Factors Influencing Noninvasive Ventilation Initiation in Amyotrophic Lateral Sclerosis

Abstract

SESSION TITLE: Respiratory Care SESSION TYPE: Original Investigation Slide PRESENTED ON: Tuesday, October 31, 2017 at 08:45 AM - 10:00 AM PURPOSE: Respiratory failure is the most common cause of death in Amyotrophic Lateral Sclerosis (ALS). Noninvasive ventilation (NIV) has been shown to improve survival and quality of life in patients with daytime respiratory symptoms or when forced vital capacity (FVC) falls below 50% of predicted value. However, the optimal timing to initiate NIV is unknown. Preliminary data suggests that early NIV initiation (at FVC>50% predicted), applied during nocturnal sleep, may prevent respiratory function decline and further improve survival. Current practice guidelines recommend NIV initiation when FVC is ≤ 50% predicted. Our objective is to describe NIV practices at a tertiary ALS referral center with respect to guidelines. METHODS: We retrospectively reviewed a cohort of 96 patients between 2015-2017. We analyzed respiratory and bulbar symptoms, FVC at diagnosis and NIV initiation, time gap between diagnosis and NIV initiation. Logistic regression analysis was performed to determine predictors of early NIV initiation (FVC>50). RESULTS: NIV was initiated in 67.7% of patients (mean age 63.7). At time of diagnosis, mean FVC was 63.3%, mean FVC at NIV initiation was 51.6%. Respiratory and bulbar symptoms were present in 75% and 60% of patients, respectively. Mean FVC was 65.6% versus 77.7% for those with and without bulbar involvement, respectively. Mean FVC at NIV initiation was 49% versus 56.6% for those with and without bulbar involvement, respectively. Early NIV (initiated at FVC>50) was implemented in 51% of patients due to respiratory (67%) or bulbar symptoms (52%). Mean FVC at early NIV initiation was 66.6%. Average time from diagnosis to NIV initiation was 232.3 days, with a mean FVC decline of 9%. NIV was implemented in 49% of patients per practice guidelines (FVC≤50). Mean FVC at NIV initiation per guidelines was 36%. Respiratory and bulbar symptoms were present in 84% and 68.7%, respectively. Average time from diagnosis to NIV initiation was 42.7 days, with a mean FVC decline of 14.8%. Logistic regression analysis showed that respiratory symptoms were significantly associated with early NIV initiation (OR 10.4, 95% CI 2.6-41.8, p<0.001). Only 10 patients (15%) with baseline FVC>50% at time of diagnosis were started on NIV late in the disease course (i.e. FVC≤40). CONCLUSIONS: Majority of patients were initiated on nocturnal NIV appropriately or earlier than current practice guidelines due to respiratory or bulbar symptoms. Early NIV initiation may be considered for patients with symptoms related to respiratory or bulbar involvement. CLINICAL IMPLICATIONS: Further research is needed to clarify optimal timing of a critical intervention (NIV) which may further prolong survival, improve quality of life, and potentially delay respiratory function decline. DISCLOSURE: The following authors have nothing to disclose: Pradeep Doddamreddy, Gaurav Singh, Brittany Schultz, Michelle Cao No Product/Research Disclosure Information