Miscellaneous topics 3 Flashcards
Causes of drug-induced hyperpyrexia include:
malignant hyperthermia
neuroleptic malignant syndrome
serotonin syndrome
anticholinergic poisoning
Neuroleptic malignant syndrome is caused by
dopamine depletion
Serotonin syndrome is caused by
an excess 5-HT activity
Anticholinergic poisoning is caused by
excess ACh blockade
Methylene blue has ______________ inhibiting properties
MAO-A
Methylene blue can increase the risk of
serotonin syndrome in patients taking other serotonergic drugs
Treatment for serotonin syndrome is
cyproheptadine
Treatment for anticholinergic poisioning is
physostigmine
Treatment for neuroleptic malignant syndrome is
bromocriptine, dantrolene
What are causes of sympathomimetic syndrome?
amphetamines
cocaine
What are key features of sympathomimetic syndrome?
agitation
hallucinations
arrhythmias
myocardial ischemia
What are treatments for sympathomimetic syndrome
vasodilators
labetalol
supportive care
What is the cause of tricyclic antidepressant overdose?
tricyclic antidepressants- amitriptyline, nortriptyline
What are the key features of tricyclic antidepressant overdose?
hypotension
decreased LOC/coma
polymorphic VT
What are the treatments for tricyclic antidepressant overdose?
magnesium
serum alkalization
supportive care
What drugs can cause serotonin syndrome?
SSRIS, SNRIs, MAOIs, MDMA (ecstasy), methylene blue, meperidine, fentanyl
Key features of serotonin syndrome include
akathisia
mydriasis
tremor
AMS
clonus
muscle rigidity
Key features of anticholinergic syndrome are
red, hot dry skin
mydriasis
delirium
Causes of neuroleptic malignant syndrome are
dopamine antagonists- haloperidol, metoclopramide, chlorpromazine, risperidone or withdrawal from dopamine agonists
Key features of neuroleptic malignant syndrome include
bradykinesia
decreased LOC/coma
rhabdomyolysis
myoglobinuria
acidosis
ANS instability
normal pupils
MAOIs combine with _________ increase the risk of serotonin syndrome.
meperidine or ephedrine
SSRIs combined with _________ increase the risk of serotonin syndrome.
meperidine or fentanyl
Identify the statements that BEST represents the anesthetic considerations for ophthalmic surgery.
a. intraocular perfusion pressure equals MAP-CVP
b. Aqueous humor is reabsorbed by the ciliary process
c. hypocarbia increases intraocular pressure
d. nitrous oxide is contraindicated for 10 days after a sulfur hexafluoride bubble is placed
d. nitrous oxide is contraindicated for 10 days after sulfur hexafluoride bubble is placed
IOP is determined by
the choroidal blood volume
aqueous fluid volume
extraocular muscle tone
Normal IOP is
10-20 mmHg
Factors that increase IOP include
hypercarbia
hypoxemia
increased CVP
increased MAP
laryngoscopy
Trendelenburg position
An increased IOP in a patient with an open globe injury can
cause permanent blindness
What paralytic is recommended for the patient with an open eye injury?
succinylcholine is okay to use in a patient with an open eye injury and a full stomach
rocuronium 1.2 mg/kg is also a suitable option
Succinylcholine increases IOP by
5-15 mmHg for up to 10 minutes
Glaucoma is caused by a
chronically elevated IOP that leads to retinal artery compression
IOP is reduced by
drugs that reduce aqueous humor production or facilitate aqueous humor drainage
Unique anesthetic considerations for strabismus surgery include
increased risk of PONV & activation of the oculocardiac reflex (bradycardia)
Nitrous oxide is contraindicated for __________ after a patient undergoes sulfur hexafluoride bubble placement
7-10 days
Intraocular perfusion pressure equation is
IPP= MAP-IOP
Aqueous humor is produced by
the ciliary process
Aqueous humor is reabsorbed by the
canal of schlemm
Factors that decrease IOP include
hypocarbia
decreased CVP
decreased MAP
volatile anesthetics
nitrous oxide
nondepolarizing NMB
propofol
opioids
benzodiazepines
hypothermia
Anticholinergics ______________ IOP
do not increase
LMA placement and/or removal ____________ IOP
has a minimal effect on
What drug can be used to facilitate aqueous humor drainage?
echothiphate
Echothiophate can prolong the duration of
succinylcholine and ester-type local anesthetics
How long does N2O need to be avoided with silicone oil?
0 days
How long does N2O need to be avoided with an air bubble?
5 days
How long does N2O need to be avoided with perfluoropropane?
30 days
What causes open-angle glaucoma?
sclerosis of the trabecular meshwork. impairs aqueous humor drainage
What causes closed-angle glaucoma?
closure of the anterior chamber; creates a mechanical outflow obstruction
