Abstract
Amyotrophic Lateral Sclerosis (ALS) leads to a progressive decline in respiratory function, requiring volumetric expansion techniques to prevent hypoventilation. However, the mechanical performance of devices used for this purpose requires evaluation under controlled conditions in bench simulation studies. Devices, such as the manual resuscitator, are commonly used, but present limitations, including high pressures, variable flow, among others. A novel respiratory muscle training device designed to provide controlled flow and pressure (ILLIFE-T) was developed. To evaluate the behavior of the variables pressure, volume, and flow during the volumetric expansion technique, comparing the new device with the manual resuscitator and the manual resuscitator + Positive Expiratory Pressure (PEP), using simulated models of healthy and ALS affected lungs. This bench simulation study used the ASL 5000 simulator, configured with predefined respiratory profiles representing healthy and ALS respiratory conditions. Four repetitions of the volumetric expansion maneuver were performed for each device and simulated respiratory condition, with five insufflations per repetition. One recording was randomly selected from each repetition for analysis, resulting in four observations per device and simulated respiratory condition. In the simulation with healthy respiratory conditions, the new device generated higher pressure (23.38±3.81 cmH2O), volume (1991.25 ±174.10 mL), and lower flow variability (-1.47±11.43 L/min) compared with the manual resuscitator (12.25±11.73 cmH2O; 1113.64±131.75 mL; 18.84±61.31 L/min) and the manual resuscitator with PEP valve (16.89±0.64 cmH2O; 1817.25±86.77 mL; -49.49±9.96 L/min), respectively. In ALS simulated models, the new device also achieved higher pressure (23.69±3.29 cmH2O) and volume (2235.28±264.74 mL) compared with the manual resuscitator (8.33±8.34 cmH2O; 563.45±212.03 mL, respectively) and the manual resuscitator with PEP valve (14.89±7.60 cmH2O; 1449.86±153.09 mL, respectively). Flow values were similar among devices: 15.10 ± 18.00 L/min for the new device, 19.28±56.03 L/min for the manual resuscitator, and 0.18±51.67 L/min for the manual resuscitator with PEP valve. Pressure and volume were higher with the new device in both simulated models. Flow did not differ significantly among devices, although lower variability was descriptively observed with the new device.