General Otolaryngology Flashcards
Define minimum alveolar concentration
Alveolar concentration of vapor needed to suppress movement in response to pain in 50% of people
Rank the following gases in order of increasing MAC: sevoflurane, desflurane, nitrous oxide
Sevo < Desflurane < NO2
What is the difference between amide and ester local anesthetics in terms of metabolism?
Esters are metabolized in plasma by pseudocholinesterase and produce PABA (para-aminobenzoic acid), making them more prone to cause allergic reactions. Amides are degraded by liver and excreted in urine, and do not create a byproduct.
Classify the following into amide vs ester: cocaine, lidocaine, procaine, tetracaine, mepivacaine, benzocaine, bupivacaine.
AmIdes have an “I” before the “caine.” Esters do not.
Which local anesthetics cause methemoglobinemia?
prilocaine, benzocaine, lidocaine, and tetracaine
What is the first-line treatment for methemoglobinemia? When is that treatment contraindicated?
Methylene Blue. Contraindicated in G6PD.
What enzyme metabolizes codeine?
CYP2D6
What opioid is typically used in TIVA and why?
Remifentanyl; quick-on and quick-off. It’s highly lipid soluble at physiologic pH and thus crosses BBB quickly. Also has a short half life with metabolism by plasma and tissue esterases.
Name that headache: A. Pulsatile, unilateral, frontotemporal/orbital area, associated with auras, nausea/vomiting, photophobia. B. Bilateral, throbbing, fronts-occipital tightening, C. Shock-like sensations from corner of mouth to angle of jaw or upper teeth to eye area, worsens in < 20s and lessens to burning, D. Severe, unilateral pain that is temporal, orbital, or Supra orbital and associated with conjunctival injection, lacrimation, congestion/rhinorrhea, may occur 1-8 times daily.
Migraine, tension, trigeminal neuralgia, cluster headaches
Name three medical/nonoperative treatments/strategies for elevated ICP
Raise HOB, hypertonic saline, mannitol, chemically induced coma, hyperventilation, acetazolamide, lasix
What kind of tumor arises from the Rathke cleft?
Craniopharyngioma
What are some common supplements that are associated with increased bleeding?
ginkgo baloba, vitamin E, magnesium, chamomile (among others)
What is the mechanism of action of rivaroxaban, apixaban (Eliquis), edoxaban?
Factor Xa inhibitor (they “ban” Xa, as in they inhibit Factor Xa)
What are some common drugs that interact with direct oral anticoagulants?
Bisphosphonates (dronedarone), CYP450 drugs, amiodarone, verapamil, dilt, a bunch of antiepileptics
What is enveloped in the superficial, middle, and deep layers of the deep cervical fascia?
superficial - SCM, strap muscles, muscles of mastication, salivary glands. middle (visceral) - pharynx, thyroid/parathyroid, larynx, cervical esophagus. constrictors and buccinator. deep (prevertebral) - cervical spine, paraspinal muscles.
What is special about the carotid sheath fascia?
Carotid sheath fascia comprises of all 3 layers, the “lincoln highway” of infectious spread
Where does the retropharyngeal space lie?
Between middle/visceral and ala layers of the deep layer of the deep cervical fascia.
Where does the prevertebral space lie?
Prevertebral space is posterior to the prevertebral fascia, anterior to spine.
Where is the danger space?
Danger space is between the ala and prevertebral layer. Ala goes to mediastinum and prevertebral layer goes to coccyx
Contents of pre vs post styloid space?
Pre - fat, deep lobe of parotid, V3, lingual, imax, medial/lateral pterygoids. Post - carotid, IJV, sympathetic chain
In what space/fossa is V2? What space/fossa(s) does V3 run through?
Pterygomaxillary fossa - V2. V3 runs in the prestyloid parapharyngeal space.
what structures divides the submandibular space into submaxillary and sublingual?
Mylohyoid
What structure causes retropharyngeal space abscesses to be unilateral?
Midline raphe (superior constrictor)
Cutoff for mm thickening at C2 on lateral neck films suggestive of retropharyngeal infection?
5mm in kids; 7mm in adults
Name 1-2 indications/considerations for quinsy tonsillectomy?
Gigantic tonsils causing airway obstruction, already going to OR due to inability to drain at bedside
What is Lemierre’s? Most common organism in this condition?
IJV thrombophlebitis; Fusobacterium necrophorum (gram neg bacillus, anaerobe).
What is the Tobey-Ayer test?
Tobey-Ayer - LD placement; compression of the IJV does not increase CSF pressure on the diseased side but it does on the non-diseased side
