987 resultados para Diagnostic techniques, respiratory system
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SETTING: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death among adults in Brazil. OBJECTIVE: To evaluate the mortality and hospitalisation trends in Brazil caused by COPD during the period 1996-2008. DESIGN: We used the health official statistics system to obtain data about mortality (1996-2008) and morbidity (1998-2008) due to COPD and all respiratory diseases (tuberculosis: codes A15-16; lung cancer: code C34, and all diseases coded from J40 to 47 in the 10th Revision of the International Classification of Diseases) as the underlying cause, in persons aged 45-74 years. We used the Joinpoint Regression Program log-linear model using Poisson regression that creates a Monte Carlo permutation test to identify points where trend lines change significantly in magnitude/direction to verify peaks and trends. RESULTS: The annual per cent change in age-adjusted death rates due to COPD declined by 2.7% in men (95%CI -3.6 to -1.8) and -2.0% (95%CI -2.9 to -1.0) in women; and due to all respiratory causes it declined by -1.7% (95%CI 2.4 to -1.0) in men and -1.1% (95%CI -1.8 to -0.3) in women. Although hospitalisation rates for COPD are declining, the hospital admission fatality rate increased in both sexes. CONCLUSION: COPD is still a leading cause of mortality in Brazil despite the observed decline in the mortality/hospitalisation rates for both sexes.
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Introduction: Smoking is a serious worldwide public health problem. Animal models act as a bridge between laboratory and human studies. The models applied are difficult to reproduce because of the use of different types of inhalation chambers and mainly because of the lack of continuous monitoring of smoke concentration. Objective: To develop an inhalation chamber for rats (with only the nose exposed) in which the amount of carbon monoxide (CO) can be maintained and monitored constantly. Material and methods: Male Wistar rats weighing 250 g were exposed to 50 ppm CO produced by the smoke from a filter-free cigarette. The animals were submitted to a single 2-h exposure and then sacrificed at 0, 4, 24 and 48 h. The control group was left restrained inside the small perpendicular chambers, receiving only 5 L/min of compressed air. Results: The model was able to increase HbCO levels immediately after the end of exposure (p < 0.001). with a decrease being observed from 2 h onwards when compared to the levels of the control group. Plasma cotinine increased immediately after exposure, and showed still detectable levels at 2 and 4 h (p < 0.05). Conclusion: We conclude that the presented inhalation chamber system is able to maintain a controlled CO concentration in a model in which small animals are exposed to the inhalation of cigarette smoke, permitting well-controlled studies, as well as investigations involving other toxic gases and air pollutants. (C) 2008 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.
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Objectives: We sought to compare long-term outcomes after coronary bypass surgery with and without an internal thoracic artery graft. Methods: We analyzed clinical outcomes over a median follow-up of 6.7 years among 3,087 patients who received coronary bypass surgery as participants in one of 8 clinical trials comparing surgical intervention with angioplasty. We used 2 statistical methods (covariate adjustment and propensity score matching) to adjust for the nonrandomized selection of internal thoracic artery grafts. Results: Internal thoracic artery grafting was associated with lower mortality, with hazard ratios of 0.77 (confidence interval, 0.62-0.97; P = .02) for covariate adjustment and 0.77 (confidence interval, 0.57-1.05; P = .10) for propensity score matching. The composite end point of death or myocardial infarction was reduced to a similar extent, with hazard ratios of 0.83 (confidence interval, 0.69-1.00; P = .05) for covariate adjustment to 0.78 (confidence interval, 0.61-1.00; P = .05) for propensity score matching. There was a trend toward less angina at 1 year, with odds ratios of 0.81 (confidence interval, 0.61-1.09; P = .16) in the covariate-adjusted model and 0.81 (confidence interval, 0.55-1.19; P = .28) in the propensity score-adjusted model. Conclusions: Use of an internal thoracic artery graft during coronary bypass surgery seems to improve long-term clinical outcomes. (J Thorac Cardiovasc Surg 2011; 142: 829-35)
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Objective: To evaluate whether the number of vessels disease has an impact on clinical outcomes as well as on therapeutic results accordingly to medical, percutaneous, or surgery treatment in chronic coronary artery disease. Methods: We evaluated 825 individuals enrolled in MASS study, a randomized study to compare treatment options for single or multivessel coronary artery disease with preserved left ventricular function, prospectively followed during 5 years. The incidence of overall mortality and the composite end-point of death, myocardial infarction, and refractory angina were compared in three groups: single vessel disease (SVD n = 214), two-vessel disease (2VD n = 253) and three-vessel disease (3VD n = 358). The relationship between baseline variables and the composite end-point was assessed using a Cox proportional hazards survival model. Results: Most baseline characteristics were similar among groups, except age (younger in SVD and older in 3VD, p < 0.001), lower incidence of hypertension in SVD (p < 0.0001), and lower levels of total and LDL-cholesterol in 3VD (p = 0.004 and p = 0.005, respectively). There were no statistical differences in composite end-point in 5 years among groups independent of the kind of treatment; however, there was a higher mortality rate in 3VD (p < 0.001). When we stratified our analysis for each treatment option, bypass surgery was associated with a tower number of composite end-point in all groups (SVD p < 0.001, 2VD p = 0.002, 3VD p < 0.001). In multivariate analysis, we found higher mortality risk in 3VD comparing to SVD (p = 0.005, HR 3.14, 95%Cl 1.4-7.0). Conclusion: Three-vessel disease was associated with worse prognosis compared to single-or two-vessel disease in patients with stable coronary disease and preserved ventricular function at 5-year follow-up. In addition, event-free survival rates were higher after bypass surgery, independent of the number of vessels diseased in these subsets of patients. (c) 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.
A Randomized Trial of a Skin Sealant to Reduce the Risk of Incision Contamination in Cardiac Surgery
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Background. Immobilizing skin microbes is a rational approach to reducing contamination of surgical sites by endogenous microorganisms. Methods. This randomized, controlled, parallel-group, multicenter, open-label clinical trial (ClinicalTrials.gov NCT00467857) enrolled 300 adults scheduled for elective coronary artery bypass graft surgery. Patients received iodine-based skin preparations followed by a cyanoacrylate-based skin sealant or skin preparations alone. Microbiological samples collected from sternal and graft incision sites immediately before any skin preparation, at the wound border after skin incision, and at the incision after fascial closure were evaluated quantitatively. Results. In evaluable patients, mean microbial counts in collected samples increased at the sternal site after fascial closure compared with after skin incision by 0.37 log(10) colony-forming units (CFU)/mL in the skin sealant group (n = 120) and by 0.57 log10 CFU/mL in the control group (n = 132) (p = 0.047, Wilcoxon rank sum test). At the graft site, mean microbial counts increased by 0.09 (n = 119) and 0.27 (n = 127) log(10) CFU/mL, respectively (p = 0.037). There was a 35.3% relative risk reduction in surgical site infection (SSI) occurring in the skin sealant group (9 of 146 patients, 6.2%) versus the control group (14 of 147 patients, 9.5%). In obese patients (body mass index [BMI] > 30.0 to <= 37.0 kg/m(2)), the relative risk reduction for SSI associated with skin sealant was 83.3%. Conclusions. Pretreatment with skin sealant protects against contamination of the surgical incision by migration of skin microbes. Further data are needed to confirm the impact of this technology on SSI rates in clinical practice. (Ann Thorac Surg 2011;92:632-7) (C) 2011 by The Society of Thoracic Surgeons ADULT CARDIAC
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Background: Chagas` disease is the illness caused by the protozoan Trypanosoma cruzi and it is still endemic in Latin America. Heart transplantation is a therapeutic option for patients with end-stage Chagas` cardiomyopathy. Nevertheless, reactivation may occur after transplantation, leading to higher morbidity and graft dysfunction. This study aimed to identify risk factors for Chagas` disease reactivation episodes. Methods: This investigation is a retrospective cohort study of all Chagas` disease heart transplant recipients from September 1985 through September 2004. Clinical, microbiologic and histopathologic data were reviewed. Statistical analysis was performed with SPSS (version 13) software. Results: Sixty-four (21.9%) patients with chronic Chagas` disease underwent heart transplantation during the study period. Seventeen patients (26.5%) had at least one episode of Chagas` disease reactivation, and univariate analysis identified number of rejection episodes (p = 0.013) and development of neoplasms (p = 0.040) as factors associated with Chagas` disease reactivation episodes. Multivariate analysis showed that number of rejection episodes (hazard ratio = 1.31; 95% confidence interval [CI]: 1.06 to 1.62; p = 0.011), neoplasms (hazard ratio = 5.07; 95% CI: 1.49 to 17.20; p = 0.009) and use of mycophenolate mofetil (hazard ratio = 3.14; 95% CI: 1.00 to 9.84; p = 0.049) are independent determinants for reactivation after transplantation. Age (p = 0.88), male gender (p = 0.15), presence of rejection (p = 0.17), cytomegalovirus infection (p = 0.79) and mortality after hospital discharge (p = 0.15) showed no statistically significant difference. Conclusions: Our data suggest that events resulting in greater immunosuppression status contribute to Chagas` disease reactivation episodes after heart transplantation and should alert physicians to make an early diagnosis and perform pre-emptive therapy. Although reactivation led to a high rate of morbidity, a low mortality risk was observed.
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Background and objective: Hyperinflation with a decrease in inspiratory capacity (IC) is a common presentation for both unstable and stable COPD patients. As CPAP can reduce inspiratory load, possibly secondary to a reduction in hyperinflation, this study examined whether CPAP would increase IC in stable COPD patients. Methods: Twenty-one stable COPD patients (nine emphysema, 12 chronic bronchitis) received a trial of CPAP for 5 min at 4, 7 and 11 cmH(2)O. Fast and slow VC (SVC) were measured before and after each CPAP trial. In patients in whom all three CPAP levels resulted in a decreased IC, an additional trial of CPAP at 2 cmH(2)O was conducted. For each patient, a `best CPAP` level was defined as the one associated with the greatest IC. This pressure was then applied for an additional 10 min followed by spirometry. Results: Following application of the `best CPAP`, the IC and SVC increased in 15 patients (nine emphysema, six chronic bronchitis). The mean change in IC was 159 mL (95% CI: 80-237 mL) and the mean change in SVC was 240 mL (95% CI: 97-386 mL). Among these patients, those with emphysema demonstrated a mean increase in IC of 216 mL (95% CI: 94-337 mL). Six patients (all with chronic bronchitis) did not demonstrate any improvement in IC. Conclusions: The best individualized CPAP can increase inspiratory capacity in patients with stable COPD, especially in those with emphysema.
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Background: Asthma symptoms reduce patients daily activities, impair their health-related quality of life (HRQoL), and increase their reports of anxiety and depress, all of which seem to be related to a decrease in asthma control. Aerobic exercise training is known to improve aerobic fitness and reduce dyspnea in asthmatics; however, its effect in reducing psychologic distress and symptoms remains poorly understood. We evaluated the role of an aerobic training program in improving HRQoL (primary aim) and reducing psychologic distress and asthma symptoms (secondary aims) for patients with moderate or severe persistent asthma. Methods: A total of 101 patients were randomly assigned to either a control group or an aerobic training group and studied during the period between medical consultations. Control group patients (educational program plus breathing exercises) (n = 51) and training group patients (educational program plus breathing exercises plus aerobic training) (n = 50) were followed twice a week during a 3-month period. HRQoL and levels of anxiety and depression were quantified before and after treatment. Asthma symptoms were evaluated monthly. Results: At 3 months, the domains (physical limitations, frequency of symptoms, and psychosocial) and total scores of HRQoL, significantly improved only in the training group patients (P < .001); the number of asthma-symptom-free days and anxiety and depression levels also significantly improved in this group (P < .001). In addition, a linear relationship between improvement in aerobic capacity and the days without asthma symptoms was observed (r = 0.47; P < .01). Conclusions: Our results suggest that aerobic training can play an important role in the clinical management of patients with persistent asthma. Further, they may be especially useful for patients with higher degrees of psychosocial distress.
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Aerobic training (AT) decreases dyspnoea and exercise-induced bronchospasm, and improves aerobic capacity and quality of life; however, the mechanisms for such benefits remain poorly understood. The aim of the present study was to evaluate the AT effects in a chronic model of allergic lung inflammation in mice after the establishment of airway inflammation and remodelling. Mice were divided into the control group, AT group, ovalbumin (OVA) group or OVA+AT group and exposed to saline or OVA. AT was started on day 28 for 60 min five times per week for 4 weeks. Respiratory mechanics, specific immunoglobulin (Ig)E and IgG(1), collagen and elastic fibres deposition, smooth muscle thickness, epithelial mucus, and peribronchial density of eosinophils, CD3+ and CD4+, IL-4, IL-5, IL-13, interferon-gamma, IL-2, IL-1ra, IL-10, nuclear factor (NF)-kappa B and Foxp3 were evaluated. The OVA group showed an increase in IgE and IgG1, eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kappa B, collagen and elastic, mucus synthesis, smooth muscle thickness and lung tissue resistance and elastance. The OVA+AT group demonstrated an increase of IgE and IgG(1), and reduction of eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kappa B, airway remodelling, mucus synthesis, smooth muscle thickness and tissue resistance and elastance compared with the OVA roup (p < 0.05). The OVA+AT group also showed an increase in IL-10 and IL-1ra (p < 0.05), independently of Foxp3. AT reversed airway inflammation and remodelling and T-helper cell 2 response, and improved respiratory mechanics. These results seem to occur due to an increase in the expression of IL-10 and IL-1ra and a decrease of NF-kappa B.
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Furosemide, a potent diuretic, affects ion and water movement across the respiratory epithelium. However, the effects of furosemide, as clinically used, on mucociliary clearance, a critical respiratory defense mechanism, are still lacking in humans. Fourteen young healthy subjects were assigned to three random interventions, spaced one-week apart: no intervention (control), oral furosemide (40 mg), and furosemide + oral volume replacement (F + R). Nasal mucociliary clearance was assessed by saccharine test (STT), and mucus properties were in vitro evaluated by means of contact angle and transportability by sneeze. Urine output and osmolality were also evaluated. Urine output increased and reduced urine osmolality in furosemide and F + R compared to the control condition. STT remained stable in the control group. In contrast, STT increased significantly (40%) after furosemide and F + R. There were no changes in vitro mucus properties in all groups. In conclusion, furosemide prolongs STT in healthy young subjects. This effect is not prevented by fluid replacement, suggesting a direct effect of furosemide on the respiratory epithelium. (C) 2010 Elsevier B.V. All rights reserved.
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The present study aimed to evaluate the role of nitric oxide (NO) on hyperpnea-induced bronchoconstriction (HIB) and airway microvascular hyperpermeability (AMP). Sixty-four guinea pigs were anesthetized, tracheotonnized, cannulated, and connected to animal ventilator to obtain pulmonary baseline respiratory system resistance (Rrs). Animals were then submitted to 5 minutes hyperpnea and Rrs was evaluated during 15 minutes after hyperpnea. AMP was evaluated by Evans blue dye (25 mg/kg) extravasation in airway tissues. Constitutive and inductible NO was evaluated by pretreating animals with N(G)-nitro-1-arginine methyl ester (I-NAME) (50 mg/kg), aminoguadinine (AG) (50 mg/kg), and I-arginine (100 mg/kg) and exhaled NO (NOex) was evaluated before and after drug administration and hyperpnea. The results show that I-NAME potentiated (57%) HIB and this effect was totally reversed by I-arginine pretreatment, whereas AG did not have effect on HIB. I-NAME decreased basal AMP (48%), but neither I-NAME nor AG had any effect on hyperpnea-induced AMP. NOex levels were decreased by 50% with I-NAME, effect that was reversed by I-arginine treatment. These results suggest that constitutive but not inducible NO could have a bronchoprotective effect on HIB in guinea pigs. The authors also observed that neither constitutive nor inducible NO seems to have any effect on hyperpnea-induced AMP.
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Background: Patients with idiopathic pulmonary fibrosis (IPF) present an important ventilatory (imitation reducing their exercise capacity. Non-invasive ventilatory support has been shown to improve exercise capacity in patients with obstructive diseases; however, its effect on IPF patients remains unknown. Objective: The present study assessed the effect of ventilatory support using proportional, assist ventilation (PAV) on exercise capacity in patients with IPF. Methods: Ten patients (61.2 +/- 9.2 year-old) were submitted to a cardiopulmonary exercise testing, plethysmography and three submaximal. exercise tests (60% of maximum load): without ventilatory support, with continuous positive airway pressure (CPAP) and PAV. Submaximal tests were performed randomly and exercise capacity, cardiovascular and ventilatory response as well as breathlessness subjective perception were evaluated. Lactate plasmatic levels were obtained before and after submaximal. exercise. Results: Our data show that patients presented a limited exercise capacity (9.7 +/- 3.8 mL O(2)/kg/min). Submaximal. test was increased in patients with PAV compared with CPAP and without ventilatory support (respectively, 11.1 +/- 8.8 min, 5.6 +/- 4.7 and 4.5 +/- 3.8 min; p < 0.05). An improved arterial oxygenation and lower subjective perception to effort was also observed in patients with IPF when exercise was performed with PAV (p < 0.05). IPF patients performing submaximal exercise with PAV also presented a lower heart rate during exercise, although systolic and diastolic pressures were not different among submaximal tests. Our results suggest that PAV can increase exercise tolerance and decrease dyspnoea and cardiac effort in patients with idiopathic pulmonary fibrosis. (C) 2009 Elsevier Ltd. All rights reserved.
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Vieira RP, de Andrade VF, Duarte AC, dos Santos AB, Mauad T, Martins MA, Dolhnikoff M, Carvalho CR. Aerobic conditioning and allergic pulmonary inflammation in mice. II. Effects on lung vascular and parenchymal inflammation and remodeling. Am J Physiol Lung Cell Mol Physiol 295: L670-L679, 2008. First published August 29, 2008; doi: 10.1152/ajplung.00465.2007.-Recent evidence suggests that asthma leads to inflammation and remodeling not only in the airways but also in pulmonary vessels and parenchyma. In addition, some studies demonstrated that aerobic training decreases chronic allergic inflammation in the airways; however, its effects on the pulmonary vessels and parenchyma have not been previously evaluated. Our objective was to test the hypothesis that aerobic conditioning reduces inflammation and remodeling in pulmonary vessels and parenchyma in a model of chronic allergic lung inflammation. Balb/c mice were sensitized at days 0, 14, 28, and 42 and challenged with ovalbumin ( OVA) from day 21 to day 50. Aerobic training started on day 21 and continued until day 50. Pulmonary vessel and parenchyma inflammation and remodeling were evaluated by quantitative analysis of eosinophils and mononuclear cells and by collagen and elastin contents and smooth muscle thickness. Immunohistochemistry was performed to quantify the density of positive cells to interleukin (IL)-2, IL-4, IL-5, interferon-gamma, IL-10, monocyte chemotatic protein (MCP)-1, nuclear factor (NF)-kappa B p65, and insulin-like growth factor (IGF)-I. OVA exposure induced pulmonary blood vessels and parenchyma inflammation as well as increased expression of IL-4, IL-5, MCP-1, NF-kappa B p65, and IGF-I by inflammatory cells were reduced by aerobic conditioning. OVA exposure also induced an increase in smooth muscle thickness and elastic and collagen contents in pulmonary vessels, which were reduced by aerobic conditioning. Aerobic conditioning increased the expression of IL-10 in sensitized mice. We conclude that aerobic conditioning decreases pulmonary vascular and parenchymal inflammation and remodeling in this experimental model of chronic allergic lung inflammation in mice.
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Background. The mechanical alterations related to the overload of respiratory muscles observed in adults with persistent asthma might lead to the development of chronic alterations in posture, musculoskeletal dysfunction and pain; however, these changes remain poorly understood. Objective. This study aimed to assess postural alignment, muscle shortening and chronic pain in adults with persistent asthma. Methods. This cross-sectional and controlled study enrolled 30 patients with mild (n = 17) and severe ( n = 13) persistent asthma. Fifteen non-asthmatic volunteers were also assessed. Asthma was classified by the Global Initiative for Asthma (GINA) guidelines. Postural alignment and muscle shortening were evaluated by head and shoulder positions, chest wall mobility, and posterior ( trunk and lower limb) muscle flexibility. In addition, the measures used were previously tested for their reproducibility. Pain complaints were also assessed. Results. In comparison with non-asthmatic subjects, patients with mild or severe persistent asthma held their head and shoulders more forward and had lower chest wall expansion, decreased shoulder internal rotation, and decreased thoracic spine flexibility. Chronic lower thoracic, cervical, and shoulder pain was significantly increased in patients with mild or severe asthma compared with non-asthmatic subjects (p < 0.05). Conclusion. Adults with persistent asthma have musculoskeletal dysfunction and chronic pain that is independent of the severity of their disease but that might be related to their age at the onset of disease symptoms.
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This paper describes the application of two relatively new diagnostic techniques for the determination of insulation condition in aged transformers. The techniques are (a) measurements of interfacial polarization spectra by a DC method and (b) measurements of molecular weight and its distribution by gel permeation chromatography. Several other electrical properties of the cellulose polymer were also investigated. Samples were obtained from a retired power transformer and they were analysed by the developed techniques. Six distribution transformers were also tested with the interfacial polarization spectra measurement technique, and the molecular weight of paper/pressboard samples from these transformers were also measured by the gel permeation chromatography. The variation of the results through different locations in a power transformer is discussed in this paper. The possible correlation between different measured properties was investigated and discussed in this paper.