Análise da cinemática dos compartimentos da parede torácica nas posições supino e sentada de pacientes com esclerose lateral amiotrófica

Abstract

Amyotrophic Lateral Sclerosis (ALS) is characterized by deterioration of upper and lower motor neurons. The main components, which alter the respiratory muscles are the inspiratory, expiratory, and bulbar, leading to chronic respiratory failure. One way to improve gas exchange of these individuals is by employing non-invasive ventilation (NIV). Therefore, the aims of the present study were to analyze the movements and the operational chest wall volumes in supine and sitting positions in patients with ALS, as well as with and without the use of NIV in the supine position, and compare these measures to a sex and age-matched healthy control group. Ten patients with ALS, five men and five women, with a mean age of 54±13 years and body mass index (BMI) of 21 ± 4 kg/m2 and 10 healthy ones with a mean age of 53 14years and a BMI of 242 kg/m2, were included. The kinematic variables related to the chest wall and its compartments were assessed with the optoelectronic plethysmography (BTS, Milan, Italy). All participants were evaluated in the sitting and supine positions for five minutes each. In addition, patients with ALS were evaluated in the supine position using NIV for five minutes (Trilogy 100, Respironics, USA, used in the spontaneous/timed mode, with inspiratory and expiratory pressures of 14 cmH2O and 4cmH2O, respectively). For the intra-group analyses, paired t-tests were employed to investigate differences between the primary variables obtained in the sitting and supine positions, as well as for ALS group (with and without NIV). Independent Student t-tests were used to investigate differences between the groups regarding the anthropometric and kinematic data in the supine and sitting positions without NIV). The significance level was set at <0.05 for all comparisons. The results demonstrated that: 1) For both groups, the contribution of the chest wall compartment was significantly lower than that of the abdominal compartment in the supine, compared with the sitting positions; 2) lower percentages of contribution of the abdominal compartment were observed in the supine position for the ALS group, compared with the controls (p=0.049); 3) the NIV led to significant changes in the chest wall volumes, with increases in the tidal (p=0.025), end-inspiratory (p=0.008), and end-expiratory volumes (p=0.019); 4) no significant differences between the compartments were found regarding their percentage of contribution with and without NIV for the ALS patients. In conclusion, the findings suggested that optoelectronic plethysmography proved to be a useful tool to identify significant decreases of thediaphragmatic movements in patients with ALS and the NIV led to significant increases in the tidal, end-inspiratory, and end-expiratory volumes, with no changes in the contributions of the three chest wall compartments.