What is the management approach for a patient with myasthenia gravis (MG) exacerbation, including indications for intravenous immunoglobulin (IVIG) or plasma exchange (PLEX), and escalation of Mestinon (pyridostigmine) or steroid doses?

Management of Myasthenia Gravis Exacerbation: Comprehensive Admission Order Slip

For patients with myasthenia gravis exacerbation, initiate IVIG (2 g/kg IV over 5 days at 0.4 g/kg/day) or plasmapheresis (3-5 days) for moderate to severe generalized weakness, respiratory compromise, or rapidly progressive symptoms, along with corticosteroids and optimization of pyridostigmine dosing. 1

Initial Assessment and Monitoring

• Obtain neurology consultation immediately
• Assess MGFA severity class (I-V)
• Monitor vital signs with continuous cardiac monitoring
• Perform pulmonary function tests:
  • Negative Inspiratory Force (NIF)
  • Vital Capacity (VC)
  • Repeat q4-6h for first 24 hours, then as clinically indicated
• Check for bulbar symptoms (dysphagia, dysarthria)
• Assess respiratory muscle strength
• Daily neurological examinations

Laboratory and Diagnostic Workup

• AChR and anti-striated muscle antibodies
• If AChR negative, order MuSK and LPR4 antibodies
• CPK, aldolase, ESR, CRP (to evaluate for concurrent myositis)
• Troponin, ECG (to rule out myocarditis)
• Consider MRI brain/spine if symptoms warrant
• Electrodiagnostic studies (repetitive stimulation, jitter studies)

Medication Management

Pyridostigmine (Mestinon) Management

• Starting dose: 30 mg PO TID
• Titration: Gradually increase based on symptoms
• Maximum dose: 120 mg PO QID
• Adjust based on clinical response
• Avoid abrupt discontinuation
• Wean based on symptom improvement

Corticosteroid Management

• Initiate prednisone 0.5 mg/kg/day orally for mild cases
• For moderate-severe cases: Methylprednisolone 2-4 mg/kg/day IV
• For severe cases: Consider pulse methylprednisolone 1g daily for 5 days
• Steroid taper should begin 3-4 weeks after initiation
• Wean based on symptom improvement

Indications for IVIG or PLEX

IVIG Indications

• MGFA class III-V (moderate to severe generalized weakness)
• Any respiratory muscle weakness
• Any dysphagia or facial weakness
• Rapidly progressive symptoms
• Failure to respond to pyridostigmine and steroids

IVIG Administration

• Dosing: 2 g/kg IV divided over 5 days (0.4 g/kg/day)
• Premedicate with acetaminophen and diphenhydramine
• Monitor for infusion reactions
• Assess response daily

PLEX Indications

• Same as IVIG indications
• Consider as first-line for myasthenic crisis with respiratory compromise
• May be preferred over IVIG when faster response is needed

PLEX Administration

• 3-5 exchanges over 5-7 days
• Replace with albumin
• Monitor coagulation parameters and electrolytes

Escalation Algorithm

Mild Exacerbation (MGFA Class I-II)

1. Optimize pyridostigmine dosing
2. If inadequate response within 24-48 hours, add prednisone 0.5 mg/kg/day
3. If no improvement in 3-5 days or worsening symptoms, escalate to IVIG/PLEX

Moderate-Severe Exacerbation (MGFA Class III-IV)

1. Admit patient
2. Optimize pyridostigmine dosing
3. Start IV methylprednisolone 2-4 mg/kg/day
4. Initiate IVIG or PLEX concurrently
5. Consider ICU monitoring for signs of respiratory compromise

Myasthenic Crisis (MGFA Class V)

1. ICU admission
2. Secure airway if needed (intubation may be necessary)
3. Initiate PLEX or IVIG immediately
4. IV methylprednisolone 1g daily for 5 days
5. Hold pyridostigmine temporarily if cholinergic crisis suspected
6. Resume pyridostigmine at lower dose once stabilized

Important Precautions

• Differentiate between myasthenic crisis (underdosage) and cholinergic crisis (overdosage) 2
• For cholinergic crisis: withdraw pyridostigmine and administer atropine
• Avoid medications that may worsen MG: beta-blockers, fluoroquinolones, aminoglycosides, macrolide antibiotics, IV magnesium
• Monitor for steroid-related complications
• Consider adding steroid-sparing agent if long-term immunosuppression needed

Discharge Planning

• Ensure stable symptoms for at least 24-48 hours
• Establish clear medication regimen
• Arrange follow-up with neurology within 1-2 weeks
• Provide patient education on warning signs requiring immediate medical attention
• Consider home pulmonary function monitoring if available

This comprehensive approach addresses both symptomatic treatment with pyridostigmine and immunomodulatory therapy with IVIG/PLEX and corticosteroids, tailored to the severity of MG exacerbation.