Profile of respiratory impairment in patients with amyotrophic lateral sclerosis at initial admittance

PURPOSE: To evaluate the initial respiratory impairments [pulmonary functions and arterial blood gases (ABGs)] in patients with amyotrophic lateral sclerosis (ALS) according to Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) at the time of admission. METHOD: Forty-five patients with ALS were evaluated between January 2004 and December 2007 by pulmonary function tests (PFTs) and ABG results at the time of admission. ALSFRS-R was used to quantify the severity of ALS patients. ALS patients were divided into 2 subgroups according to their ALSFRS-R scores as equal or below 26 (group 1, moderate-severe) and above 26 (group 2, mild). PFTs and ABG results were compared between these 2 subgroups. RESULTS: As 13 of the 45 patients with ALS were unable to perform PFTs, data of only 32 patients were evaluated (n=7 for group 1, n=25 for group 2). PFTs and ABG results except for forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) % (P=0.003) and partial arterial oxygen tension (pO2) (P=0.02) did not differ significantly between the 2 groups. While FEV1/FVC (r=-0.42, P=0.01) was negatively correlated with ALSFRS-R score, pO2 (r=0.36, P=0.02) was positively correlated. CONCLUSIONS: We thought that the increase in FEV1/FVC (%) was more susceptible for reflecting early respiratory impairments than FVC (%) in ALS patients at the initial admittance. Copyright © 2010 by Lippincott Williams & Wilkins