Asma severa en adultos: enfoque diagnóstico y tratamiento / Severe asthma in adults: diagnosis and treatment approach

El asma es una enfermedad frecuente de fisiopatología compleja. El asma severa constituye aproximadamente el 5% de la población de asmáticos, sin embargo representa un desafío clínico y una carga sanitaria importante. Estudios recientes demuestran la existencia de fenotipos en todo el espectro de gravedad. La eosinofilia en esputo y sangre ha demostrado utilidad como marcador de inflamación Th-2 y de respuesta clínica a esteroides, sin embargo aún no existe mucho conocimiento sobre el asma no-eosinofílica. Los tratamientos actuales en asma se enfocan a estrategias de terapia escalonada según severidad, pero en pacientes con asma severa se requiere también del manejo multidisciplinario de las comorbilidades y la determinación del fenotipo, para aplicar terapias más especificas. El desarrollo acelerado de nuevos tratamientos en asma severa como consecuencia del mejor conocimiento de los distintos fenotipos ha ampliado el arsenal terapéutico para un enfrentamiento personalizado y específico en los pacientes con asma severa.

Asthma is a common disease of complex pathophysiology. Severe asthma accounts about 5% of asthma population, however represents a clinical challenge and a significant health burden. Recent studies show the existence of phenotypes through all the spectrum of severity. Eosinophilia in blood and sputum has proven as a useful marker of Th-2 inflammation and clinical steroid response, however there is still little knowledge about non-eosinophilic asthma. Current treatments for asthma are focused on step-up approaches according to severity, but severe asthma patients also require multidisciplinary management of comorbidities and phenotyping to apply more specific therapies. The fast development of new treatments in severe asthma as a result of better understanding of different phenotypes has broadened the therapeutic arsenal for a personalized and targeted management in severe asthma patients.

Prueba de caminata en seis minutos en sujetos chilenos sanos de 20 a 80 años / Reference values for the 6-minutes walking test in healthy subjects 20-80 years old

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.

La prueba de caminata en seis minutos en la evaluación de la capacidad de ejercicio en pacientes con enfermedad pulmonar obstructiva crónica / Six minutes walk for the assessment of patients with chronic obstructive pulmonary disease

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 valué of mortality and its usefulness to evalúate 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 valúes for the 6WDY and the results obtained with different therapeutic interventions, based on data from the literature and from the authors experíence. We also review its predictive valué for mortality and its valué in the assessment of patients with more severe COPD.

Etiología de la neumonía adquirida en la comunidad en adultos hospitalizados en Santiago, Chile: implicancias para las guías clínicas / Etiology of community acquired pneumonia requiring hospitalization in Chile: implications for the guidelines

Background: There are a few studies examining the etiology of community acquired pneumonia (CAP) in Chile. Aim: To evaluate the etiology of CAP in hospitalized adults. Method: We prospectively studied 130 patients (mean age +/- SD: 68 +/- 18 y.o.; overall hospital mortality: 6.2 percent), over a 16 month period. Microbiological evaluation included blood and sputum cultures for bacteria; serology for C. pneumoniae, C. psittaci and M. pneumoniae; urine antigen for L. pneumophila; and nasopharyngeal swab for respiratory viruses. Results: Etiology was identified from 64 (49 percent) patients (two or more pathogens in 6). The most frequent microorganisms were S. pneumoniae (34 percent), Parainfluenza types 1 to 3 (22 percent), Influenza A or B (14 percent ), C. pneumoniae (6 percent), M. pneumoniae (6 percent), H. influenzae (5 percent) and S. marcescens (5 percent). Twenty-five of 27 (93 percent) respiratory viruses were identified in autumn or winter. Pneumococcal pneumonia patients (19) compared to those infected with respiratory virus (23) were younger (59 +/- 18 versus 72 +/- 17 y.o.; p = 0.021) and had less comorbidities (47 versus 87 percent; p = 0.0001). No patients with bacteremia (13 of 121: 11 percent) died. Conclusions: S. pneumoniae remains the most important pathogen to cover by initial antibiotic therapy; the second most frequent etiological agents were respiratory viruses followed by "atypical pathogens". Recommendations for the management of patients infected with these two last categories of agents should be included in future national guidelines.

Fundamento: Hay escasos estudios que examinen la etiología de la neumonía adquirida en la comunidad (NAC) en población adulta chilena. Objetivo: Identificar la etiología de la NAC en adultos inmunocompetentes hospitalizados. Método: Estudiamos, prospectiva y consecutivamente durante 16 meses, a 130 pacientes (edad promedio +/ - DS: 68 +/ - 18 años; letalidad en el hospital: 6,2 por ciento). La evaluación microbiológica incluyó cultivo de expectoración y hemocultivos para bacterias; Financiamiento: Fondo de Investigación de la Sociedad Chilena de Enfermedades Respiratorias (2002) y fondo de la Dirección de Investigación de la Pontificia Universidad Católica de Chile (DIPUC 2003/10E). Serología para C. pneumoniae, C. psittaci, M. pneumoniae; antígeno urinario para L. pneumophila e hisopado nasofaríngeo para virus respiratorios. Resultados: Se identificó la etiología en 64 (49 por ciento) pacientes (dos o más patógenos en 6). Los principales microorganismos fueron: S. pneumoniae (34 por ciento), virus Parainfluenza 1 a 3 (22 por ciento), virus Influenza A o B (14 por ciento), C. pneumoniae (6 por ciento), M. pneumoniae (6 por ciento), H. influenzae (5 por ciento) y S. marcescens (5 por ciento). El 93 por ciento (25/27) de los virus respiratorios se identificaron en otoño-invierno. Los pacientes con neumonía neumocócica (19) comparados con aquéllos infectados por virus respiratorios (23) eran más jóvenes (59 + /- 18 versus 72 +/ - 17 años; p = 0,021) y tenían menos comorbilidades (47 por ciento versus 87 por ciento; p = 0,0001). Ninguno de los 13 (11 por ciento) pacientes con bacteremia falleció en el hospital. Conclusiones: S. pneumoniae sigue siendo el principal patógeno a cubrir por el tratamiento antibiótico empírico; los virus respiratorios y los agentes atípicos fueron los que siguieron en frecuencia. Las futuras guías clínicas nacionales deberían incluir recomendaciones para el manejo de los pacientes infectados por estos dos últimos grupos de...