Amyotrophic lateral sclerosis (ALS) is characterized by a progressive decline of motor function. The degenerative process affects the respiratory system. Butz et al. (A-10) investigated the longitudinal impact of nocturnal noninvasive positive-pressure ventilation on patients with ALS. Prior to treatment, they measured partial pressure of arterial oxygen (Pao2) and partial pressure of arterial carbon dioxide (Paco2) in patients with the disease. The results were as follows:

Paco2 Pao2 40.0 101.0 47.0 69.0 34.0 132.0 42.0 65.0 54.0 72.0 48.0 76.0 53.6 67.2 56.9 70.9 58.0 73.0 45.0 66.0 54.5 80.0 54.0 72.0 43.0 105.0 44.3 113.0 53.9 69.2 41.8 66.7 33.0 67.0 43.1 77.5 52.4 65.1 37.9 71.0 34.5 86.5 40.1 74.7 33.0 94.0 59.9 60.4 62.6 52.5 54.1 76.9 45.7 65.3 40.6 80.3 56.6 53.2 59.0 71.9 Source: M. Butz, K. H. Wollinsky, U. Widemuth-Catrinescu, A. Sperfeld, S. Winter, H. H. Mehrkens, A. C. Ludolph, and H. Schreiber, “Longitudinal Effects of Noninvasive PositivePressure Ventilation in Patients with Amyotrophic Lateral Sclerosis,” American Journal of Medical Rehabilitation, 82

(2003) 597–604.