The chronic bronchitis phenotype in subjects with and without COPD: the PLATINO study.

Little information exists regarding the epidemiology of the chronic bronchitis phenotype in unselected chronic obstructive pulmonary disease (COPD) populations. We examined the prevalence of the chronic bronchitis phenotype in COPD and non-COPD subjects from the PLATINO study, and investigated how it is associated with important outcomes. Post-bronchodilator forced expiratory volume in 1 s/forced vital capacity <0.70 was used to define COPD. Chronic bronchitis was defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs. We also analysed another definition: cough and phlegm on most days, at least 3 months per year for ≥ 2 yrs. Spirometry was performed in 5,314 subjects (759 with and 4,554 without COPD). The proportion of subjects with and without COPD with chronic bronchitis defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs was 14.4 and 6.2%, respectively. Using the other definition the prevalence was lower: 7.4% with and 2.5% without COPD. Among subjects with COPD, those with chronic bronchitis had worse lung function and general health status, and had more respiratory symptoms, physical activity limitation and exacerbations. Our study helps to understand the prevalence of the chronic bronchitis phenotype in an unselected COPD population at a particular time-point and suggests that chronic bronchitis in COPD is possibly associated with worse outcomes.

Analysis of risk factors for extubation failure in subjects submitted to non-emergency elective intracranial surgery.

BACKGROUND: Extubation failure is defined as the re-institution of respiratory support ranging from 24 to 72 hours following scheduled extubation and occurs in 2% to 25% of extubated patients. The aim of this study was to determine clinical and surgical risk factors that may predict extubation failure in patients submitted to non-emergency intracranial surgery. METHODS: This was a prospective observational cohort study. The study was carried out on 317 subjects submitted to non-emergency intracranial surgery for tumors, aneurysms, and arteriovenous malformation. Preoperative assessment was performed and subjects were followed up for the determination of extubation failure until either discharge from hospital or death. RESULTS: Twenty-six (8.2%) of the 317 subjects experienced extubation failure following surgery. The following variables were considered for the multivariate analysis: level of consciousness at the time of extubation, duration of mechanical ventilation prior to extubation, sex and the use of intraoperative mannitol. The multivariate analysis determined that the most important variable for extubation failure was the level of consciousness at the time of extubation (P = .001), followed by female sex, which also showed to be significant (P = .006). CONCLUSIONS: Lower level of consciousness (GCS 8T-10T) and female sex were considered risk factors for extubation failure in subjects submitted to elective intracranial surgery.

Reversibility of impaired nasal mucociliary clearance in smokers following a smoking cessation programme.

BACKGROUND AND OBJECTIVE: Smoking cessation (SC) is recognized as reducing tobacco-associated mortality and morbidity. The effect of SC on nasal mucociliary clearance (MC) in smokers was evaluated during a 180-day period. METHODS: Thirty-three current smokers enrolled in a SC intervention programme were evaluated after they had stopped smoking. Smoking history, Fagerström's test, lung function, exhaled carbon monoxide (eCO), carboxyhaemoglobin (COHb) and nasal MC as assessed by the saccharin transit time (STT) test were evaluated. All parameters were also measured at baseline in 33 matched non-smokers. RESULTS: Smokers (mean age 49 ± 12 years, mean pack-year index 44 ± 25) were enrolled in a SC intervention and 27% (n = 9) abstained for 180 days, 30% (n = 11) for 120 days, 49.5% (n = 15) for 90 days or 60 days, 62.7% (n = 19) for 30 days and 75.9% (n = 23) for 15 days. A moderate degree of nicotine dependence, higher education levels and less use of bupropion were associated with the capacity to stop smoking (P < 0.05). The STT was prolonged in smokers compared with non-smokers (P = 0.002) and dysfunction of MC was present at baseline both in smokers who had abstained and those who had not abstained for 180 days. eCO and COHb were also significantly increased in smokers compared with non-smokers. STT values decreased to within the normal range on day 15 after SC (P < 0.01), and remained in the normal range until the end of the study period. Similarly, eCO values were reduced from the seventh day after SC. CONCLUSIONS: A SC programme contributed to improvement in MC among smokers from the 15th day after cessation of smoking, and these beneficial effects persisted for 180 days.

Reasons to avoid vitamin D deficiency during COVID-19 pandemic.

The effects of vitamin D on the musculoskeletal system are well established. Its deficiency causes osteomalacia, secondary hyperparathyroidism, and an increased risk for fractures and falls. However, clinical and experimental evidence points to extra-skeletal actions of vitamin D, including on immune and respiratory systems. Thus, during this COVID-19 pandemic, a possible deleterious role of vitamin D deficiency has been questioned. This paper aims to present a brief review of the literature and discuss, based on evidence, the role of vitamin D in the lung function and in the prevention of respiratory infections. Relevant articles were searched in the databases MEDLINE/PubMed and SciELO/LILACS. The mechanisms of vitamin D action in the immune system response will be discussed. Clinical data from systematic reviews and meta-analyses show benefits in the prevention of respiratory infections and improvement of pulmonary function when vitamin D-deficient patients are supplemented. At the time of writing this paper, no published data on vitamin D supplementation for patients with COVID-19 have been found. Vitamin D supplementation is recommended during this period of social isolation to avoid any deficiency, especially in the context of bone outcomes, aiming to achieve normal values of 25(OH)D. The prevention of respiratory infections and improvement of pulmonary function are additional benefits observed when vitamin D deficiency is treated. Thus far, any protective effect of vitamin D specifically against severe COVID-19 remains unclear. We also emphasize avoiding bolus or extremely high doses of vitamin D, which can increase the risk of intoxication without evidence of benefits.

Impact of asthma control on different age groups in five Latin American countries.

BACKGROUND: Asthma is a chronic airway inflammatory condition of the airway and is classified as controlled, partially controlled, and uncontrolled. Patients with uncontrolled asthma are at greater risk for hospitalizations and visits to emergencies, and the condition has greater impact on their daily lives. The aim of this study was to evaluate asthma control, the use of health resources, and asthma's impact on the activities of daily living of patients with different age groups in 5 Latin American countries. METHODS: This was a retrospective analysis of The Latin America Asthma Insights and Management (LA AIM) study carried out in Argentina, Brazil, Mexico, Venezuela, and Puerto Rico. Asthmatics were splited into 3 age groups: 12-17, >17-40 and > 40 years old. An interview face to face was carried out and patients answered a questionnaire of 53 questions related to 5 main domains of asthma: symptoms, impact of asthma on daily living activities, patients' perceptions of asthma control, exacerbations, and treatment/medication. RESULTS: A total of 2167 asthmatics were interviewed. There was a low percentage of controlled patients (mean 9%) in all 3 groups with no particular difference among the five countries, but Venezuelan patients had a 71% chance of having uncontrolled asthma (p < 0.001). CONCLUSION: In the 3 age groups, patients experienced poor asthma control, with no significant differences among the countries. Patients who used control medication had a greater chance of controlling their asthma, and those who had emergency health care visits had a greater chance of having uncontrolled asthma.

Multidisciplinary education with a focus on COPD in primary health care.

OBJECTIVE: To evaluate the use of video lessons on the topic of COPD as a training tool for a multidisciplinary team working in the primary health care sector. METHODS: This was a quasi-experimental study involving a multidisciplinary team working at a primary health care clinic. The level of knowledge about COPD was measured by applying a specific, 16-item questionnaire - before, immediately after, and three months after the video lessons. In a set of six structured video lessons, the training focused on the prevention, case-finding, treatment, and monitoring of cases of COPD. The data were analyzed with the Friedman test, the Kruskal-Wallis test, Tukey's post hoc test, Dunnett's test, and the Bonferroni test. RESULTS: There was a significant difference between the periods before and immediately after the training in terms of the scores on 15 of the 16 items on the questionnaire regarding the level of knowledge about COPD. The median total score of the participants increased significantly, from 60 points before the training to 77 points immediately thereafter and 3 months thereafter (p < 0.001 for both). Before the training, 23 (63.9%) and 13 (36.1%) of the members of the multidisciplinary team presented strong and very strong levels of agreement, respectively, among the 16 questionnaire items. After the training, 100% of the individuals presented a very strong degree of agreement. CONCLUSIONS: Multidisciplinary education through video lessons increased the knowledge of COPD on the part of a primary health care team, and the knowledge acquired was retained for at least three months after the intervention.

Anthropometric status of individuals with COPD in the city of São Paulo, Brazil, over time - analysis of a population-based study.

OBJECTIVE: To evaluate the anthropometric data obtained for residents of the city of São Paulo, Brazil, in a study of Latin America conducted in two phases (baseline, in 2003, and follow-up, in 2012). METHODS: This was an analysis of data obtained for São Paulo residents in a two-phase population-based study evaluating the prevalence of COPD and its relationship with certain risk factors among individuals ≥ 40 years of age. The anthropometric data included values for weight, height, body mass index (BMI), and waist circumference. In the follow-up phase of that study, the same variables were evaluated in the same population sample as that of the baseline phase. RESULTS: Of the 1,000 São Paulo residents enrolled in the baseline phase of that study, 587 participated in the follow-up phase, and 80 (13.6%) of those 587 subjects had COPD. Comparing the baseline and follow-up phases, we found increases in all anthropometric measures in both groups (COPD and non-COPD), although the differences were significant only in the non-COPD group. The subjects with mild COPD showed increases in weight and BMI (Δweight = 1.6 ± 5.7 and ΔBMI = 0.7 ± 2.2), whereas those with moderate or severe COPD showed reductions (Δweight = -1.7 ± 8.1 and ΔBMI = -0.4 ± 3.0), as did those with severe or very severe COPD (Δweight = -0.5 ± 5.4 and ΔBMI = -0.8 ± 3.3). CONCLUSIONS: Between the two phases of the study, the subjects with mild COPD showed increases in weight and BMI, whereas those with a more severe form of the disease showed reductions.

Incidence and risk factors for postoperative pulmonary complications in elective intracranial surgery.

OBJECT: It has been shown that craniotomy may lead to a decrease in lung volumes and arterial blood gas tensions as well as a change in the respiratory pattern. The purpose of this study was to determine the incidence of postoperative pulmonary complications (PPCs) and the mortality rate in patients who have undergone elective craniotomy and to evaluate the associations between preoperative and postoperative variables and PPCs in this population. METHODS: Two hundred thirty-six patients were followed up based on a protocol including a clinical questionnaire, physical examination and observation of clinical characteristics in the preoperative period, type of surgery performed, duration of surgery, time spent in the intensive care unit (ICU) and hospital, and the occurrence of any PPCs. RESULTS: Postoperative pulmonary complications occurred in 58 patients (24.6%) and 23 other patients (10%) died. Predicting factors for PPCs according to multivariate analyses were as follows: type of surgery performed (p < 0.0001), prolonged mechanical ventilation >or= 48 hours (p < 0.0001), time spent in the ICU > 3 days (p < 0.0001), decrease in level of consciousness (p < 0.002), duration of surgery >or= 300 minutes (p < 0.01), and previous chronic lung disease (p < 0.04). CONCLUSIONS: The incidence from March 2003 to March 2005 of PPCs in patients who had undergone craniotomy was 25% and death occurred in 10%. Some risk factors for PPCs may be predicted such as the type of surgery performed, prolonged mechanical ventilation, a longer time in the ICU, a decreased level of consciousness, duration of surgery, and previous chronic lung disease.

Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study.

BACKGROUND: The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD. METHODS: COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2)). RESULTS: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI. CONCLUSIONS: BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.

[Treatment of chronic obstructive pulmonary disease in 5 Latin American cities: the PLATINO study]. / Tratamiento de la EPOC en 5 ciudades de América Latina: estudio PLATINO.

OBJECTIVE: PLATINO project is a population-based study designed to determine the prevalence of chronic obstructive pulmonary disease (COPD) in São Paulo, Brazil; Mexico City, Mexico; Montevideo, Uruguay; Santiago de Chile, Chile; and Caracas, Venezuela. The objective of this portion of PLATINO was to describe preventive and pharmacological treatment of COPD patients and factors associated with such treatment. PATIENTS AND METHODS: Eligible subjects completed a questionnaire and underwent postbronchodilator spirometry. RESULTS: Of the total of 5529 individuals who answered items referring to treatment, 758 had COPD (ratio of postbronchodilator forced expiratory volume in 1 second to forced vital capacity of <0.7), and 86 of them had been previously diagnosed by a physician. Among all COPD patients, only half of smokers or former smokers had been advised to quit and 24.7% had received some type of respiratory medication. Only 13.5% had used inhaled corticosteroids, and those were the patients with the most severe disease. In the group of patients who had a previous medical diagnosis of COPD, 69% of the smokers or former smokers had been advised to quit by a physician and 75.6% had received respiratory medication in the preceding year: 43% reported having used inhaled medication and 36% had used bronchodilators. Rates of vaccination against influenza and the use of mucolytic drugs and inhalers varied from one health care facility to another. All drug prescriptions were based on previous spirometry. CONCLUSIONS: Spirometry emerged not only as a diagnostic tool, but also as a factor associated with treatment, against a background of uneven use of available health care resources in these 5 Latin American cities.

Postoperative study of vital capacity and ventilation measurements following elective craniotomy.

CONTEXT AND OBJECTIVE: Changes in pulmonary function commonly occur after general surgery. The aims were to evaluate vital capacity, tidal volume and respiratory frequency among patients undergoing elective craniotomy and to determine possible correlations of these parameters with surgery duration and etiology for neurosurgery. DESIGN AND SETTING: Prospective, open study at a tertiary university hospital. METHODS: Twenty-six patients underwent elective craniotomy for aneurysm clipping (11) or tumor resection (15). Vital capacity (VC), tidal volume (TV), minute volume (VE) and respiratory rate were determined before the operation and on the first to fourth postoperative days. RESULTS: There were significant decreases of 25% in VC, 22% in TV and 12% in VE (p < 0.05) and no significant increase in respiratory frequency (5%) on the first postoperative day. VE returned to baseline on the second postoperative day and TV on the third postoperative day, while VC was 8% lower on the fourth postoperative day, compared with before the operation (p < 0.05). VC reduction was significantly greater in patients undergoing aneurysm clipping (43%) than in patients undergoing tumor resection (14%) when surgery duration was more than four hours (p < 0.05), with no significant change when surgery duration was less than four hours. CONCLUSION: Reductions in VC, TV and VE were observed during the postoperative period in patients undergoing aneurysm clipping or tumor resection. The reductions in VC and TV were greater in patients undergoing craniotomy due to aneurysm and with longer surgery duration.

Translation and cultural adaptation of the stroke impact scale 2.0 (SIS): a quality-of-life scale for stroke.

BACKGROUND: No specific quality-of-life scale for stroke patients has previously been translated and evaluated for reproducibility, for use in the Portuguese language. Internationally, the instrument for this purpose is the Stroke Impact Scale 2.0 (SIS). Use of of SIS enables comprehensive analysis on the impact of mild and moderate stroke on patients' lives. The aims here were to translate SIS into Portuguese, adapt it culturally, evaluate its reproducibility and correlate it with SF-36 among stroke patients. DESIGN AND SETTING: Translation and validation study. METHODS: The process of initial and retrograde translation was performed, in addition to cultural adaptation to the Brazilian language and culture. SIS was applied to 40 patients, who answered the questions three times. On the first day, the scale was applied twice by two independent researchers (to evaluate interobserver reproducibility). Fifteen days later, the scale was applied for a third time by another researcher (intraobserver reproducibility). The intraclass correlation coefficient (ICC) was used to measure the reproducibility of the SIS scale. RESULTS: The reproducibility of the whole scale was very good (ICC: 0.73 to 0.99). Intraobserver reproducibility in all domains was also very good (ICC: 0.85 to 0.95). Comparison of SIS with SF-36 showed that the domains of strength, mobility and activities of daily living (ADLs) correlated moderately with the functional capacity domain, as did the ADL domain with general health status. The other correlations were weak. The depression domain showed a moderate negative correlation with the memory and communication domains. CONCLUSION: The translation of the SIS 2.0 scale was easy to understand and it had good reproducibility among stroke patients.

Replacement of the 6-min walk test with maximal oxygen consumption in the BODE Index applied to patients with COPD: an equivalency study.

INTRODUCTION: Patients with COPD have decreased exercise capacity and low oxygen consumption (Vo(2)) during formal cardiopulmonary exercise testing, and lower scores on health-related quality of life questionnaires. When isolated, these three variables show different correlations with COPD mortality. The multidimensional BODE (body mass index[BMI], airflow obstruction, dyspnea, and exercise capacity in COPD) index, which comprises four variables including the 6-min walk test (6MWT), predicts survival in COPD. OBJECTIVES: To evaluate the degree of association between the values of the BODE index using the 6MWT with the BODE index using maximal Vo(2) (Vo(2)max) obtained in a maximal incremental test. MATERIALS AND METHODS: Fifty patients with mild-to-severe COPD (average age, 63.5 +/- 9.9 years; FEV(1), 65.3 +/- 23.6% of predicted) [+/- SD] had BMI, spirometric function (FVC and FEV(1)), and dyspnea status (Medical Research Council) evaluated. Two BODE index scores were then completed: one with the 6MWT, and one with the Vo(2)max obtained during maximal incremental testing on a treadmill. RESULTS: Correlation between BODE index and Vo(2) in milliliters per minute per kilogram (r = - 0.41) was weak; the correlation was moderate (r = - 0.64) when Vo(2) percentage of predicted was used. The BODE index modified by replacing the 6MWT with Vo(2) showed excellent correlations with Vo(2) in milliliters per minute per kilogram (r = 0.92) and Vo(2) percentage of predicted (r = 0.95). CONCLUSION: The excellent correlation between the conventional BODE index and the modified BODE index with Vo(2) replacing the 6MWT enables us to reach the conclusion that the original BODE index is very effective in the evaluation of COPD patients.

Diagnostic labeling of COPD in five Latin American cities.

BACKGROUND: COPD is a major worldwide problem with a rising prevalence. Despite its importance, there is a lack of information regarding underdiagnosis and misdiagnosis of COPD in different countries. As part of the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar study, we examined the relationship between prior diagnostic label and airway obstruction in the metropolitan areas of five Latin American cities (São Paulo, Santiago, Mexico City, Montevideo, and Caracas). METHODS: A two-stage sampling strategy was used in each of the five areas to obtain probability samples of adults aged >or= 40 years. Participants completed a questionnaire that included questions on prior diagnoses, and prebronchodilator and postbronchodilator spirometry. A study diagnosis of COPD was based on airway obstruction, defined as a postbronchodilator FEV(1)/FVC < 0.70. RESULTS: Valid spirometry and prior diagnosis information was obtained for 5,303 participants; 758 subjects had a study diagnosis of COPD, of which 672 cases (88.7%) had not been previously diagnosed. The prevalence of undiagnosed COPD was 12.7%, ranging from 6.9% in Mexico City to 18.2% in Montevideo. Among 237 subjects with a prior COPD diagnosis, only 86 subjects (36.3%) had postbronchodilator FEV(1)/FVC < 0.7, while 151 subjects (63.7%) had normal spirometric values. In the same group of 237 subjects, only 34% reported ever undergoing spirometry prior to our study. CONCLUSIONS: Inaccurate diagnostic labeling of COPD represents an important health problem in Latin America. One possible explanation is the low rate of spirometry for COPD diagnosis.

Evaluation of obstructive sleep apnea in non-cystic fibrosis bronchiectasis: A cross-sectional study.

The relationship between sleep disorders and bronchiectasis has not been well described. We hypothesize that, due to the irreversible dilatation of the bronchi, the presence of secretions, and airflow obstruction, patients with non-cystic fibrosis bronchiectasis may be predisposed to hypoxemia during sleep, or to symptoms that may lead to arousal. A cross-sectional observational study was performed involving 49 patients with a clinical diagnosis of non-cystic fibrosis bronchiectasis (NCFB). All patients underwent clinical evaluation, spirometry, and polysomnography, and were evaluated for the presence of excessive daytime sleepiness (EDS) and risk of obstructive sleep apnea (OSA). The mean age of the participants was 50.3 ± 13.6 years; 51.1% of patients were male and had a mean body mass index of 23.8 ± 3.4 kg/m2. The mean total sleep time (TST) was 325.15 ± 64.22 min with a slight reduction in sleep efficiency (84.01 ± 29.2%). Regarding sleep stages, stage 1 sleep and REM sleep were abnormal. OSA was present in 40.82% of the patients. The mean arousal index was 5.6 ± 2.9/h and snoring was observed in 71.43% of the patients. The oxygen desaturation index (ODI) was 14.35 ± 15.36/h, mean minimum oxygen saturation (SpO2 nadir) was 83.29 ± 7.99%, and mean TST with an SpO2 less than 90% was 30.21 ± 60.48 min. EDS was exhibited by 53.06% of the patients and 55.1% were at high risk of developing OSA. The patients infected by Pseudomonas aeruginosa had higher apnea-hypopnea indices, ODI, and TST with SpO2 < 90%, and lower values of SpO2 nadir. Adult patients with clinically stable NCFB, especially those infected by Pseudomonas aeruginosa, display EDS and a high prevalence of OSA, associated with considerable oxygen desaturation during sleep.

Recommendations for the pharmacological treatment of COPD: questions and answers.

The treatment of COPD has become increasingly effective. Measures that range from behavioral changes, reduction in exposure to risk factors, education about the disease and its course, rehabilitation, oxygen therapy, management of comorbidities, and surgical and pharmacological treatments to end-of-life care allow health professionals to provide a personalized and effective therapy. The pharmacological treatment of COPD is one of the cornerstones of COPD management, and there have been many advances in this area in recent years. Given the greater availability of drugs and therapeutic combinations, it has become increasingly challenging to know the indications for, limitations of, and potential risks and benefits of each treatment modality. In order to critically evaluate recent evidence and systematize the major questions regarding the pharmacological treatment of COPD, 24 specialists from all over Brazil gathered to develop the present recommendations. A visual guide was developed for the classification and treatment of COPD, both of which were adapted to fit the situation in Brazil. Ten questions were selected on the basis of their relevance in clinical practice. They address the classification, definitions, treatment, and evidence available for each drug or drug combination. Each question was answered by two specialists, and then the answers were consolidated in two phases: review and consensus by all participants. The questions answered are practical questions and help select from among the many options the best treatment for each patient and his/her peculiarities.

Chronic obstructive pulmonary disease in five Latin American cities (the PLATINO study): a prevalence study.

BACKGROUND: Both the prevalence and mortality attributable to chronic obstructive pulmonary disease (COPD) seem to be increasing in low-income and middle-income countries, but few data are available. The aim of the PLATINO study, launched in 2002, was to describe the epidemiology of COPD in five major Latin American cities: São Paulo (Brazil), Santiago (Chile), Mexico City (Mexico), Montevideo (Uruguay), and Caracas (Venezuela). METHODS: A two-stage sampling strategy was used in the five areas to obtain probability samples of adults aged 40 years or older. These individuals were invited to answer a questionnaire and undergo anthropometry, followed by prebronchodilator and postbronchodilator spirometry. We defined COPD as a ratio less than 0.7 of postbronchodilator forced expiratory volume in the first second over forced vital capacity. FINDINGS: Complete information, including spirometry, was obtained from 963 people in São Paulo, 1173 in Santiago, 1000 in Mexico City, 885 in Montevideo, and 1294 in Caracas. Crude rates of COPD ranged from 7.8% (78 of 1000; 95% CI 5.9-9.7) in Mexico City to 19.7% (174 of 885; 17.2-22.2) in Montevideo. After adjustment for key risk factors, the prevalence of COPD in Mexico City remained significantly lower than that in other cities. INTERPRETATION: These results suggest that COPD is a greater health problem in Latin America than previously realised. Altitude may explain part of the difference in prevalence. Given the high rates of tobacco use in the region, increasing public awareness of the burden of COPD is important.

The long-term stability of portable spirometers used in a multinational study of the prevalence of chronic obstructive pulmonary disease.

BACKGROUND: We report the performance of an ultrasound-based portable spirometer (EasyOne) used in a population-based survey of the prevalence of chronic obstructive pulmonary disease, conducted in 5 Latin American cities: São Paulo, Brazil; México City, México; Montevideo, Uruguay; Santiago, Chile; and Caracas, Venezuela (the Latin American COPD Prevalence Study [PLATINO]). METHODS: During the survey period (which ranged from 3 months to 6 months in the various locations) we collected daily calibration data from the 70 EasyOne spirometers used in the 5 survey cities. The calibrations were conducted with a 3-L syringe, and the calibration data were stored in the spirometer's database. RESULTS: Ninety-seven percent of the calibration volumes were within +/- 64 mL (2.1%) of the 3-L calibration signal. Excluding data from the first city studied (São Paulo), where one calibration syringe had to be replaced, 98% of the calibration checks were within +/- 50 mL (1.7%). The measured volume was affected only minimally by the syringe's peak flow or emptying time. CONCLUSION: In these 70 EasyOne spirometers neither calibration nor linearity changed during the study. Such calibration stability is a valuable feature in spirometry surveys and in the clinical setting.

[Optimizing exercise performance with a continuously paced shuttle walk test for patients with chronic obstructive pulmonary disease]. / Optimización de la capacidad de realización de ejercicio físico mediante una prueba de la lanzadera por tramos con estimulación auditiva continua en pacientes con EPOC.

BACKGROUND: A continuously paced shuttle walk test (SWTp) was developed to test the hypothesis that speed and rhythm could be more optimally imposed by an easier-to-follow sound stimulus at every step. The objective of this study was to assess the reproducibility of the SWTp and to compare the performance of patients with chronic obstructive pulmonary disease (COPD) on the conventional and optimally paced forms of the test. PATIENTS AND METHODS: The walk test results of 24 COPD patients were studied. All patients completed 2 SWTp sessions and a conventional SWT in random order, after an initial practice test for each. A portable device was used to measure peak oxygen uptake (VO2) in 6 patients. RESULTS: The intraclass correlation coefficient (Cronbach's alpha) was 0.95 for the STWp. The Pearson correlation coefficient between distance walked and peak VO2 in the SWTp was 0.86 (P < .02). Better performance was achieved during the SWTp (peak VO2, 3.30 mL/kg/min; P < .01; distance walked, 32 m, P < .001) than during the conventional SWT. The SWTp showed excellent reproducibility. CONCLUSIONS: COPD patients can achieve better performance with the stimuli provided in the SWTp than on the SWT.

[Spirometric reference values in 5 large Latin American cities for subjects aged 40 years or over]. / Valores de referencia espirométrica en 5 grandes ciudades de Latinoamérica para sujetos de 40 o más años de edad.

OBJECTIVE: In clinical practice, spirometry is a extremely useful test that requires strict quality control, an appropriate strategy for interpretation, and reliable reference values. The aim of this study was to report spirometric reference values for 5 cities in Latin America. PATIENTS AND METHODS: From data for 5315 subjects who had undergone spirometry in the PLATINO study in Caracas, Mexico City, Santiago, São Paulo, and Montevideo, we selected information for 906 (17%) individuals aged between 40 years and 90 years to provide reference values. The chosen subjects had never smoked, were asymptomatic, had not been diagnosed with lung disease, and were not obese. Multiple regression models were constructed with the following spirometric parameters: forced expiratory volume in 1 second (FEV1) and in 6 seconds (FEV6), peak expiratory flow, forced vital capacity (FVC), FEV1/FEV6, FEV1/FVC, and forced midexpiratory flow rate. Height, sex, and age were also included in the model. RESULTS: Average values for the subjects studied were similar to those for the white North American population and the Mexican-American population of the third National Health and Nutrition Examination Survey, but exceeded those of the black population of the same survey by 20%. CONCLUSIONS: The proposed reference values are an improvement on those currently available for Latin America because the participants were chosen by population sampling methods and standardized up-to-date methodology was used.