Sniff Nasal Inspiratory Pressure (Snip): A Prognostic Factor Of Percutaneous Endoscopic Gastrostomyinpatients With Amyotrophic Lateral Sclerosis

ObjectiveTo investigate the role of sniff nasal inspiratory pressure (SNIP) at onset of amyotrophic lateral sclerosis (ALS) as predictive factor of percutaneous endoscopic gastrostomy (PEG)insertion.BackgroundMalnutrition is associated with a reduced survival in ALS and it’s an important cause of diaphragmatic weakness. PEG is the standard procedure for enteral nutrition in ALS patients with impaired swallowing. An early respiratory dysfunction determines greater energy expenditure. Early detection of increased energy needs is important to prevent additional muscle loss.Design/MethodsIn this retrospective study we enrolled 139 ALS patients between April 2006-December 2012. We collected demographic and clinical data at baseline (censoring date April 2014). Main outcome was PEG. Cox regression models were performed. Calibration, discrimination (C-index and continuous net reclassification improvement (cNRI) index) were assessed for all models.ResultsSixty-nine patients with ALS reached the outcome during a mean follow-up of 3.6±2.1 years. Two multivariate models were estimated considering patients without missing values (n=91). The first one was a clinical-based model including: age, sex, BMI , ALSFRSr, Charlson Comorbidity Index, Forced Vital Capacity, site of onset, onset-diagnosis interval. The second model included SNIP as new predictor factor. Both models showed adequate calibration. The model including SNIP improved significantly the predictive accuracy compared with the clinical-based model (c-index: 0.800, 0.782, respectively; p=0.017). SNIP correctly classified the risk of the event within 3-years of follow-up with cNRI of 0.52 (p=0.005).ConclusionsSNIP was reported as the most reliable respiratory test in ALS, combining linear decline, good sensitivity, high reproducibility both in early and in advanced stage of disease. At onset of disease, SNIP test is a predictor of early PEG insertion. Decline of respiratory functions, being an indicator of energy expenditure due to higher respiratory muscle activity, is a marker of the clinical need of establish a nutritional intake through PEG. Disclosure: Dr. QUARANTA has nothing to disclose. Dr. Capozzo has nothing to disclose. Dr. Arcuti has nothing to disclose. Dr. DRAGONIERI has nothing to disclose. Dr. Tortelli has nothing to disclose. Dr. PIERLUIGI has nothing to disclose. Dr. Panza has nothing to disclose. Dr. Cassano has nothing to disclose. Dr. Simone has received personal compensation for activities with Sanofi Aventis and Biogen. Dr. Resta has nothing to disclose. Dr. Logroscino has received personal compensation in an editorial capacity for Karger.