Myasthenia Gravis in Acute Care

Referral Criteria

Urgent

• Contact on-call neurology registrar at Queen Elizabeth University Hospital (QEUH) as soon as possible (including out of hours) for patients with a history of Myasthenia Gravis (MG) who are experiencing MG related issues - see Appendix 6 for contact details.

Routine

• Contact on-call neurology registrar after admission for patients with a history of MG but are not experiencing symptoms - see Appendix 6 for contact details.

Symptoms of MG 

These include:

• Difficulty swallowing, speaking or chewing
• Double vision and ptosis
• Neck and limb weakness
• Type II respiratory failure.

Important points

• It is crucial not to withhold MG medicines for any significant length of time, i.e. >2 hours, or to miss any doses of pyridostigmine or steroids as there is a risk of myasthenic crisis.
• Before prescribing any new medicine, check if the medicine may affect patients with MG by referring to the guideline Myasthenia Gravis or Lambert-Eaton Myasthenia Syndrome, medicines that may affect patients on NHSGGC's Clinical Guidelines Platform (alternatively, the guideline can be accessed from NHSGGC's Clinical Guidelines Platform / Central Nervous System / Myasthenia or using the search function).
• High risk situations include: nil by mouth status, infection and surgical procedures.

Pyridostigmine

• It is important for pyridostigmine to be administered at exact times. Ensure no missed doses. For further guidance see Pyridostigmine for Myasthenia Gravis Q&A on NHSGGC's Clinical Guidelines Platform (alternatively, the guideline can be accessed from NHSGGC's Clinical Guidelines Platform / Central Nervous System / Myasthenia or using the search function).
• Where a patient does not have an individual supply of pyridostigmine (Mestinon^®), this must be obtained urgently via pharmacy during working hours or the on-call pharmacist via switchboard if out of hours.
• Overdose of pyridostigmine can lead to cholinergic crisis. For further guidance, refer to Pyridostigmine for Myasthenia Gravis Q&A on NHSGGC's Clinical Guidelines Platform (alternatively, the guideline can be accessed from NHSGGC's Clinical Guidelines Platform / Central Nervous System / Myasthenia or using the search function).

Nil by mouth

• Administration of medication via nasogastric (NG) feeding tube is the preferred option in patients who are unable to swallow. Pyridostigmine and prednisolone (not enteric coated, E/C) tablets can be crushed and mixed with water.  See Pyridostigmine for Myasthenia Gravis Q&A on NHSGGC's Clinical Guidelines Platform for further guidance (alternatively, the guideline can be accessed from NHSGGC's Clinical Guidelines Platform / Central Nervous System / Myasthenia or using the search function).
• Any delays in passing NG tube, or if NG insertion is not possible, seek senior medical and neurology advice as soon as possible.

Infection

• Certain antimicrobials should be avoided (e.g. gentamicin) or used with caution. Refer to the guideline Myasthenia Gravis or Lambert-Eaton Myasthenia Syndrome, medicines that may affect patients on NHSGGC's Clinical Guidelines Platform for more information (alternatively, the guideline can be accessed from NHSGGC's Clinical Guidelines Platform / Central Nervous System / Myasthenia or using the search function).
• Do not automatically double steroid dose in the context of infection in a patient with MG (see information below).

Minor infection

1. Continue regular immunosuppressant drugs.
2. Stable MG patients may not require any change in steroid dose.

Severe infection or sepsis

1. Withhold regular immunosuppressant drugs (and discuss with MG team).
2. Consider increasing steroid dose after consulting with MG/neurology team.

Patients with stable MG can usually revert to baseline steroid dose once infection is treated (provided <3 weeks on higher dose). Patients with active MG may require slower reduction in steroid dose (consult MG team).

Patients undergoing surgical procedures

• Patients should continue with regular medication for MG pre- and post-operatively.
• Discuss on a case by case basis with an anaesthetist and MG team.