Myasthenia Gravis Nursing Care Plan Notes

 

Description
  1. Myasthenia Gravis is a neuromuscular disease characterized by considerable weakness and abnormal fatigue of the voluntary muscles.MG
  2. A defect in the transmission of nerve impulses at the myoneural junction occurs.
  3. Causes include insufficient secretion of acetylcholine, excessive secretion of cholinesterase, and unresponsiveness of the muscle fibers to acetylcholine.
Causes

MG, thought to be an autoimmune disorder, is caused by a loss of acetylcholine (ACh) receptors in the postsynaptic neurons at the neuromuscular junction. About 80% of all MG patients have elevated titers for ACh receptor antibodies, which can prevent the ACh molecule from binding to these receptor sites or can cause damage to them. MG is often associated with thymic tumors.

Assessment
  1. Weakness and fatigue
  2. Difficulty chewing
  3. Dysphagia
  4. Ptosisptosis
  5. Diplopia
  6. Weak, hoarse voice
  7. Difficulty breathing
  8. Diminished breath sounds
  9. Respiratory paralysis and failure
Complications
Myasthenic Crisis
  • This sudden onset of muscle weakness is usually the result of undermedication or no cholinergic medication at all. Myasthenic crisis may result from progression of the disease, emotional upset, systemic infections, medications, surgery, or trauma. The crisis is manifested by sudden onset of acute respiratory distress and inability to swallow or speak.
Cholinergic Crisis
  • Caused by overmedication with cholinergic or anticholinesterase drugs, cholinergic crisis produces muscle weakness and the respiratory depression of myasthenic crisisas well as gastrointestinal symptoms (nausea, vomiting, diarrhea), sweating, increased salivation, and bradycardia.
Primary Nursing Diagnosis
  • Ineffective airway clearance related to difficulty in swallowing and aspiration
Diagnostic Evaluation
  • Injection of edrophonium (Tensilon) is used to confirm the diagnosis (have atropine available for side effects). Improvement in muscle strength represents a positive test and usually confirms the diagnosis.
  • MRI may demonstrate an enlarged thymus gland.
  • Test includes serum analysis for acetylcholine receptor and electromyography (EMG) to measure electrical potential of muscle cells.
Holding your arms above your shoulders until they drop is one exercise that may be performed during the Tensilon test. In this test, the drug Tensilon is administered, and the response in the muscles are evaluated to help diagnose myasthenia gravis or to help differentiate between myasthenia gravis and other conditions.

Holding your arms above your shoulders until they drop is one exercise that may be performed during the Tensilon test. In this test, the drug Tensilon is administered, and the response in the muscles are evaluated to help diagnose myasthenia gravis or to help differentiate between myasthenia gravis and other conditions.

Medical Management

Management is directed at improving function through the administration of anticholinesterase medications and by reducing and removing circulating antibodies. Patients with MG are usually managed on an outpatient basis unless hospitalization is required for managing symptoms or complications.

Pharmacologic Highlights
  • Anticholinesterase drugs such as Pyridostigmine bromide (Mestinon), neostigmine bromide (Prostigmine); neostigmine methylsulfate can be given as a continuous infusion if the patient cannot take oral medication. Anticholinesterase drugs blocks the action of the enzyme anticholinesterase, thereby producing symptomatic improvement; atropine must be readily available to treat cholinergic side effects and medications must be administered on time, or the patient may be too weak or unable to swallow the drug.
  • Prednisone is used to suppresses the autoimmune activity of MG
  • Nonsteroidal immunosuppressants such as Azathioprine (Imuran), cyclophosphamide (Cytoxin) is used to suppress autoimmune activity when patients do not respond to prednisone; can produce extreme immunosuppression and toxic side effects
Nursing Interventions
  1. Monitor respiratory status and ability to cough and deep breathe adequately.
  2. Monitor for respiratory failure.
  3. Maintain suctioning and emergency equipment at the bedside.
  4. Monitor vital signs.
  5. Monitor speech and swallowing abilities to prevent aspiration.
  6. Encourage the client to sit up when eating.
  7. Assess muscle status.
  8. Instruct the client to conserve strength.
  9. Plan short activities that coincide with times of maximal muscle strength.
  10. Monitor for myasthenic and cholinergic crises.
  11. Administer anticholinesterase medications as prescribed.
  12. Instruct the client to avoid stress, infection, fatigue, and over-the counter medications.
  13. Instruct the client to wear a Medic-Alert bracelet.
  14. Inform the client about services from the Myasthenia Gravis Foundation.
Documentation Guidelines
  • Respiratory status: Rate, quality, depth, ease, breath sounds, arterial hemoglobin saturation with oxygen
  • Ability to chew, swallow, and speak (swallowing can be subjectively rated by the patient in anticipating ability to swallow food [0 =unable to swallow liquids to 5 = able to swallow regular diet]), food intake, daily weights
  • Muscle weakness and strength, speed and degree of fatigue, ability to perform activities of daily living, response to rest, and plans for modification of activity
  • Ptosis (can be rated by the nurse [0 = unable to open lid to 5 =uppermost edge of iris visible])
Discharge and Home Healthcare Guidelines
  • Instruct the patient and family on the importance of rest and avoiding fatigue. Be alert to factors that can cause exacerbations, such as infection (an annual flu shot is suggested), surgery, pregnancy, exposure to extreme temperatures, and tonic and alcoholic drinks. Instruct the patient and family about drug actions and side effects, the indications for dosage alteration, and the selective use of atropine for any overdose.
  • Stress the importance of taking the medication in a timely manner. It is advisable to time the dose 1 hour before meals for best chewing and swallowing. Explain the potential drug interactions (especially aminoglycosides and neuromuscular blocking agents, which include many pesticides). Encourage the patient to inform the dentist, ophthalmologist, and pharmacist of the myasthenic condition.
  • Instruct patients about the symptoms that require emergency treatment, and encourage them to locate a neurologist familiar with MG management for any follow-up needs. Suggest that they collect a packet of literature to take to the emergency department in case the available physician is unfamiliar with this disease. (The Physician’s Handbook is available on request from the MG Foundation.)
  • Instruct patients to wear MG identification jewelry. Suggest having an “emergency code” to alert family if they are too weak to speak (such as ringing the phone twice and hanging up).
  • Instruct the family about cardiopulmonary resuscitation techniques, how to perform the Heimlich maneuver, how to contact the rescue squad, and how to explain the route to the hospital.
  • Make a referral to a vocational rehabilitation center if guidance for modifying the home or work environment, such as a raised seat and handrail for the toilet, would be beneficial.