David Romero

Prognostic Value of the Objective Measurement of Daily Physical Activity in Patients With COPD

BACKGROUND Subjective measurement of physical activity using questionnaires has prognostic value in COPD. However, their lack of accuracy and large individual variability limit their use for evaluation on an individual basis. We evaluated the capacity of the objective measurement of daily physical activity in patients with COPD using accelerometers to estimate their prognostic value. METHODS In 173 consecutive subjects with moderate to very severe COPD, daily physical activity was measured using a triaxial accelerometer providing a mean of 1-min movement epochs as vector magnitude units (VMUs). Patients were evaluated by lung function testing and 6-min walk, incremental exercise, and constant work rate tests. Patients were followed for 5 to 8 years, and the end points were all-cause mortality, hospitalization for COPD exacerbation, and annual declining FEV(1). RESULTS After adjusting for relevant confounders, a high VMU decreased the mortality risk (adjusted hazard ratio [HR], 0.986; 95% CI, 0.981-0.992), and in a multivariate model, comorbidity, endurance time, and VMU were retained as independent predictors of mortality. The time until first admission due to COPD exacerbation was shorter for the patients with lower levels of VMU (adjusted HR, 0.989; 95% CI, 0.983-0.995). Moreover, patients with higher VMU had a lower hospitalization risk than those with a low VMU (adjusted incidence rate ratio, 0.099; 95% CI, 0.033-0.293). In contrast, VMU was not identified as an independent predictor of the annual FEV(1) decline. CONCLUSION The objective measurement of the daily physical activity in patients with COPD using an accelerometer constitutes an independent prognostic factor for mortality and hospitalization due to severe exacerbation.

Dynamic Hyperinflation, Arterial Blood Oxygen, and Airway Oxidative Stress in Stable Patients With COPD

BACKGROUND There is considerable evidence that oxidative stress is increased in patients with COPD, although little information is available about its relationship with the structural and functional alterations produced by COPD. In this study, we evaluated the relationship between 8-isoprostane in exhaled breath condensate (EBC) of stable patients with COPD and the main parameters of the disease (such as dyspnea), stages of severity, lung parenchyma densities, lung function impairment, and exercise tolerance in order to identify the predictors of airway oxidative stress. METHODS In a cross-sectional study, we included 76 men with moderate to very severe COPD. 8-Isoprostane levels in EBC were measured by enzyme immunoassay. Regional lung densities were measured by lung densitometry with high-resolution CT scanning. Arterial blood gas levels, lung volumes, and diffusing capacity were determined. Patients performed a 6-min walk test and an incremental exercise test with measurement of breathing pattern and operating lung volumes. RESULTS Significant severity-related differences in 8-isoprostane were identified according to the BMI, obstruction, dyspnea, and exercise (BODE) index. 8-Isoprostane levels were related to smoking intensity, lung densities in expiration, static lung volumes, PaO(2), diffusion capacity, distance walked in 6 min, peak oxygen uptake, and anaerobic threshold. Concentration of 8-isoprostane was higher in the 60 patients (79%) who developed dynamic hyperinflation than in the remaining 16 (21%) who did not. In a multivariate linear regression analysis using 8-isoprostane as a dependent variable, end-expiratory lung volume change and PaO(2) were retained in the prediction model (r(2) = 0.734, P < .001). CONCLUSIONS In stable patients with COPD, oxygen level and dynamic hyperinflation are related to airway oxidative stress.

Association Between Obstructive Sleep Apnea and Pulmonary Embolism

OBJECTIVES To compare the prevalence of obstructive sleep apnea (OSA) in patients with pulmonary embolism (PE) with a sex-, age-, and body mass index (BMI)-matched, population-based control group and to assess the association between OSA and PE. METHODS We performed a case-control study from October 1, 2006, through November 30, 2009. We included 107 patients with PE and a control group (n=102) without PE in University Hospitals Son Espases and La Paz in Spain. Variables included in the analysis were medical history, anthropometric variables (weight, height, BMI, and neck circumference), Epworth Sleepiness Scale score, home respiratory polygraphy, basic biochemical profile and hemogram, spirometry, and physical activity. RESULTS The mean ± SD apnea-hypopnea index (AHI) was significantly higher in patients with PE than population controls (21.2±20.6 vs 11.5±15.9 h(-1); P<.001). The presence of an AHI greater than 5 h(-1) and hypersomnolence (Epworth Sleepiness Scale score ≥11) was more frequent in PE patients than in controls (14.0% vs 4.9%; P=.0002). A crude model analysis by several cutoffs revealed that the AHI was significantly associated with PE. After adjustment for age, sex, smoking, BMI, lung function, and all known PE risk factors, the odds ratio for PE was 3.7 (95% CI, 1.3-10.5; P=.01). CONCLUSION A higher prevalence of OSA was detected in patients diagnosed as having acute PE than controls. This study identified a significant and independent association between OSA and PE.

Utility of Two-Compartment Models of Exhaled Nitric Oxide in Patients with Asthma

Two-compartment models provide more precise information about the contribution of the different portions of the airways to exhaled nitric oxide (NO). Airway wall concentration of NO (Caw,NO) and maximum flux of NO in the airways (J′aw,NO) reflect the tissue production rate of NO and they can be modified by corticosteroids. The airway wall diffusing capacity of NO (Daw,NO) depends on diverse physical and anatomical determinants of the airways, such as gas exchange surface area. Daw,NO can be modified by structural and physiological changes that are characteristic of airway remodeling, which take place over the long term. The alveolar concentration of NO (Calv,NO) represents the degree of small airway inflammation. The persistence of high Calv,NO in patients treated with inhaled corticosteroids could reflect the incapacity of these drugs to reach distal locations due to the heterogeneity of the acinar ventilation. In this review, we evaluate the parameters provided by the compartmentalized analysis of exhaled NO that could be useful in characterizing asthma patients.

Does airway hyperresponsiveness monitoring lead to improved asthma control

The current guidelines recommend an approach to asthma management based on asthma control, rather than asthma severity. Although several specific questionnaires have been developed and control criteria have been established based on clinical guidelines, the evaluation of asthma control is still not optimal. In general, these indicators provide adequate assessment of current control, but they are more limited when estimating future risk. There is much evidence demonstrating the persistence of airway inflammation and airway hyperresponsiveness (AHR) in patients with total control. Therefore, the objective of this review was to analyse the possible role of AHR monitoring as an instrument for assessing asthma control. We will evaluate its capacity as an indicator for future risk, both for estimating the possibility of clinical deterioration and loss of lung function or exacerbations. Furthermore, its relationship with inhaled corticosteroid treatment will be analysed, while emphasizing its capacity for predicting response and adjusting dosage, as well as information about the capability of AHR for monitoring treatment. Last of all, we will discuss the main limitations and emerging opportunities of AHR as an assessment instrument for asthma control.

High D-dimer levels after stopping anticoagulants in pulmonary embolism with sleep apnoea

Obstructive sleep apnoea is a risk factor for pulmonary embolism. Elevated D-dimer levels and other biomarkers are associated with recurrent pulmonary embolism. The objectives were to compare the frequency of elevated D-dimer levels (>500 ng·mL−1) and further coagulation biomarkers after oral anticoagulation withdrawal in pulmonary embolism patients, with and without obstructive sleep apnoea, including two control groups without pulmonary embolism. We performed home respiratory polygraphy. We also measured basic biochemical profile and haemogram, and coagulation biomarkers (D-dimer, prothrombin fragment 1+2, thrombin-antithrombin complex, plasminogen activator inhibitor 1, and soluble P-selectin). 64 (74.4%) of the pulmonary embolism cases and 41 (46.11%) of the controls without pulmonary embolism had obstructive sleep apnoea. Plasmatic D-dimer was higher in PE patients with OSA than in those without obstructive sleep apnoea. D-dimer levels were significantly correlated with apnoea–hypopnoea index, and nocturnal hypoxia. There were more patients with high D-dimer after stopping anticoagulants in those with pulmonary embolism and obstructive sleep apnoea compared with PE without obstructive sleep apnoea (35.4% versus 19.0%, p=0.003). Apnoea–hypopnoea index was independently associated with high D-dimer. Pulmonary embolism patients with obstructive sleep apnoea had higher rates of elevated D-dimer levels after anticoagulation discontinuation for pulmonary embolism than in patients without obstructive sleep apnoea and, therefore, higher procoagulant state that might increase the risk of pulmonary embolism recurrence. Pulmonary embolism patients with sleep apnoea are more likely to have elevated post-anticoagulation plasma D-dimer http://ow.ly/NHoiu

Síndrome de Swyer-James-McLeod; descripción de un caso y breve revisión de la literatura

Resumen El sindrome de Swyer-James-McLeod se caracteriza por ser una patologia adquirida, generalmente de causa infecciosa, en las primeras etapas de la vida. Ello provoca una hipoplasia del pulmon afectado, con caracteristicas anatomopatologicas que se describen como una bronquiolitis obliterante adquirida. La clinica que presentan los pacientes es muy variada, desde formas paucisintomaticas hasta cuadros graves con infecciones respiratorias severas de repeticion.

Bronchiectasis in severe asthma: Clinical features and outcomes

BACKGROUND Bronchiectasis is increasingly being identified in patients with severe asthma and could contribute to disease severity. OBJECTIVE To determine the prevalence of bronchiectasis in a population of patients with severe asthma and to better characterize the clinical features of these patients and their outcomes. METHODS We retrospectively reviewed the medical files of 184 subjects with confirmed severe asthma who had undergone high-resolution thoracic computed tomography and compared the characteristics and outcomes of subjects with and without bronchiectasis. RESULTS Bronchiectasis was identified in 86 patients (47%). These patients had concomitant hypersensitivity to nonsteroidal anti-inflammatory drugs (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.00-5.03) and gastroesophageal reflux disease (OR 1.89, 95% CI 1.05-3.41) more frequently than subjects without bronchiectasis, but had less atopic dermatitis (OR 0.188, 95% CI 0.04-0.88). Subjects with bronchiectasis were more frequently hospitalized for asthma exacerbations (OR 2.09, 95% CI 1.08-4.05) and had higher blood eosinophil levels (464 vs 338; P = .005) than subjects without bronchiectasis. CONCLUSION Our study suggests that in subjects with severe asthma, the presence of bronchiectasis is associated with more frequent hospitalizations, concomitant gastroesophageal reflux disease, hypersensitivity to nonsteroidal anti-inflammatory drugs, and higher blood eosinophil counts. Bronchiectasis could represent an additional phenotypic feature of severe eosinophilic asthma.