Objective: To investigate the relationship between respiratory function, functionality, and mortality in amyotrophic lateral sclerosis (ALS) patients and to determine which respiratory parameters show the strongest correlation with functionality and mortality. Methods: The study was conducted in Rio Grande do Norte, Northeast Brazil, between January 2018 and December 2023. This was a retrospective cohort, following individuals with ALS who were evaluated at the University Laboratory. Results: A total of 74 ALS patients were included in the analysis, with a mean age of 55.7 ± 13.5 years. Most were male (66.2%) and predominantly presented with spinal-onset ALS (51.3%). Respiratory variables (except peak expiratory flow (PEF)) showed a weak but significant inverse correlation with mortality (FVC% predicted (r_pb = −0.260; p < 0.001), SNIP (r_pb = −0.235; p = 0.001), MEP (r_pb = −0.207; p = 0.007), MIP (r_pb = −0.198; p = 0.009), and PEF% predicted (r_pb = −0.156; p = 0.013)). When analyzing their correlation with ALSFRS-R, all variables showed a significant positive correlation (ranging from weak to moderate) with functionality. A reduction of one unit in the respiratory variables PEF% of predicted, maximal inspiratory pressure (MIP), and sniff nasal inspiratory pressure (SNIP) increased the risk of death by an average of 300% (OR = 2.99; 95% CI: 2.05–4.35), 2% (OR = 1.02; 95% CI: 1.01–1.03), and 1% (OR = 1.01; 95% CI: 1.00–1.02), respectively. Conclusions: Our findings suggest that direct measurements of respiratory function and muscle strength, particularly PEF and SNIP, may serve as more useful markers to guide early interventions such as non-invasive ventilation, thereby improving quality of life and potentially prolonging survival.

Background: Mechanical insufflation-exsufflation (MI-E) consists of increasing expiratory air flow, thereby promoting an increase in cough peak flow (CPF) and secretion clearance. Respiratory impairment, characterized by reduced lung volumes and ineffective cough, is the major cause of morbidity and mortality in patients with amyotrophic lateral sclerosis (ALS). This study aimed to assess the acute effects of MI-E on CPF and chest wall compartmental and operational volumes in patients with ALS. Methods: Ten ALS subjects (6 males) were studied by optoelectronic plethysmography (OEP) to assess the immediate effects of MI-E on CPF, chest wall volume variations and their distribution in the chest wall compartments, breathing pattern, and shortening velocity of the respiratory muscles before, during, and after the application of MI-E. Results: No differences were observed in the CPF analysis between time points (pre, MI-E, post). A significant increase in CPF (P = .01) was obtained immediately after the application of MI-E in subjects with spinal-onset ALS (n = 7). No significant differences in total and compartmental lung volumes and chest wall operational volumes were observed between pre MI-E (quiet breathing), during MI-E (after coughs 1, 2, and 3), and post MI-E time points. Conclusions: The application of the MI-E technique may increase CPF in individuals with spinal ALS. However, no significant changes in total thoracic volumes, total and compartmental chest wall volumes, or changes in breathing patterns in the participants in our sample after the application of the technique were observed.

Compare the electromyographic activity of the respiratory muscles during the SNIP and SNEP maneuvers in a sitting position and inclined at 45º. Subjects with ALS and age-matched control group. Spirometry, surface electromyography (EMGs) of the sternocleidomastoid, scalene, rectus abdominis and external oblique muscles were evaluated during maximal respiratory pressure maneuvers (MIP and MEP) in a sitting position and nasal pressures breathing (SNIP and SNEP) in the sitting and inclined at 45º position (randomized). Twenty male individuals, 9 healthy (43.6 ± 11.6 years) and 11 with ALS (46.8 ± 12.5 years) were evaluated. Pulmonary function in subjects with ALS presents FVC (%pred) of 78.7 ± 18 and FEV₁/FVC ratio of 0.79 ± 0.07 and in healthy subjects FVC (%pred) of 83.1 ± 17.9% and FEV₁/FVC ratio of 0.84 ± 0.12. In subjects with ALS, the basal electromyographic activity of the ECM, at rest and during SNIP, was higher than that of healthy subjects in both positions (p<0.05). No significant differences were found in electrical activity in the other variables and measurements. SNEP values in the inclined position were lower than in the sitting position in subjects with ALS (70.3 ± 26.7 vs. 57.3 ± 22.8 cmH₂O, p<0.05). SNIP and SNEP were lower in subjects with ALS in the 45º inclined position vs. healthy subjects (69.1 ± 2.72 vs. 95.5 ± 23.5 cmH₂O; 57.3 ± 22.5 vs. 92.7 ± 26.4 cmH₂O, p<0.05, respectively). Subjects with ALS showed lower respiratory muscle strength values when compared to healthy subjects. Basal ECM muscle electrical activity was higher in the ALS group in boths positions.

Objectives: The aim of this study was to investigate the acute physiological effects of the BS on CPF and chest wall volumes in healthy individuals, comparing two body positions: supine and 45° trunk inclination. Methods: Observational, analytical, and cross-sectional study conducted with 14 healthy individuals (7 males) who underwent the BS in two different body positions. CPF, tidal chest wall volumes and the contribution of thoracoabdominal compartments were assessed using Optoelectronic Plethysmography. Statistical analyses included two-way ANOVA and Bonferroni post hoc tests, with a significance level of 5%. Results: A significant increase in CPF was observed after the BS in the inclined position (p < 0.05), with no relevant changes in the supine position. Tidal chest wall volumes also increased in both positions, with a more pronounced effect in the 45° inclination (p < 0.05). The volume increase was predominantly thoracic, with a ventilatory redistribution favouring the pulmonary rib cage compartment, especially in the inclined posture. Conclusions: The BS produced immediate beneficial physiological effects in healthy individuals, with greater efficacy in the inclined position, enhancing expiratory flow and thoracic ventilation. These findings support the clinical applicability of BS as a physiotherapeutic strategy even in populations without respiratory dysfunction.