A drop of 20-25% in vital capacity from sitting to lying down position was associated with diaphragmatic weakness, in some studies in Duchenne muscular dystrophy. Also, there are few studies about the quality of life in these patients. We aimed to provide a better understanding of pulmonary function and quality of life of Duchenne muscular dystrophy patients and to evaluate the significance of the vital capacity drop from sitting to lying position. This was a cross-sectional study, with Duchenne muscular dystrophy patients, aged 6 to 18 years. A total of 14 patients were included in the study. There was a positive correlation between seated vital capacity z-score and maximal expiratory pressures (r=0.78; p<0.01). There was a negative correlation between lying vital capacity z-score, age (r=- 0.7; p<0.01) and partial pressure of carbon dioxide (r=-0.57; p<0.05). The mean drop in vital capacity from seated to lying was -8.5 ± 9.02%. The vital capacity drop did not show a correlation with the analyzed parameters. The quality of life questionnaire means score was 55.02 ± 10.03. Patients had low vital capacity and maximal expiratory pressure results. Adding a second spirometric maneuver in lying position did not add much in terms of previewing diaphragmatic muscular compromise.
Isabel C.S. Ferreira*, Letícia R. Machado, Diego D. Brandenburg, Paulo J.C. Maróstica