Myasthenic Crisis

Admission Plan

Drugs Contraindicated in Myasthenia

Respiratory Support

.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 Workup:
 -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 Plan
– 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

Patient Friendly List of Medications to Avoid


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.