In an ALS patient with FVC 60–70% predicted, normal daytime ABG, and normal nocturnal oximetry, but persistent orthopnea and unrefreshing sleep, do you initiate nocturnal NIV — and if so, how do you navigate the CMS coverage gap?

In our assisted ventilation clinic, we lean toward symptom-based initiation for patients with neuromuscular disease, including ALS. There are several strategies for navigating the coverage gap.

We have found that performing both FVC and MIP measurements with supine positioning will often reveal that a patient's orthopnea is substantiated by PFT changes that fall within the CMS coverage criteria.

If supine spirometry and MIP are not revealing, I would have the patient undergo PSG. This requires communication with the sleep lab ahead to time to let them know that if hypopneas are observed, they may not be treatable by very high levels of CPAP and that BiPAP should be attempted sooner rather than later. I would then continue to reevaluate PFTs...

I follow the updated CHEST guidelines presented as part of the ONMEP TEP summary from 2021 (Gay et al., PMID 34339685). In patients with FVC <80% with symptoms (particularly orthopnea), I would initiate nocturnal NIV therapy with BIPAP-ST, AVAPS, or AVAPS-AE mode depending on the particular clinical scenario. I do this a majority of the time without a polysomnogram titration study. For the diagnosis of ALS, I have not had difficulty getting ventilators covered by Medicare or other payers. This may not be true for non-ALS neuromuscular diagnoses. I do include a statement in my note describing that the patient has an invariably progressive motor neuron disease that affects respiratory muscles, which necessitates the covered device to have vol...

This patient with symptomatic orthopnea needs a supine forced vital capacity (FVC) and maximal inspiratory pressure (MIP) measurement. The rule for the 50% threshold for FVC is also applicable in the supine position and often catches the patients who are escaping the criteria in the upright position. MIP is more sensitive in earlier disease. One word of caution in utilizing MIP in an asymptomatic patient with poor bulbar function: have an honest discussion with the patient about the benefits of early initiation versus false-positive testing and collectively decide. If I do not hit any of these criteria, then get a sleep study to see if other etiologies explain the lack of refreshing sleep and, or could qualify for positive airway pressure (...