Predictors of non-invasive ventilation tolerance in amyotrophic lateral sclerosis

The most frequent cause of death in patients with Amyotrophic Lateral Sclerosis (ALS) is respiratory failure. Recently, it has been shown that non-invasive ventilation improves survival and quality of life in ALS patients with respiratory failure, but little is known about predictors of non-invasive ventilation adaptation and tolerance. In this study we evaluated the effect of a comprehensive information about non-invasive ventilation use and a prolonged and intensive monitoring on tolerance to this palliative care.

We prospectively monitored all consecutive ALS patients with chronic respiratory failure and indication to non-invasive ventilation between January 2005 and December 2007. Non-invasive ventilation adaptation was always performed in a hospital setting.

Forty-four patients were considered eligible: six declined the non-invasive ventilation proposal and one was excluded due to severe fronto-temporal dementia. Non-invasive ventilation was offered to thirty-seven inpatients in our ALS Centre, thirty-two of whom presented with severe (n=9) or mild-moderate (n=23) bulbar impairment at non-invasive ventilation initiation. The mean time interval for adaptation to ventilation was 5±2 days, but patients remained in hospital for an average extended period of one week. Thirty-five of the 37 patients who started non-invasive ventilation, including those with severe bulbar impairment, remained tolerant at twelve months follow-up.

Our study shows that an intensive educational training and adaptation on non-invasive ventilation, when performed in a hospital multidisciplinary setting, increases compliance and tolerance over time, even in those patients with severe bulbar impairment. However, the design of our study, mainly based on a continuous monitoring and educational training of the patients, might not make it fully applicable to an outpatients setting.