Myasthenic crisis in ED- check the negative inspiratory pressure (<25) and Fvc (15L/kg)

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