Easy Day Flashcards
Sphenomandibular ligament is from
Meckels cartilage
- meckel’s creates the malleus, symphysis, mandible
What composes Keisselbach’s plexus
GASS
- greater palatine
- anterior ethmoid
- sphenopalatine
- superior labial
Location of greater palatine foramen
Posterior angle of the hard palate
- related to upper 3rd (55%)
- 2nd molar (12%)
- between 2nd and 3rd (19%)
- retromolar (14%)
- 0.35 cm from the posterior hard palate
Name the intramembranous bones
Skull
Facial bones except condyle
Clavicle
What passes through the optic canal
Ophthalmic artery or vein
Optic nerve
Optic artery
Sympathetic fibers
(Optic vein is in the superior orbital fissure)
Efferent and afferent of corneal reflex
Afferent: nasociliary of V1
Efferent: temporal and zygomatic of VII
Superior orbital fissure contents
CN III, IV, V1, VI
Superior ophthalmic v.
Cavernous plexus sympathetic fibers
Inferior orbital fissure contents
Zygomatic branch of V2, ascending branches from pterygopalatine ganglion
Infraorbital vessels
Where is the inferior oblique muscle located
Originate from medial orbital surface of maxilla
Perichondritis after otoplasty organisms
Staph aureus, e. Coli, pseudomonas
Ideal auriculocephalic angle
25-35 degrees
What age to consider otoplasty
4 years
Where is McGregor’s patch located
“Bloody gulch”
- area of zygomatic prominence with plexus of vessels and strong fibrous attachments that can present as skin dimpling or retraction (important in rhytidectomies)
What nerves are of concern of McGregor’s patch
Facial n. Becomes more superficial and buccal nerve lies deep
What direction should the chisel be directed when osteotomizing the pterygoid plates during lefort
Downward, forward, and medial
Where is the maxillary artery in the pterygomaxillary fossa
Approx 20-25 mm superior to the pterygomaxillary fissure
A 1 cm osteotome has a wide 1+ safety margin
How to prevent hemorrhage during Lefort
Only chisel back 30 mm on lateral nose to avoid DPAs
Where is Erb’s point and significance
6 cm inferior to ear lobule on POSTERIOR border of SCM
- greater auricular and accessory nerves just deep to fascia at this point
What surrounds the lacrimal sac
Lacrimal bone and frontal process of the maxilla
- also vascular plexus called cavernous body)
- anterior and posterior limbs of medial canthal tendon
What is the modiolus
Area of confluence of 5 facial expression muscles just lateral to the corner of the mouth
- represents the configuration of the nasolabial fold along with the cheek bone
- levator anguli oris, zygomaticus major, risorius, platysma, depressor anguli oris
Levator veli palatini inserts onto what
Palatine aponeurosis in normal people but onto hard palate in clefts
Facial muscles are usually innervated from the deep side except which muscles
Levator anguli superioris, buccinators, and mentalis
Where does the lacrimal duct exit
Opening of the nasolacrimal duct into the INFERIOR nasal meatus is partially covered by the VALVE OF HASNER
Name the visual field deficit in
1. Optic radiation and optic tract lesions
2. Optic chiasm lesions
3. Optic n. Injury
- Contralateral visual field deficit in both eyes (homonymous hemianopsia)
- Bitemporal hemianopsia
- Ipsilateral blind eye
What is the danger zone of the facial nerve as it crosses the zygomatic arch
0.8 to 3.2 cm anterior to the tragus
What attaches to Whitnall’s tubercle (lateral orbital tubercle) and why is it clinically important
Confluence of lateral canthal tendon
Inferior suspensory/Lockwood’s ligament
Multiple check ligaments of the lateral rectus that form the lateral retinaculum
- clinically important bc lateral canthal tendon should be reattached to the tubercle
- located 1 cm inferior to frontozygomatic suture and 3-4 mm internal to lateral orbital rim
What structure is an extension of periosteum in orbit
Orbital septum
What % of the time is the lingual n. Above the alveolar crest
14%
Generally located 2 mm medially and 3 mm inferiorly to crest on average in 3rd molar region
What is the most common reason for permanent lingual n. Injury
Lingual plate fracture
Indications for coronectomy
- Significant risk of nerve injury
- roots remain vital and get bony fill of socket
OR
- roots need extraction at later date but will migrate away from nerve as they should continue to erupt following crown removal
Most common radiographic finding associated with IAN damage with 3rds
Rood criteria
Loss of cortical border of nerve
Darkening of root
Deviation of canal
Optic canal is located how far posterior to the posterior ethmoid canal
4-7 mm posterior
General rule of medial orbit: 24, 12, 6
Anterior ethmoid = 24 mm posterior to anterior portion of lacrimal bone
Posterior ethmoid is 12 mm posterior to that
Optic canal is 6 mm posterior to that
MRI basics with T1 and T2
T1: hyperintense fat, hypointense fluid
T2: fat and fluid are both hyperintense
Marginal mandibular branch in relation to mandible anterior/posterior to facial artery
- anterior to crossing the facial artery, always superior to mandible
- posterior to crossing facial artery, below (19-53%) the mandible but never lower than 1.5 cm
- risdon incision is made 2 cm inferior to mandible
Why is Risdon incision made 2 cm inferior to the mandible
Posterior to where marginal mandibular branch crosses the facial artery, below the mandible 19-53% of time but never lower than 1.5 cm below mandible
What muscles are supplied by facial n.
Muscles of facial expression
Stapedus
Posterior belly of digastric
Stylohyloid
What glands supplied by parasympathetics from facial n.
Sublingual
Submandibular
Lacrimal glands
What nerve supplies parasympathetics to the parotid
Glossopharyngeal (IX)
What muscles does the vagus supply
Cricothyroid
Levator veli palatine
Salpingopharyngeus
Palatoglossus
Palatopharyngeus
Sup/mid/inferior pharyngeal constrictors
Muscles of the larynx
What intrinsic muscle of the larynx is NOT supplied by the recurrent laryngeal
Cricothyroid (superior laryngeal n.)
What muscles does the hypoglossal supply
All muscles of the tongue EXCEPT THE PALATOGLOSSUS (X)
What muscle does the glossopharyngeal supply
Stylopharyngeus
What muscles are supplied by CN V
Mastication muscles, tensor veli palatini, mylohyoid, anterior digastric, tensor tympani
Taste to posterior 1/3 of tongue
Glossopharyngeal (IX)
Taste to posterior epiglottis
Vagus n. (X)
Nerve that carries sensory info from carotid sinus to carotid body
IX
What does the nucleus of Edinger-Westphal supply
Parasympathetics to the iris sphincter and ciliary muscles via CN III
Superior salivary nucleus function
Parasympathetics to the lacrimal, sublingual, submandibular glands via CN VII
Solitary nucleus function
Taste from facial n., glossopharyngeal and vagus n.
Chemo/mechano receptors from carotid body via CN IX and aortic body via X
Nucleus ambiguus function
Motor neurons to CN IX and X supplied muscles
Inferior salivatory nucleus function
Parasympathetics to parotid via CN IX
What derives from the 1st brachial arch
- Mastication muscles, anterior digastric, mylohyoid, tensor tympani, tensor veli palatine
- Trigeminal n. (V)
- Maxillary artery, external carotid artery
What derives from the 2nd brachial arch
- Facial n. (VII)
- Facial muscles
- Stapedial a. And hyoid a.
What derives from the 3rd brachial arch
- Glossopharyngeal n. (IX)
- Stylopharyngeus m.
- Common and internal carotid arteries
- INFERIOR parathyroid
What derives from the 4th brachial arch
- Vagus (superior laryngeal n.)
- Cricothyroid m.
- Intrinsic soft palate muscles except tensor veli palatine
- Thyroid cartilage
- SUPERIOR thyroids
- Epiglottic cartilage
What is derived from the 6th brachial arch
- Vagus n. (Recurrent laryngeal)
- All intrinsic larynx muscles EXCEPT cricothyroid
What divides the lateral pharyngeal space
Styloid process
Fascial attachments of the levator veli palatini called the aponeurosis of Zuckerkandl and Testut
Where should extraoral incision for drainage of superior/deep temporal spaces be placed
Essentially a Gilles approach incision
Where should extraoral incision for drainage of submandibular, sublingual, submasseteric and pterygomandibular spaces be placed
Essentially smaller versions of a Risdon incision
- incision large enough to get your finger into
Blunt dissection with tonsils, Kelly’s or your finger +/- drain placement t
Where should extraoral incision for lateral pharyngeal and retropharyngeal spaces be placed
Very low risdon type incision
OR
Vertically down the anterior border of the SCM if need to go deeper or access carotid sheath
Lymph node levels of the neck
Level 1: submandibular (Ia) and submental (Ib)
Level II: upper 1/3 of jugular from skull base to inferior border of hyoid
- posterior border is the posterior SCM and anterior is sternohyoid
Level III: from hyoid to inferior cricoid cartilage and bounded anteriorly and posterior just like II
Level IV: inferior cricoid to clavicle along the SCM
Level V: posterior SCM back to anterior trap and extends from apex of SCM and trap junction down to clavicle
Level VI: central compartment between carotids and bounded superiorly by hyoid and inferiorly by sternal notch
What is the lymph node on the cricothyroid membrane called that is frequently encountered in thyroidectomy just deep to the thyroid
Delphian lymph node
Antihypertensive with fat and glucose metabolism destruction
Beta-blocking anti-HTN
Name the lung volumes and what makes up each
- Inspiratory capacity = Inspiratory reserve volume + Tidal volume
- vital capacity = IRV + TV + ERV
- Functional residual capacity = ERV + residual volume
What is restrictive lung disease and what happens to FEV1/FVC
- Related to fibrotic process: ARDS, sarcoidosis, etc
FEV1/FVC is normal or increased
Functional residual capacity (FRC), TLC and RV are all decreased
What is obstructive lung disease and what happens to FEV1/FVC
Asthma, COPD, emphysema
FEV1 significantly reduced
Volumes are unchanged, but flow rates are impeded
Name some non-selective beta blockers
Carvedilol
Labetalol
Pindolol
Propranolol
Sotalol
What is histotoxic hypoxia
Inability of cells to take up O2 despite normal delivery
Usually results from poisoning with alcohol, narcotics, cyanide, etc
Name beta blockers with intrinsic sympathomimetic activity
Acebutolol
Oxyprenolol
Penbutolol
Pindolol
Which beta blockers also have alpha blocking activity
Carvedilol
Labetalol
Beta-1 selective antagonist agents
Atenolol
Esmolol
Metoprolol
Some contraindications to beta blocker use
Asthma
Hx of cocaine use
Treatment of beta blocker overdose
- Glucagon - increases strength of heart contractions, increases intracellular cAMP, and decreases renal vascular resistance
- Cardiac pacing if unresponsive
- If bronchospasm, use anticholinergics (ipratropium - muscarinic antagonist)
What is Parkinson’s disease
Degenerative CNS disorder resulting in death of dopamine-generating cells in the substantia nigra
Why is reglan contraindicated in Parkinson’s disease
Dopamine and 5-HT3 blockers can cause extrapyramidals (dystonia, bradykinesia, tremors, tardive dyskinesia, akathisia)
Digitalis toxicity and electrolytes
Hyperkalemia —> arrhythmia
Digitalis overdose leads to PVCs
Tx: supportive tx after administration of antidote Digoxin immune fab
Sulfonylureas MOA
Stimulate production of insulin
Glyburide, Glimepiride, glipizide
Metformin MOA
Biguanide
- reduces gluconeogenesis in liver
- increases insulin sensitivity
- risk of lactic acidosis and VIT B12 deficiency
What is the concern of QT (depolarization and repolarization of ventricles) elongation and what is the treatment
Progression to torsades de pointes
- tx is MAGNESIUM
Antiemetics that cause QT prolongation
- 5-HT3 blockers (-setrons i.e odansetron)
- Droperidol (dopamine and alpha blocker)
Alpha-glucosidase inhibitors MOA and indication
Reduce glucose absorbance in small intestine by decreasing enzymes needed to digest carbs
- miglitol, acarbose, voglibose
Thiazolidinediones MOA
Reduce insulin resistance by activating PPAR-gamma in fat and muscle
- pioglitazone
- risks: heart failure, edema, anemia, MI, bladder cancer, hepatotoxicity (requires frequent monitoring)
Horner’s syndrome symptoms that develop 2/2 sympathetic nerve damage
Ipsilateral
Miosis (constricted pupil), eyelid ptosis, relative enophthalmus, sometimes anhydrosis (decreased sweating)
In the PACU, pt was treated for laryngospasm with positive pressure now satting at 86%. What do you do
Assuming intubate if not improving
- support with CPAP, BiPAP first and move quickly to intubation
-ABG
Which anesthetic drug do you avoid in pts with CAD
Ketamine
- causes tachycardia
Which narcotic receptors do what and which one specifically causes respiratory depression
Delta: analgesia, antidepressant, dependence
Kappa: same as delta + diuresis + depression
Mu: RESPIRATORY DEPRESSION (MU 1), miosis, euphoria, REDUCED GI MOTILITY
What is MAC
Concentration at which 50% of pt’s wont respond to skin incision
Methohexital properties
GABA-nergic drug that suppresses reticular activating system
- 1-2 mg/kg induction dose, 0.2-0.4 mg/kg sedation dose
- wide swings in BP
- decrease in cerebral blood flow/ICP, increase in O2 consumption
- CAN CAUSE SEIZURES
Pt is taking amitriptylline and has sedation with fentanyl and midazolam, then given atropine. Becomes very agitated, what do you give
Amitriptyline (TCA) = potent anticholinergic and antihistamine + action on norepi and serotonin
- Give physostigmine (cholinesterase inhibitor) to tx atropine-induced emergence delirium
What lung capacity is decreased in a pregnant pt and obese pt
FRC decreased
Test for prolonged blockade and suspected MG
Edrophonium/Tensilon test (acetylcholinesterase inhibitor)
- 2 mg IV q30 s up to 9 mg
- looking for improvement in muscle strength
In anesthesia, when do you give atropine vs. adenosine
- Atropine: anticholinergic for bradycardia (0.5 mg for ACLS, 1 mg for Asystole/PEA arrest)
— in kids, 0.02 mg/kg for bradycardia - Adenosine: antiarrhythmic for tachycardia/SVT conversion if narrow complex and stable (6 mg rapid push)
Dopamine effects on the body
Stimulates alpha, beta-1, and dopaminergic receptors (motivation, pleasure, cognition, memory)
Myotonic dystonia with laryngospasm. How to treat
Avoid succinylcholine - unpredictable response
Rocuronium, positive pressure, etc
Local anesthetic that is contraindicated in pt on MAOi
Anything with epinephrine in it
- MAOi’s potentiate and prolong its effect
Ketamine MOA
NMDA antagonist
Malignant hyperthermia is via what enzyme
Creatine phosphokinase
- trend CKs as you are treating pt
How is malignant hyperthermia treated
Dantrolene: 2.5 mg/kg q5 minutes until reversal up to a total of 10-20 mg/kg
- Creatine kinase should be followed
Mechanism via which nitrous can be a teratogen
Inhibits methionine synthase and vitamin B12
Do barbiturates cause seizures
No, except methohexital/brevital
- others can treat seizures
Main complication with prolonged intubation
Tracheal stenosis
Why do you use a cuffless tube in pediatric patients
Narrowest portion is at cricoid cartilage
- want seal but avoid excess pressure on the tracheal tissues and reduce post-extubation stridor
Desflurane has rapid onset and offset due to
Very low blood-gas partition coefficient
- low solubility —> more rapidly increases in alveolar concentration
- relatively insoluble in fat —> emergence rapid
Mechanism responsible for determining the time a drug has clinical effect
Redistribution
Infant has hypotension without tachycardia, why
Infants dependent on HR to increase CO
Parasympathetics tend to predominate in life
How do benzodiazepines affect sleep
Reduce time to sleep onset and increase total sleep time
- reduce N1 (light sleep) and increase N2 sleep
- D/C can cause rebound insomnia
How much REM sleep per night
20-25% of total sleep
What narcotic is metabolized by plasma cholinesterases
Remifentanyl
How is articaine metabolized
Plasma and liver esterases
- unique among AMIDE LA’s
- Amide LA’s primarily metabolized in liver EXCEPT articaine
- Ester LA’s are primarily metabolized in plasma
What liver damage does sevoflurane cause
Decrease portal vein flow but increases hepatic artery flow
- converts to trifluoroacetylated reactive intermediates
Local anesthetic with lowest pKa
Mepivacaine/carbocaine: 7.6
Etidocaine: 7.7
Lido/prilo/articaine = 7.8
Bupivacaine: 8.1
Procaine: 9.2
What determines LA potency
Lipid solubility (bupivacaine = most potent)
What determines LA duration
Protein binding
What determines LA onset time
PKA
Closer to tissue pKa = faster onset
Tissue is 7.4 so mepivacaine (carbocaine) is fastest onset with pKa of 7.6
Max dosages of lidocaine, articaine, bupivacaine, carbocaine
Lidocaine: 4.4 mg/kg without epi; 7 mg/kg with epi
Articaine: 7 mg/kg
Bupivacaine = 1.3 mg/kg
Carbocaine: 4 mg/kg
Which LA can significantly prolong succinylcholine action
Procaine
Which test can be used to determine if someone has atypical plasma cholinesterase
Dibucaine number
- >80 is normal
<80 = prolonged effects of succinylcholine
Why do old people require less anesthetic
Decrease in levels of neurotransmitters and receptors in brain
What happens to lungs as they age
Reduced alveolar surface area
Etomidate side effects
PONV and adrenal suppression
Why can succinylcholine be used without issue in myasthenia gravis
Fewer functional receptors so may even require more succinylcholine than normal
- MG patients ARE MORE SENSITIVE to non-depolarizing muscle relaxants (rocuronium)
What anesthetic agents are NOT thought to cause acute intermittent porphyria
Narcotics and nitrous
Initial dose of dantrolene for MH
2-3 mg/kg
How is dantrolene mixed
60 mL of sterile water/20 mg bottle
Appropriate 2.5 mg/kg dose injected rapidly after reconstitution
- should have 36 bottle on hand
What BP drug class is contraindicated when administered with dantrolene and why
Calcium channel blockers
- can cause severe myocardial depression
What drugs can cause methemoglobinemia
Articaine
Benzocaine
Prilocaine
Abx: bactrim, sulfonamides, dapsone
Treatment for methemoglobinemia
O2 and methylene blue 1% solution
1-2 mg/kg and given over 5 minutes
How to treat torsades de pointes
1-2 mg Mg over 5-60 minutes then infusion following
Fentanyl dose and metabolization
Wide range (2-50 mcg/kg) intraop
Metabolized by the liver
How is remi fentanyl metabolized
Hydrolyzed by red cell esterases
Maintenance infusion dose for remifentanyl
0.5-3 mcg/kg/min
- usually kept at 0.2 mcg/kg/min when used with propofol or volatile agent
Large bolus doses of remifentanyl can cause
Chest wall rigidity
Meperidine dose for shivering
12.5 mg
Why should meperidine be avoided in pts with MAOIs
Cardiac instability, hyperpyrexia, coma, respiratory arrest, SEROTONIN SYNDROME
Dilaudid dose
0.01-0.02 mg/kg
Can cause histamine release
Morphine metabolism and kidney
5-10% excreted unchanged by kidney
- kidney failure = significantly prolongs duration of action
Dose of naloxone
0.1-0.2 mg q2-3 min
MAC of sevoflurane
2.0
Low solubility
- QT prolongation
- nephrotoxicity due to inorganic fluoride or Compound A
MAC of isofluorane
1.2
Dilates coronary arteries
Desflurane MAC
6.0
Rapid induction and emergence
Can cause increase HR, BP, catecholamines
Nitrous MAC and MOA
MAC = 105
NMDA receptor antagonist
- does NOT trigger MH
Why is nitrous contraindicated in conditions with trapped air
35x more soluble than nitrogen in blood
- pneumos, bowel obstruction, etc
Propofol induction dose
1-2 mg/kg
- need more in kids 2/2 larger vol of distribution
Why do you have to use propofol within 6 hrs
Supports bacterial growth
Egg allergy with propofol?
Propofol contains egg lecithin (yolk) not albumin from egg white
Safe to use
What is propofol infusion syndrome
Long infusions can cause lipemia, metabolic acidosis, and death
Etomidate induction dose
0.3 mg/kg
Associated with adrenal-cortical suppression
30-60% incidence of myoclonus with induction
- minimal cardiovascular effects, popular in older pop
- PONV very common
Methohexital effects on seizures
0.2-0.4 mg/kg doses for sedation
- will not suppress seizure and can potentiate seizures
- GABAnergic
Midazolam sedation dose
0.05 mg/kg - 0.1 mg/kg
- commonly given in 1 mg/2.5 mg bolus
Midazolam effects and MOA
Anterograde amnesia
Erythromycin and midazolam
Erythromycin inhibits metabolism and will prolong and increase potency 2-3x
Ketamine MOA, effect on vitals, dosing
- NMDA antagonist, dissociative anesthetic
- increases BP, HR, CO
- Induction: 1-2 mg/kg, 3-5 mg/kg IM for sedation
- typical: 10 mg q 10 min with limit to <20-30 mg/hr to limit post-op delirium
Dexmedetomidine (precedex) MOA and dosing
Central alpha 2 agonist
- little to no respiratory depression
Loading dose: 1 mcg/kg over 1 min by infusion of 0.4 mcg/kg/hr
Flumazenil dose
0.2 mg q 2 min
Up to 5 doses
Why does diazepam/lorazepam cause venous irritation
Are in propylene glycol
Succinylcholine dosing
Can you give in kids?
Induction: 1 mg/kg (can give some non-depolarizing NMB first due to fasciculations)
- contraindicated in routine management of kids d/t risk of hyperkalemia, rhabdomyolysis, and cardiac arrest with undiagnosed myopathies
- kids can have profound bradycardia —> give 0.02 mg/kg of atropine prior
Rocuronium dose
0.6-0.8 mg/kg induction dose for intubation
Excretion of rocuronium
Liver - can get prolonged blockade in severe liver disease patients
Vecuronium intubation dose
0.1 mg/kg
- renal and hepatic excretion
Cis-atracarium intubation dose and elimination
0.2 mg/kg
Degraded via Hoffman elimination
Does glycopyrolate cross the blood brain barrier
NO
Does not cross BBB
Atropine adult and kid dosing and indications
Kids: 0.02 mg/kg
Adults: 0.05 mg/kg
- best anticholinergic for treating bradyarrhythmia
