Objective: To determine whether COPD patients with diaphragmatic dysfunction present higher risk of mortality than do those without such dysfunction. Methods: We evaluated pulmonary function, diaphragm mobility and quality of life, as well as determining the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index, in 42 COPD patients. The patients were allocated to two groups according to the degree to which diaphragm mobility was impaired: low mobility (LM; mobility ≤ 33.99 mm); and high mobility (HM; mobility ≥ 34.00 mm). The BODE index and the quality of life were quantified in both groups. All patients were followed up prospectively for up to 48 months in order to determine the number of deaths resulting from respiratory complications due to COPD. Results: Of the 42 patients evaluated, 20 were allocated to the LM group, and 22 were allocated to the HM group. There were no significant differences between the groups regarding age, lung hyperinflation or quality of life. However, BODE index values were higher in the LM group than in the HM group (p = 0.01). During the 48-month follow-up period, there were four deaths within the population studied, and all of those deaths occurred in the LM group (15.79%; p = 0.02). Conclusions: These findings suggest that COPD patients with diaphragmatic dysfunction, characterized by low diaphragm mobility, have a higher risk of death than do those without such dysfunction.

Keywords: Pulmonary disease, chronic obstructive/mortality; Diaphragm; Exercise tolerance; Quality of life.

Objective: To assess, using ultrasound, the effects that changes in body position have on diaphragmatic mobility in healthy subjects during spontaneous breathing. Methods: The study involved seven healthy female volunteers, all of whom were nonsmokers, well nourished, and free of any cardiopulmonary disease. They were submitted to pulmonary function testing and ultrasound evaluation of the mobility of the right diaphragm by the craniocaudal displacement of the left branch of the portal vein using an ultrasound device in mode B. The mobility of the right diaphragm was evaluated in right decubitus and in left decubitus. The order of evaluation was previously determined in a random drawing. Results: The average mobility of the right diaphragm in right decubitus (51.30 ± 9.69 mm) was significantly higher (p = 0.03) than that observed in left decubitus (45.93 ± 10.37 mm). Conclusion: The results suggest that, during spontaneous ventilation, the dependent portion of the diaphragm presents greater mobility than does the nondependent portion, and that the technique used was sufficiently sensitive to detect variations in diaphragmatic mobility related to changes in posture.

Keywords: Diaphragm; Ultrasonography; Respiratory function tests; Posture.