Ž . Journal of the Neurological Sciences 191 2001 75–78 www.elsevier.comrlocaterjns A preliminary evaluation of a prospective study of pulmonary function studies and symptoms of hypoventilation in ALSrMND patients C.E. Jackson a, ) , J. Rosenfeld b , D.H. Moore c , W.W. Bryan d , R.J. Barohn d , M. Wrench a , D. Myers a , L. Heberlin d , R. King b , J. Smith b , D. Gelinas c , R.G. Miller c a Department of Medicine r Neurology, UniÕersity of Texas Health Science Center at San Antonio, 7703 Floyd Curl DriÕe, Mail Code 7883, San Antonio, TX 78229 3900, USA b Carolinas Neuromuscular r ALS-MDA Center r Carolinas Medical Center, Charlotte, NC, USA c California Pacific Medical Center, San Francisco, CA, USA d Department of Neurology, UniÕersity of Texas Southwestern Medical Center, Dallas, TX, USA Abstract There is still no consensus as to which physiologic marker should be used as a trigger for the initiation of non-invasive positive Ž . Ž . pressure ventilation NPPV in patients with amyotrophic lateral sclerosis ALS . Current practice parameters recommend that the Ž . 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 Ž . Ž . Ž . version ALSFRS-R , pulmonary symptom scale, Short form 36 SF-36 , FVC%, maximal inspiratory pressure MIP , maximal Ž . expiratory pressure MEP , and nocturnal oximetry. Patients were randomized to receive NPPV based upon nocturnal oximetry studies Ž . Ž . suggesting oxygen desaturation -90% for one cumulative minute Aearly interventionB or a FVC -50% Astandard of careB . 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 5r6 patients randomized to Aearly interventionB 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. q 2001 Published by Elsevier Science B.V. Keywords: Non-invasive positive pressure ventilation; Amyotrophic lateral sclerosis; Pulmonary function studies; Nocturnal hypoventilation; Bi-modal positive airway pressure; Respiratory failure 1. Introduction Although the benefits of non-invasive positive pressure Ž . ventilation NPPV in patients with amyotrophic lateral Ž . w x sclerosis ALS are apparent in several studies 1–3 , there is still no clear consensus as to which physiologic marker Ž. andror clinical symptom s should be used to initiate NPPV. In addition, at the present time, there is no single test that has been shown to reliably detect early respiratory insufficiency. A recent evidence-based review of the sub- ject pointed out that most patients with ALS are symp- tomatic of hypoventilation by the time the vital capacity Ž . wx FVC falls below 50% of predicted 4 . The authors provided a management algorithm that suggests that NPPV ) Corresponding author. Tel.: q 1-210-567-1945; fax: q 1-210-567- 1948. Ž . E-mail address: jacksonce@uthscsa.edu C.E. Jackson . should be instituted when patients are symptomatic and when FVC reaches 50% of the predicted value based on age, sex and height. Ž . The Health Care Financing Administration HCFA has wx recently established criteria 5 for initial coverage of respiratory assist devices which also serves to establish a Astandard of careB. In order for NPPV to be covered by Medicare, the patient must have documentation of symp- toms characteristic of sleep-associated hypoventilation, such as hypersomnolence, excessive fatigue, morning headache, cognitive dysfunction, or dyspnea. In addition, a patient must demonstrate one of the following: an arterial blood gas PaCO which is ) 45 mm Hg while awake, 2 have nocturnal oximetry data demonstrating oxygen desat- uration - 88% for at least five continuous minutes, have FVC - 50% of predicted or a maximum inspiratory pres- sure - 60 cm H O. Most of these HCFA criteria are 2 based on measurements corresponding with relatively se- vere respiratory insufficiency. 0022-510Xr01r$ - see front matter q 2001 Published by Elsevier Science B.V. Ž . PII: S0022-510X 01 00617-7