title: Effect of inspiratory resistance and theophylline on respiratory muscle strength in patients with amyotrophic lateral sclerosis.
abstract: The effect of breathing through inspiratory flow resistive loads ranging between 4.5 and 27.0 cm H2O/L/s was assessed in eight patients with amyotrophic lateral sclerosis (ALS) and in eight control subjects. ALS patients developed respiratory muscle fatigue manifested by significant declines in negative inspiratory pressure (18.3%), vital capacity (7.2%), and peak inspiratory flow rate (5.5%). Control subjects did not fatigue with these resistances. In ALS patients, theophylline increased respiratory muscle strength after resistive breathing as manifested by an increase in negative inspiratory pressure (28.2%), vital capacity (10%), and peak inspiratory flow rate (11.8%). It is concluded that in patients with ALS, the already weakened respiratory muscles are easily fatigued. Furthermore, theophylline can strengthen loaded respiratory muscles in patients with ALS.
authors.affiliation: Department of Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick 08903-0019.
authors.forename: P L
authors.initials: PL
authors.lastname: Schiffman
authors.forename: J M
authors.initials: JM
authors.lastname: Belsh
mesh_terms: D000403:Airway Resistance; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D012123:Pulmonary Ventilation; D012119:Respiration / Q000187:drug effects*; D012132:Respiratory Muscles / Q000187:drug effects / Q000503:physiopathology*; D013806:Theophylline / Q000009:adverse effects / Q000494:pharmacology*; D014797:Vital Capacity
chemical_list: D013806:Theophylline