Efficacy of nasal high flow therapy (NHFT) in chronic hypercapnic amyotrophic lateral sclerosis

Abstract

Introduction: Recent data demonstrate a positive effect of NHFT in alternative to non-invasive positive pressure ventilation (NIV) in chronic hypercapnic COPD. Amyotrophic lateral sclerosis (ALS) patients with respiratory insufficiency initially refuse the ventilatory support. We report the preliminary data on the role for NHFT in ALS. Aim: This preliminary study was conducted to assess the impact of HFNT on ventilatory parameters and comfort compared with face NIV in moderate hypercapnic ALS. Methods: Six hypercapnic ALS patients with arterial oxygen tension >60 mmHg underwent two 60-min trials: HFNT at 40 L/min flow rate using nasal prongs with closed mouth and NIV with face mask. Subjects were ventilated by NIV with a pressure support level targeting a derived inspired tidal volume of 7-8 ml/kg. After each trial spontaneous breathing was reinstituted for 60 min. Arterial blood gas analyses were assessed before and after each 1-h ventilatory trial. Further, we assessed breathing frequency and used a visual comfort scale to evaluate patient satisfaction. Results: Arterial carbon dioxide oxygen tension (PaCO2) decreased but not significantly with HFNT at 40 L/min and NIV compared with baseline data (mean±SD 55.2±12.2 basal value, 51.7±10.6 after HFNT trial, 52.2±8.2 mmHg after NIV). Breathing frequency did not change between the different trials. Comfort score was higher with HFNT compared with NIV (mean 7.1 vs 5.5 score). Conclusions: These preliminary data show that NHFT leads to a reduction in PaCO2 in ALS patients. HFNT is better tolerated than NIV. Results indicate a possible role for HFNT in the long-term management of hypercapnic ALS patient.