PURPOSE:Non-invasive ventilation (NIV) can improve survival in amyotrophic lateral sclerosis (ALS) patients with advanced respiratory impairment, but it is not known if it is beneficial earlier in the disease course. Moreover the current literature has not yet offered any gold standard which decides when to start NIV in ALS patients. The aim of the study was to investigate factors predicting survival in ALS patients when treated with NIV.
METHODS:A prospective analysis of ALS patients referred to our neuromuscular clinic was performed since 2001. We determined the median time from diagnosis and initiation of NIV to death/trachestomy ventilation (failure event) and factors predicting failure event in subjects who started NIV use when their FVC was > 60% pred (Early NIV) or < 60% pred (Standard NIV). Statistical analysis was performed using the Kaplan-Meier test and Cox proportional hazards model.
RESULTS:The mean (SD) FVC % pred at starting NIV was 73.9±10.8 and 37.3±12.9 (p < 0.0001) in the Early and Standard NIV groups, respectively and the mean PaC02 was 42 and 45 mmHg, respectively. The mean time (Standard Error) from ALS diagnosis and NIV to failure event was not statistically different between the Early NIV group (27.9±4.3 months and 20.0±4.1) and the Standard NIV group (44.8±7.5 months and 21.1±5.7). An acute respiratory infection (p =0.009) but not respiratory parameters, sleep disorders or bulbar dysfunction predicted the failure event.
CONCLUSION:Our study shows that acute respiratory event is the negative prognostic factor of death/trachestomy ventilation in ALS patients treated with the Early or Standard NIV protocol. Early NIV use seems not to influence survival from time of ALS diagnosis.
CLINICAL IMPLICATIONS:Prevention of acute respiratory event might be the best therapeutic strategy to prolong survival in ALS patients on NIV.
DISCLOSURE:Alessia Verduri, No Financial Disclosure Information; No Product/Research Disclosure Information