AB 4. Lung function and disability in patients with ALS at the time of respiratory assessment

Background: Amyotrophic Lateral Sclerosis (ALS) affects the respiratory function of patients throughout the disease progress. Prompt diagnosis of pulmonary involvement is important in order to decide the ventilator support of the patients.

Patients and methods: We studied 54 ALS patients, who visit our chest department because of respiratory symptoms, by spirometry, arterial blood gases and respiratory muscle strength assessment (MIP, MEP). Time from diagnosis, ALSFS and demographic characteristics of all subjects were recorded.

Results: The time elapsed between onset of symptoms and diagnosis of ALS was 12.2±16 months and the time between diagnosis and the first assessment of respiratory function was 13.9±11 month. Twenty four patients presented with medullary symptoms. Pulmonary examination took place after 13.3±18.8 months from the diagnosis and after 10±7.3 months in patients with peripheral symptoms. Statistical significant correlation was observed between ALSFS and the time elapsed until the respiratory system examination (r=–0.483, P<0.05). Respiratory function measurements were: FVC 53.8±23%, FEV₁ 53.6±24%, PaO₂ 71.6±13.5 mmHg, PaCO₂ 43.4±9.2 mmHg, MIP 28.4±21 cmH₂O, MEP 39.1±22.1 cmH₂O. Seven patients had been hospitalized in ICU because of acute respiratory failure. They had statistical significant higher PaCO₂ (P<0.05) than the other patients. Twenty nine patients accepted to use non invasive ventilation (NIV). Statistical significant difference was noted in ALSFS (P<0.05) in FVC (P<0.05), PaCO₂ (P<0.001) PaO₂ (P<0.01) between them and the rest of the group.

Conclusions: The baseline examination of pulmonary function in ALS patients was overdue, even in patients with medullary symptoms. Physical and respiratory functions were both reduced. Physicians related to ALS disease should be vigilant aiming at the prompt management of the respiratory consequences during the disease progress.