La prueba de la marcha de 6 minutos como factor pronóstico y de capacidad de ejercicio en pacientes con silicosis / The 6-Minute Walk Test as a Tool for Determining Exercise Capacity and Prognosis in Patients with Silicosis

Objetivo: Evaluar la capacidad de ejercicio, utilizando la prueba de la marcha de 6 minutos (6MWT), en pacientes con silicosis complicada, e identificar factores relacionados con dicho resultado, así como su valor pronóstico de hospitalización y mortalidad. Método: Estudio observacional prospectivo en 143 pacientes diagnosticados de silicosis complicada atendidos en consulta de neumología desde 2009 hasta diciembre 2016, sin limitación para hacer la 6MWT. Se evaluaron las pruebas de función pulmonar, los hallazgos de la tomografía computarizada y los parámetros de la 6MWT (distancia caminada y desaturación de oxígeno). Resultados: Los pacientes con silicosis complicada caminaban una media de 387 ± 92m. Los resultados fueron peores al aumentar la gravedad de la enfermedad; en silicosis A: 407 ± 97; B: 370 ± 88, y C: 357 ± 68 (p=0,022). La 6MWT mostraba una correlación positiva con la función pulmonar e inversa con la disnea (p < 0,001). Los pacientes con enfisema moderado/severo y un mayor tiempo con saturación nocturna de oxígeno por debajo del 90% presentaban resultados significativamente peores en la 6MWT. Los pacientes que caminaban < 350 m tenían más hospitalizaciones (3,7 ± 4,0) que los que caminaban>350 (1,1 ± 2,9). Los fallecidos al final del seguimiento caminaron 327,9 ± 73,0 frente a los que sobreviven, que caminaron 404,5 ± 89,7 m (p < 0,001). Conclusiones: Los valores de la espirometría y la categoría de la silicosis se relacionan con el resultado de la 6MWT, que resultó ser factor pronóstico para hospitalización y mortalidad. La 6MWT se perfila como una herramienta útil en salud ocupacional para el seguimiento de pacientes con silicosis

Objective: To evaluate exercise capacity using the 6-minute walk test (6MWT) in patients with complicated silicosis, and to determine how results shape the prognostic value of 6MWT for hospitalization and mortality. Method: Prospective observational study in 143 patients with complicated silicosis who performed the 6MWT in our outpatient pulmonology clinic between 2009 and the end of 2016. Lung function tests, computed tomography findings and 6MWT parameters (distance walked and oxygen desaturation) were evaluated. Results: Patients with complicated silicosis walked 387±92m. Results deteriorated as silicosis severity increased; category A: 407 ± 97m, B: 370±88m, and C: 357 ± 68m (P=.022). The 6MWT correlated positively with lung function and inversely with dyspnea determined by mMRC (P < .001). Patients with moderate/severe emphysema and greater CT90 presented a worse result on 6MWT. Patients who walked < 350m had more hospitalizations (3.7 ± 4.0) than those who walked > 350m (1.1 ± 2.9). There was an impact on survival: non-survivors walked 327.9 ± 73.0m, while survivors walked 404.5 ± 89.7m (P < .001). Conclusions: Spirometry values and category of complicated silicosis correlated with 6MWT and distance walked was a prognostic factor for hospitalization and mortality. The 6MWT is a useful tool in occupational health for monitoring patients with silicosis

The 6-Minute Walk Test as a Tool for Determining Exercise Capacity and Prognosis in Patients with Silicosis. / La prueba de la marcha de 6 minutos como factor pronóstico y de capacidad de ejercicio en pacientes con silicosis.

OBJECTIVE: To evaluate exercise capacity using the 6-minute walk test (6MWT) in patients with complicated silicosis, and to determine how results shape the prognostic value of 6MWT for hospitalization and mortality. METHOD: Prospective observational study in 143 patients with complicated silicosis who performed the 6MWT in our outpatient pulmonology clinic between 2009 and the end of 2016. Lung function tests, computed tomography findings and 6MWT parameters (distance walked and oxygen desaturation) were evaluated. RESULTS: Patients with complicated silicosis walked 387±92m. Results deteriorated as silicosis severity increased; category A: 407±97m, B: 370±88m, and C: 357±68m (P=.022). The 6MWT correlated positively with lung function and inversely with dyspnea determined by mMRC (P<.001). Patients with moderate/severe emphysema and greater CT90 presented a worse result on 6MWT. Patients who walked<350m had more hospitalizations (3.7±4.0) than those who walked>350m (1.1±2.9). There was an impact on survival: non-survivors walked 327.9±73.0m, while survivors walked 404.5±89.7m (P<.001). CONCLUSIONS: Spirometry values and category of complicated silicosis correlated with 6MWT and distance walked was a prognostic factor for hospitalization and mortality. The 6MWT is a useful tool in occupational health for monitoring patients with silicosis.