Continuous ventilatory support for prolongation of life in amyotrophic lateral sclerosis: a retrospective cohort analysis

Abstract

Introduction: Amyotrophic lateral sclerosis (ALS), or motor neuron disease (MND), is a progressive and incurable neurodegenerative condition. Noninvasive ventilation (NIV) is a key intervention associated with longer survival and better quality of life. This study analyzed the clinical course of ALS patients on continuous noninvasive ventilatory support (CNVS) and its impact on survival, including progression to invasive mechanical ventilation via tracheostomy. Methods: This is a retrospective cohort study of 136 patients with amyotrophic lateral sclerosis (ALS) who used continuous noninvasive ventilatory support (CNVS), followed between 2004 and 2025 at three reference centers (two in Portugal and one in Brazil). Sociodemographic, clinical, and pulmonary function data were collected, as well as characteristics of NIV use (such as daily use time, ventilation modes, interfaces), in addition to information on percutaneous endoscopic gastrostomy (PEG), use of a cough machine (MI-E), and palliative care follow-up. The primary outcome was survival time with NCV and tracheostomy. Statistical analysis included Kaplan-Meier curves and Cox regression models, with significance set at p < 0.05. Results: The sample included 136 patients (61% male) with a mean age at diagnosis of 64.7 years. The spinal form of ALS was 75.7% and the bulbar form was 24.3%. The mean time between diagnosis and initiation of NIV was 7.7 months, and 66.9% of patients started NIV with <8 hours/day. Overall survival from diagnosis was 37.4 months (95% CI: 27.9-46.9) with Kaplan-Meier analysis. Patients who underwent tracheostomy (n = 23) had significantly longer survival (58.0 months; 95% CI: 16.4-99.5) compared to those without tracheostomy (32.7 months; 95% CI: 26.9-38.4; p = 0.019). Similarly, patients with bulbar ALS had shorter survival (28.7 months; 95% CI: 21.0-36.3) than those with spinal ALS (44.5 months; 95% CI: 31.7-57.1; p=0.04). Conclusion: CNVS, either alone or with transition to tracheostomy, prolongs the life of patients with ALS and should be considered an essential part of treatment and used in conjunction with palliative care. The decision for tracheostomy should always be individualized and supported by adequate multidisciplinary and palliative care.