A comparison of maximal inspiratory pressure and forced vital capacity as potential criteria for initiating non-invasive ventilation in amyotrophic lateral sclerosis.
Using a retrospective analysis of 161 patients with amyotrophic lateral sclerosis (ALS) from the Western ALS study group (WALS) database, the sensitivity of maximal inspiratory pressure (MIP)< -60 cm H(2)O and forced vital capacity (FVC)< 50% as US Medicare thresholds for initiating non-invasive ventilation (NIV) were compared. Sixty-five per cent of patients at enrollment met the MIP criterion, compared with only 8% of patients who met the FVC criterion. There were no cases in which FVC< 50% antedated MIP< -60 cm H(2)O. The longitudinal data showed that patients reached the MIP criterion 4 to 6.5 months earlier than the FVC criterion. For patients with clinical signs and symptoms needing treatment with NIV, a MIP< -60 cm H(2)O allows US clinicians to obtain non-invasive ventilatory support for patients earlier than if using the FVC criterion alone.
Mendoza
Michelle
M
Forbes Norris MDA/ALS Research Center, San Francisco, CA 94115, USA. mendozmc@cpmcri.org
Gelinas
Deborah F
DF
Moore
Dan H
DH
Miller
Robert G
RG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000628:therapy*; D005260:Female; D006801:Humans; D007320:Inspiratory Capacity; D008297:Male; D008451:Maximal Voluntary Ventilation; D008875:Middle Aged; D018579:Patient Selection; D011379:Prognosis; D015203:Reproducibility of Results; D012121:Respiration, Artificial / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014797:Vital Capacity