Outcomes of patients with Amyotrophic Lateral Sclerosis admitted to the ICU for acute respiratory failure

Background Data on patients with amyotrophic lateral sclerosis (ALS) admitted to the intensive care unit (ICU) for acute respiratory failure are scarce, and early prognostic markers are lacking. Methods We conducted a retrospective cohort study of consecutive patients with ALS admitted for acute respiratory failure to two ICUs of a tertiary referral center between 2016 and 2022. The primary outcome was 3-month mortality. Factors associated with 3-month mortality were assessed using multivariable Cox proportional hazards regression. Survival and functional outcomes were evaluated up to 12 months. Results Among 139 patients [median age 66 (IQR 57–73) years, 61.2% being men], 109 (78.4%) patients presented with hypercapnia and 82 (59.0%) with hypoxemia (defined as PaO₂/FiO₂ ratio < 300) at ICU admission, with frequent overlap between both conditions. Non-invasive ventilation was used in 79.9% of patients, while 13.7% were intubated, and 2.2% underwent tracheostomy. Three-month mortality was 48.2%, increasing to 61.2% and 74.1% at 6 and 12 months respectively. In multivariable analysis, hypoxemia at ICU admission was independently associated with increased 3-month mortality (HR = 2.27, 95% CI: 1.28–4.01; P = 0.005), along with older age (HR=1.03 per year, 95% CI: 1.00–1.06; P = 0.035). Among patients alive at 3 months, a majority (79.2%) were living at home. Conclusion ICU admission for acute respiratory failure in ALS is associated with substantial short-term mortality, consistent with the poor prognosis inherent to the natural history of the disease. Hypoxemia at admission identifies a subgroup at particularly high risk of death and may help inform early prognostic assessment and shared decision-making. However, patients who survive the acute ICU phase frequently achieve favorable short-term outcomes, with most living at home at 3 months.