Factors involved in the one‐year changes in the tracheal diameter of patients with amyotrophic lateral sclerosis undergoing tracheostomy positive pressure ventilation

Abstract Background Tracheostomy positive pressure ventilation ( TPPV ) is associated with complications in patients with amyotrophic lateral sclerosis ( ALS ), particularly tracheostomy tube‐related problems. Aim To determine the frequency of patients with ALS who received TPPV that have tracheal enlargement and factors associated with changes in tracheal diameter. Methods We included 43 patients with ALS undergoing TPPV who were admitted at Sayama Neurological Hospital in October 2019. The tracheal diameter at the height of the tracheostomy tube cuff was measured radiographically at specific time points. Tidal volume, inspiratory maximum pressure ( PIP ), dynamic lung compliance (Cdyn), tracheostomy tube cuff data, and patient demographic information and data were also collected. Results The frequency of tracheomegaly was 60.5% at the initial data collection. The differences in tracheal diameter between the first measurement, after 12 months, and between 3 and 12 months were significant. ΔTracheal diameter correlated with TPPV duration, PIP , Cdyn, ΔPIP , ΔCdyn , and tracheal diameter. Multiple regression analysis, with Δtracheal diameter as the objective variable and TPPV duration, Cdyn, and tracheal diameter as explanatory variables, revealed an adjusted R ‐square value of 0.36. Conclusion Tracheomegaly and more enlarged tracheal diameters over time were more frequently observed in patients with ALS receiving TPPV . Furthermore, the trachea dilates over time and the tracheal diameter was related to baseline TPPV time, Cdyn, and tracheal diameter. Patients with shorter baseline TPPV duration, higher baseline Cdyn, and smaller baseline tracheal diameter were more likely to have larger tracheal diameters. Therefore, early prevention is important.