TYPE II CYTOTOXIC

IgG Mediated Cytotoxic Hypersensitivity

Type II is known as"?

failure of transmission of nerve impulses at the myoneural junction.

Myasthenia gravis:

A neuromuscular disorder characterized by ___________at ______

acetylcholine receptor sites.

• autoimmune disorders

MG may be caused by decreased functioning of ________ It is also associated with __________

1. autoimmune reaction

2. Thymus gland abnormalities

3. triggered by worsened  infection, surgery, stress, pregnancy, certain medications (e.g., aminoglycosides).

The exact cause of myasthenia gravis is not fully understood, but it is believed to be related to the following factors:

• (hyperplasia, thymoma).

• More common in women <40 and men >60.

Thymus gland abnormalities ( cause of MG)

1. autoimmune problem

2. blocked communication

3. less muscle stimulation

4. Muscle weakness

Pathophysiology of MG

• antibodies | neuromuscular junction.

• acetylcholine (ACh) | antibodies

• receptors

• tire quickly with activity and improve with rest | drooping eyelids

PATHOPHYSIOLOGY OF MG

Autoimmune problem: The body produces _______- that attack receptors at the ___________

Blocked communication: Normally, ________- binds to receptors on the muscle to cause contraction. In MG,_______ block or destroy these receptors.

Less muscle stimulation: With fewer _______-available, muscles receive weaker signals.

Muscle weakness: Muscles ______________ Commonly affects eyes (__________)

1. Muscle weakness associated with activity relieved by rest, e.g., dyspnea, dysphagia, decreased physical activity

2. fatigue

3. ptosis, diplopia, strabismus

4. Impaired speech

5. Snarl smile

6. Dysphagia, drooling

7. Respiratory difficulty

CLINICAL MANIFESTATION OF MG

Tensilon Test (Edrophonium Test)

how is MG diagnosed?

•  a short – acting cholinergic – treatment for MG

What is tensilon test?

IV (2mg first, then 8 mg).

How is tensilon test administered?

• improvement in muscular strength

• 3 to 5 minutes

• Positive Tensilon test is observed as__________. Muscle weakness returns in ________

•  Atropine sulfate (anticholinergic)

The antidote for cholinergic

1. Assess swallowing and gag reflex before feeding client to prevent aspiration 

2. Administer medications 20 -30 minutes before meals to improve ability to swallow and prevent aspiration 

3. Administer medication at the right time to prevent myasthenic crisis that results to respiratory distress 

4. Protect client from falls due to muscle weakness 

5. Implement aspiration precaution

6. Start meal with cold beverage. To contract muscles of the throat and improve ability to swallow

7. Promote adequate ventilation to relieve respiratory difficulty

8. Avoid infections. Infections may trigger exacerbations of MG

9. Provide adequate rest with alternating activity

MANAGEMENT for MG

Plasmapheresis

Separation of antibodies from the plasma to inhibit autoimmune response

• Acetylcholinesterase Inhibitors/Cholinesterase Inhibitor

• Glucocorticoids

• Antacids

• Surgery: thymectomy

PHARMACOTHERAPY

• Prostigmin (Neostigmine)

• Mestinon (Pyridostigmine)

• Mytelase (Ambenomium)

enumerate

• Acetylcholinesterase Inhibitors/Cholinesterase Inhibitor

Acetylcholinesterase Inhibitors/Cholinesterase Inhibitor

These medications transmit neuromuscular impulses by preventing the destruction of acetylcholine. Therefore, there is increased muscle strength

Glucocorticoids

• For anti-inflammatory effects 

Antacids

• To prevent GI upset due to glucocorticoids 

Thymectomy

• Thymoma

• 5 to 10 years

• surgical removal of the thymus gland

• 25% of people with MG have  been found to have _____ (tumor of the thymus gland). The surgery achieves remission for _____

1. Monitor improvement of muscle strength and respirations

2. Observe signs and symptoms of cholinergic crisis

3. Have readily available on antidote for cholinergic crisis (Atropine Sulfate)

4. wear Medic-Alert bracelet

5. Instruct the client to take the medication before meals

6. Observe and report possible side effects and adverse

NURSING INTERVENTION FOR
ACETYCHOLINESTERATE INHIBITOR

cholinergic crisis

• muscle weakness, increased salivation, sweating, tearing, miosis

overdosing of drugs in MG is called ________. what are the signs and symptoms:

health problem and the drug taken

Medic-Alert Bracelets indicates what?

1. Nausea, vomiting, diarrhea, abdominal cramps

2. Increased salivation

3. Tearing

4. Miosis (constriction of pupils)

5. Possible hypertension

Possible side effects and adverse reactions:

• Myasthenic Crisis

• Cholinergic Crisis

2 major complications of MG

Myasthenic Crisis

Caused by undermedication or delayed medication

1. Sudden marked rise in BP due to hypoxia

2. Increased heart rate

3. Severe respiratory distress and cyanosis

4. Absent cough and swallowing reflex

5. Increased secretions, increased diaphoresis, and increased lacrimation (tearing)

6. Restlessness, dysarthria

7. Bowel and bladder incontinence

• Clinical manifestations of myasthenic crisis are as follows:

1. Increased doses of cholinergic as long as the client responds positively to edrophonium treatment

2. Possible mechanical ventilation of respiratory muscle paralysis is acute

Interventions for Myasthenic crisis

Cholinergic crisis

Caused by excessive medications

• Weakness with difficulty swallowing, chewing, speaking, and breathing

• Apprehension, nausea and vomiting

• Abdominal cramps and diarrhea

• Increased salivation and secretions

• Sweating, lacrimation, fasciculations, and blurred vision

• Clinical manifestations of cholinergic crisis:

1. Discontinue all cholinergic drugs until cholinergic effects decrease

2. Provide adequate ventilator support

3. Atropine 1mg/IV may be necessary to counteract severe cholinergic reactions

Intervention for Cholinergic crisis

• Muscle relaxants

• Barbiturates

• Morphine sulfate 

• Tranquilizers

• Neomycin

• The following drugs should be avoided by the clients with MG:

1. Reschedule daily tasks. To prevent weakness

2. Secure “handicapped” parking sticker

3. Frequent rest periods

4. Have an alarm clock available – to take medications on time. This prevents myasthenic crisis

5. Patch each eye alternately for diplopia (double vision)

6. Start a meal with a cold beverage. To contract muscles of the throat and prevent aspiration

7. Avoid factors that affect respiratory functions and may cause respiratory infections:

• Very hot or very cold weather

• Aerosol, pesticides, cleaners

• Alcohol, tonic water, cigarette smoke

SURVIVAL GUIDE FOR CLIENTS WITH MG