Myasthenic Crisis — Management Pathway

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Respiratory/bulbar involvement?
   Respiratory/bulbar involvement (single-breath count, FVC)? (MG exacerbation causing respiratory failure needing intubation/NIV, bulbar weakness causing aspiration. Triggers: infection/surgery/pregnancy/drugs (beta-blockers, IV magnesium, fluoroquinolones, aminoglycosides, macrolides). Monitor: single-breath count (unable to reach 20 is a warning), FVC, NIF; generalized weakness can mask respiratory distress. Differentiate from cholinergic crisis (cholinergic excess: SLUDGE, fasciculations).)
   • Respiratory/bulbar involvement, falling FVC → Crisis → ICU + respiratory support
   • Stable, no respiratory involvement → Stable · monitor + immunotherapy
2. [End] Stable · monitor + immunotherapy
   No significant respiratory/bulbar involvement: admit for close monitoring — single-breath count, FVC/NIF, bulbar function, cough strength; find and treat the trigger (infection), stop aggravating drugs. May start immunotherapy (PLEX or IVIG) + steroids. Escalate if progressing (FVC <15–20 mL/kg, cannot count to 20, bulbar weakness).
3. [End] Crisis → ICU + respiratory support
   Respiratory/bulbar involvement (crisis): ICU, respiratory support (NIV/BiPAP can avoid some intubations; intubate once clinical indications are clear, not on numbers alone); hold/reduce pyridostigmine during crisis (reduces secretions and helps distinguish cholinergic crisis); plasma exchange (preferred, faster) or IVIG 0.4 g/kg × 5 days (draw serum antibodies first), plus corticosteroids; find and treat the trigger, avoid aggravating drugs (beta-blockers/magnesium/fluoroquinolones/aminoglycosides/macrolides).

Source guidelines & references

• Myasthenic crisis (EMCrit IBCC; MGFA consensus)

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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