Objective: To determine whether COPD patients with diaphragmatic dysfunction present higher risk of mortality than do those without such dysfunction. Methods: We evaluated pulmonary function, diaphragm mobility and quality of life, as well as determining the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index, in 42 COPD patients. The patients were allocated to two groups according to the degree to which diaphragm mobility was impaired: low mobility (LM; mobility ≤ 33.99 mm); and high mobility (HM; mobility ≥ 34.00 mm). The BODE index and the quality of life were quantified in both groups. All patients were followed up prospectively for up to 48 months in order to determine the number of deaths resulting from respiratory complications due to COPD. Results: Of the 42 patients evaluated, 20 were allocated to the LM group, and 22 were allocated to the HM group. There were no significant differences between the groups regarding age, lung hyperinflation or quality of life. However, BODE index values were higher in the LM group than in the HM group (p = 0.01). During the 48-month follow-up period, there were four deaths within the population studied, and all of those deaths occurred in the LM group (15.79%; p = 0.02). Conclusions: These findings suggest that COPD patients with diaphragmatic dysfunction, characterized by low diaphragm mobility, have a higher risk of death than do those without such dysfunction.

Keywords: Pulmonary disease, chronic obstructive/mortality; Diaphragm; Exercise tolerance; Quality of life.

Objective: To evaluate diaphragmatic mobility in relation to lung function, respiratory muscle strength, dyspnea, and physical activity in daily life (PADL) in patients with COPD. Methods: We included 25 patients with COPD, classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria, and 25 healthy individuals. For all of the participants, the following were evaluated: anthropometric variables, spirometric parameters, respiratory muscle strength, diaphragmatic mobility (by X-ray), PADL, and the perception of dyspnea. Results: In the COPD group, diaphragmatic mobility was found to correlate with lung function variables, inspiratory muscle strength, and the perception of dyspnea, whereas it did not correlate with expiratory muscle strength or PADL. Conclusions: In patients with COPD, diaphragmatic mobility seems to be associated with airway obstruction and lung hyperinflation, as well as with ventilatory capacity and the perception of dyspnea, although not with PADL.

Keywords: Pulmonary disease, chronic obstructive; Diaphragm; Spirometry; Dyspnea; Maximal respiratory pressures.

Objective: To compare diaphragmatic mobility, lung function, and respiratory muscle strength between COPD patients with and without thoracic hyperkyphosis; to determine the relationship of thoracic kyphosis angle with diaphragmatic mobility, lung function, and respiratory muscle strength in COPD patients; and to compare diaphragmatic mobility and thoracic kyphosis between male and female patients with COPD. Methods: Participants underwent anthropometry, spirometry, thoracic kyphosis measurement, and evaluation of diaphragmatic mobility. Results: A total of 34 patients with COPD participated in the study. Diaphragmatic mobility was significantly lower in the group of COPD patients with thoracic hyperkyphosis than in that of those without it (p = 0.002). There were no statistically significant differences between the two groups of COPD patients regarding lung function or respiratory muscle strength variables. There was a significant negative correlation between thoracic kyphosis angle and diaphragmatic mobility (r = −0.47; p = 0.005). In the sample as a whole, there were statistically significant differences between males and females regarding body weight (p = 0.011), height (p < 0.001), and thoracic kyphosis angle (p = 0.036); however, there were no significant differences in diaphragmatic mobility between males and females (p = 0.210). Conclusions: Diaphragmatic mobility is lower in COPD patients with thoracic hyperkyphosis than in those without it. There is a negative correlation between thoracic kyphosis angle and diaphragmatic mobility. In comparison with male patients with COPD, female patients with COPD have a significantly increased thoracic kyphosis angle.

Keywords: Pulmonary disease, chronic obstructive; Kyphosis; Diaphragm.

Objective: To evaluate the role of right heart catheterization in the diagnosis of pulmonary arterial hypertension (PAH). Methods: We evaluated clinical, functional, and hemodynamic data from all patients who underwent right heart catheterization because of diagnostic suspicion of PAH-in the absence of severe left ventricular dysfunction (LVD), significant changes in pulmonary function tests, and ventilation/perfusion lung scintigraphy findings consistent with chronic pulmonary thromboembolism-between 2008 and 2013 at our facility. Results: During the study period, 384 patients underwent diagnostic cardiac catheterization at our facility. Pulmonary hypertension (PH) was confirmed in 302 patients (78.6%). The mean age of those patients was 48.7 years. The patients without PH showed better hemodynamic profiles and lower levels of B-type natriuretic peptide. Nevertheless, 13.8% of the patients without PH were categorized as New York Heart Association functional class III or IV. Of the 218 patients who met the inclusion criteria, 40 (18.3%) and 178 (81.7%) were diagnosed with PH associated with LVD (PH-LVD) and with PAH, respectively. The patients in the HP-LVD group were significantly older than were those in the PAH group (p < 0.0001). Conclusions: The proportional difference between the PAH and PH-LVD groups was quite significant, considering the absence of echocardiographic signs suggestive of severe LVD during the pre-catheterization investigation. Our results highlight the fundamental role of cardiac catheterization in the diagnosis of PAH, especially in older patients, in whom the prevalence of LVD that has gone undiagnosed by non-invasive tests is particularly relevant.

Keywords: Hypertension, pulmonary; Cardiac catheterization, Ventricular dysfunction, left.

Objective: To compare the diaphragmatic mobility of healthy subjects during incentive spirometry with a volume-oriented device, during incentive spirometry with a flow-oriented device, and during diaphragmatic breathing. To compare men and women in terms of diaphragmatic mobility during these three types of breathing exercises. Methods: We evaluated the pulmonary function and diaphragmatic mobility of 17 adult healthy volunteers (9women and 8 men). Diaphragmatic mobility was measured via ultrasound during diaphragmatic breathing and during the use of the two types of incentive spirometers. Results: Diaphragmatic mobility was significantly greater during the use of the volume-oriented incentive spirometer than during the use of the flow-oriented incentive spirometer (70.16 ± 12.83 mm vs. 63.66 ± 10.82 mm; p = 0.02). Diaphragmatic breathing led to a greater diaphragmatic mobility than did the use of the flow-oriented incentive spirometer (69.62 ± 11.83 mm vs. 63.66 ± 10.82 mm; p = 0.02). During all three types of breathing exercises, the women showed a higher mobility/FVC ratio than did the men. Conclusions: Incentive spirometry with a volume-oriented device and diaphragmatic breathing promoted greater diaphragmatic mobility than did incentive spirometry with a flow-oriented device. Women performed better on the three types of breathing exercises than did men.

Keywords: Diaphragm; Breathing exercises; Respiratory function tests; Ultrasonography; Respiratory muscles.

Objective: To evaluate the association between adherence to treatment and mortality among Chronic Obstructive Pulmonary Disease (COPD) patients treated in the Brazilian public health system. Methods: This is cohort study of moderate-to-severe COPD patients monitored in a public pharmaceutical care-based Disease Management Program (DMP). All subjects who died one year after the beginning of the cohort were age-matched with those who remained alive at the end of the cohort period. Treatment adherence was measured through pharmacy records. Patients who received at least 90% of the prescribed doses were considered adherent to treatment. Results: Of the 333 patients (52.8% age = 65 years, 67.9% male), 67.3% were adherent to treatment (adherence rate, 87.2%). Mortality was associated with lack of adherence (p = 0.04), presence of symptoms (mMRC = 2) and COPD treatment use. The death was associated with non-adherence, presence of symptoms and previous hospitalization. After adjustment, non-adherent patients to treatment were almost twice times likely to die compared to those adherents (Hazard Ratio (HR) 1.86; CI 1.16-2.98, p = 0.01). Conclusion: Non-adherence to treatment was associated with higher mortality among moderate-to-severe COPD patients treated in the Brazilian public health system. Strategies to monitor and optimize adherence should be strengthened to reduce COPD-related mortality.

Keywords: COPD; Treatment adherence; Mortality; Pharmaceutical care.

O prejuízo funcional parece diferir entre membros superiores e membros inferiores de pacientes com DPOC. Dois possíveis mecanismos explicam os sintomas importantes de dispneia e fadiga relatados pelos pacientes ao executar tarefas com membros superiores não sustentados: a disfunção neuromecânica dos músculos respiratórios e a alteração dos volumes pulmonares durante as atividades realizadas com membros superiores. A disfunção neuromecânica está relacionada à alteração do padrão respiratório e à simultaneidade de estímulos aferentes e eferentes musculares, o que causaria a dissincronia na ação dos músculos respiratórios em pacientes com DPOC durante esse tipo de exercício. Adicionalmente, o aumento da ventilação durante os exercícios com membros superiores em pacientes com DPOC induz à hiperinsuflação dinâmica em diferentes cargas de trabalho. Nos membros inferiores, há redução da força e da endurance muscular do quadríceps femoral nos pacientes com DPOC comparados a indivíduos saudáveis. Uma explicação para essas reduções é a anormalidade no metabolismo muscular (diminuição da capacidade aeróbia), a dependência do metabolismo glicolítico e o acúmulo rápido de lactato durante o exercício. Quando contrastadas as atividades de membros superiores e membros inferiores, os exercícios com membros superiores resultam em maior demanda metabólica e ventilatória com mais intensa sensação de dispneia e fadiga. Devido às diferenças nas adaptações morfofuncionais dos músculos dos membros superiores e membros inferiores em pacientes com DPOC, protocolos específicos de treinamento de força e/ou endurance devem ser desenvolvidos e testados para os grupos musculares desses segmentos corporais.

Keywords: Pulmonary disease, chronic obstructive; Muscle fatigue; Upper extremity; Lower extremity.

Objective: To compare the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index scores and its individual components between COPD patients with and without severe physical inactivity, as well as to correlate the number of steps/day with scores of physical activity questionnaires, age, and the BODE index (including its components). Methods: We included 30 patients, who were evaluated for body composition, pulmonary function (FEV1), perception of dyspnea (modified Medical Research Council scale), and exercise capacity (six-minute walk distance [6MWD]). The patients also completed the International Physical Activity Questionnaire (IPAQ), short version, and the modified Baecke questionnaire (mBQ). The level of physical activity was assessed by the number of steps/day (as determined by pedometer), using the cut-off of 4,580 steps/day to form two groups: no severe physical inactivity (SPI−) and severe physical inactivity (SPI+). We used the Mann-Whitney test or t-test, as well as Pearson's or Spearman's correlation tests, in the statistical analysis. Results: In comparison with the SPI− group, the SPI+ group showed more advanced age, higher mBQ scores (leisure domain), lower 6MWD (in m and % of predicted), and lower IPAQ scores (metabolic equivalent-walk/week domain and total). The IPAQ scores showed weak correlations with steps/day (r = 0.399), age (r = −0.459), and 6MWD-in m (r = 0.446) and in % of predicted (r = 0.422). Conclusions: In our sample, the cut-off of 4,580 steps/day was not sensitive enough to identify differences between the groups when compared with the predictors of mortality. The IPAQ, short version score correlated with steps/day.

Keywords: Pulmonary disease, chronic obstructive/mortality; Pulmonary disease, chronic obstructive/ prevention and control; Motor activity.

Objective: To identify factors associated with prolonged weaning and mortality in critically ill COVID-19 patients admitted to ICUs and under invasive mechanical ventilation. Methods: Between March of 2020 and July of 2021, we retrospectively recorded clinical and ventilatory characteristics of critically ill COVID-19 patients from the day of intubation to the outcome. We classified the patients regarding the weaning period in accordance with established criteria. A logistic regression analysis was performed to identify variables associated with prolonged weaning and mortality. Results: The study involved 303 patients, 100 of whom (33.0%) had a prolonged weaning period. Most of the patients were male (69.6%), 136 (44.8%) had more than 50% of pulmonary involvement on chest CT, and 93 (30.6%) had severe ARDS. Within the prolonged weaning group, 62% died within 60 days. Multivariate analysis revealed that lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were significantly associated with prolonged weaning, whereas age and prolonged weaning were significantly associated with mortality. Conclusions: Prolonged weaning can be used as a milestone in predicting mortality in critically ill COVID-19 patients. Lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were identified as significant predictors of prolonged weaning. These results might provide valuable information for healthcare professionals when making clinical decisions regarding the management of critically ill COVID-19 patients who are on mechanical ventilation.

Keywords: COVID-19; Pneumonia, viral; Respiratory distress syndrome; Respiration, artificial; Ventilator weaning; Cohort studies; Hospital mortality; Patient outcome assessment.

Objective: To assess ICU patients with COPD, in terms of in-hospital characteristics, two-year mortality and two-year functional status of survivors. Methods: A prospective cohort study involving patients with acute exacerbation of COPD admitted to the ICUs of two hospitals in the city of Porto Alegre, Brazil, between July of 2005 and July of 2006. At two years after discharge, survivors were interviewed by telephone in order to determine Karnofsky scores and scores on a scale regarding activities of daily living (ADL). Results: The sample comprised 231 patients. In-hospital mortality was 37.7%, and two-year post-discharge mortality was 30.3%. Of the 74 survivors, 66 were interviewed (89%). The mean age at ICU admission was 74 ± 10 years, and the mean Acute Physiology and Chronic Health Evaluation II score was 18 ± 7. Two or more comorbidities were present in 87.8% of the patients. Of the 66 interviewees, 57 (86.3%) lived at home, 58 (87.8%) were self-sufficient, 12 (18.1%) required oxygen therapy, and 4 (6.1%) still required ventilatory support. There was a significant reduction in the quality of life and autonomy of the survivors, as evidenced by the Karnofsky scores (85 ± 9 vs. 79 ± 11, p = 0.03) and ADL scale scores (29 ± 5 vs. 25 ± 7; p = 0.01), respectively. Conclusions: In this patient sample, two-year mortality was quite high. Although there was a noticeable reduction in the functional status of the survivors, they remained self-sufficient.

Keywords: Pulmonary disease, chronic obstructive/mortality; Quality of life; Intensive care units.

Objective: To examine the trends in overall COPD mortality, as well as trends in in-hospital morbidity and mortality due to COPD, in Brazil, and to validate predictive models. Methods: This was a population-based study with a time-series analysis of cause-specific morbidity and mortality data for individuals ≥ 40 years of age, obtained from national health information systems for the 2000-2016 period. Morbidity and mortality rates, stratified by gender and age group, were calculated for the same period. We used regression analyses to examine the temporal trends and double exponential smoothing in our analysis of the predictive models for 2017. Results: Over the study period, COPD mortality rates trended downward in Brazil. For both genders, there was a downward trend in the southern, southeastern, and central-western regions. In-hospital morbidity rates declined in all regions, more so in the south and southeast. There were significant changes in the number of hospitalizations, length of hospital stay, and hospital expenses. The predictive models for 2017 showed error rates below 9% and were therefore validated. Conclusions: In Brazil, COPD age-adjusted mortality rates have declined in regions with higher socioeconomic indices, where there has been an even sharper decrease in all in-hospital morbidity and mortality variables. In addition to factors such as better treatment adherence and reduced smoking rates, socioeconomic factors appear to be involved in controlling COPD morbidity and mortality. The predictive models estimated here might also facilitate decision making and the planning of health policies aimed at treating COPD.

Keywords: Pulmonary disease, chronic obstructive/mortality; Pulmonary disease, chronic obstructive/epidemiology; Socioeconomic factors.

We report the case of a child with tetraplegia after cervical trauma, who subsequently underwent diaphragmatic pacemaker implantation. We reviewed the major indications for diaphragmatic pacing and the types of devices employed. We highlight the unequivocal benefit of diaphragmatic pacing in the social and educational reintegration of individuals with tetraplegia.

Keywords: Spinal cord injuries; Respiration, artificial; Pacemaker, artificial; Quadriplegia.

Objective: To determine whether COPD severity correlates with sputum cell counts, atopy, and asthma. Methods: This was a cross-sectional study involving 37 patients with COPD and 22 healthy subjects with normal lung function (controls). Sputum cell counts were determined by microscopy after centrifugation of samples. Skin prick tests were performed, and serum cytokines were determined by ELISA. Results: Patients were stratified by bronchodilator response: a non-reversible airflow limitation (nonRAL) group comprised 24 patients showing no significant post-bronchodilator change in FEV1; and a partially reversible airflow limitation (partialRAL) group comprised 13 patients showing FEV1 reversibility (post-bronchodilator FEV1 increase ≥ 12%). The proportion of eosinophils in sputum was higher in the partialRAL group than in the nonRAL group (p < 0.01), and there was an inverse correlation between the proportion of eosinophils and FEV1 (p < 0.05). However, none of the patients had a history of asthma and skin prick test results did not differ between the two groups. In the patient sputum samples, neutrophils predominated. Serum levels of TNF, IL-6, IL-8, and RANTES (CCL5) were higher in patients than in controls (p < 0.001) but did not differ between the two patient groups. Conclusions: COPD patients with partial FEV1 reversibility appear to have higher sputum eosinophil counts and greater airway hyperresponsiveness than do those with no FEV1 reversibility. However, we found that COPD severity did not correlate with atopy or with the cytokine profile.

Keywords: Pulmonary disease, chronic obstructive; Cytokines; Chemokines; Eosinophils; Sputum/cytology; Forced expiratory volume.

Objective: To identify symptoms of dysphagia in individuals with COPD, based on their responses on a self-perception questionnaire. Methods: The study comprised 35 individuals with COPD and 35 healthy individuals, matched for age and gender. The study group was assessed regarding COPD severity; sensation of dyspnea; body mass index (BMI); and symptoms of dysphagia. The control group was assessed regarding BMI and symptoms of dysphagia. Results: The most common symptoms of dysphagia in the study group were pharyngeal symptoms/airway protection (p < 0.001); esophageal symptoms/history of pneumonia (p < 0.001); and nutritional symptoms (p < 0.001). Positive correlations were found between the following pairs of variables: FEV1 and BMI (r = 0.567; p < 0.001); pharyngeal symptoms/airway protection and dyspnea (r = 0.408; p = 0.015); and esophageal symptoms/history of pneumonia and pharyngeal symptoms/airway protection (r = 0.531; p = 0.001). There was a negative correlation between nutritional symptoms and BMI (r = −0.046; p < 0.008). Conclusions: Our results show that the individuals with COPD presented with symptoms of dysphagia that were associated with the pharyngeal and esophageal phases of swallowing, as well as with the mechanism of airway protection, a history of pneumonia, and nutritional symptoms.

Keywords: Deglutition disorders; Pulmonary disease, chronic obstructive; Pathological conditions, signs and symptoms.

Objective: To determine the prevalence of atopy and to evaluate clinical, laboratory, and radiological profiles in patients with COPD. Methods: This was a cross-sectional study involving outpatients with stable COPD (defined by the clinical history and a post-bronchodilator FEV1/FVC < 70% of the predicted value). The patients completed a questionnaire regarding clinical characteristics and atopy, after which they underwent nasal lavage cytology, skin prick testing, chest X-rays, arterial blood gas analyses, and determination of total serum IgE. Results: Of the 149 subjects studied, 53 (35.6%), 49 (32.8%), and 88 (59.1%) presented with nasal eosinophilia, a positive skin prick test result, and symptoms of allergic rhinitis, respectively. Correspondence analysis confirmed these findings, showing two distinct patterns of disease expression: atopy in patients with COPD that was less severe; and no evidence of atopy in those with COPD that was more severe (reduced FEV1 and hyperinflation). There was a statistically significant association between nasal eosinophilia and a positive bronchodilator response. Conclusions: Using simple and reproducible methods, we were able to show that there is a high frequency of atopy in patients with COPD. Monitoring inflammation in the upper airways can be a useful tool for evaluating respiratory diseases in the elderly and in those with concomitant asthma and COPD, a clinical entity not yet fully understood.

Keywords: Pulmonary disease, chronic obstructive; Allergy and immunology; Nasal lavage fluid; Asthma; Rhinitis, allergic, perennial.

Objective: There are few studies on chronic obstructive pulmonary disease (COPD) establishing differences between the functional parameters of the disease and variants of sleep. The aim of the authors is to describe the sleep patterns of these patients and to investigate possible correlations among spirometric, gasometric, and polysomnographic variants. Methods: Transversal study using patients with COPD, submitted to spirometry, arterial gasometry, and polysomnography. Results: 21 male patients were studied with average age = 67 ± 9, 7 ± 4 average points in the Epworth sleep scale, average FEV1/FVC% = 54 ± 13.0, average PaO2 = 68 ± 11 mmHg, average PaCO2 = 37 ± 6 mmHg. Sleep efficiency decreased (65 ± 16%) with the decrease in slow wave sleep (8 ± 9%) and in rapid eye movement (REM) sleep (15 ± 8%). Average T90 = 43 ± 41%. Average apnea-hypopnea index (AHI) = 3 ± 5/h, two patients (9.5%) presented overlap syndrome. In the correlation analysis a correlation was observed between PaO2 and T90 (p < 0.01), PaCO2 and T90 (p < 0.05), and AHI and the cardiac rate in REM (p < 0.01). There was no correlation between spirometric and polysomnographic variants. Conclusion: The low sleep efficiency, the high number of awakenings, and shift in stages show the low quality of sleep. There were no linear correlations between the spirometric and polysomnographic variants.

Objective: To evaluate sleep-onset time variability, as well as sleep characteristics on weekday and weekend nights, in individuals with moderate-to-severe COPD. Methods: Sleep was objectively assessed by an activity/sleep monitor for seven consecutive nights in individuals with COPD. For analysis, individuals were divided into two groups according to sleep-onset time variability results, characterized by intrasubject standard deviation of sleep-onset time (SOTV) = 60 min or < 60 min. Results: The sample comprised 55 individuals (28 males; mean age = 66 ± 8 years; and median FEV1 % of predicted = 55 [38-62]). When compared with the SOTV<60min group (n = 24), the SOTV=60min group (n = 31) presented shorter total sleep time (5.1 ± 1.3 h vs. 6.0 ± 1.3 h; p = 0.006), lower sleep efficiency (73 ± 12% vs. 65 ± 13%; p = 0.030), longer wake time after sleep onset (155 ± 66 min vs. 115 ± 52 min; p = 0.023), longer duration of wake bouts (19 [16-28] min vs. 16 [13-22] min; p = 0.025), and higher number of steps at night (143 [104-213] vs. 80 [59-135]; p = 0.002). In general, sleep characteristics were poor regardless of the day of the week, the only significant difference being that the participants woke up about 30 min later on weekends than on weekdays (p = 0.013). Conclusions: Sleep-onset time varied over 1 h in a standard week in the majority of individuals with COPD in this sample, and a more irregular sleep onset indicated poor sleep quality both on weekdays and weekends. Sleep hygiene guidance could benefit these individuals if it is integrated with their health care.

Keywords: Pulmonary disease, chronic obstructive; Sleep; Actigraphy.

Objective: To infer the prevalence and variables predictive of isolated nocturnal hypoxemia and obstructive sleep apnea (OSA) in patients with COPD and mild hypoxemia. Methods: This was a cross-sectional study involving clinically stable COPD outpatients with mild hypoxemia (oxygen saturation = 90-94%) at a clinical center specializing in respiratory diseases, located in the city of Goiânia, Brazil. The patients underwent clinical evaluation, spirometry, polysomnography, echocardiography, arterial blood gas analysis, six-minute walk test assessment, and chest X-ray. Results: The sample included 64 patients with COPD and mild hypoxemia; 39 (61%) were diagnosed with sleep-disordered breathing (OSA, in 14; and isolated nocturnal hypoxemia, in 25). Correlation analysis showed that PaO2 correlated moderately with mean sleep oxygen saturation (r = 0.45; p = 0.0002), mean rapid eye movement (REM) sleep oxygen saturation (r = 0.43; p = 0.001), and mean non-REM sleep oxygen saturation (r = 0.42; p = 0.001). A cut-off point of PaO2 ≤ 70 mmHg in the arterial blood gas analysis was significantly associated with sleep-disordered breathing (OR = 4.59; 95% CI: 1.54-13.67; p = 0.01). The model showed that, for identifying sleep-disordered breathing, the cut-off point had a specificity of 73.9% (95% CI: 51.6-89.8%), a sensitivity of 63.4% (95% CI: 46.9-77.9%), a positive predictive value of 81.3% (95% CI: 67.7-90.0%), and a negative predictive value of 53.1% (95% CI: 41.4-64.4%), with an area under the ROC curve of 0.69 (95% CI: 0.57-0.80), correctly classifying the observations in 67.2% of the cases. Conclusions: In our sample of patients with COPD and mild hypoxemia, the prevalence of sleep-disordered breathing was high (61%), suggesting that such patients would benefit from sleep studies.

Keywords: Pulmonary disease, chronic obstructive/complications; Sleep wake disorders/epidemiology; Anoxia/etiology.

Objective: To evaluate the frequency of asthma-COPD overlap (ACO) in patients with COPD and to compare, from a clinical, laboratory, and functional point of view, patients with and without ACO, according to different diagnostic criteria. Methods: The participants underwent evaluation by a pulmonologist, together with spirometry and blood tests. All of the patients were instructed to record their PEF twice a day. The diagnosis of ACO was based on the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar (PLATINO, Latin American Project for the Investigation of Obstructive Lung Disease) criteria, the American Thoracic Society (ATS) Roundtable criteria, and the Spanish criteria. We investigated patient histories of exacerbations and hospitalizations, after which we applied the COPD Assessment Test and the modified Medical Research Council scale, to classify risk and symptoms in accordance with the GOLD criteria. Results: Of the 51 COPD patients, 14 (27.5%), 8 (12.2%), and 18 (40.0) were diagnosed with ACO on the basis of the PLATINO, ATS Roundtable, and Spanish criteria, respectively. The values for pre-bronchodilator FVC, post-bronchodilator FVC, and pre-bronchodilator FEV1 were significantly lower among the patients with ACO than among those with COPD only (1.9 ± 0.4 L vs. 2.4 ± 0.7 L, 2.1 ± 0.5 L vs. 2.5 ± 0.8 L, and 1.0 ± 0.3 L vs. 1.3 ± 0.5 L, respectively). When the Spanish criteria were applied, IgE levels were significantly higher among the patients with ACO than among those with COPD only (363.7 ± 525.9 kU/L vs. 58.2 ± 81.6 kU/L). A history of asthma was more common among the patients with ACO (p < 0.001 for all criteria). Conclusions: In our sample, patients with ACO were more likely to report previous episodes of asthma and had worse lung function than did those with COPD only. The ATS Roundtable criteria appear to be the most judicious, although concordance was greatest between the PLATINO and the Spanish criteria.

Keywords: Asthma/diagnosis; Pulmonary disease, chronic obstructive/diagnosis; Asthma-chronic obstructive pulmonary disease overlap syndrome/diagnosis.