Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series

Abstract

BackgroundThe effects of non-invasive ventilation (NIV) on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS) are unknown.Objectives1) To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2) to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV).MethodNine ALS patients were evaluated in the supine position using NIV. In addition, the ALS patients and nine healthy individuals were evaluated in both sitting and supine positions. Statistical analysis was performed using the paired Student t-test or Wilcoxon test and the Student t-test for independent samples or Mann-Whitney U test.ResultsChest wall volume increased significantly with NIV, mean volume=0.43 (SD=0.16)L versus 0.57 (SD=0.19)L (p=0.04). No significant changes were observed for the pulmonary rib cage, abdominal rib cage, or abdominal contribution. The index of the shortening velocity of the diaphragmatic muscle, mean=0.15 (SD=0.05)L/s versus 0.21 (SD=0.05)L/s (p<0.01), and abdominal muscles, mean=0.09 (SD=0.02)L/s versus 0.14 (SD=0.06)L/s (p<0.01), increased during NIV. Comparisons between the supine and sitting positions showed similar changes in chest wall motion in both groups. However, the ALS patients presented a significantly lower contribution of the abdomen in the supine position compared with the controls, mean=56 (SD=13) versus 69 (SD=10) (p=0.02).ConclusionsNIV improved chest wall volumes without changing the contribution of the chest wall compartment in ALS patients. In the supine position, ALS patients had a lower contribution of the abdomen, which may indicate early diaphragmatic dysfunction.

Influence of posture, sex, and age on breathing pattern and chest wall motion in healthy subjects

“…The V RCa% was also reduced with trunk horizontalization, except in the change from the inclined posture to supine. Priori et al 8 and Magalhães et al 34 also observed a significant reduction of this variable in healthy individuals, when comparing the sitting position with the supine. However, in these studies, the authors evaluated the responses between supine and seated positions only, thereby preventing a comparison with the results obtained in the present study regarding inclined positions.…”

The Relationship Between Respiratory-Related Premotor Potentials and Small Perturbations in Ventilation

“…Furthermore, in the sub-group with a premotor potential, there are parallel reductions in respiratory discomfort and premotor potential incidence during non-invasive ventilation ( Georges et al, 2016 ). Although from a separate cohort of ALS patients, non-invasive ventilation typically increases tidal volume ( Magalhaes et al, 2016 ), which suggests the reduction in premotor potential observed by Georges et al (2016) was not associated with decreases in ventilation (and the associated reduction in respiratory afferent feedback). Impaired automatic drive to breathe in CCHS is associated with a 100% incidence of premotor potentials to maintain ventilation during resting breathing in wakefulness ( Tremoureux et al, 2014a ).…”

Effects of noninvasive ventilation in amyotrophic lateral sclerosis: The complication of bulbar impairment

“…Among these, 8 were retrospective studies [27][28][29][30][31][32][33][34] and 18 were prospective studies 24,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] (Table 1). Six studies had control groups, 24,38,39,42,48,49 and only one study was a randomized controlled trial (RCT). 42 The population size in these studies varied from 5 to 140 patients.…”

“…Significant difference between cough peak flow, manually assisted cough peak flow, and manually assisted cough peak flow in NIV tolerant (p < 0.001) more efficient use of these muscles and possibly explaining the increase in lung volumes. 49 Although their findings were limited to ALS patients without significant bulbar impairment, they provide insight into how NIV helps with respiratory function. Another possible explanation for NIV's beneficial effects is that it may be improving central respiratory drive and lung compliance.…”