Emergency Management of Myasthenia Gravis

Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder. It is characterized by fluctuating weakness of voluntary muscle groups. Muscle groups most commonly affected include the eye muscles, facial, chewing and swallowing muscles, and shoulder and hip muscles. Muscles that assist breathing may be affected also. MG signs & symptoms may include drooping eyelids, double vision, slurred speech, nasal quality to speech, inability to speak, drooling, nasal regurgitation, problems chewing and/or swallowing, choking, trouble sitting up or holding head erect, trouble walking, weak cough, feeling short of breath Medical emergencies ("crises") may occur when the muscles that support respirations are so weak that breathing becomes very difficult. Respirations may be shallow and ineffective. The airway may become obstructed due to weakened throat muscles and accumulated secretions. The myasthenic patient can go into a crisis quickly. Be prepared to breathe for this patient with an ambu bag. Due to facial muscle weakness, a slurred speech pattern and/or an inability to respond normally, an individual who is severely weakened by MG may appear to be intoxicated. Look for a medic alert bracelet or necklace. Medications the patient is on may include Mestinon, Prednisone, Imuran and/or CellCept. DO NOT ADMINISTER ANY DRUG THAT MAY HAVE A DEPRESSANT EFFECT.
FAILURE TO TREAT SYMPTOMS PROMPTLY CAN RESULT IN POOR AIR EXCHANGE AND RESPIRATORY INSUFFICIENCY OR ARREST. SEEK MEDICAL CARE EARLY TO PREVENT EMERGENCIES MAINTAIN AN OPEN AIRWAY SUPPORT AIR EXCHANGE
Severe Respiratory Difficulty Subjective findings may include shortness of breath at rest, air hunger, inability to lay flat, anxiety, restlessness, fatigue. Evaluate airway patency strength of cough respiratory rate & effort cardiac status skin & nailbed color and temperature mental status Physical examination may reveal skin & nailbed color changes (pale to cyanotic), cool and moist skin, weak cough, rapid heart rate, increased blood pressure, rapid or shallow respirations, confusion, lethargy. First Responder Management Keep airway open. Suction pooled oral secretions as needed. Elevate head and shoulders. Keep a calm & peaceful atmosphere. Support respirations if needed.		Severe Swallowing Difficulty Subjective findings may include gagging, choking, inability to swallow medications or food, anxiety, restlessness. Evaluate airway patency pooled oral secretions or retained food strength of cough respiratory rate & effort cardiac status speech effort and quality Physical examination may reveal drooling, weak cough, pooled secretions, retained food in the mouth, rattling sounds in the throat or chest, slurred or absent speech.   First Responder Management If actively choking, open mouth and remove any visible food particles. Perform Heimlich Maneuver only if foreign body (food or other object) obstruction in airway is suspected. Keep airway open. Suction pooled oral secretions as needed. Keep a calm & peaceful atmosphere.
Clinical Manifestations of MG MG weakness occurs in specific muscles or muscle groups. MG weakness may fluctuate over time and during the course of the day. Individuals with MG are usually stronger in the morning. MG weakness increases after prolonged use of the affected muscles MG symptoms may worsen with emotional upset, systemic illness, fever, surgery, menses, pregnancy, thyroid dysfunction and drugs affecting neurotransmission. Crisis Although a rare occurrence, "crisis" occurs when the individual with MG is unable to breathe or swallow adequately. "Myasthenic crisis" may result from factors that exacerbate the weakness of the disorder. "Cholinergic crisis" may result from anticholinesterase over dosage. A commonly prescribed anticholinesterase drug is pyridostigmine bromide (Mestinon ). General Treatment Guidelines Avoid lengthy questioning as it may unduly fatigue the individual with MG. Administration of narcotics may worsen symptoms of MG and further compromise breathing.