Jorge Yáñez V

Prueba de caminata en seis minutos en sujetos chilenos sanos de 20 a 80 años

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.

Dermatomiositis refractaria asociada a neumonía en organización tratada con rituximab: Reporte de un caso

Chronic organizing pneumonia (COP) has often been reported asa pulmonary manifestation of collagen vascular diseases, mainly rheumatoid arthritis, but theassociation of COP and dermatomyositis (DM) has rarely been documented. We report a 55year-old woman with well-documented DM and a COP. She was refractory to steroids and twoother immunosuppressive agents therapy (cyclophosphamide and azathioprine). Therefore,rituximab (2 x 1 g infusions) was used for treatment. During the following weeks her strengthgradually increased while creatine kinase (CK), C reactive protein and erythrocytesedimentation rate normalized. After 6 months, she had a relapse with increased muscleenzymes, fever and moderate muscle weakness. After a second course of rituximab (2 x 1 ginfusions), the patient demonstrated a remarkable clinical response as indicated by an increasein muscle strength and moderate decline in creatine kinase levels. Lung abnormalities resolvedsignificantly on high resolution chest CT scan. Thus, B-cell depletion therapy with rituximabused alone or in combination with other immunosuppressants may be a viable option inpatients with polymyositis-dermatomyositis and pneumonia refractory to current therapies (RevMed Chile 2008; 136: 88-93).(

Impacto de la evaluación infectológica en el uso racional de antimicrobianos en pacientes con bacteriemia por Streptococcus pneumoniae

The increasing reporting of Streptococcus pneumoniae resistance to penicillin has lead to the recommendation of third generation cephalospirins for the treatment of serious pneumococcal infections. As a consequence, clinicians usually do not prescribe first line antibiotics despiste the availability of susceptibility studies. Whit the aim to evaluate the impact of the infectious diseases specialist evaluation in the apropriate use oh the susceptibility studies, two series were compared: a historic control one (1998-2002, n = 50) and a prospectuve group that had the advisement of one infectious diseases specialist (2003-2006, n = 60). In both series, pneumonia stood out as the source of the bacteremia, and -alcoholism/hepatic insufficiency as associated factor. In the first series, 48 isolates resulted susceptible to penicillin by agar diffusion, and 1 out of 36 patients with pneumonia had a change in the antibiotic therapy to penicillin. In the prospective series, we found 56 susceptible isolates, and the remaining four were classified as intermediate susceptibility according to the MIC value. Antibiotics were changed in 36 out of 50 patients with bacteremic pneumococcal pneumonia (p < 0.05). The infectious diseases specialist evaluation had a positive impact on the use of the microbiological information for therapeutics purposes.

Neumonía grave por Streptococcus pyogenes: Reporte de un caso

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).(

Compromiso pleural en la leucemia de células plasmáticas: Reporte de un caso

El mieloma multiple es una neoplasia maligna de celulas plasmaticas que invade la medula osea y otros tejidos. Las manifestaciones extramedulares son relativamente raras. El derrame pleural en el mieloma multiple es poco frecuente (6% de los casos), y el derrame pleural neoplasico es extremadamente raro. La leucemia de celulas plasmaticas, que se produce de novo o en pacientes con mieloma multiple, es la variedad menos comun de discrasia de celulas plasmaticas. Los autores describen el cuadro clinico de un paciente de 63 anos con leucemia de celulas plasmaticas, donde la primera manifestacion de la enfermedad fue una neumonia neumococica bacteriemica asociado a un derrame pleural contralateral, que correspondio a un exudado predominio mononuclear. El examen citologico revelo abundantes celulas plasmaticas inmaduras en el liquido pleural y la sangre periferica. El derrame pleural desaparecio despues del primer ciclo de quimioterapia (vincristina, adriamicina, dexametasona). Despues de tres meses de remision, la enfermedad neoplasica recidivo, siendo el paciente sometido a trasplante autologo de medula osea. El paciente se ha mantenido en remision completa un ano despues del diagnostico. El derrame pleural es una complicacion poco comun, pero importante, del mieloma multiple y no necesariamente conlleva un mal pronostico.

Smoking related interstitial lung disease

Cigarette smoking has a clear epidemiological association with lung diseases, characterised by chronic inflammation of both the bronchiolar and the interstitial lung compartments. There are several different smoking-related interstitial lung diseases, mainly desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease and pulmonary Langerhans’ cell histiocytosis. The epidemiology of such diseases is largely unknown, although the prevalence of cigarette smoking, particularly in low-income developing countries, indicates that smoking-induced interstitial lung disorders represent a high burden of disease worldwide. The role of chest high-resolution computed tomography has become increasingly important in differential diagnosis and follow-up. A new entity, the syndrome of combined pulmonary fibrosis and emphysema, emerged as another important smoking-related lung disorder with a poor prognosis, associated with the high prevalence of pulmonary hypertension. At the moment the role of anti-inflammatory and immunosuppressive treatment remains unclear, although in clinical practice most of these patients will receive at least one course of corticosteroid therapy. It is vital to stress the importance of identifying these patients and helping them quit smoking.la enfermedad pulmonar difusa asociada al consumo de tabaco no ha sido claramente definida, la bronquiolitis respiratoria (RB) es un hallazgo morfologico frecuente en fumadores asintomaticos, se caracteriza por la acumulacion de macrofagos pigmentados en los bronquiolos respiratorios. Solo una pequena proporcion de los sujetos fumadores presenta una respuesta inflamatoria exagerada que compromete el intersticio y espacio alveolar, lo cual corresponde a la bronquiolitis respiratoria asociada a enfermedad pulmonar difusa (RBIID), que se manifiesta por disnea de esfuerzos y tos. la neumonia intersticial descamativa (DIP) se caracteriza por compromiso panlobular, fibrosis intersticial discreta e infiltracion masiva del espacio aereo por macrofagos. El patron histopatologico de RBIID y DIP se pueden sobreponer, siendo los principales elementos diferenciadores entre ambas entidades, la distribucion y extension de las lesiones: compromiso bronquiolo-centrico en RBIID y difuso en DIP. Se ha planteado que la RB, RBIID y DIP pueden constituir diferentes fases de una misma enfermedad asociada al consumo de tabaco, lo cual aun es motivo de controversia. Con el proposito de ilustrar este problema, se presenta el caso clinico de un paciente fumador que consulto por disnea progresiva, tos e infiltrados pulmonares bilaterales sugerentes de enfermedad pulmonar difusa asociada al tabaquismo.

Enfermedad pulmonar difusa asociada al consumo de tabaco: Case report

Cigarette smoking has a clear epidemiological association with lung diseases, characterised by chronic inflammation of both the bronchiolar and the interstitial lung compartments. There are several different smoking-related interstitial lung diseases, mainly desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease and pulmonary Langerhans’ cell histiocytosis. The epidemiology of such diseases is largely unknown, although the prevalence of cigarette smoking, particularly in low-income developing countries, indicates that smoking-induced interstitial lung disorders represent a high burden of disease worldwide. The role of chest high-resolution computed tomography has become increasingly important in differential diagnosis and follow-up. A new entity, the syndrome of combined pulmonary fibrosis and emphysema, emerged as another important smoking-related lung disorder with a poor prognosis, associated with the high prevalence of pulmonary hypertension. At the moment the role of anti-inflammatory and immunosuppressive treatment remains unclear, although in clinical practice most of these patients will receive at least one course of corticosteroid therapy. It is vital to stress the importance of identifying these patients and helping them quit smoking.la enfermedad pulmonar difusa asociada al consumo de tabaco no ha sido claramente definida, la bronquiolitis respiratoria (RB) es un hallazgo morfologico frecuente en fumadores asintomaticos, se caracteriza por la acumulacion de macrofagos pigmentados en los bronquiolos respiratorios. Solo una pequena proporcion de los sujetos fumadores presenta una respuesta inflamatoria exagerada que compromete el intersticio y espacio alveolar, lo cual corresponde a la bronquiolitis respiratoria asociada a enfermedad pulmonar difusa (RBIID), que se manifiesta por disnea de esfuerzos y tos. la neumonia intersticial descamativa (DIP) se caracteriza por compromiso panlobular, fibrosis intersticial discreta e infiltracion masiva del espacio aereo por macrofagos. El patron histopatologico de RBIID y DIP se pueden sobreponer, siendo los principales elementos diferenciadores entre ambas entidades, la distribucion y extension de las lesiones: compromiso bronquiolo-centrico en RBIID y difuso en DIP. Se ha planteado que la RB, RBIID y DIP pueden constituir diferentes fases de una misma enfermedad asociada al consumo de tabaco, lo cual aun es motivo de controversia. Con el proposito de ilustrar este problema, se presenta el caso clinico de un paciente fumador que consulto por disnea progresiva, tos e infiltrados pulmonares bilaterales sugerentes de enfermedad pulmonar difusa asociada al tabaquismo.