Myasthenic Crisis


An example of an admission note of myasthenic crisis patient to the ICU: 

***-year-old, right-handed woman with:
1. Myathenic Crisis:
Seropositive myasthenia gravis (IIIb) presenting with myasthenic crisis manifested by worsening shortness of breath, dysphagia, diplopia, nasal intonation, and generalized weakness.

Home meds:
 -Mestinone 120mg 4 times daily
-Prednisone 30mg daily

 -Today's NIF/FVC: -10*** cmH2O / 30*** ml/kg
-Routine labs CBC/BMP unremarkable
-Prior workup:
-Acetylcholine receptor antibody positive ***
-AChR  blocking antibody elevated ***
-Striated muscle ab negative ***
-CT chest with and without contrast negative *** for thymoma

- Neurological checks q4h
- Low threshold for intubation, Oxygen sturation is not a good monitor since MG can maintain good sats. Will follow PFT (FVC/NIF/MEF) q6h.
- Meds:
-Will start on IVIG 0.4gm/kg daily for 5 days (normal kidney functions --> can be given over 3 days)
-Will continue on home dose of Mestinone 120mg q6h
-Will continue on home dose of Prednisone 30mg daily
- Aspiration precautions, head of bed above 30 degrees
- PRN O2
- Chest PT with vest q4hr
- Baseline CXR
- Suctioning q1-2 hours
- Meds:
- None
- Continuous cardiac telemetry
- Meds:
- Renal function normal
- Monitor daily BMP, Mg, Phos while on IVIG
- Meds:
- IVFs NS @ 75/hr
- NPO for now till speech evaluation
- Meds:
- Famitidine 20mg tab bid
- FSBS q6hr
- Meds:
- Insulin SS
- Monitor CBC daily
- SCDs for prophylaxis; Lovenox 40mg SC daily
- Meds:
- Lovenox 40mg SC daily
Infectious Disease:
- Current access: PIVs
- Meds:
DVT: SCDs, Lovenox 40mg SC daily
GI: famotidine
Discharge Planning:
Patient requires ICU (or Step down ***) level of care for monitoring of respiratory functions.


Important Issues for Myasthenic patients


      Drugs contraindicated with myasthenia:

      Antibiotics: Quinolones - Monobactams - Lactams - Macrolides - Aminoglycozides

      Antiarrythmics: Quinine - Quinidine - Procainamide

      BP medications: Beta blockers (including timolol eye drops) - Calcium channel blockers

      CNS medications: Antiepileptic drugs - Lithium

      Local anasthetics: Procainamide

      Neuromuscular blocking agents: Succinylcholine - Curare medications

      Others: Penicillamine - Steroids (needs supervision) - Iodinated contrast agents - Magnesium containing medications


Pulmonary function tests for MG/GBS:

- The 20/30/40 role: alarming values if FVC < 20ml/kg or NIF < 30cmH2O or MEP < 40cmH2O. These measures help to guide the level of admission (ICU/step down/floor), not to guide the decision for intubation. If FVC < 20ml/kg --> ICU admission is preferred.

- FVC is the most sensitive measure, NIF/MEP are effort dependent and less reproducible compared to FVC. Moreover NIF/MEP are unreliable if the face mask is leaking.

- Don't depend on the numbers only for intubation. Patient should be either in respiratory distress while resting in bed without activity or hypercapnic to consider intubation.


Steps for respiratory support:

- No respiratory distress --> no need for respiratory support --> admit to step down

- Mild/Moderate respiratroy distress --> consider BIPAP or Hiflow nasal cannula if BIPAP is contraindicated (secretions - nausea - vomiting). It must be done in ICU for lose monitoring of respiratory distress, if didn't improve (RR decrease, less use of accessory muscles) --> intubate.

- Severe respiratory distress --> intubation and mechanical ventillation.