Alveolar Ventilation-Targeted Versus Spontaneous/Timed Mode for Home Noninvasive Ventilation in Amyotrophic Lateral Sclerosis

BACKGROUND: Home noninvasive ventilation (NIV) is increasingly used in amyotrophic lateral sclerosis (ALS) to improve symptoms and survival. Our primary objective was to compare intelli-gent volume-assured pressure support (iVAPS) versus spontaneous/timed (S/T) modes regarding time to first change in ventilator parameters and the number of interventions over 6 months in subjects with ALS in a respiratory therapist (RT)-led program. METHODS: In this study, 30 sub-jects with ALS meeting criteria for NIV initiation were randomized to iVAPS or S/T. NIV was ini-tiated using standardized protocols targeting optimal tidal volume and comfort in a daytime session. Download data were recorded at 1 week and 1 and 6 months. Any changes in ventilator pa-rameters were recorded. RESULTS: Of the 30 subjects, 56.7% had bulbar onset ALS, 8 died, and 11 in each group completed the study. Median time to first parameter change was 33.5 (interquar-tile range [IQR] 7.7-96.0) d versus 41.0 (IQR 12.5-216.5) d for iVAPS versus S/T groups, respec-tively, (P = .48). The average number of RT interventions was similar between groups (1.1 +/- 1.1 vs 0.9 +/- 0.9 at 1 month, P = .72; 2.4 +/- 2.1 vs 2.4 +/- 2.3 at 6 months, P = .95, for iVAPS vs S/T, respec-tively). Adherence was significantly lower with iVAPS than S/T at 1 week but not at 1 or 6 months. Download parameters were similar between groups at 1 week and 6 months except for higher re-sidual apnea-hypopnea index (AHI) and less spontaneously triggered breaths with iVAPS at 6 months. CONCLUSIONS: The time to first change of parameters and the number of interventions at 6 months from NIV initiation were similar for the iVAPS and S/T modes in subjects with ALS. With iVAPS, adherence was lower transiently at NIV initiation, and the residual AHI was higher at 6 months. Alveolar ventilation-targeted NIV may require a longer adaptation period and result in greater upper-airway instability predominantly in patients with bulbar ALS.