title: A preliminary evaluation of a prospective study of pulmonary function studies and symptoms of hypoventilation in ALS/MND patients.
abstract: There is still no consensus as to which physiologic marker should be used as a trigger for the initiation of non-invasive positive pressure ventilation (NPPV) in patients with amyotrophic lateral sclerosis (ALS). Current practice parameters recommend that the decision to begin treatment be based upon forced vital capacity (FVC) measurements. A prospective, randomized study was performed in 20 ALS patients who had an FVC of 70-100%. Patients received baseline assessments including: ALS functional rating scale-respiratory version (ALSFRS-R), pulmonary symptom scale, Short form 36 (SF-36), FVC%, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and nocturnal oximetry. Patients were randomized to receive NPPV based upon nocturnal oximetry studies suggesting oxygen desaturation <90% for one cumulative minute ("early intervention") or a FVC <50% ("standard of care"). At enrollment, there was no significant correlation between FVC% and the ALSFRS-R, symptom score, MEP, MIP, or duration of nocturnal desaturation <90%. An increase in the vitality subscale of the SF-36 was demonstrated in 5/6 patients randomized to "early intervention" with NPPV. Our data indicate that FVC% correlates poorly with respiratory symptoms and suggests that MIP and nocturnal oximetry may be more sensitive measures of early respiratory insufficiency. In addition, intervention with NPPV earlier than our current standard of care may result in improved quality of life.
authors.affiliation: Department of Medicine/Neurology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7883, TX 78229-3900, USA. jacksonce@uthscsa.edu
authors.forename: C E
authors.initials: CE
authors.lastname: Jackson
authors.forename: J
authors.initials: J
authors.lastname: Rosenfeld
authors.forename: D H
authors.initials: DH
authors.lastname: Moore
authors.forename: W W
authors.initials: WW
authors.lastname: Bryan
authors.forename: R J
authors.initials: RJ
authors.lastname: Barohn
authors.forename: M
authors.initials: M
authors.lastname: Wrench
authors.forename: D
authors.initials: D
authors.lastname: Myers
authors.forename: L
authors.initials: L
authors.lastname: Heberlin
authors.forename: R
authors.initials: R
authors.lastname: King
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: D
authors.initials: D
authors.lastname: Gelinas
authors.forename: R G
authors.initials: RG
authors.lastname: Miller
mesh_terms: D018450:Disease Progression; D006801:Humans; D007040:Hypoventilation / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D016472:Motor Neuron Disease / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D010092:Oximetry; D011175:Positive-Pressure Respiration; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011788:Quality of Life; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D016037:Single-Blind Method; D011795:Surveys and Questionnaires; D014797:Vital Capacity