Suspected Myasthenic Crisis
Patient with MG presenting with worsening weakness or respiratory compromise
All Pathways
NeurologyEmergency
Myasthenia Gravis Crisis Management
Myasthenia Gravis Crisis Management: Suspected Myasthenic Crisis → Respiratory Assessment → Elective Intubation → Identify Crisis Trigger → ⚠️ Avoid The...
Pathway Overview
13 steps
Algorithm Steps
13 total
01Start 02Decision Respiratory Assessment
Check FVC, NIF, and clinical signs
- FVC <20 mL/kg = ICU admission
- FVC <15 mL/kg = consider intubation
- NIF < -30 cmH2O = respiratory weakness
- Dyspnea, weak cough, paradoxical breathing
- Unable to count to 20 in one breath
03Action Elective Intubation
Early intubation preferred over emergent
- Avoid succinylcholine (unpredictable response)
- Reduce non-depolarizing NMB dose by 50%
- Consider awake fiberoptic if bulbar weakness
- Plan for difficult weaning
04Action Identify Crisis Trigger
Search for precipitating factors
- Infection (most common - 40%)
- Medication changes/non-compliance
- Surgery or anesthesia
- Drugs: aminoglycosides, β-blockers, fluoroquinolones
- Taper of immunosuppression
05Warning ⚠️ Avoid These Medications
Can precipitate or worsen crisis
- Aminoglycosides, fluoroquinolones, macrolides
- Beta-blockers
- Magnesium sulfate
- Neuromuscular blocking agents
- Statins, IV contrast (iodinated)
06Decision Select Immunomodulatory Treatment
IVIG vs Plasma Exchange (PLEX)
- Both equally effective (Class I evidence)
- PLEX: faster response (2-3 sessions)
- IVIG: response in 2-3 weeks
- Choose based on availability and urgency
07Action IVIG
Intravenous Immunoglobulin
- 2 g/kg total dose over 2-5 days
- Pre-treat: acetaminophen, diphenhydramine
- Monitor for aseptic meningitis, renal failure
- Contraindicated: IgA deficiency
08Action Manage Cholinesterase Inhibitors
Consider holding pyridostigmine in crisis
- May hold during intubation (secretions)
- Risk of cholinergic crisis if excessive
- Restart at lower dose when improving
- 60 mg PO q4-6h typical maintenance
09Action Corticosteroids
Initiate with caution in crisis
- Can cause transient worsening first 2 weeks
- Start low and titrate: prednisone 10-20 mg/day
- Or high-dose after IVIG/PLEX initiated
- Target: 1 mg/kg/day (max 100 mg)
10Outcome Clinical Improvement
Wean vent support, transfer from ICU
- Continue immunotherapy
- Optimize long-term immunosuppression
- Consider thymectomy if indicated
11Warning Refractory Crisis
Consider additional interventions
- Repeat IVIG or PLEX
- Rituximab or eculizumab
- Prolonged mechanical ventilation
- Neuromuscular specialist consultation
12Action Plasma Exchange (PLEX)
Plasmapheresis
- 5 exchanges over 7-10 days
- 1.0-1.5 plasma volumes per exchange
- Requires central venous access
- Avoid in hemodynamic instability, sepsis
- Improvement by 2nd-3rd session
- Path rejoins step 08Shared downstream outcome
13Action ICU Monitoring
Serial respiratory assessments
- Check FVC/NIF every 2-4 hours
- Continuous pulse oximetry
- Aspiration precautions
- HOB elevated 30-45°
- Path rejoins step 04Shared downstream outcome
Guideline Source
International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Does not address pediatric MG crisis
- Requires ICU-level monitoring
- Drug dosing may require adjustment for renal/hepatic function
- Does not cover all immunosuppressive agents in detail
Contraindicated Populations
pediatric
Applicable Regions
USEUglobal
EU: Similar recommendations; access to PLEX may vary by center
US: IVIG and PLEX equally effective; choice depends on availability
Version 1Next review: 2028-01-01
Next steps
Finish the workflow by opening the most relevant calculator, then convert the session into a live account when you are ready.
Related Resources
Frequently Asked Questions
What is the Myasthenia Gravis Crisis Management?
The Myasthenia Gravis Crisis Management is a emergency clinical algorithm for Neurology. It provides a structured decision tree to guide clinical decision-making, based on International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update.
What guideline is the Myasthenia Gravis Crisis Management based on?
This algorithm is based on International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update (DOI: 10.1212/WNL.0000000000011124).
What are the limitations of the Myasthenia Gravis Crisis Management?
Known limitations include: Does not address pediatric MG crisis; Requires ICU-level monitoring; Drug dosing may require adjustment for renal/hepatic function; Does not cover all immunosuppressive agents in detail. Individual patient factors may require deviation from these recommendations.
Get AI-Powered Analysis Alongside This Algorithm
In AttendMe.ai, the Myasthenia Gravis Crisis Management appears automatically when your clinical question matches — alongside evidence from 3M+ peer-reviewed articles.
Try AttendMe Free