Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
What is the cause of myasthenia gravis?
|
decreased acetylcholine receptors on the postsynaptic site on the NMJ due to destruction by circulating antibodies
|
|
What are some of the hallmark findings in myasthenia gravis?
|
respiratory insufficiency, aspiration, cardiomyopathy, and cardiac failure
|
|
How is muscle weakness manifested in myasthenia gravis?
|
ptosis, diplopia, dysphagia, increased risk of respiratory failure and aspiration, cardiomyopathy, smooth muscle is not affected
|
|
What are the types of myasthenia gravis?
|
type 1: limited to extraocular muscles
type 2a: mild form with respiratory muscles spared type 2b: more rapidly progressive with involvement of respiratory muscles type 3: acute onset, rapid progression, high mortality type 4: severe form resulting from progression of 1 or 2 |
|
what conditions are consistent with cholinergic crisis?
|
SLUDE: Salivation, Lacrimation, Urination, Defecation, Erection
|
|
How is cholinergic crisis treated?
|
maintain oxygenation and ventilation, and atropine should be given
|
|
How is myasthenic crisis treated?
|
maintain oxygenation and ventilation and give neostigmine
|
|
What is the tensilon test used for?
|
distinguish myasthenic from cholinergic crisis
|
|
What tests should you get preop in a patient with suspected myasthenia?
|
ABG and PFTs, consider tensilon test to distinguish myasthenic from cholinergic crisis
|
|
What preop sedation should you give a patient with myasthenia gravis?
|
typically no preop sedation is required
|
|
What should you inform patients with myasthenia gravis about prior to general anesthesia?
|
possible need for prolonged mechanical ventilation postop
|
|
How should you change your doses of neuromuscular blockers in myasthenia gravis patients?
|
possible resistance to SCh(less receptors to cause muscle stimulation), decreased dose of nondepolarizer(1/5 normal dose)
|
|
When do patients with myasthenia gravis get a thymectomy?
|
drug resistant disease
|
|
What different should you do in pregnant patients with myasthenia gravis in labor?
|
continue anticholinesterase medications during labor, use great caution when giving sedatives
|
|
How are neonates of mothers with myasthenia gravis affected?
|
neonatal myasthenia gravis is present in 20-30% of newborns, generalized weakness is most important manifestation, anticholinesterase therapy is generally needed for 3-4 weeks, higher risk of developing respiratory therapy
|
|
What is the mechanism of myasthenia syndrome(lamber-eaton)
|
decreased acetylcholine release following nerve stimulation
|
|
How are patients with myasthenic syndrome affected by NMBDs
|
marked sensitivity to both depolarizers(decreased ACh leads to increased sites for SCh to bind) and nondepolarizers(decreased ACh leads more competitive inhibition from nondepolarizers)
|
|
How is myasthenic syndrome affected by removal of bronchial cancer?
|
temporary but not permanent improvement
|
|
What are the manifestations of myasthenic syndrome?
|
muscular weakness, associated with bronchial carcinomas, increased muscle strength with exercise, no improvement following administration of anticholinesterases, involves proximal muscles of the limbs and not the bulbar muscles
|