Noninvasive positive-pressure ventilation in ALS: predictors of tolerance and survival.
OBJECTIVE
To identify factors associated with tolerance and survival after noninvasive positive-pressure ventilation (NIPPV) and to investigate the influence of NIPPV on lung function in patients with ALS.


METHODS
NIPPV was offered to 71 patients with ALS in accordance with currently published guidelines. Effects of NIPPV on lung function and factors influencing tolerance and survival after NIPPV were studied.


RESULTS
Forty-four patients (61.9%; 95% CI: 50.6 to 73.2) tolerated NIPPV (NIPPV use >or=4 h/day) and 27 (38.1%; 95% CI: 26.8 to 49.4) were intolerant (NIPPV use <4 h/day). Patients with mild or moderate bulbar symptoms were more likely to tolerate NIPPV than those with severe impairment (odds ratio = 6.09, 95% CI: 1.18 to 31.52, p = 0.031). After NIPPV introduction, a slower decline in forced vital capacity (FVC) was observed in tolerant vs intolerant patients (p = 0.002). The slope of FVC decline after NIPPV initiation (risk ratio [RR]: 0.78, 95% CI: 0.65 to 0.94, p = 0.01) together with NIPPV tolerance (RR: 0.32, 95% CI: 0.13 to 0.78, p = 0.013) were the only independent predictors of survival in the overall group of patients. In multivariate analysis, body mass index was the most powerful predictor of longer survival after NIPPV in tolerant patients (RR: 0.77, 95% CI: 0.61 to 0.96, p = 0.022).


CONCLUSIONS
Survival after noninvasive ventilation was independently related to ventilatory use (>or=4 h/day) and to the modifications of forced vital capacity decline after treatment initiation. The severity of bulbar impairment and the nutritional status of the ALS patients at the introduction of ventilation may predict tolerance and survival.
Lo Coco
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ALS Research Center, Department of Neurology, Ophthalmology, Otorhinolaryngology, and Psychiatry, Università di Palermo, Via G La Loggia, 1, 90129 Palermo, Italy. danielelococo@yahoo.com
Marchese
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Pesco
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La Bella
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Piccoli
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Lo Coco
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D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology / Q000628:therapy*; D003710:Demography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011175:Positive-Pressure Respiration / Q000379:methods* / Q000401:mortality*; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies; D018434:Sickness Impact Profile; D015996:Survival Rate; D013997:Time Factors; D012122:Ventilators, Mechanical