total protein in plasma (%) as an indicator of colostrum intake. Treatment with oxytocin and carbetocin reduced farrowing duration (P = 0.023) and sows treated with carbetocin had piglets with the least umbilical cord blood lactate (P = 0.008) and plasma protein (P = 0.005) concentrations. These data indicate carbetocin has the efficacy to accelerate piglet delivery and reduce piglet hypoxia, although the reason for reduced plasma protein with this treatment remains unexplained.


Assuntos
Ocitocina/análogos & derivados , Ocitocina/farmacologia , Animais , Animais Recém-Nascidos , Feminino , Sangue Fetal/química , Hipóxia/sangue , Hipóxia/etnologia , Hipóxia/prevenção & controle , Hipóxia/veterinária , Ácido Láctico/sangue , Ocitócicos/farmacologia , Parto/efeitos dos fármacos , Gravidez , Suínos
5.
J Cardiothorac Surg ; 14(1): 89, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060627

RESUMO

BACKGROUND: One lung ventilation (OLV) is the technique used during lung resection surgery in order to facilitate optimal surgical conditions. OLV may result in hypoxemia due to the shunt created. Several techniques are used to overcome the hypoxemia, one of which is continuous positive airway pressure (CPAP) to the non-dependent lung. Another technique is ventilating the non-dependent lung with a minimal volume, thus creating differential lung ventilation (DLV). In this study we compared the efficacy of CPAP to DLV during video assisted thoracoscopic lung resection. PATIENTS AND METHOD: This is a prospective study of 30 adult patients undergoing elective video assisted thoracoscopic lung lobectomy. Each patient was ventilated in four modes: two lung ventilation, OLV, OLV + CPAP and OLV + DLV. Fifteen patients were ventilated with CPAP first and DLV next, and the other 15 were ventilated with DLV first and then CPAP. Five minutes separated each mode, during which the non-dependent lung was open to room air. We measured the patient's arterial blood gas during each mode of ventilation. The surgeons, who were blinded to the ventilation technique, were asked to assess the surgical conditions at each stage. RESULTS: Oxygenation during OLV+ CPAP was significantly lower that OLV + DLV (p = 0.018). There were insignificant alterations of pH, PCO2 and HCO3 during the different ventilating modes. The surgeons' assessments of interference in the field exposure between OLV + CPAP or OLV + DLV was found to be insignificant (p = 0.073). CONCLUSIONS: During OLV, DLV is superior to CPAP in improving patient's oxygenation, and may be used where CPAP failed. TRIAL REGISTRATION: ClinicalTrials.gov NCT03563612 . Registered 9 June 2018, retrospectively (due to clerical error).


Assuntos
Hipóxia/terapia , Ventilação Monopulmonar/métodos , Oxigênio/sangue , Procedimentos Cirúrgicos Pulmonares/métodos , Idoso , Gasometria , Pressão Positiva Contínua nas Vias Aéreas , Estudos Cross-Over , Feminino , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Masculino , Pessoa de Meia-Idade , Pneumonectomia , Estudos Prospectivos , Método Simples-Cego , Cirurgia Torácica Vídeoassistida
6.
Artigo em Inglês | MEDLINE | ID: mdl-31075501

RESUMO

Zebrafish (Danio rerio) are widely used animal models. Nevertheless, the mechanisms underlying hypoxia tolerance in this species have remained poorly understood. In the present study, we have determined the effects of hypoxia on blood-O2 transport properties and mitochondrial respiration rate in permeabilized muscle fibres of adult zebrafish exposed to either 1) a gradual decrease in O2 levels until fish lost equilibrium (~1 h, acute hypoxia), or 2) severe hypoxia (PO2 ∼ 15 Torr) for 48 h (prolonged hypoxia). Acute, short-term hypoxia caused an increase in hemoglobin (Hb) O2 affinity (decrease in P50), due to a decrease in erythrocyte ATP after erythrocyte swelling. No changes in isoHb expression patterns were observed between hypoxic and normoxic treatments. Prolonged hypoxia elicited additional reponses on O2 consumption: lactate accumulated in the blood, indicating that zebrafish relied on glycolysis for ATP production, and mitochondrial respiration of skeletal muscle was overall significantly inhibited. In addition, male zebrafish had higher hypoxia tolerance (measured as time to loss of equilibrium) than females. The present study contributes to our understanding of the adaptive mechanisms that allow zebrafish, and by inference other fish species, to cope with low O2 levels.


Assuntos
Hipóxia/sangue , Músculo Esquelético/metabolismo , Consumo de Oxigênio , Oxigênio/sangue , Peixe-Zebra/sangue , Animais , Transporte Biológico Ativo , Hemoglobinas/metabolismo , Proteínas de Peixe-Zebra/metabolismo
7.
Oxid Med Cell Longev ; 2019: 4093018, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31093313

RESUMO

Objective: Obstructive sleep apnea (OSA) is characterized by recurrent airway collapse that causes chronic intermittent hypoxia (CIH). OSA is associated with systemic inflammation and oxidative stress resulting in endothelial dysfunction and cardiovascular disease (CVD). Alpha lipoic acid (ALA) is a potent antioxidant with anti-inflammatory properties. We hypothesized that dietary ALA can improve endothelial function of mice exposed to CIH. Methods: Mice were exposed to either CIH or intermittent air (IA) and treated with dietary ALA (0.2% w/w) or a regular chow diet for 8 weeks. Endothelial function, endothelial nitric oxide (eNOS) uncoupling, systemic oxidative stress, systemic inflammation, aortic expression of inflammatory cytokines, and antioxidant enzymes were measured after 8 weeks. Results: Mice exposed to CIH exhibited endothelial dysfunction accompanied by systemic oxidative stress and inflammation as well as increased aortic expression of inflammatory cytokines. Furthermore, CIH led to eNOS uncoupling. Treatment with dietary ALA reversed endothelial dysfunction in mice exposed to CIH, lowered systemic oxidative stress and inflammation, prevented the increases of inflammatory cytokine gene expression, increased the expression of antioxidant enzymes, and preserved eNOS in a coupled state. Conclusion: ALA attenuates endothelial dysfunction by preventing oxidative stress and inflammation and restoring nitric oxide bioavailability in mice exposed to CIH. Our data suggests the potential beneficial use of ALA as adjunctive therapy in OSA.


Assuntos
Endotélio Vascular/fisiopatologia , Hipóxia/patologia , Hipóxia/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Ácido Tióctico/farmacologia , Aldeído Desidrogenase/metabolismo , Aldeídos/metabolismo , Animais , Arginina/análogos & derivados , Arginina/sangue , Biomarcadores/sangue , Biomarcadores/urina , Doença Crônica , Citocinas/genética , Citocinas/metabolismo , Endotélio Vascular/efeitos dos fármacos , Hipóxia/sangue , Hipóxia/urina , Inflamação/sangue , Inflamação/patologia , Inflamação/urina , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo III/metabolismo , Regulação para Cima/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
8.
PLoS Genet ; 15(4): e1007739, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30990817

RESUMO

Sleep disordered breathing (SDB)-related overnight hypoxemia is associated with cardiometabolic disease and other comorbidities. Understanding the genetic bases for variations in nocturnal hypoxemia may help understand mechanisms influencing oxygenation and SDB-related mortality. We conducted genome-wide association tests across 10 cohorts and 4 populations to identify genetic variants associated with three correlated measures of overnight oxyhemoglobin saturation: average and minimum oxyhemoglobin saturation during sleep and the percent of sleep with oxyhemoglobin saturation under 90%. The discovery sample consisted of 8,326 individuals. Variants with p < 1 × 10(-6) were analyzed in a replication group of 14,410 individuals. We identified 3 significantly associated regions, including 2 regions in multi-ethnic analyses (2q12, 10q22). SNPs in the 2q12 region associated with minimum SpO2 (rs78136548 p = 2.70 × 10(-10)). SNPs at 10q22 were associated with all three traits including average SpO2 (rs72805692 p = 4.58 × 10(-8)). SNPs in both regions were associated in over 20,000 individuals and are supported by prior associations or functional evidence. Four additional significant regions were detected in secondary sex-stratified and combined discovery and replication analyses, including a region overlapping Reelin, a known marker of respiratory complex neurons.These are the first genome-wide significant findings reported for oxyhemoglobin saturation during sleep, a phenotype of high clinical interest. Our replicated associations with HK1 and IL18R1 suggest that variants in inflammatory pathways, such as the biologically-plausible NLRP3 inflammasome, may contribute to nocturnal hypoxemia.


Assuntos
Hexoquinase/genética , Subunidade alfa de Receptor de Interleucina-18/genética , Oxiemoglobinas/metabolismo , Sono/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Moléculas de Adesão Celular Neuronais/genética , Biologia Computacional , Proteínas da Matriz Extracelular/genética , Feminino , Redes Reguladoras de Genes , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Hipóxia/sangue , Hipóxia/genética , Masculino , Pessoa de Meia-Idade , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteínas do Tecido Nervoso/genética , Oxigênio/sangue , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Serina Endopeptidases/genética , Síndromes da Apneia do Sono/sangue , Síndromes da Apneia do Sono/genética , Adulto Jovem
9.
High Alt Med Biol ; 20(1): 78-88, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30892968

RESUMO

AIM: High altitude exposure alters biochemical, metabolic, and physiological features of heart and skeletal muscles, and hence has pathological consequences in these tissues. Central to these hypoxia-associated biochemical/metabolic shuffling are energy deficit accumulation of free radicals and ensuing oxidative damage in the tissue. Recent preclinical/clinical studies indicate sphingosine-1-phosphate (S1P) axis, comprising S1P G protein coupled receptors (S1PR1-5) and its synthesizing enzyme-sphingosine kinase (SphK) to have key regulatory roles in homeostatic cardiac and skeletal muscle biology. In view of this, the aim of the present study was to chart the initiation and progression of biochemical/metabolic shuffling and assess the coincident differential modulation of S1PR(1-5) expression and total SphK activity in cardiac and skeletal muscles from rats exposed to progressive hypobaric hypoxia (HH; 21,000 feet for 12, 24, and 48 hours). RESULTS: HH-associated responses were evident as raised damage markers in plasma, oxidative stress, decreased total tissue protein, imbalance of intermediate metabolites, and aerobic/anaerobic enzyme activities in cardiac and skeletal muscles (gastrocnemius and soleus) culminating as energy deficit. CONCLUSION: Cardiac and gastrocnemius muscles were more susceptible to hypoxic environment than soleus muscle. These differential responses were directly and indirectly coincident with temporal expression of S1PR(1-5) and SphK activity.


Assuntos
Hipóxia/metabolismo , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Doença da Altitude/sangue , Doença da Altitude/metabolismo , Animais , Biomarcadores/sangue , Hipóxia/sangue , Lisofosfolipídeos/metabolismo , Oxirredução , Ratos , Ratos Sprague-Dawley , Esfingosina/análogos & derivados , Esfingosina/metabolismo
10.
PLoS One ; 14(2): e0211742, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30721271

RESUMO

Subjects with sleep apnea-hypopnea syndrome (SAHS) show an increased carotid intima-media thickness. However, no data exist about earlier markers of atheromatous disease, such as the proliferation and expansion of the adventitial vasa vasorum (VV) to the avascular intima in this setting. Our aim was to assess carotid VV density and its relationship with sleep parameters in a cohort of obese patients without prior vascular events. A total of 55 subjects evaluated for bariatric surgery were prospectively recruited. A non-attended respiratory polygraphy was performed. The apnea-hypopnea index (AHI) and the cumulative percentage of time spent with oxygen saturation below 90% (CT90) were assessed. Serum concentrations of soluble intercellular adhesion molecule 1, P-selectin, lipocalin-2 and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured. Contrast-enhanced carotid ultrasound was used to assess the VV density. Patients with SAHS (80%) showed a higher adventitial VV density (0.801±0.125 vs. 0.697±0.082, p = 0.005) and higher levels of sVCAM-1 (745.2±137.8 vs. 643.3±122.7 ng/ml, p = 0.035) than subjects with an AHI lower than 10 events/hour. In addition, a positive association exist between mean VV density and AHI (r = 0.445, p = 0.001) and CT90 (r = 0.399, p = 0.005). Finally, in the multiple linear regression analysis, female sex, fasting plasma glucose and AHI (but not CT90) were the only variables independently associated with the mean adventitial VV density (R2 = 0.327). In conclusion, a high VV density is present in obese subjects with SAHS, and chronic intermittent hypoxia is pointed as an independent risk factor for the development of this early step of atheromatous disease.


Assuntos
Túnica Adventícia/diagnóstico por imagem , Artérias Carótidas/efeitos dos fármacos , Hipóxia , Apneia Obstrutiva do Sono , Vasa Vasorum/diagnóstico por imagem , Rigidez Vascular , Adulto , Meios de Contraste/administração & dosagem , Feminino , Humanos , Hipóxia/sangue , Hipóxia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/diagnóstico por imagem
11.
J Bronchology Interv Pulmonol ; 26(2): 90-95, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30640825

RESUMO

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) coil treatment is an increasingly used treatment modality for selected severe emphysema patients in recent years. Emphysema causes dynamic hyperinflation, loss of elastic recoil, air trapping, and decreased exercise capacity in advanced stages. This process progresses over time, leading to hypoxic and hypercapnic respiratory failure. The goal of this study is to elucidate the effects of BLVR coil treatment on arterial blood gas parameters in severe emphysema patients with respiratory failure. METHODS: This is a retrospective study performed at a single pneumology center in Turkey. In total, this study included 39 patients diagnosed with severe emphysema who underwent bilateral BLVR coil treatment according to the general inclusion and exclusion criteria in the literature. The patients baseline and 12-month data were collected from medical records. RESULTS: Twelve months after BLVR coil treatment, significant improvements were observed in patients' pulmonary function tests, an increase in partial pressure of oxygen in arterial blood (PaO2) from 58.05±9.36 to 73.82±13.3 (P<0.000) and decrease in partial pressure of carbon dioxide in arterial blood (PaCO2) of hypercapnic patients (from 51.60±4.1 to 46.55±6.6 mm Hg; P=0.001). CONCLUSION: BLVR coil treatment is reliable and effective in emphysema patients who have hypoxic or mild hypercapnic respiratory failure. Besides improving lung function, BLVR coil treatment can significantly increase PaO2 and decrease PaCO2 in the medium term.


Assuntos
Broncoscopia/métodos , Pneumonectomia/métodos , Enfisema Pulmonar/cirurgia , Idoso , Idoso de 80 Anos ou mais , Gasometria , Dióxido de Carbono/sangue , Feminino , Humanos , Hipercapnia/sangue , Hipercapnia/etiologia , Hipóxia/sangue , Hipóxia/etiologia , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Pressão Parcial , Enfisema Pulmonar/sangue , Enfisema Pulmonar/complicações , Insuficiência Respiratória/sangue , Insuficiência Respiratória/etiologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento , Turquia
12.
Eur J Anaesthesiol ; 36(4): 279-289, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30664011

RESUMO

BACKGROUND: Rapid identification and treatment of tissue hypoxia reaching anaerobiosis (dysoxia) may reduce organ failure and the occurrence of major postoperative complications (MPC) after cardiac surgery. The predictive ability of PCO2-based dysoxia biomarkers, central venous-to-arterial PCO2 difference (ΔPCO2) and ΔPCO2 to arteriovenous oxygen content difference ratio, is poorly studied in this setting. OBJECTIVES: We evaluated the ability of PCO2-based tissue dysoxia biomarkers, blood lactate concentration and central venous oxygen saturation measured 2 h after admission to the ICU as predictors of MPC. DESIGN: A prospective, observational cohort study. SETTING: Single-centre, academic hospital cardiovascular ICU. PATIENTS: We included adult patients undergoing cardiac surgery with cardiopulmonary bypass and measured dysoxia biomarkers at ICU admission, and after 2, 6 and 24 h. MAIN OUTCOME MEASURES: The primary endpoint was MPC, a composite of cardiac and noncardiac MPC evaluated in the 48 h following surgery. After univariate analysis of MPC covariates including dysoxia biomarkers measured at 2 h, multivariate logistic regression analyses were performed to identify the association of these biomarkers with MPC for confounders. Areas under the receiver operating characteristic curves were determined for biomarkers which remained independently associated with MPC. RESULTS: MPC occurred in 56.5% of the 308 patients analysed. ΔPCO2, blood lactate concentration and central venous oxygen saturation measured at 2 h, but not ΔPCO2 to arteriovenous oxygen content difference ratio, were significantly associated with MPC. However, only ΔPCO2 was independently associated with MPC after multivariate analysis. The areas under the receiver operating characteristic curves of ΔPCO2 measured at 2 h for MPC prediction was 0.64 (95% CI 0.57 to 0.70, P < 0.001). CONCLUSION: After cardiac surgery with cardiopulmonary bypass, ΔPCO2 measured 2 h after ICU admission was the only dysoxia biomarker independently associated with MPC, but with limited performance. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03107572.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Hipóxia/sangue , Complicações Pós-Operatórias/diagnóstico , Idoso , Biomarcadores/sangue , Gasometria , Dióxido de Carbono/sangue , Feminino , Humanos , Hipóxia/etiologia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Prospectivos , Medição de Risco , Resultado do Tratamento
13.
Acta Ophthalmol ; 97(6): 567-576, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30690927

RESUMO

PURPOSE: To assess novel differences in serum levels of glucose, lactate and amino acids in patients with normal-tension glaucoma (NTG) compared to age-matched controls, at baseline and in response to universal hypoxia. METHODS: Twelve patients diagnosed with NTG and eleven control subjects underwent normobaric hypoxia for 2 hr. Peripheral venous blood samples were taken at baseline, during hypoxia and in the recovery phase. Serum glucose and lactate levels were measured by a blood gas analyser. Amino acids were analysed by high-performance liquid chromatography. RESULTS: Baseline levels of lactate and total amino acids were significantly lower in patients with NTG compared to healthy controls. No differences were seen in blood glucose levels between the two groups. Lactate levels remained unchanged during hypoxia in the control group, but increased in patients with NTG. In the recovery phase, total amino acid levels were reduced in the control group, whereas no changes were found in patients with NTG. CONCLUSION: Reduced serum levels of lactate and total amino acids were identified as potential markers for NTG. Moreover, significant differential regulatory patterns of certain amino acids were found in patients with NTG compared to control subjects. Overall, our results suggest a link between systemic energy metabolites and NTG and support a novel understanding of glaucoma as an inner retinal manifestation of a systemic condition.


Assuntos
Aminoácidos/sangue , Glicemia/metabolismo , Glaucoma/sangue , Hipóxia/sangue , Pressão Intraocular/fisiologia , Ácido Láctico/sangue , Idoso , Biomarcadores/sangue , Cromatografia Líquida de Alta Pressão , Feminino , Glaucoma/complicações , Glaucoma/fisiopatologia , Humanos , Hipóxia/complicações , Masculino , Estudos Retrospectivos
14.
Kidney Int ; 95(1): 173-177, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30522768

RESUMO

The production of erythropoietin (Epo) is modulated by renal tissue oxygen tension, which in principle depends on both arterial oxygen content (CaO2) and arterial oxygen tension (PaO2). Uncontrolled observational studies suggest that alterations in CaO2 fundamentally regulate Epo synthesis. We sought to establish whether reduced CaO2 enhances plasma Epo concentration independently of PaO2. In a blinded crossover study, 8 healthy young subjects were exposed to three conditions: room air (normoxia); 11% oxygen balanced in nitrogen, which lowers both CaO2 and PaO2 (hypoxia); and carbon monoxide plus normoxia, which decreases CaO2 to the same degree as hypoxia while preserving PaO2 (hypoxemia). Arterial blood samples were obtained prior to and throughout the 5 hours of exposure to each condition. In the hypoxic conditions, average CaO2 was reduced to similar levels, whereas PaO2 was only decreased with exposure to hypoxia. Plasma Epo concentration was increased in both hypoxic conditions relative to normoxia after 150 min of exposure and was augmented more than two-fold after 300 min, with no difference between hypoxic conditions. Reduced CaO2 induces similar increases in circulating Epo concentration irrespective of PaO2 manipulation, demonstrating that CaO2 is the critical variable regulating Epo production.


Assuntos
Artérias/metabolismo , Eritropoetina/metabolismo , Hipóxia/sangue , Rim/metabolismo , Oxigênio/sangue , Adulto , Gasometria , Monóxido de Carbono/sangue , Estudos Cross-Over , Eritropoetina/sangue , Voluntários Saudáveis , Humanos , Hipóxia/diagnóstico , Rim/irrigação sanguínea , Masculino , Consumo de Oxigênio , Adulto Jovem
15.
Am J Physiol Lung Cell Mol Physiol ; 316(1): L114-L118, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30335497

RESUMO

A new noninvasive method was used to measure the impairment of pulmonary gas exchange in 34 patients with lung disease, and the results were compared with the traditional ideal alveolar-arterial Po2 difference (AaDO2) calculated from arterial blood gases. The end-tidal Po2 was measured from the expired gas during steady-state breathing, the arterial Po2 was derived from a pulse oximeter if the SpO2 was 95% or less, which was the case for 23 patients. The difference between the end-tidal and the calculated Po2 was defined as the oxygen deficit. Oxygen deficit was 42.7 mmHg (SE 4.0) in this group of patients, much higher than the means previously found in 20 young normal subjects measured under hypoxic conditions (2.0 mmHg, SE 0.8) and 11 older normal subjects (7.5 mmHg, SE 1.6) and emphasizes the sensitivity of the new method for detecting the presence of abnormal gas exchange. The oxygen deficit was correlated with AaDO2 ( R2 0.72). The arterial Po2 that was calculated from the noninvasive technique was correlated with the results from the arterial blood gases ( R2 0.76) and with a mean bias of +2.7 mmHg. The Pco2 was correlated with the results from the arterial blood gases (R2 0.67) with a mean bias of -3.6 mmHg. We conclude that the oxygen deficit as obtained from the noninvasive method is a very sensitive indicator of impaired pulmonary gas exchange. It has the advantage that it can be obtained within a few minutes by having the patient simply breathe through a tube.


Assuntos
Oximetria , Oxigênio/sangue , Troca Gasosa Pulmonar , Adulto , Dióxido de Carbono/sangue , Feminino , Humanos , Hipóxia/sangue , Masculino
16.
Drug Chem Toxicol ; 42(3): 321-327, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30426789

RESUMO

Methyl isocyanate (MIC) is a highly toxic industrial chemical causing acute lethality after inhalation. The objective of this study was to determine whether alterations in hemostasis also occur in the immediate hours after exposure. Male rats were exposed to MIC (125-500 ppm) by nose-only vapor inhalation for 30 min. Arterial O2 saturation was monitored prior to exposure, and hourly thereafter. Rats were euthanized at 1, 2, 4, and 8 hr and plasma analyzed for recalcification clotting time, tissue factor (TF) activity, and protein levels. Hypoxemia, as assessed by pulse oximetry, was an early feature of MIC inhalation. In contrast to sham or low (125 ppm) concentrations, 250 and 500 ppm MIC caused significant declines in blood oxygen saturation (% SpO2) at 1 hr, which remained at deficit during the postexposure period. Commensurate with hypoxemia, plasma clotting time was significantly accelerated 1 hr after MIC inhalation (sham treatment: 955 ± 62.8 s; 125 ppm MIC: 790 ± 62 s; 250 ppm: 676 ± 28.0 s; 500 ppm: 581 ± 175 s). This procoagulant effect was transient, with no difference observed between sham and all MIC groups by 8 hr. Similarly, elevated TF activity and protein were detected in plasma 1 hr after MIC inhalation, each of which showed a progressive decline back to control levels at later timepoints. This study demonstrates that MIC inhalation resulted in hypoxemia and transient hypercoagulability of blood. Accelerated clotting occurred rapidly and was likely due to intravascular TF, which initiates the extrinsic coagulation pathway.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Exposição por Inalação/efeitos adversos , Isocianatos/toxicidade , Tromboplastina/metabolismo , Animais , Relação Dose-Resposta a Droga , Hipóxia/sangue , Hipóxia/induzido quimicamente , Masculino , Oxigênio/sangue , Ratos , Ratos Sprague-Dawley
17.
Lung ; 197(1): 67-72, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30474708

RESUMO

PURPOSE: There is clinical significance to a delay in response time for detecting desaturation by pulse oximetry. Our aim in this study was to compare the response time of the reflectance and transmittance saturation probes during fiberoptic bronchoscopy (FOB) under monitored anesthesia care. METHODS: A prospective study included 104 patients scheduled for FOB. Patients were monitored with transmittance (finger) and reflectance (ear) oximetry probes. The response time was evaluated during desaturation and resaturation. We also acquired blood tests for arterial oxygen saturation to assess the agreement with the oximetry probes. RESULTS: Ninety patients had a desaturation episode during FOB and were included in the final analysis. Mean time difference between the reflectance ear probe (reference probe) and transmittance finger probe for the detection of desaturation (SpO2 = 90%) was + 36 s (CI 27.0-45.0, P < 0.001). The time difference between probes at end of desaturation episode (SpO2 = 95%) was + 31 s (CI 19.0-43.0; P < 0.001). A significant difference in response time was evident throughout the episode in all saturation values. The reflectance ear probe showed better agreement with arterial blood gases. The bias (and precision) for the earlobe and finger oximeters were of 0.24 (1.04) and 2.31 (3.37), respectively. CONCLUSION: The data displayed by a centrally located reflectance probe are more accurate and allows for earlier identification, treatment, and resolution of desaturation events. In light of these data and the added value of the reflectance probe ability to measure transcutaneous PCO2, we recommend monitoring bronchoscopy by a reflectance oximetry probe.


Assuntos
Broncoscopia/métodos , Orelha/irrigação sanguínea , Tecnologia de Fibra Óptica , Dedos/irrigação sanguínea , Hipóxia/diagnóstico , Monitorização Intraoperatória/métodos , Oximetria/instrumentação , Oxigênio/sangue , Transdutores , Adulto , Idoso , Biomarcadores/sangue , Broncoscopia/efeitos adversos , Desenho de Equipamento , Feminino , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Hipóxia/terapia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo
18.
Funct Integr Genomics ; 19(1): 205-215, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30341547

RESUMO

High altitude (HA) is associated with number of stresses. Response of these stresses may vary in different populations depending upon altitude, duration of residency, ancestry, geographical variation, lifestyle, and ethnicities. For understanding population variability in transcriptome, array-based global gene expression profiling was performed on extracted RNA of male volunteers of two different lowland population groups, i.e., Indians and Kyrgyz, at baseline and day 7 of HA exposure (3200 m). A total of 97 genes were differentially expressed at basal in Kyrgyz as compared to Indians (82 downregulated and 15 upregulated), and 196 were differentially expressed on day 7 of HA (118 downregulated and 78 upregulated). Ingenuity Pathway Analysis and gene ontology highlighted eIF2 signaling with most significant negative activation z score at basal in Kyrgyz compared to Indians with downregulation of various L- and S-ribosomal proteins indicating marked translational repression. On day 7, cAMP-mediated signaling is most enriched with positive activation z score in Kyrgyz compared to Indians. Plasma cAMP levels were higher in Kyrgyz on day 7 compared to Indians. Extracellular adenosine levels were elevated in both the groups upon HA, but higher in Kyrgyz compared to Indians. Valedictory qRT-PCR showed upregulation of ADORA2B and CD73 along with downregulation of ENTs in Kyrgyz compared to Indians indicating elevated levels of extracellular nucleotides mainly adenosine and activation of extracellular cAMP-adenosine pathway which as per literature triggers endogenous protective mechanisms under stress conditions like hypoxia. Thus, transcriptome changes at HA are population-specific, and it may be necessary to take care while interposing similar results in different populations.


Assuntos
Aclimatação/genética , Regulação da Expressão Gênica , Hipóxia/etnologia , Hipóxia/genética , Transcriptoma , 5'-Nucleotidase/sangue , 5'-Nucleotidase/genética , Adenosina/sangue , Adulto , Altitude , AMP Cíclico/sangue , Fator de Iniciação 2 em Eucariotos/sangue , Fator de Iniciação 2 em Eucariotos/genética , Proteínas Ligadas por GPI/sangue , Proteínas Ligadas por GPI/genética , Perfilação da Expressão Gênica , Humanos , Hipóxia/sangue , Hipóxia/fisiopatologia , Índia , Quirguistão , Masculino , Receptor A2B de Adenosina/sangue , Receptor A2B de Adenosina/genética , Proteínas Ribossômicas/sangue , Proteínas Ribossômicas/genética , Transdução de Sinais
19.
J Clin Monit Comput ; 33(2): 269-279, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29876708

RESUMO

The golden standard method to obtain accurate blood oxygen saturation is blood gas analysis that needs invasive procedure of blood sampling. Photoacoustic technique enables us to measure real-time blood oxygen saturation without invasive procedure. The aim of this study is to use the photoacoustic technique, an optical method, for accurately determining oxygen saturation in vivo. We measured induced photoacoustic signals of arterial blood in the rabbit model of stable hypoxemia after irradiation at 750 and 800 nm. Oxygen saturation was calculated from the photoacoustic signals using two calibration curves. Calibration curve 1 is a conventional curve derived from the absorbance coefficient of hemoglobin, whereas calibration curve 2 is derived from the photoacoustic signals obtained from the original blood vessel model. Simultaneously, blood-gas analysis was performed to obtain the reference standard of oxygen saturation. Regression analysis and Bland-Altman analysis were performed to assess the accuracy of oxygen saturation obtained using the two methods. The oxygen saturation calculated using calibration curves 1 and 2 showed strong correlations with the reference standard in regression analysis (R = 0.965, 0.964, respectively). The Bland-Altman analysis revealed better agreement and precision with calibration curve 2, whereas there was significant underestimation of values obtained using calibration curve 1. Photoacoustic measurement of oxygen saturation using calibration curve 2 provided an accurate estimate of oxygen saturation, which was similar to that obtained using a portable blood-gas analyzer.


Assuntos
Gasometria , Hipóxia/sangue , Oximetria/métodos , Técnicas Fotoacústicas , Animais , Calibragem , Feminino , Hemoglobinas/análise , Oxigênio/sangue , Oxigênio/química , Troca Gasosa Pulmonar , Coelhos , Análise de Regressão
20.
Arch Dis Child Fetal Neonatal Ed ; 104(3): F274-F279, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29925540

RESUMO

OBJECTIVE: Describe the likelihood of hypoxemia and hyperoxemia across ranges of oxygen saturation (SpO2), during mechanical ventilation with supplemental oxygenation. DESIGN: Retrospective observational study. SETTING: University affiliated tertiary care neonatal intensive care unit. PATIENTS: Two groups of neonates based on postmenstrual age (PMA): <32 weeks (n=104) and >36 weeks (n=709). MAIN MEASURES: Hypoxemia was defined as a PaO2 <40 mm Hg, hyperoxemia as a PaO2 of >99 mm Hg and normoxemia as a PaO2 of 50-80 mm Hg. Twenty-five per cent was defined as marked likelihood of hypoxemia or hyperoxemia. RESULTS: From these infants, 18 034 SpO2-PaO2 pairs were evaluated of which 10% were preterm. The PMA (median and IQR) of the two groups were: 28 weeks (27-30) and 40 weeks (38-41). With SpO2 levels between 90% and 95%, the likelihoods of hypoxemia and hyperoxemia were low and balanced. With increasing levels of SpO2, the likelihood of hyperoxemia increased. It became marked in the preterm group when SpO2 was 99%-100% (95% CI 29% to 41%) and in the term group with SpO2 levels of 96%-98% (95% CI 29% to 32%). The likelihood of hypoxemia increased as SpO2 decreased. It became marked in both with SpO2 levels of 80%-85% (95% CI 20% to 31%, 24% to 28%, respectively). CONCLUSIONS: The likelihood of a PaO2 <40 mm Hg is marked with SpO2 below 86%. The likelihood of a PaO2 >99 mm Hg is marked in term infants with SpO2 above 95% and above 98% in preterm infants. SpO2 levels between 90% and 95% are appropriate targets for term and preterm infants.


Assuntos
Hiperóxia/diagnóstico , Hipóxia/diagnóstico , Doenças do Prematuro/diagnóstico , Idade Gestacional , Humanos , Hiperóxia/sangue , Hipóxia/sangue , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/sangue , Unidades de Terapia Intensiva Neonatal , Terapia Intensiva Neonatal/métodos , Oximetria/métodos , Oxigênio/sangue , Pressão Parcial , Estudos Retrospectivos
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