Myasthenia Gravis

Patient teaching and family teaching for MG

Schedule periods of rest and avoid stress, conserve energy when possible Avoid cigarette smoke, alcohol, and beverages with quinine (tonic water) Take medications as prescribed. If manifestations change, consult the physician; the dose may need to be adjusted. Avoid extremes of temperature; an environment that is too hot or too cold may cause an exacerbation of MG Avoid people with upper respiratory infections, infections can result in an exacerbation and extreme weakness

To determine type of medical treatment myasthenia gravis

Steroids Plasmapheresis Thymectomy

The primary medications used to treat MG are the

anticholinesterases

The difference in determining myasthenic crisis and cholinergic crisis is determined by the reaction of

edrophonium choloride (Tensilon) In myasthenic crisis the test is positive and in cholinergic crisis the test is negative

Another pharmacologic therapy aimed at improving muscle strength is using

glucocorticoids for immunosuppression (Prednisone)

Patients with MG injected with Tensilon show significant improvement in muscle strength that lasts approximately

5 minutes

The onset of manifestations of MG usually begin after the age of what?

50

Having a thymectomy perioperative care is to

Reinforce the physician's explanation of the procedure, and prepare the patient for chest tubes and tracheostomy Anticipate the need for alternative communication. Allow sufficient time for questions

In MG, antibodies destroy or block neuromuscular junction receptor sites resulting in...

A decreased number of acetycholine receptors

The goal of plasmapheresis is to

Remove antiacetylcholine receptor antibodies, improving severe muscle weakness, fatigue and other manifestations

Myasthenia gravis has a deficiency of what at the NEUROMUSCULAR junction?

Ach.

Myasthenia gravis is the autoimmune destruction of what receptors?

Ach.

Anticholinesterases do what?

Act at the neuromuscular junction and allow acetylcholine to concentrate at the receptor sites, promoting muscle contraction

Nursing care for myasthenia gravis

Alteration in nutrition r/t difficulty swallowing/chewing Ineffective airway clearance r/t thoracic muscle weakness, ↓ coughing and swallowing ability Impaired gas exchange r/t muscle weakness, secretions RF aspiration r/t cranial nerve involvement Activity intolerance r/t muscle weakness: Organization is the key!! Knowledge deficit r/t precipitating factors for exacerbation: Stressors: infection, surgery, pregnancy, etc.

Cholinergic crisis is caused by overdosage of what?

Anticholinesterase (cholinergic) medications

Myasthenia gravis is confirmed by administration of what drug?

Anticholinesterase drug: Tensilon

The medical treatment of myasthenia gravis is

Anticholinesterase drugs: block breakdown of Ach.

Health education for the patient and family

Balancing symptom control with dosage is crucial; record time of dose and response in a journal. Note the time of day when fatigued and any adverse effects, such as excess salivation, sweating, slow heartbeat, and diarrhea Take the medication about 30 minutes prior to meals to enhance swallowing and chewing Report manifestations of myasthenic crisis immediately severe muscle weakness, fast heartbeat, restlessness, difficulty breathing, increasing difficulty swallowing or speaking Report slow heartbeat, increased salivation or sweating, and/or decreased blood pressure immediately Review possible causes of myasthenic crisis: physical or emotional stress, infection, or reduction in the medication dosage

Complications of MG in respiratory

Decreasing ability to walk, eat, and perform other ADLs Pneumonia

What does the autoimmune destruction do?

Destroys or inactivates the receptor sites on the muscle: acetylcholine receptor antibody present in 90% of cases

Complications of MG in ocular and facial

Difficulty closing eyes Aspiration Impaired communication and nutrition

What happens to the muscle in myasthenia gravis?

Does not receive the impulse properly Contracts poorly or not at all

The removal of the thymus gland happens when?

During 1st two years Remission

Anticholinesterase drugs used for myasthenia gravis

Prostigmine: given prior to meals; more frequent adm. Mestinon: drug of choice d/t timed release Crisis: both present with ↑ muscle weakness -Myasthenic: d/t too little med -Cholinergic: d/t too much med

Diagnostic tests are conducted and pay special attention to what muscles

Facial Oculomotor Laryngeal Respiratory

Myasthenia gravis is a chronic autoimmune neuromuscular disorder that is characterized by

Fatigue and severe weakness of skeletal muscles.

The signs are cholinergic crisis are

Gastrointestinal manifestations Severe muscle weakness Vertigo Respiratory distress

Tensilon acts within one minute

Has a 5 min half life. So not used for treatment

DX of myasthenia gravis depends on..

History and physicals. Classical pictures.

Nutritional in MG are

Inability to chew and shallow Decreasing ability to move tongue Impairment of fine motor movments, inability to feed self

Complications of MG in musculoskeletal

Inability to perform ADLs and self care activities Complications related to immobility and myasthenic and choligeneric crisis

Plasma exchange in MG may be used in conjunction with other therapies

May be performed prior to surgical intervention or following administration of high-dose intravenous immune globulin

Pyridostigmine is administered to prevent what during the perioperative period?

Muscular manifestations

What is a sudden exacerbation of motor weakness putting the patient at rrisk of respiratory failure and aspiration in MG?

Myasthenic crisis

Having a thymectomy postoperative care is

Provide meticulous pulmonary hygiene: turning, deep breathing, and coughing at least every 2 hours; use an IS Patients with a thoracotomy and sternal split procedure will require care of the anterior chest tube. Observe complications, such as pneumothorax Manage pain with scheduled analgesic therapy

Myasthenia gravis is an overall decrease in..

Neurotransmitter available for transmission of impulses at the neuromuscular junction

Care during and after the plasmapheresis procedure

Observe for dizziness or hypotension Apply pressure dressing to access site Monitor for infection and bruises at the intravenous port site Monitor electrolytes and signs of electrolyte loss. Report imbalances, and replace electrolytes as ordered. Observe for circumoral tingling, Chvostek's and Trousseau's signs if calcium levels are low, and cardiac dysrhythmias and leg cramps if postassium levels are low Reevaluate preprocedure laboratory data, especially CBC, platelet count, clotting times

Nursing responsibilities with anticholinesterases

Obtain a baseline assessment of muscle strength and abilities, concentrating on swallowing and ptosis Administer the medication parenterally if the patient has dysphagia. Check the dose of the medication carefully when changing from oral to parenteral routes Evaluate the effectiveness of the medication and document the response, for example, time when fatigue occurs in relation to activities Promptly recognize and respond to manifestations of excessive stimulation of muscarinic receptors: excess salivation, urinary urgency, bradycardia, gastrointestinal hypermobility, diaphoresis. Atropine can be administered to combat these manifestations. Respiratory depression and failure can occur and require mechanical ventilation Have muscarinic antagonist (physotigmine) readily available to treat poisioning

Manifestations of MG

Ocular and facial Musculoskeletal Respiratory Nutritional

The clinical presentation of myasthenia gravis is?

Onset insidious and progresses slowly; more common in women age 20-30 Progressive weakness of muscles as they are being used; after rest, function improves Ocular muscle weakness: most common 1st symptom in 90% of patients; Progress of disease may stop here

Ocular and facial in MG are

Ptosis Diplopia Facial weakness Dysphagia Dysarthria

Postoperative nursing care focuses on

Preventing complication and controlling pain

What are the two most commonly used acetylcholinesterase inhibitors?

Pyridostigmine (Mestinon) Neostigimine (Prostigmin)

What is myasthenic crisis consist of?

Tachycardia, tachypnea, severe respiratory distress, dysphagia, restlessness, impaired speech, and anxiety

Preprocedure care with a plasmapheresis

Teach about the procedure and what to expect, including what the machine looks like, the need for arterial and venous insertion sites, and the length of time of the procedure (2 to 5 hours) Check with physician about holding medications until after the procedure Asses vital signs and weight Assess CBC, platelet count, and clotting studies Check blood type and crossmatch for replacement blood products

The net result of MG is a decrease in..

The muscles ability to contract despite a sufficient number of acetycholine

The surgery recommended for patients younger than 60 is a...

Thymectomy

It is believed that what gland is the source of autoantigen that triggers and autoimmune response in MG?

Thymus

What gland in involved with myasthenia gravis?

Thymus gland

The thymus glad has...

Undergone malignant or infectious changes in many of these patients; it forms antibodies to attack its own epithelial cells which also attack those in the muscles

Myasthenic crisis is most often caused because of what?

Undermedication, missed doses of medications, or developing infection

Respiratory in MG are

Weakening of intercostal muscles Decrease in diaphragm movment Breathlessness and dyspnea Poor gas exchange

Musculoskeletal in MG are

Weakness and fatigue Decreased function of hands, arms, legs, and neck

The clinical presentation as the disease progresses for myasthenia gravis is...

Weakness of muscles used for chewing, swallowing, and speaking; neck muscles Upper extremities affected before lower, proximal before distal Eventually may involve muscles of respiration, bowel and bladder Muscles strongest in the AM

Complications of MG in nutritional

Weight loss Dehydration Malnutrition Aspiration

Preoperatively patients my be tapered from

steroid therapy