myasthenia gravis

Question 1

major issue with myasthenia gravis

Answer 1

not enough acetocholine

Question 2

myasthenia gravis definition

Answer 2

Definition:

a. Disease of the neuromuscular junction characterized by fluctuating weakness of certain skeletal muscle groups especially the face & throat.
b. Affects neuromuscular transmission of voluntary muscles of the body especially those innervated by the cranial nerves.

Question 3

issues with myasthenia gravis

Answer 3

c. Is purely a motor disorder with no effect on sensation or coordination.
d. Results in inability for muscles to contract.
e. There are periods of remission & exacerbations and a milder form does exist.
f. Considered an autoimmune disease where antibodies destroy or block neuromuscular acetylcholine receptor sites.

Question 4

severity of myasthenia gravis

Answer 4

there are many different levels of this disease from mild symptoms to debilitating

Question 5

thymus gland and myasthenia gravis

Answer 5

. Thymus gland, which is usually inactive after puberty, continues to produce antibodies. It is believed that the thymus is the source of autoantigen that triggers the autoimmune response inMG.
H. Prevents acetycholine from attaching to receptor site and from stimulating muscle contraction.

Question 6

viral infections and myasthenia gravis

Answer 6

Viral infections are suspected of precipitating an attack.

Question 7

statistics on myasthenia gravis

Answer 7

43 to 84 persons/ million affected.
Peak age of onset in women is 20 to 40 yrs. Majority of men are over 50 yrs.
Women are affected 3X more than men

Question 8

manifestations of myasthenia gravis

Answer 8

Fatigue and weakness of skeletal muscles generally worse with effort and relieved by rest. Patients can tire from combing hair or chewing.

Question 9

bulbar symptoms of myasthenia gravis

Answer 9

Bulbar symptoms:
a. Weakness of face & throat
b. Diplopia ( eye droop) , Ptosis, facial weakness, dysarthria, dysphagia, dysphonia.
Complications: Difficulty closing eyes, aspiration, impaired communication & nutrition

Question 10

musculoskeletal and respiratory problems in myasthenia gravis

Answer 10

decreased function of hands, arms, legs and neck muscles.
b. Weakening of intercostal muscles , decreased diaphragm movement, dyspnea, and poor gas exchange.
Complications:
a. Decreased ability to perform ADLs
b. Immobility complications
c. Inability to walk or eat
d. Respiratory infections.
There is no sensory loss. Reflexes are normal and muscle atrophy is rare.

Question 11

the course of myasthenia gravis

Answer 11

The course of the disease varies. Some have short-term remissions, others stabilize and others have severe progressive involvement.

Question 12

exacerbations of myasthenia gravis

Answer 12

Exacerbations can be precipitated by emotional stress, pregnancy, menses, illness, trauma, temperature extremes, hypokalemia, surgery & drugs

Question 13

diagnosis of myasthenia gravis

Answer 13

Patient history and physical exam
Have person look upward for 2 to 3 minutes. If MG there will be an increased droop of the eyelids so the person can barely keep eyes open.

IV tensilon (anticholinesterase) test

Electromyography ( EMG ) to measure electrical potential of muscle cells
Anti-ACH receptor antibodies in serum. Seen in 70 to 80 % of patients.

Question 14

IV tensilon (anticholinesterase) test

Answer 14

a. Drug facilitates transmission of impulses at myoneural junction.
b. Within 30 seconds of injection most patients with MG improve substantially but is only temporary.

Question 15

prognosis of myasthenia gravis

Answer 15

No known cure but drug therapy helps

Question 16

medical management of myasthenia gravis

Answer 16

Drug Therapy: Maintenance of stable blood levels of medications is imperative to stabilize muscle strength. Meds must be given on time.
a. Anticholinesterase Inhibitors:
1. Mestinon ( Pyridostigmine Bromide )
2. Prostigmin ( Neostigmin Bromide
b. Corticosteroids
c. Immunosuppressive Therapy
Plasmapheresis
Surgical Management: Thymectomy
a. Results in symptom remission in about
40%. Best if within 2 years of diagnosis

Question 17

what to remember about myasthenia gravis

Answer 17

drugs need to be on time. Do not want to be late. need to maintain a constant blood level

Question 18

anticholinesterase inhibitors for Myasthenia gravis

Answer 18

. Drugs increase available acetycholine at the junction. Given to increase the response of the muscles to nerve impulses to improve strength. Gives symptomatic relief. The maintenance dose is determined by testing.
B. Maintenance of stable blood levels of these meds is imperative to stabilize muscle strength. Meds must be given on time since a delay can exacerbate muscle weakness and make it impossible for the patient to take meds by mouth.
C. Common side effects of these drugs:
CNS—irritability, anxiety, insomnia, headache, dysarthria, syncope, seizures,
coma, diaphoresis
RESP—increased bronchial secretions, bronchial spasm
CARDIO—hypotension, tachycardia
GI—abdominal cramps, nausea, vomiting, diarrhea, anorexia, increase salivation
SKELETAL—spasms, fine twitching, weakness of muscles
INTEG—rash, flushing, increased lacrimation
D. Examples:
1. PYRIDOSTIGMINE BROMIDE (MESTINON)
a. Most commonly used. Peaks in2hours. Duration is 3-6 hours
2. PROSTIGMIN (NEOSTIGMINE BROMIDE)
a. Has less side effects than Mestinon. Dosage is increased gradually until
maximum benefits.
b. Give with milk, crackers, and buffering substances for GI distress. Small
doses of Atropine may be given to decrease above side effects.

Question 19

corticosteroids and immunosuppresive therapy for myasthenia gravis

Answer 19

II. CORTICOSTEROIDS:

A. Suppress immune response and decrease amount of antibody production.
B. May use alternate day therapy.

III. IMMUNOSUPPRESSIVE THERAPY:

A. Reduces production of antireceptor antibodies. Are cytotoxic meds.
B. Use drugs like Imuran, Cytoxan.

Question 20

common side effects of anti cholinesterase drugs

Answer 20

CNS: Irritability, fine twitching, anxiety, insomnia, headache, dysarthria, syncope, seizures, coma, spasms, weakness
RESP: Bronchial spasm, increased bronchial secretions
Cardio: Hypotension, bradycardia
GI: Abdominal cramps, nausea, vomiting, diarrhea, heartburn, anorexia, increased salivation
Skin: rash, flushing, sweating, tearing

Question 21

***Myasthenia Crisis

Answer 21

Usually caused by under medication. Can be triggered by infection, surgery, emotional stressors, and drugs. Many drugs are contraindicated or must be used with caution. These include anesthetics, antidysrhythmics, antibiotics, quinine, hypnotics, cathartics, diuretics, antipsychotics, barbituates, muscle relaxants, thyroid medications, sedatives, tranquilizers

Question 22

how is a myasthenia crisis manifested

Answer 22

Manifested by acute exacerbation of muscular weakness with acute respiratory distress, and inability to swallow or speak.
Weakness of respiratory muscles causes respiratory depression and airway obstruction.
Can have periods of apnea, extreme fatigue, fever, anxiety, restlessness, irritability, unable to move jaw and raise one or both eyelids.

Question 23

how can you determine its a myasthenia crisis

Answer 23

Need to confirm with Tensilon Test
May need plasmaphresis. Given meds parenterally until able to swallow
Will be in ICU. Considered medical emergency.

Question 24

cholinergic crisis

Answer 24

Over medication is usually the cause.
In addition to muscle weakness and respiratory depression, patients will have a variety of GI symptoms.
Is a medical emergency. Will be in ICU. Confirm with Tensilon Test.

Question 25

Nursing care for a patient with myasthenia crisis

Answer 25

Improve respiratory function:
a. Respiratory assessment, PFTs, ABGs, O2
sats.
b. TCDB q 1-2 hrs, Spirometry, Chest PT,
postural drainage, suctioning to remove
secretions.
c. Semi-fowlers position. Give emotional
support. Maintain hydration to liquify
secretions. Avoid drugs that aggravate the
disease.

Question 26

Nursing care for a patient with myasthenia crisis

Answer 26

Impaired swallowing:
	a.  Assess ability to manage various  
	consistencies of foods.  Get Speech 
	Therapy consult.
	b.  Assess for drooling, regurgitation 
	through mouth & nose, and choking
	when swallowing.  Standby suction.

Question 27

Nursing care for a patient with myasthenia crisis

Answer 27

c. Plan to promote medication
effectiveness. Give drug 30 minutes prior
to feeding.
d. Rest prior to meals to decrease muscle
fatigue. Have patient eat slowly, small
bites of foods. Give cues. Upright position
with head slightly flexed to facilitate
swallowing. Know Heimlick manuever.
e. Muscles of mastication are stronger in
the morning so calories should be greatest
at breakfast.
Increases physical mobility:
a. Plan rest periods with a realistic daily
schedule. Use appropriate clothing
b. Avoid activities that lead to crisis.
c. Cervical collar for those with weak neck
muscles. Adaptive self-care devices.
d. ROJM, physical therapy, occupational therapy

Question 28

Nursing care for a patient with myasthenia crisis

Answer 28

Improve communication:
	a.  Listen!  Repeat what they say to clarify
	b.  Set up some signals
Impaired vision:
	a. Tape eyes open for short periods.
	b.  Artificial tears if lids don’t close
	completely.  Sunglasses.  Eye patch for
	double vision.

Question 29

how do you determine if its a myasthenia crisis or cholinergic crisis

Answer 29

tensilon test

Question 30

patient teaching for myasthenia gravis

Answer 30

Take medications at scheduled time.
Report toxic effects of drugs and symptoms of disease.
Take meds with milk or food to decrease GI effects
Wear medi-alert. Check with MD regarding use of other medications.
Maintain adequate diet, rest & activity.
Avoid infections, extremes in temperature, alcohol, tobacco, and tonic water (quinine)