Non-invasive ventilation effectiveness and the effect of ventilatory mode on survival in ALS patients

Abstract

Non-invasive ventilation (NIV) prolongs survival in amyotrophic lateral sclerosis (ALS), but there are no data with which to compare the effectiveness of the different ventilator modes – volume (Vol-NIV) or pressure-cycled (Pres-NIV) ventilation – in ALS. We aimed to determine whether the ventilatory mode has an effect on ventilation effectiveness and survival of ALS patients using NIV. We used a retrospective study that included all ALS patients for whom NIV was indicated in two referral units: one using Vol-NIV and the other using Pres-NIV. Demographic, functional and nocturnal gas exchange parameters at NIV initiation were recorded. Eighty-two ALS patients ventilated using Pres-NIV and 62 using Vol-NIV were included. No differences were found in survival from NIV initiation between Vol-NIV (median 15.00 (7.48–22.41) months) and Pres-NIV (median 15.00 (10.25–19.75) months, p = 0.533) patients. Effective NIV was achieved in 72.41% Vol-NIV patients and in 48.78% Pres-NIV patients (p < 0.001). Ventilator mode (OR 12.066 (4.251–32.270), p < 0.001) and severity of bulbar dysfunction (OR 1.07 (1.011–1.133), p = 0.02) were the variables correlated with effective NIV. In conclusion, although Vol-NIV provides more effective ventilation, Vol-NIV and Pres-NIV present similar survival in ALS. Effectiveness of NIV is related to the severity of bulbar dysfunction.

Key words::

• Amyotrophic lateral sclerosis
• non-invasive ventilation
• respiratory failure
• survival
• ventilatory modes

Disclosure of interest: The authors have no potential conflicts of interest with any companies or organizations whose products or services are discussed in this manuscript. The authors alone are responsible for the content and writing of the paper.