Neuromuscular Flashcards
Pathophysiology of MG
Neuromuscular disorder
Issues with transmission of impulses at the post-synaptic neuromuscular junction
Autoimmune involvement with MG
Involves antibody-mediated disruption of Acetylcholine receptors
Possible cause of MG?
Thymus tumors often associated with MG
Occurrence of MG
more commonly women/men
Women 30, men 40/50
What relation to activity does MG have?
Increased muscle weakness with activity, relieved with rest
What medication is used to treat MG since it is progressive not curable
anticholinergic
Subjective assessments
Muscle fatigue- increased with use, improves with rest Dysphagia diplopia-double vision dysarthria- difficulty speaking Dyspnea
Objective assessments
Ptosis of eyelid- Early sign
Myasthenic smile- snarling/ nasal smile
Strabismus- cross-eyed
Voice weakness
Articulation problem- w/ continued conversation
Muscle strength decreases with use C/O resp failure, bowel bladder incontinence
What is the thymus responsible for1
Produces T lymphocytes
How is MG dx
Tension test
What is given for the tension test?
IV edrophonium
muscle weakness is relieved for +/- 5 mins for positive
Worse for negative results
Electrophysiologic tests
Decrease in action potential amplitude in 60%
AchR serum Antibody titer
Sensitivity 90% in generalized
Ocular 50%
Medical management
Anticholinesterases
Pyridostigmine- mestinon PO
Neostigmine- Prostigmin IV
Immunosuppressants- corticosteroids
What is the antidote for anticholinesterase
Atropine
Surgery?
Thymectomy d/ tumor- may cause remission
Myasthenic crisis
R/T medication- too little too late
Onset of Myasthenic crisis
Abrupt, sever, generalized muscle weakness
Inability to speak, swallow, or maintain RESP!!
Cause of myasthenic crisis?
under medication!
infection, stress (physical or emotional)
Test for Myasthenic crisis
IV edrophonium
Symptoms will improve +/- 5 mins (positive tensilon test)
Nursing considerations for myasthenic crisis
increase medication drugs as rxd by prescriber
Cholinergic crisis
r/t Medication- too much or taken too soon
Symptoms of cholinergic crisis
excessive salivating, sweating, urinary incontinence, hyperperistalsis (N/V/D) Bronchorrhea, wheezing bradycardia Miosis Muscle fasciculations & weakness Anxious, agitated
Test for cholinergic crisis
Iv edrophonium, if muscle symptoms get worse +/- 5 mins= Negative tensilon test
Keep antidote atropine and emergency equipment on hand
