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Resumen La neumonía adquirida en la comunidad (NAC) es una enfermedad infecciosa común y potencialmente grave que ocasiona elevada morbilidad y mortalidad. La terapia con corticosteroides (CS) sistémicos se ha propuesto para el manejo de pacientes adultos hospitalizados por neumonía adquirida en la comunidad. Objetivos: Evaluar la eficacia y seguridad del tratamiento con corticosteroides sistémicos en pacientes con NAC grave. Métodos: Se buscó la información actualizada en cinco bases de datos: PubMed, Scielo, Epistemonikos, Lilacs y Cochrane Library. Se evaluaron los ensayos clínicos controlados aleatorizados que examinaron la eficacia y seguridad de los corticosteroides en adultos hospitalizados con NAC grave. Resultados: Se incluyeron diez revisiones sistemáticas y quince estudios primarios que reclutaron pacientes hospitalizados con NAC grave. La terapia con corticosteroides redujo significativamente la mortalidad por todas las causas (cociente de riesgo [RR]: 0,58; IC95%: 0,40 a 0,84), fracaso clínico precoz (RR: 0,32; IC95%: 0,15 a 0,7), riesgo de síndrome de dificultad respiratoria del adulto (RR: 0,23; IC95%: 0,07 a 0,80), necesidad de ventilación mecánica (RR: 0,40; IC95%: 0,20 a 0,77) y se acortó la estancia hospitalaria (diferencia media: −2.91 días; IC95%: − 4,92 a −0,89). La terapia esteroidal aumentó el riesgo de hiperglicemia (RR: 1,72; IC95%: 1,38 a 2,14) pero no la frecuencia de hemorragia gastrointestinal (RR: 0,91; IC95%: 0,40 a 2,05). Conclusión: La terapia con corticosteroides sistémicos disminuye significativamente la mortalidad, riesgo de complicaciones y acorta la estancia hospitalaria en pacientes con NAC grave. Estos resultados deben ser confirmados por estudios controlados aleatorizados de mayor potencia.

El cáncer pulmonar es la principal causa de muerte por neoplasia a nivel mundial. En Chile se desconoce la magnitud del problema y la sobrevida asociada al diagnóstico. Material y Métodos: Se examinó una cohorte de 202 pacientes adultos con cáncer pulmonar confirmados histopatológicamente en una red de salud entre Enero de 2007 y Diciembre de 2011. Se accedió a las fichas clínicas y archivos de imágenes de los pacientes, registrando las variables clínicas, histológicas, imagenológicas y la etapificación clínica. Se siguió prospectivamente a los pacientes hasta Diciembre de 2013 para determinar sobrevida. Resultados: La edad promedio de la cohorte fue de 68,1 ± 11,5 años, 53% eran varones y 86% tenía historia de tabaquismo. El 82,2% de los casos presentaron síntomas al momento del diagnóstico, siendo la tos el más frecuente. La variedad histológica preponderante fue el adenocarcinoma (42%), seguido del carcinoma escamoso (26,2%). En las mujeres la mayoría de los tumores correspondieron a adenocarcinomas (56,4% del total) y en varones predominaron el adenocarcinoma (37%) y el carcinoma escamoso (33,3%). La mayoría de los pacientes se diagnosticaron en estadios avanzados de la enfermedad. La sobrevida global a los 36 meses fue 46,1%. La sobrevida media por estadio clínico fue de 70,7 meses en el estadio I, 60,3 meses en estadio II, 47,1 meses en IIIA, 12,3 meses en IIIB y 11,7 meses en IV Según histología, la sobrevida media en meses fue de 36,6 en adenocarcinoma, 33,8 en carcinoma escamoso, 20,9 en células grandes, 11,9 en células pequeñas y 19,6 en tumor no células pequeñas indiferenciado. No hubo diferencias significativas en la sobrevida por edad y género. Conclusión: La variedad histológica más frecuente es el adenocarcinoma y la sobrevida está relacionada a la etapificación clínica y variedad histológica.

Introducción: En ausencia de ecuaciones de referencia nacionales, la ATS recomienda comparar los resultados de capacidad de difusión de monóxido de carbono de sujetos sanos en una muestra representativa de la población, con ecuaciones internacionales y escoger entre estas, aquella que presente la menor suma de los residuos. Objetivo: Comparar las ecuaciones de referencia disponibles en la literatura e identificar cuál cumple mejor los criterios de selección. Método: Revisamos 10 ecuaciones de referencia; calculamos la suma de los residuos de cada una de ellas para una muestra de 71 sujetos sanos y describimos las características que inciden en la variabilidad de cada una. Resultados: Desde 1985 se ha utilizado el método de respiración única. Sólo las ecuaciones de Thompson y cols. 2008fueron obtenidas con lectura instantánea. Las ecuaciones que presentan menor suma de residuos (Miller, Roca y Cotes) incluyen fumadores y ex fumadores. Conclusiones: Es necesaria una ecuación nacional en sujetos sanos no fumadores, con metodología que asegure baja variabilidad.

Introducción: La actividad física diaria está reducida en la EPOC lo que se asocia a una mayor morbimortalidad. La indicación médica de caminar más se ha demostrado poco eficaz y, en nuestro medio, se desconoce el beneficio del uso de los contadores de pasos en la EPOC. Objetivo: Determinar el efecto de los contadores de pasos para incentivar la actividadfísica en la EPOC. Método: 55 Pacientes con EPOC fueron incorporados a un programa de tres meses destinado a aumentar su actividad física y fueron asignados aleatoriamente a dos grupos: en uno el paciente autocontroló su actividad con un contador de pasos (grupo experimental) y en el otro se siguió el manejo habitual (grupo control). Al comienzo y al final del estudio se realizaron las siguientes mediciones: promedio de pasos caminados por día medidos en una semana, espirometría, caminata de seis minutos (C6M), disnea con escala de la Medical Research Council Modificada (mMRC) y calidad de vida mediante cuestionario de Saint George (SGRQ) y COPD Assessment Test (CAT). Resultados: 69% de los pacientes eran hombres, edad promedio 68 años, VEF1ICVF = 55%, VEF(1)63%predicho. El grupo experimental (n = 29) y el control (n = 26) presentaron características basales comparables. El grupo experimental presentó una diferencia significativa en el incremento de los pasos por día en comparación con el grupo control (mediana de 2073,5 versus -68, p < 0,001). También hubo diferencia en la reducción del componente síntomas del SGRQ (promedio de -9,65 versus 0,05 puntos, grupo experimental versus control, p = 0,048). Conclusión: Un programa de incentivo de la actividad física apoyado con contadores de pasos es útil para incentivar la actividad física en la EPOC.

Background: Chest computed tomography (CT) scan may improve lung cancer detection at early stages in high risk populations. Aim: To assess the diagnostic performance of chest CT in early lung cancer detection in patients with chronic obstructive pulmonary disease (COPD). Patients and Methods: One hundred sixty one patients aged 50 to 80 years, active or former smokers of 15 or more pack-years and with COPD were enrolled. They underwent annual respiratory functional assessment and chest computed tomography for three years and were followed for five years. Results: Chest CT allowed the detection of lung cancer in nine patients (diagnostic yield: 5.6%). Three cases were detected in the initial CT and six cases in follow-up scans. Most patients were in early stages of the disease (6 stage Ia and 1 stage Ib). Two patients were diagnosed at advanced stages of the disease and died due to complications of cancer. Two thirds of patients had nonspecific pulmonary nodules on the initial chest CT scan (100 patients, 62%). Seventy four percent had less than three nodules and were of less than 5 mm of diameter in 57%. In 92% of cases, these were false positive findings. In the follow-up chest CT, lung nodules were detected in two thirds of patients and 94% of cases corresponded to false positive findings. Conclusions: Chest CT scans may detect lung cancer at earlier stages in COPD patients.

La neumonía adquirida en la comunidad es la principal causa de muerte de origen infeccioso en la población infantil y adulta de nuestro país. La fisioterapia respiratoria (FR) ha sido ampliamente utilizada como tratamiento adyuvante en pacientes adultos con neumonía comunitaria, sin que se haya demostrado aún su eficacia clínica. En teoría, estas técnicas podrían ayudar a mantener abiertas las vías aéreas, facilitar la eliminación de secreciones bronquiales y mejorar el intercambio de gases en pacientes con neumonía. Revisamos los estudios publicados que han examinado la eficacia y seguridad de la FR en pacientes adultos con neumonía adquirida en la comunidad. Resultados: Seis ensayos clínicos controlados han evaluado cuatro modalidades de fisioterapia respiratoria en pacientes hospitalizados por neumonía comunitaria: a) La fisioterapia torácica convencional (vibración, percusión y drenaje postural); b) La manipulación osteopática (incluyendo la inhibición paraespinal, elevación costal y la liberación diafragmática o miofascial); c) El ciclo activo de técnicas de respiración (incluyendo el control de la respiración activa, ejercicios de expansión torácica y técnicas de espiración forzada); y d) La respiración con presión espiratoria positiva. Ninguna de estas técnicas ha logrado reducir en forma significativa la mortalidad hospitalaria o ha modificado la tasa de curación. Algunos estudios sugieren que la manipulación osteopática y la respiración con presión espiratoria positiva pueden acortar la estadía hospitalaria (2,0 y 1,4 días, respectivamente). Además, la respiración con presión espiratoria positiva puede reducir la duración de la fiebre en 0,7 días, y la manipulación osteopática puede acortar el uso de antibióticos en 1,93 días. No se han reportado eventos adversos serios. En resumen, la evidencia disponible es limitada y sugiere que la fisioterapia respiratoria no debería ser recomendada como tratamiento adyuvante de rutina en pacientes adultos con neumonía comunitaria no complicada.

Background: The etiology of acute exacerbations of chronic obstructive pulmonary disease (COPD) is heterogeneous and still under discussion. Inflammation increases during exacerbation of COPD. The identification of inflammatory changes will increase our knowledge and potentially guide therapy. Aim: To identify which inflammatory parameters increase during COPD exacerbations compared to stable disease, and to compare bacterial and viral exacerbations. Material and Methods: In 85 COPD patients (45 males, mean age 68 ± 8 years, FEV1 46 ± 17% of predicted) sputum, nasopharyngeal swabs and blood samples were collected to identify the causative organism, during a mild to moderate exacerbation. Serum ultrasensitive C reactive protein (CRP), fibrinogen and interleukin 6 (IL 6), neutrophil and leukocyte counts were measured in stable conditions, during a COPD exacerbation, 15 and 30 days post exacerbation. Results: A total of 120 mild to moderate COPD exacerbations were included. In 74 (61.7%), a microbial etiology could be identified, most commonly Mycoplasma pneumoniae (15.8%), Rhinovirus (15%), Haemophilus influenzae (14.2%), Chlamydia pneumoniae (11.7%), Streptococcus pneumoniae (5.8%) and Gram negative bacilli (5.8%). Serum CRP, fibrinogen and IL 6, and neutrophil and leukocyte counts significantly increased during exacerbation and recovered at 30 days post exacerbation. Compared to viral exacerbations, bacterial aggravations were associated with a systemic inflammation of higher magnitude. Conclusions: Biomarkers of systemic inflammation increase during mild to moderate COPD exacerbations. The increase in systemic inflammation seems to be limited to exacerbations caused by bacterial infections.

Bronchiolar disorders are generally difficult to diagnose. A detailed clinical history may point toward a specific diagnosis. Pertinent clinical questions include history of smoking, collagen vascular disease, inhalation injury, medication use and organ transplantation. It is important also to evaluate possible systemic and pulmonary signs of infection, evidence of air trapping, and high-pitched expiratory wheezing, which may suggest small airways involvement. Pulmonary function tests and plain chest radiography may demonstrate abnormalities; however, they rarely prove sufficiently specific to obviate bronchoscopic or surgical biopsy. High-resolution CT (HRCT) scanning of the chest is often an important diagnostic tool to guide diagnosis in these difficult cases, because different subtypes of bronchiolar disorders may present with characteristic image findings. Some histopathologic patterns of bronchiolar disease may be relatively unique to a specific clinical context but others are nonspecific with respect to either etiology or pathogenesis. Primary bronchiolar disorders include acute bronchiolitis, respiratory bronchiolitis, follicular bronchiolitis, mineral dust airway disease, constrictive bronchiolitis, diffuse panbronchiolitis, and other rare variants. Prominent bronchiolar involvement may be seen in several interstitial lung diseases, including hypersensitivity pneumonitis, collagen vascular disease, respiratory bronchiolitis-associated interstitial lung disease, cryptogenic organizing pneumonia, and pulmonary Langerhans’ cell histiocytosis. Large airway diseases that commonly involve bronchioles include bronchiectasis, asthma, and chronic obstructive pulmonary disease. The clinical and prognostic significance of a bronchiolar lesion is best determined by identifying the etiology, underlying histopathologic pattern and assessing the correlative clinic-physiologic-radiologic context.

Streptococcus pneumoniae es el principal agente causal de la neumonía adquirida en la comunidad. Objetivos: Examinar el poder discriminativo de tres índices pronósticos en la predicción de eventos adversos clínicamente relevantes en pacientes hospitalizados por neumonía neumocóccica adquirida en la comunidad. Métodos: Evaluamos el índice de gravedad de la neumonía (IGN), CURB-65 y el índice de neumonía grave adquirida en la comunidad (INGAC) en una cohorte de 151 adultos inmunocompetentes hospitalizados por neumonía neu-mocóccica. Los eventos adversos examinados fueron la admisión a UCI, necesidad de ventilación mecánica, complicaciones en el hospital y mortalidad a 30 días. Las reglas predictoras fueron comparadas en base a su sensibilidad, especificidad y área bajo la curva receptor operador. Resultados: Se evaluaron 151 pacientes (64 ± 18 años), 58% varones, 75% tenía co-morbilidad, 26% fueron admitidos a la UCI y 9% requirieron ventilación mecánica. La tasa de eventos adversos fue más elevada y la estadía en el hospital más prolongada en las categorías de alto riesgo de los tres índices predictores. Los tres índices permitieron, a su vez, predecir el riesgo de complicaciones y muerte en el seguimiento a 30 días. El IGN fue más sensible y el INGAC más específico en la pesquisa de complicaciones en el hospital y en predecir el riesgo de muerte. El INGAC fue más sensible y específico en predecir el uso de ventilación mecánica. El CURB-65 tuvo menor poder discriminatorio comparado con el IGN e INGAC. Conclusión: Los índices pronósticos validados en la literatura médica permiten predecir el riesgo de complicaciones y muerte en el adulto hospitalizado por neumonía neumocóccica. Sin embargo, difieren en su sensibilidad, especificidad y poder discriminatorio de los distintos eventos adversos.

Objetivo : Evaluar el rendimiento de la angiografia pulmonar y la venografia por tomografia computada (TC) empleando un tomografo multidetector de 64 canales en el diagnostico de la enfermedad tromboembolica. Material y metodo : Estudio prospectivo de pacientes sometidos a angiografia pulmonar por TC (angioTC) y venografia por TC (venoTC) por sospecha clinica de enfermedad tromboembolica (ETE). Se registro la presencia y localizacion radiologica del tromboembolismo pulmonar (TEP) y de la trombosis venosa profunda (TVP) aislada o concomitante, ademas de hallazgos tomograficos con posible significacion clinica. Resultados : Se realizo angioTC y venoTC a 893 pacientes, demostrandose ETE en 240. Al desglosar estos diagnosticos, existia TEP en 218 pacientes (24,4%), aislado en 139 (63,7%) y concomitante con TVP en 79 pacientes (36,2 %). Se observo evidencia radiografica de sobrecarga ventricular derecha en 35 de los 218 pacientes con TEP . En otros 22 pacientes se diagnostico TVP aislada (10%). En consecuencia, el estudio del sistema venoso profundo incremento el rendimiento diagnostico de la tomografia en 2,46% (p En 65 de los 218 pacientes (30%) con TEP se observo una lesion de aspecto neoplasico, nueva o antigua. En los 653 casos negativos para ETE, 71 examenes (11%) presentaron hallazgos patologicos significativos. Conclusione s: El uso combinado de angiografia pulmonar por TC y venografia por TC empleando un tomografo multidetector de 64 canales aumenta el rendimiento diagnostico de la enfermedad tromboembolica. Asimismo, frecuentemente permite diagnosticar otras patologias concomitantes, en general de naturaleza neoplasica, relacionadas o no con la presencia de ETE.

Chest computed tomography (CT) scan may improve lung cancer detection at early stages in high risk populations.To assess the diagnostic performance of chest CT in early lung cancer detection in patients with chronic obstructive pulmonary disease (COPD).One hundred sixty one patients aged 50 to 80 years, active or former smokers of 15 or more pack-years and with COPD were enrolled. They underwent annual respiratory functional assessment and chest computed tomography for three years and were followed for five years.Chest CT allowed the detection of lung cancer in nine patients (diagnostic yield: 5.6%). Three cases were detected in the initial CT and six cases in follow-up scans. Most patients were in early stages of the disease (6 stage Ia and 1 stage Ib). Two patients were diagnosed at advanced stages of the disease and died due to complications of cancer. Two thirds of patients had nonspecific pulmonary nodules on the initial chest CT scan (100 patients, 62%). Seventy four percent had less than three nodules and were of less than 5 mm of diameter in 57%. In 92% of cases, these were false positive findings. In the follow-up chest CT, lung nodules were detected in two thirds of patients and 94% of cases corresponded to false positive findings.Chest CT scans may detect lung cancer at earlier stages in COPD patients.

Background: The clinical usefulness of blood cultures in the management of patients hospitalized with community-acquired pneumonia (CAP) is controversial. Aim: To determine clinical predictors of bacteremia in a cohort of adult patients hospitalized for community-acquired pneumonia. Material and Methods: A prospective cohort of 605 immunocompetent adult patients aged 16 to 101 years (54% male) hospitalized for CAP was studied. The clinical and laboratory variables measured at admission were associated with the risk of bacteremia by univariate and multivariate analysis using logistic regression models. Results: Seventy seven percent of patients had comorbidities, median hospital stay was 9 days, 7.6% died in hospital and 10.7% at 30 days. The yield of the blood cultures was 12.6% (S. pneumoniae in 69 patients, H. influenzae in 3, Gram negative bacteria in three and S. aureus in one). These results modified the initial antimicrobial treatment in one case (0.2%). In a multivariate analysis, clinical and laboratory variables associated with increased risk of bacteremia were low diastolic blood pressure (Odds ratio (OR): 1.85, 95% confidence intervals (CI) 1.02 to 3.36, p < 0.05), leukocytosis e" 15,000/mm³ (OR: 2.18, 95% CI 1.22 to 3.88, p < 0.009), serum urea nitrogen e" 30 mg/dL (OR: 2.23, 95% CI 1.22 to 4.05, p < 0.009) and serum C-reactive protein e" 30 mg/dL (OR: 2.20, 95% CI 1.22 to 3.97, p < 0.01). Antimicrobial use before hospital admission significantly decreased the blood culture yield (OR: 0.14, 95% CI 0.04 to 0.46, p < 0.002). Conclusions: Blood cultures do not contribute significantly to the initial management of patients hospitalized for community-acquired pneumonia. The main clinical predictors of bacteremia were antibiotic use, hypotension, renal dysfunction and systemic inflammation.

The clinical usefulness of blood cultures in the management of patients hospitalized with community-acquired pneumonia (CAP) is controversial.To determine clinical predictors of bacteremia in a cohort of adult patients hospitalized for community-acquired pneumonia.A prospective cohort of 605 immunocompetent adult patients aged 16 to 101 years (54% male) hospitalized for CAP was studied. The clinical and laboratory variables measured at admission were associated with the risk of bacteremia by univariate and multivariate analysis using logistic regression models.Seventy seven percent of patients had comorbidities, median hospital stay was 9 days, 7.6% died in hospital and 10.7% at 30 days. The yield of the blood cultures was 12.6% (S. pneumoniae in 69 patients, H. influenzae in 3, Gram negative bacteria in three and S. aureus in one). These results modified the initial antimicrobial treatment in one case (0.2%). In a multivariate analysis, clinical and laboratory variables associated with increased risk of bacteremia were low diastolic blood pressure (Odds ratio (OR): 1.85, 95% confidence intervals (CI) 1.02 to 3.36, p0.05), leukocytosis e" 15,000/mm³ (OR: 2.18, 95% CI 1.22 to 3.88, p0.009), serum urea nitrogen e" 30 mg/dL (OR: 2.23, 95% CI 1.22 to 4.05, p0.009) and serum C-reactive protein e" 30 mg/dL (OR: 2.20, 95% CI 1.22 to 3.97, p0.01). Antimicrobial use before hospital admission significantly decreased the blood culture yield (OR: 0.14, 95% CI 0.04 to 0.46, p0.002).Blood cultures do not contribute significantly to the initial management of patients hospitalized for community-acquired pneumonia. The main clinical predictors of bacteremia were antibiotic use, hypotension, renal dysfunction and systemic inflammation.

Mycobacterium avium complex pulmonary disease in immunocompetent adult patientsNontuberculous mycobacteria (NTM) are increasingly recognized as important pulmonary patho-gens. Mycobacterium avium intracellulare complex (MAC) causes most lung infections due to NTM. Although the organism was identified in the 1890s, its potential to cause human disease was only recog-nized 50 years later. Patients with preexisting lung disease or immunodeficiency are at greatest risk for developing MAC infection. The majority of MAC pulmonary cases, however, occur in immunocompetent elderly women in association with nodular infiltrates and bronchiectasis. More recently, pulmonary disease has also been described in immunocompetent patients after exposure to MAC-contaminated hot tubs. We describe two cases of MAC lung disease in immunocompetent adult patients without preexis-ting lung disease and we review clinical manifestations, diagnostic criteria and treatment of this entity.Key words: Mycobacterium avium complex, nontuberculous mycobacterium, bronchiectasis, diag-nosis, treatment, prognosis.ResumenLas micobacterias no tuberculosas (MNT) se reconocen cada vez mas como importantes pato-genos pulmonares. El complejo Mycobacterium avium-intracellulare (MAC) causa la mayoria de las infecciones pulmonares por MNT. Aunque el organismo fue identificado en la decada de 1890, su potencial patogenicidad en seres humanos fue reconocida solo cincuenta anos despues. Los pacientes con enfermedad pulmonar preexistente o inmunodeficiencia estan en mayor riesgo de desarrollar infeccion por MAC. Sin embargo, la mayoria de los casos se producen en mujeres de edad avanzada inmunocompetentes en asociacion con infiltrados nodulares y bronquiectasias. Recientemente, la en-fermedad pulmonar tambien se ha descrito en pacientes inmunocompetentes expuestos a equipos de hidroterapia o jacuzzis contaminados con MAC. En relacion a dos pacientes adultos inmunocompe-tentes con enfermedad pulmonar por MAC examinamos el cuadro clinico, los criterios diagnosticos y el tratamiento de esta entidad.Palabras clave: Mycobacterium avium complex, micobacterias no tuberculosas, bronquiectasias, diagnostico, tratamiento, pronostico.

BACKGROUND: A reduction in long-term survival of adult patients hospitalized with community-acquired pneumonia (CAP), especially older people with multiple comorbidities, has been reported. AIM: To examine the clinical variables associated to mortality at 72 months of adult patients older than 60 years hospitalized with CAP and compare their mortality with a control group matched for age, gender and place of admission. MATERIAL AND METHODS: Prospective assessment of 465 immunocompetent patients aged 61 to 101 years, hospitalized for CAP in a teaching hospital. Hospital and 30 day mortality was obtained from medical records. Seventy two months survival of the 424 patients who were discharged olive, was compared with a group of 851 patients without pneumonia paired for gender and age. Mortality at 72 months was obtained from death certificates. RESULTS: Eighty seven percent of patients had comorbidity. The median hospital length of stay was 10 days, 8.8% died in the hospital, 29.7% at one year follow-up and 61.9%o at 6 years. The actuarial survival at six years was similar in the cohort of adults hospitalized with CAP and the control group matched for age, gender and site of care. In a multivariate analysis, the clinical variables associated with increased risk of dying during long-term follow-up were older age, chronic cardiovascular and neurological diseases, malignancy, absence of fever, low C-reactive protein at hospital admission and high-risk parameters of the Fine index. CONCLUSIONS: Advanced age, some specific comorbidities, poor systemic inflammatory response at admission and high risk parameters of the Fine Index were associated to increased risk of dying on long-term follow-up among older adults hospitalized for CAP.

Background Mortality increases in adults, especially in older adults, after recovery from an episode of community-acquired pneumonia (CAP). Aim To analyze survival and predictors of death at one year follow up of a cohort of adult patients hospitalized with CAP. Material and methods Immunocompetent patients admitted to a clinical hospital for an episode of CAP were included in the study and were assessed according to a standardized protocol. One year mortality after admission was assessed using death records of the National Identification Service. Clinical and laboratory variables measured at hospital admission associated with risk of death at one year follow up were subjected to univariate and multivariate analysis by a logistic regression model. Results We evaluated 659 patients aged 68 ± 19 years, 52% were male, 77% had underlying conditions (especially cardiovascular, neurological and respiratory diseases). Mean hospital length of stay was 9 days, 7.1% died during hospital stay and 15.8% did so during the year of follow-up. A causal agent was identified in one third of cases. The main pathogens isolated were Streptococcus pneumoniae (12.9%), Haemophilus influenzae (4.1%), respiratory viruses (6.5%) and Gram-negative bacilli (6.5%). In multivariate analysis, the clinical variables associated with increased risk of dying during the year of follow-up were older age, chronic neurological disease, malignancies, lack of fever at admission and prolonged hospital length of stay. Conclusions Age, specific co-morbidities such as chronic neurological disease and cancer, absence of fever at hospital admission and prolonged hospital length of stay were associated with increased risk of dying during the year after admission among adult patients hospitalized with community-acquired pneumonia.

A reduction in long-term survival of adult patients hospitalized with community-acquired pneumonia (CAP), especially older people with múltiple comorbidities, has been reported.To examine the clinical variables associated to mortality at 72 months of adult patients older than 60 years hospitalized with CAP and compare their mortality with a control group matched for age, gender and place of admission.Prospective assessment of 465 immunocompetent patients aged 61 to 101 years, hospitalized for CAP in a teaching hospital. Hospital and 30 day mortality was obtained from medical records. Seventy two months survival of the 424 patients who were discharged olive, was compared with a group of 851 patients without pneumonia paired for gender and age. Mortality at 72 months was obtained from death certificates.Eighty seven percent of patients had comorbidity. The median hospital length of stay was 10 days, 8.8% died in the hospital, 29.7% at one year follow-up and 61.9%o at 6 years. The actuarial survival at six years was similar in the cohort of adults hospitalized with CAP and the control group matched for age, gender and site of care. In a multivariate analysis, the clinical variables associated with increased risk of dying during long-term follow-up were older age, chronic cardiovascular and neurological diseases, malignancy, absence of fever, low C-reactive protein at hospital admission and high-risk parameters of the Fine índex.Advanced age, some specific comorbidities, poor systemic inflammatory response at admission and high risk parameters of the Fine Index were associated to increased risk of dying on long-term follow-up among older adults hospitalized for CAP.

Mortality increases in adults, especially in older adults, after recovery from an episode of community-acquired pneumonia (CAP).To analyze survival and predictors of death at one year follow up of a cohort of adult patients hospitalized with CAP.Immunocompetent patients admitted to a clinical hospital for an episode of CAP were included in the study and were assessed according to a standardized protocol. One year mortality after admission was assessed using death records of the National Identification Service. Clinical and laboratory variables measured at hospital admission associated with risk of death at one year follow up were subjected to univariate and multivariate analysis by a logistic regression model.We evaluated 659 patients aged 68 ± 19 years, 52% were male, 77% had underlying conditions (especially cardiovascular, neurological and respiratory diseases). Mean hospital length of stay was 9 days, 7.1% died during hospital stay and 15.8% did so during the year of follow-up. A causal agent was identified in one third of cases. The main pathogens isolated were Streptococcus pneumoniae (12.9%), Haemophilus influenzae (4.1%), respiratory viruses (6.5%) and Gram-negative bacilli (6.5%). In multivariate analysis, the clinical variables associated with increased risk of dying during the year of follow-up were older age, chronic neurological disease, malignancies, lack of fever at admission and prolonged hospital length of stay.Age, specific co-morbidities such as chronic neurological disease and cancer, absence of fever at hospital admission and prolonged hospital length of stay were associated with increased risk of dying during the year after admission among adult patients hospitalized with community-acquired pneumonia.

Bronchiolar disorders are generally difficult to diagnose. A detailed clinical history may point toward a specific diagnosis. Pertinent clinical questions include history of smoking, collagen vascular disease, inhalation injury, medication use and organ transplantation. It is important also to evaluate possible systemic and pulmonary signs of infection, evidence of air trapping, and high-pitched expiratory wheezing, which may suggest small airways involvement. Pulmonary function tests and plain chest radiography may demonstrate abnormalities; however, they rarely prove sufficiently specific to obviate bronchoscopic or surgical biopsy. High-resolution CT (HRCT) scanning of the chest is often an important diagnostic tool to guide diagnosis in these difficult cases, because different subtypes of bronchiolar disorders may present with characteristic image findings. Some histopathologic patterns of bronchiolar disease may be relatively unique to a specific clinical context but others are nonspecific with respect to either etiology or pathogenesis. Primary bronchiolar disorders include acute bronchiolitis, respiratory bronchiolitis, follicular bronchiolitis, mineral dust airway disease, constrictive bronchiolitis, diffuse panbronchiolitis, and other rare variants. Prominent bronchiolar involvement may be seen in several interstitial lung diseases, including hypersensitivity pneumonitis, collagen vascular disease, respiratory bronchiolitis-associated interstitial lung disease, cryptogenic organizing pneumonia, and pulmonary Langerhans' cell histiocytosis. Large airway diseases that commonly involve bronchioles include bronchiectasis, asthma, and chronic obstructive pulmonary disease. The clinical and prognostic significance of a bronchiolar lesion is best determined by identifying the etiology, underlying histopathologic pattern and assessing the correlative clinic-physiologic-radiologic context.

La disnea y la disminucion de la capacidad de realizar ejercicio son los principales factores que limitan las actividades de la vida diaria en pacientes con enfermedades respiratorias cronicas. Los sintomas cardinales que limitan la capacidad de ejercicio en la mayoria de los pacientes con enfermedad pulmonar obstructiva cronica (EPOC) son la disnea y/o fatigabilidad, los cuales pueden ser ocasionados por trastornos de la ventilacion alveolar e intercambio gaseoso, disfuncion de los musculos esqueleticos y/o falla cardiovascular. La ansiedad, falta de motivacion y depresion tambien han sido asociadas a una menor capacidad de realizar ejercicio, probablemente afectando la percepcion de los sintomas. La relacion entre el estado psicologico y los trastornos del animo en pacientes con EPOC y la tolerancia al ejercicio es compleja y aun no ha sido completamente dilucidada. El origen de la limitacion de la capacidad de ejercicio en pacientes con EPOC es multifactorial, por lo cual la separacion de las variables involucradas con fines academicos no siempre es factible realizarlo en los pacientes. Los mecanismos patogenicos pueden relacionarse en forma compleja, a modo de ejemplo, el desacondicionamiento fisico y la hipoxemia pueden contribuir a aumentar la ventilacion alveolar ocasionando limitacion del ejercicio de causa ventilatoria. Por lo tanto, el entrenamiento fisico y el suplemento de oxigeno pueden reducir la limitacion ventilatoria durante el ejercicio sin modificar la funcion pulmonar o la capacidad ventilatoria maxima. El analisis de los factores limitantes de la capacidad de ejercicio permite identificar trastornos potencialmente reversibles que pueden mejorar la calidad de vida de los enfermos, tales como la hipoxemia, broncoespasmo, insuficiencia cardiaca, arritmias, disfuncion musculoesqueletica y/o isquemia miocardica. En esta revision se examinan los principales mecanismos que contribuyen a la limitacion de la actividad fisica en pacientes con EPOC: anomalias de la ventilacion alveolar e intercambio gaseoso, disfuncion cardiovascular y del sistema musculo-esqueletico y disfuncion de los musculos respiratorios.

the six minute walking distance test (6MWD) is widely used to evaluate exercise capacity in several diseases due to its simplicity and low cost.to establish reference values for 6MWD in healthy Chilean individuals.we studied 175 healthy volunteers aged 20-80 years (98 women) with normal spirometry and without history of respiratory, cardiovascular or other diseases that could impair walking capacity. The test was performed twice with an interval of 30 min. Heart rate, arterial oxygen saturation (with a pulse oxymeter) and dyspnea were measured before and after the test.walking distance was 576 ± 87 m in women and 644 ± 84 m in men (p0.0001). For each sex, a model including age, height and weight produced 6MWD prediction equations with a coefficient of determination (R²) of 0.63 for women and 0.55 for men.our results provide reference equations for 6MWD that are valid for healthy subjects between 20 and 80 years old.

Low grade systemic inflammation is commonly observed in chronic obstructive pulmonary disease (COPD).To evaluate the extent of systemic inflammation in a group of ex-smokers with COPD in stable condition and its relation with pulmonary function and clinical manifestations.We studied 104 ex-smokers aged 69 ± 8 years (62 males) with mild to very severe COPD and 52 healthy non-smoker subjects aged 66 ± 11 years (13 males) as control group. High sensitivity serum C reactive protein (CRP), interleukin 6 (IL6), fibrinogen (F) and neutrophil count (Nc) were measured. Forced expiratory volume in the first minute (FEV1), inspiratory capacity (IC), arterial blood gases, six minutes walking test, dyspnea and body mass index (BMI) were measured, calculating the BODE index. Health status was assessed using the Saint George Respiratory Questionnaire (SGRQ), the chronic respiratory questionnaire (CRQ), registering the number of acute exacerbations (AE) during the previous year and inhaled steroids use. Systemic inflammation was considered present when levels of CRP or IL6 were above the percentile 95 of controls (7.98 mg/L and 3.42 pg/ml, respectively).COPD patients had significantly higher CRP and IL6 levels than controls. Their F and Nc levels were within normal limits. Systemic inflammation was present in 56 patients, which had similar disease severity and frequency of inhaled steroid use, compared with patients without inflammation. Patients with systemic inflammation had more AE in the previous year; lower inspiratory capacity, greater dyspnea during the six minutes walk test and worse SGRQ and CRQ scores.Low-grade systemic inflammation was found in 56 of 104 ex-smokers with COPD. This group showed a greater degree of lung hyperinflation, dyspnea on exercise and poor quality of life.

Obstructive sleep apnea syndrome (OSA) is an important cause of morbidity and mortality in adults.To evaluate the diagnostic value of clinical features and oximetric data to screen for obstructive sleep apnea before performing polysomnograpy or respiratory polygraphy.We studied 328 consecutive adult patients referred for snoring or excessive daytime sleepiness to a sleep clinic in whom a standardized questionnaire and the Sleepiness Epworth Scale were performed and body mass index (BMI), cervical circumference (CC), and nocturnal oximetry were measured.Fifty three percent (n = 173) had evidence of clinically significant OSA (apnea/hypopnea index (AHI)15 events/h). Patients with OSA were more likely to be male, obese (BMI ≥ 26 kg/m²), smokers, to have a thick neck (CC41 cm), and to have a significant greater prevalence of relative reported apneas and excessive daytime sleepiness, as determined by Epworth scale. Male gender (Odds ratio (OR): 4.00; 95% confidence intervals (CI): 1.59-10.0, p = 0.003), BMI ≥ 26 kg/m² (OR: 3.68; 95%CI: 1.59-8.49, p = 0.002), smoking (OR: 2.29; 95% CI: 1.17-4.47, p = 0.015), Epworth index13 (OR: 2.65; 95% CI: 1.35-5.23, p = 0.005) and duration of symptoms over 2 years (OR: 2.35; 95% CI: 1.20-4.58, p = 0.012) were significant independent predictors of OSA. In nocturnal oximetry, the lowest SpO2 (SpO2 min) and the length of registries below 90% (CT-90) were independent predictors of OSA and both correlated significantly with AHI (r = -0.49 and r = 0.46 respectively, p0.001).No single factor was usefully predictive of obstructive sleep apnea. However, combining clinical features and oximetry data may be appropriate to detect clinically significant OSA patients.

Background: The six minute walking distance test (6MWD) is widely used to evaluate exercise capacity in several diseases due to its simplicity and low cost. Aim: To establish reference values for 6MWD in healthy Chilean individuals. Material and methods: We studied 175 healthy volunteers aged 20-80 years (98 women) with normal spirometry and without history of respiratory, cardiovascular or other diseases that could impair walking capacity. The test was performed twice with an interval of 30 min. Heart rate, arterial oxygen saturation (with a pulse oxymeter) and dyspnea were measured before and after the test. Results: Walking distance was 576 ± 87 m in women and 644 ± 84 m in men (p < 0.0001). For each sex, a model including age, height and weight produced 6MWD prediction equations with a coefficient of determination (R²) of 0.63 for women and 0.55 for men. Conclusions: Our results provide reference equations for 6MWD that are valid for healthy subjects between 20 and 80 years old.

Background: Obstructive sleep apnea syndrome (OSA) is an important cause of morbidity and mortality in adults. Aim: To evaluate the diagnostic value of clinical features and oximetric data to screen for obstructive sleep apnea before performing polysomnograpy or respiratory polygraphy. Material and Methods: We studied 328 consecutive adult patients referred for snoring or excessive daytime sleepiness to a sleep clinic in whom a standardized questionnaire and the Sleepiness Epworth Scale were performed and body mass index (BMI), cervical circumference (CC), and nocturnal oximetry were measured. Results: Fifty three percent (n = 173) had evidence of clinically significant OSA (apnea/hypopnea index (AHI) > 15 events/h). Patients with OSA were more likely to be male, obese (BMI ≥ 26 kg/m²), smokers, to have a thick neck (CC > 41 cm), and to have a significant greater prevalence of relative reported apneas and excessive daytime sleepiness, as determined by Epworth scale. Male gender (Odds ratio (OR): 4.00; 95% confidence intervals (CI): 1.59-10.0, p = 0.003), BMI ≥ 26 kg/m² (OR: 3.68; 95%CI: 1.59-8.49, p = 0.002), smoking (OR: 2.29; 95% CI: 1.17-4.47, p = 0.015), Epworth index > 13 (OR: 2.65; 95% CI: 1.35-5.23, p = 0.005) and duration of symptoms over 2 years (OR: 2.35; 95% CI: 1.20-4.58, p = 0.012) were significant independent predictors of OSA. In nocturnal oximetry, the lowest SpO2 (SpO2 min) and the length of registries below 90% (CT-90) were independent predictors of OSA and both correlated significantly with AHI (r = -0.49 and r = 0.46 respectively, p < 0.001). Conclusions: No single factor was usefully predictive of obstructive sleep apnea. However, combining clinical features and oximetry data may be appropriate to detect clinically significant OSA patients.

Background: Low grade systemic inflammation is commonly observed in chronic obstructive pulmonary disease (COPD). Aim: To evaluate the extent of systemic inflammation in a group of ex-smokers with COPD in stable condition and its relation with pulmonary function and clinical manifestations. Patients and Methods: We studied 104 ex-smokers aged 69 ± 8 years (62 males) with mild to very severe COPD and 52 healthy non-smoker subjects aged 66 ± 11 years (13 males) as control group. High sensitivity serum C reactive protein (CRP), interleukin 6 (IL6), fibrinogen (F) and neutrophil count (Nc) were measured. Forced expiratory volume in the first minute (FEV1), inspiratory capacity (IC), arterial blood gases, six minutes walking test, dyspnea and body mass index (BMI) were measured, calculating the BODE index. Health status was assessed using the Saint George Respiratory Questionnaire (SGRQ), the chronic respiratory questionnaire (CRQ), registering the number of acute exacerbations (AE) during the previous year and inhaled steroids’s use. Systemic inflammation was considered present when levels of CRP or IL6 were above the percentile 95 of controls (7.98 mg/L and 3.42 pg/ml, respectively). Results: COPD patients had significantly higher CRP and IL6 levels than controls. Their F and Nc levels were within normal limits. Systemic inflammation was present in 56 patients, which had similar disease severity and frequency of inhaled steroid use, compared with patients without inflammation. Patients with systemic inflammation had more AE in the previous year; lower inspiratory capacity, greater dyspnea during the six minutes walk test and worse SGRQ and CRQ scores. Conclusions: Low-grade systemic inflammation was found in 56 of 104 ex-smokers with COPD. This group showed a greater degree of lung hyperinflation, dyspnea on exercise and poor quality of life.

Streptococcus pneumoniae is the main cause of community-acquired pneumonia in adults.To describe baseline characteristics, risk factors and clinical outcomes of adult patients hospitalized with pneumococcal pneumonia.Prospective study of adult patients admitted for a community acquired pneumonia in a clinical hospital. Immune deficient patients and those with a history of a recent hospitalization were excluded.One hundred fifty one immuno-competent patients, aged 16 to 92 years, 58% males, were studied. Seventy-five percent had other diseases, 26% were admitted to the intensive care unit and 9% needed mechanical ventilation. There were no differences in clinical features, ICU admission or hospital length of stay among bacteremic and non-bacteremic patients. Thirty days lethality for bacteremic and non-bacteremic patients was 10.9% and 11.5%, respectively. The predictive values for lethality of Fine pneumonia severity index and CURB-65 (Confusion, Urea nitrogen, Respiratory rate, Blood pressure, 65 years of age and older) had an area under the ROC curve of 0.8 and 0.69, respectively. Multivariate analysis disclosed blood urea nitrogen over 30 mg/ dL (odds ratio (OR), 6.8), need for mechanical ventilation (OR, 7.4) and diastolic blood pressure below 50 mmHg (OR, 3.9), as significant independent predictors of death.Pneumococcal pneumonia was associated with a substantial rate of complications and mortality. Clinical presentation and outcome did not differ significantly among patients with and without bacteremia.

La tos convulsiva o coqueluche está siendo reconocida cada vez con mayor frecuencia como causa de tos prolongada en adolescentes y adultos. La vacunación sistemática de la población pediátrica ha determinado un cambio en el perfl epidemiológico de la enfermedad, aumentando su prevalencia en la población adulta. Se presenta el caso clínico de una paciente de 45 años, fumadora, enfermera de unidad de hemodiálisis, que consulta por malestar general y tos seca de seis semanas de evolución. La radiografía de tórax era normal y la inmunofuorescencia directa de hisopado nasofaríngeo fue positiva para Bordetella pertussis. A propósito de este caso clínico, revisamos las principales causas de tos crónica: asma bronquial, enfermedad rinosinusal y refujo gastroesofágico; el cuadro clínico, evaluación diagnóstica y tratamiento de la infección por B. pertussis en población adulta.

Background: Streptococcus pneumoniae is the main cause of community-acquired pneumonia in adults. Aim: To describe baseline characteristics, risk factors and clinical outcomes of adult patients hospitalized with pneumococcal pneumonia. Material and methods: Prospective study of adult patients admitted for a community acquired pneumonia in a clinical hospital. Immune deficient patients and those with a history of a recent hospitalization were excluded. Results: One hundred fifty one immuno-competent patients, aged 16 to 92 years, 58% males, were studied. Seventy-five percent had other diseases, 26% were admitted to the intensive care unit and 9% needed mechanical ventilation. There were no differences in clinical features, ICU admission or hospital length of stay among bacteremic and non-bacteremic patients. Thirty days lethality for bacteremic and non-bacteremic patients was 10.9% and 11.5%, respectively. The predictive values for lethality of Fine pneumonia severity index and CURB-65 (Confusion, Urea nitrogen, Respiratory rate, Blood pressure, 65 years of age and older) had an area under the ROC curve of 0.8 and 0.69, respectively. Multivariate analysis disclosed blood urea nitrogen over 30 mg/ dL (odds ratio (OR), 6.8), need for mechanical ventilation (OR, 7.4) and diastolic blood pressure below 50 mmHg (OR, 3.9), as significant independent predictors of death. Conclusions: Pneumococcal pneumonia was associated with a substantial rate of complications and mortality. Clinical presentation and outcome did not differ significantly among patients with and without bacteremia.

Short term effects of acute exacerbations in COPD patients Acute exacerbations of COPD (AECOPD) are associated with decline of FEV1 and health related quality of life. Our aim was to evaluate the short-term effects of AECOPD on several functional and clinical indices in a cohort of 60 ex-smokers patients with COPD. During a 6-month follow up, 40 patients experienced one exacerbation (Group 1), mainly moderate, evaluated 30 days after by measuring BMI, dyspnea, FVC, FEV1, inspiratory capacity (IC), SpO2, six-min walking distance (6MWD), BODE index and quality of life (SGRQ). Values were compared with those measured at recruitment in stable conditions and with those obtained in the 20 patients without AECOPD during a similar period (Group 2). Baseline values were similar in both groups. Group 1 showed a significant worsening in FVC, FEV1, SpO2, BMI, 6MWD, and BODE index. Improvement in SGRQ and BODE was found in group 2. Significant differences in changes between groups were found for all variables, except IC and SpO2. The most noteworthy differences were found for BODE index (p = 0.001) and SGRQ (p = 0.004). Results demonstrate that moderate AECOPD produces significant short term functional and clinical impairment in ex-smokers COPD.

El mieloma múltiple es una neoplasia maligna de células plasmáticas que invade la médula ósea y otros tejidos. Las manifestaciones extramedulares son relativamente raras. El derrame pleural en el mieloma múltiple es poco frecuente (6% de los casos), y el derrame pleural neoplásico es extremadamente raro. La leucemia de células plasmáticas, que se produce de novo o en pacientes con mieloma múltiple, es la variedad menos común de discrasia de células plasmáticas. Los autores describen el cuadro clínico de un paciente de 63 años con leucemia de células plasmáticas, donde la primera manifestación de la enfermedad fue una neumonía neumocócica bacteriémica asociado a un derrame pleural contralateral, que correspondió a un exudado predominio mononuclear. El examen citológico reveló abundantes células plasmáticas inmaduras en el líquido pleural y la sangre periférica. El derrame pleural desapareció después del primer ciclo de quimioterapia (vincristina, adriamicina, dexametasona). Después de tres meses de remisión, la enfermedad neoplásica recidivó, siendo el paciente sometido a trasplante autólogo de médula ósea. El paciente se ha mantenido en remisión completa un año después del diagnóstico. El derrame pleural es una complicación poco común, pero importante, del mieloma múltiple y no necesariamente conlleva un mal pronóstico.

During the past two decades there has been a resurgence of invasivegroup A streptococcal (GAS) infection, specially pneumonia and bacteremia. We report a 35 year-old female previously subjected to a thyroidectomy for a thyroid cancer, that five days afteroperation, presented with a severe community-acquired pneumonia caused by Streptococcuspyogenes (Lancefield Group A Streptococcus) that was complicated by acute respiratory failureand septic shock. She was treated with a combination of 3 g/day of cefotaxime and 1.8 g/day ofclindamycin with a good clinical response and discharged from the hospital in good conditions.Although this microorganism is an uncommon cause of community-acquired pneumonia,previously healthy individuals may be infected and the clinical course may be fulminant. Patientswith invasive GAS infection admitted to ICU have a high mortality rate. Treatment of choice ofGroup A streptococcal infection is penicillin. However, clindamycin should be added in severeinfections (Rev Med Chile 2008; 136: 1564-9).(

Exercise capacity can be evaluated in patients with chronic obstructive pulmonary disease (COPD), measuring the distance that patients are able to walk in 6 minutes (six-minute walk distance test; 6WDT). This test is simple to perform, inexpensive, reproducible and safe. It has been frequently employed for the assessment of COPD patients due to its high prognostic value of mortality and its usefulness to evaluate long-term of therapeutic interventions. In severe stages of the disease, the declining results of the best are useful to detect worsening. This review describes the method, standardization and reference values for the 6WDY and the results obtained with different therapeutic interventions, based on data from the literature and from the authors' experience. We also review its predictive value for mortality and its value in the assessment of patients with more severe COPD.

Exercise capacity can be evaluated in patients with chronic obstructive pulmonary disease (COPD), measuring the distance that patients are able to walk in 6 minutes (six-minute walk distance test; 6WDT). This test is simple to perform, inexpensive, reproducible and safe. It has been frequently employed for the assessment of COPD patients due to its high prognostic value of mortality and its usefulness to evaluate long-term of therapeutic interventions. In severe stages of the disease, the declining results of the best are useful to detect worsening. This review describes the method, standardization and reference values for the 6WDY and the results obtained with different therapeutic interventions, based on data from the literature and from the authors' experience. We also review its predictive value for mortality and its value in the assessment of patients with more severe COPD.

Resumen La prevalencia, al igual que la mortalidad de la enfermedad pulmonar obstructiva cronica(EPOC), ha aumentado en las mujeres. Esto ultimo sugiere que la enfermedad seria mas grave en elsexo femenino. El proposito de este estudio fue evaluar si existen diferencias en la gravedad segungenero en 95 pacientes (38 mujeres) con EPOC ingresados consecutivamente a un protocolo deseguimiento. Evaluamos la magnitud del tabaquismo, caracteristicas demograficas, gravedad segunVEF 1 e indice BODE y compromiso de la calidad de vida. Los resultados no demostraron diferen-cias entre hombres y mujeres en ninguno de los indices de gravedad. Sin embargo, la magnitud deltabaquismo fue inferior en las mujeres que en los hombres (35,5 ± 19,4 vs 45,7 ± 21 paquetes-ano;p = 0,02). Nuestros resultados sugieren una mayor susceptibilidad de las mujeres para desarrollarEPOC, pero no demuestran que la gravedad de la enfermedad dependa del genero. Palabras clave: EPOC, funcion pulmonar, indice BODE, genero. * Departamento de Enfermedades Respiratorias, Pontificia Universidad Catolica de Chile.** Ayudante alumno de la Escuela de Medicina, Pontificia Universidad Catolica de Chile.

Resumen de la evidenciaEstudios clinicos randomizados (ECR) . Dosdecadas atras, Rasanen y cols 18 , demostraronque el uso de CPAP por 3 horas en pacientescon EPA producia una mejoria mas rapida delintercambio gaseoso y una mayor reduccion deltrabajo respiratorio que el tratamiento estandar.Sin embargo, no lograron demostrar un efectoestadisticamente significativo sobre la tasa deintubacion endotraqueal ni sobre la mortalidad.Numerosos ECR han sido publicados desde en-tonces, con resultados discordantes (Tablas 1-3) 17,19-39 . El ultimo de ellos, aparecido durante lapreparacion del presente documento, sera dis-cutido en detalle al final 4 .Los ECR mencionados han incluido un nu-mero muy variable de enfermos, que en los gru-pos tratados ha oscilado entre 9 26 y 65 34 , sinmencionar los 702 del estudio mas reciente 4 . Enlos grupos control, la tasa de intubacion ha va-riado entre 0 29 y 60% 18 ; la mortalidad generalentre 0 26 y 64% 22 ; y la tasa de nuevos infartosdel miocardio (esto es, aquellos ocurridos des-pues del ingreso al hospital) entre 0