Bb Myasthenia

Front 1

What is the cause of myasthenia gravis?

Back 1

decreased acetylcholine receptors on the postsynaptic site on the NMJ due to destruction by circulating antibodies

Front 2

What are some of the hallmark findings in myasthenia gravis?

Back 2

respiratory insufficiency, aspiration, cardiomyopathy, and cardiac failure

Front 3

How is muscle weakness manifested in myasthenia gravis?

Back 3

ptosis, diplopia, dysphagia, increased risk of respiratory failure and aspiration, cardiomyopathy, smooth muscle is not affected

Front 4

What are the types of myasthenia gravis?

Back 4

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

Front 5

what conditions are consistent with cholinergic crisis?

Back 5

SLUDE: Salivation, Lacrimation, Urination, Defecation, Erection

Front 6

How is cholinergic crisis treated?

Back 6

maintain oxygenation and ventilation, and atropine should be given

Front 7

How is myasthenic crisis treated?

Back 7

maintain oxygenation and ventilation and give neostigmine

Front 8

What is the tensilon test used for?

Back 8

distinguish myasthenic from cholinergic crisis

Front 9

What tests should you get preop in a patient with suspected myasthenia?

Back 9

ABG and PFTs, consider tensilon test to distinguish myasthenic from cholinergic crisis

Front 10

What preop sedation should you give a patient with myasthenia gravis?

Back 10

typically no preop sedation is required

Front 11

What should you inform patients with myasthenia gravis about prior to general anesthesia?

Back 11

possible need for prolonged mechanical ventilation postop

Front 12

How should you change your doses of neuromuscular blockers in myasthenia gravis patients?

Back 12

possible resistance to SCh(less receptors to cause muscle stimulation), decreased dose of nondepolarizer(1/5 normal dose)

Front 13

When do patients with myasthenia gravis get a thymectomy?

Back 13

drug resistant disease

Front 14

What different should you do in pregnant patients with myasthenia gravis in labor?

Back 14

continue anticholinesterase medications during labor, use great caution when giving sedatives

Front 15

How are neonates of mothers with myasthenia gravis affected?

Back 15

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

Front 16

What is the mechanism of myasthenia syndrome(lamber-eaton)

Back 16

decreased acetylcholine release following nerve stimulation

Front 17

How are patients with myasthenic syndrome affected by NMBDs

Back 17

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)

Front 18

How is myasthenic syndrome affected by removal of bronchial cancer?

Back 18

temporary but not permanent improvement

Front 19

What are the manifestations of myasthenic syndrome?

Back 19

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