Myasthenic patients may present to ED with shortness of breath without obvious signs of distress ( because resp accessory muscles are weak and fatiguing !)
Common precipitants are infections and antibiotics or other meds – sometimes disease course
Measure the negative inspiratory pressure or the FVC – if <25 cm h2o or 15L/kg – discuss with icu and neurology need for:
NIV or CVM
IVIG
Plasmapharesis or Steroids

Physostigmine is NOT used for acute myasthenia