ENT Modified Flashcards
Trigeminal Nerve
CN V
Sensory and Motor
Ophthalmic, Maxillary, mandibular
Glossopharyngeal Nerve
CN 9 sensory Posterior 1/3 of tongue oropharynx anterior of epiglottis vallecula
Facial Nerve
CN 7 both 6 branches: anterior: temporal zygomatic buccal mandibular inferior: cervical posterior: posterior auricle
Vagus Nerve
Both
CNX
Superior laryngeal nerve
Recurrent laryngeal nerve
Superior laryngeal nerve
Internal branch: sensory innervation to the vocal cord folds and posterior epiglottis
Motor: motor innervation below the vocal cords
Recurrent Laryngeal Nerve
Internal: sensory innervation to below vocal cords and trachea
Motor: all intrinsic muscles below the larynx
What is considered critical in your ENT pre-operative assessment
thorough history and extensive evaluation
-deliberate approach to airway management
need for additional equipment and assistance
determine need for alternative approaches
anticipation and approach of the difficult airway
What does sharing the airway require?
preparation
planning
communication
Common Considerations for ENT surgery (10)
Bed turned 90/180 True sharing of airway with surgeon Precordial or esophageal stethoscope Management of extreme stimulation prevention of airway fires nerve monitoring prevent extubation, disconnects, and leaks ALWAYS reassess patient after turning Management of intraoperative blood loss prevention of postoperative airway obstruction
What are some specialized equipment for ENT surgery?
small diameter ETT (decreased ventilation and increased resistance)
standard tubes may result limited cuff contact
Oral and nasal RAE tubes
Armored and reinforced tubes (resist kinking)
metal-impregnanted (reduce airway fire)
LMA
Special considerations for ENT surgery
vasoactive drugs anticholinergics corticosteroids postoperative nausea and vomiting deliberate controlled hypotension
Epinephrine in ENT causes
vasoconstriction
1:200,000 5mg/ml
epinephrine 1:100,000 (10mcg/ml)
1:50,000 (20mcg/ml)
Cocaine in ENT cases
naturally occurring ester of benzoic acid that provides vasoconstriction and analgesia
Combination of epi and cocaine can result in
headaches, HTN, tachycardia, dysrhythmias
Local anesthetics (3)
cocaine (4%)
lidocaine (2%,4%, 10%)
bupivacaine (0.25%,0.5%, 0.75%)
What is the purpose of anticholinergics?
antisialague effects
reduced vagal tone
Not for closed angle glaucoma
What is the purpose of glucorticoids?
reduce nausea and vomiting (give early)
inhibit production of prostaglandins reducing pain, edema
Why use deliberate controlled hypotension in ENT cases?
reduces blood loss in prolonged cases
reduce MAP to pre-determined limits of cerebral autoregulation (50-60mmHg) 10-20% of baseline
arterial line prudent
How do you achieve deliberate controlled hypotension?
beta blockade, propofol infusions (TIVA), remifentanil 0.05-0.2mcg/kg/min
Advantages of nitroprusside for hypotension
potent reliable, rapid onset
Dose of nitroprusside for hypotension
1-8mcg/kg/min
Disadvantages of nitroprusside for hypotension
reflex tachycardia and rebound HTN
Dose of Nitroglycerin for hypotension
125-500mcg/kg/min
Children: 10-15mcg/kg/min
Advantages of nitroglycerin for hypotension
preserve myocardial blood flow
Disadvantages of nitroglycerin for hypotension
variable dosing
What is the dose of nicardapine for hypotension?
5mcg/kg/min
What are the advantages of nicardipine for hypotension
preserves cerebral blood flow
What are common techniques used in ENT surgery?
laser surgery
endoscopy
jet ventilation
What are common lasers in ENT
co2
Nd: YAG
Argon
Describe a CO2 laser
(longer wavelength, shallow depth and precise)
Describe a nd: YAG laser
shorter wavelength, passes through superficial structures
How can the laser light be?
monochromatic (one wave-length)
coherent
collimated
What are the keys to laser safety?
warning signs outside the OR
eye protection
Prevention of airway fires
How do you prevent airway fires?
use lowest O2 concentration possible (goal <30%)
avoid nitrous oxide
fill ET with saline/methylene blue
laser “plume” should be suctioned from surgical field
avoid paper drapes
use water based lubricants
metal impregnanted ETT
What is the fire triad?
oxidizer
ignition source
fuel
What needs to happen if there is an airway fire?
remove ETT immediately and replace with new tube
bronchoscopy and evaluate airway
Considerations for endoscopy (3)
manage brief periods of extreme stimulation (no movement)
short procedures
constantly sharing airway with surgeon
How can you manage brief periods of extreme stimulation?
consider lidocaine, remifentanil, esmolol to block sympathetic stimulation
What do have to be aware of with short procedures?
NMR
What are considerations for sharing the airway with the surgeon?
small, cuffed ETT 5-6 for adult
intermittent apnea
What is jet ventilation?
manual ventilation using hand valve or mechanical device
inspiration is high velocity jet stream (60psi)
expiration is passive
What happens if jet ventilating and airway mass is above level of gas delivery
increased risk of air trapping resulting in subcutaneous emphysema or pneumothorax
What are other considerations for jet ventilation?
TIVA
TCO2
When is TJV contraindicated?
Full stomach
hiatal hernia
trauma
When is high frequency jet ventilation used?
limited access to the airway
How is high frequency jet ventilation performed?
done through small needle, ETT, catheter or side port to a rigid bronchoscopy
what does high frequency jet ventilation provide
low tidal volumes and high respiratory rates
What nerves are most commonly monitored ?
facial, recurrent and inferior laryngeal nerves, vagus nerve, spinal accessory nerve
What are alternatives to prevent patient movement?
remifentanil 0.05-0.2mcg/kg/min
TIVA
Nitrous Oxide
BMT Bilateral Myringotomy and Tympanostomy
creates an opening in the tympanic membrane through which fluid can drain
placement of ventilation tube (tympanostomy) with a lumen is frequently also performed
What does a BMT do?
alleviates pressure from middle ear and serves as stent allowing continued drainage until the tubes are naturally extruded in 6months to 1 year
What can chronic media lead to?
hearing loss and formation of cholesteatoma
What is recurrent otitis media?
three or more acute infection in a six month periof
4 in a one year period
Anesthetic considerations for BMT
short operations (watch oral sedatives may outlast procedure)
mask induction
antibiotics and steroids placed in ear
mild pain medications given orally or rectally
often mask anesthetic only
(IV placed if other procedure being completed)
What is the middle ear?
refers to the air filled space between the tympanic membrane and oval window
What are common middle ear surgeries?
tympanoplasty
stapedectomy or ossiculoplasty
mastoidectomy
cochlear implants
Surgical considerations for middle ear
congenital defects trauma treatment of disease bloodless field microsurgery
Anesthesia considerations for middle ear
no nitrous oxide and muscle relaxants if nerve monitoring
local anesthesia: ability to test hearing during surgery
PONV common
controlled hypotension
deep extubation
What is an indication for a tympanoplasty?
perforated eardrum
What are the two approaches for tympanoplasty?
post auricular (posterior auditory canal) Temporal fascial graft (ossicular chain abnormalities repaired with prothesis)
What are mastoid cells?
cells that are open to air
What are indications for a mastoidectomy
cholesteatoma
mastoiditis
What is the approach to a mastoidectomy?
entry through the post auricular region
What are anesthetic considerations for a mastoidectomy
no nitrous oxide or muscle relaxation
cholesteatomas
destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process.
result in the destruction of the bones of the middle ear, as well as growth through the base of the skull into the brain. They often become infected and can result in chronically draining ears
what is a septoplasty?
correct derformities of nasal septum
What is a rhinoplasty?
repair or re-shaping of the nose
cosmetic
airway restoration
What are indications for sinus surgery?
sinus obstruction (infection, polyps, tumors) sinusotomies
What are surgical options for sinus surgery?
endoscopic
External
fluroscopy
brain lab
In sinus surgery what are polyps associated with?
asthma and cystic fibrosis
reactive airway
allergies
no nsaids
What are strategies to decrease bleeding in sinus surgery?
mild hypotension (Deep anesthesia or antihypertensive) vasoconstrictor use
What are complications to sinus surgery?
dural puncture
How do you treat a dural puncture?
discontinue nitrous oxide ET 25-30mmHg mild hypotension consider mannitol 25-50gm IV (place foley) patch by surgeon deep extubation (do not want to cough)
Where can clefts occur?
one or more different places on the face, such as lips, the palate, or the gum ridge (alveolus)
What are signs and symptoms of cleft palate?
difficulty feeding, malnutrition, speech development, congenital heart defects
What tube is needed for cleft palates?
oral RAE with flexible connector
What are anesthetic considerations for cleft palates?
airway can be difficult
mouth gag (reassess breath sounds once positioned)
secretions and blood (clear airway before emergence) [no yanker]
possibility of airway and tongue edema
extubate once return of protective airway reflexes
protect surgical site from child’s manipulation
S/S of foreign body aspiration
wheezing
coughing
aphonia
cyanosis
What determines the FB lodgement?
size and shape if ends in larynx, trachea, bronchial, gastrointestinal system
How is a FB removed from the larynx?
laryngoscopy and removal of magill forceps
How is a FB removed from distal larynx or trachea?
rigid bronchoscopy
(mouth guard avoids injury)
tracheal tears, inadequate ventilation
In a FB xray, how do the xray look?
if in lung, hypodense (darker lung) because air does not escape
Perioperative management of FB
NPO administer oxygen if respiratory distress experienced ENT/OHN and anesthesia team corticosteroids PIV Avoid coughing and agitation
What is a rigid bronchoscope?
Gold standard extremely stimulating passed through vocal cords side port for ventilation/ jet ventilation telescopic eye piece is exchanged for optical forceps -leak, hypoxia Use high flows and TIVA avoid coughing
Describe the anesthesia technique for distal larynx or trachea
inhalation induction
maintain spontaneous respiration
turn bed
Full stomach (RSI) be prepared for full airway obstruction
Who needs to be in the room for induction of distal larynx/trachea FB?
all team members in room
Postoperative distal larynx/trachea FB
may intubate the trachea to provide ventilation during emergence
edema may occur for next 24 hours
What is the most common indication for T&A in america?
OSA
Are are the surgical methods of tonsillectomy?
cold steel (more pain hemorrhage)
electro-dissection (heat of cautery, pain)
microdebrider (associated with less m&M)
coblation (provides dissection, cautery, suction and hemostasis in same machine)
radio frequency
laser
Intraoperative T&A
standard induction Oral RAE (cuffed with 2cmH20)/ LMA-- secure midline table turned 45/90 degrees mouth gag analgesia management
Anesthesia implications for a mouth gag
requires adequate depth of anesthesia
re-evaluate airway after placement to ensure no dislodgement of ETT or LMA
throat pack
Analgesia management for T&A
increase dose of dexamethasone (0.5-1mg/kg)
zofran 0.1mg/kg
dex at 0.1-0.5mcg/kg IV
What should be avoided in T&A
codeine d/t its metabolism varies in children and cause respiratory distress
For T&A emergence why should you be cautious administering opioids?
a restless child may be indicative of airway compromise or hypoxia
Describe anesthetic considerations for the bleeding tonsil
ensure adequate IV access hypovolemia- needs fluids potential for hemodynamic instability on induction H&H, T&C coagulation studies considered a full stomach requires RSI (adequate O2), propofol or ketamine followed by succinylcholind 2mg/kg IV potential difficult airway OG to empty stomach
What is the largest endocrine gland in the body?
thyroid
What two nerve course along lateral lobes of thyroid?
RLN and External branch of SLN
What are preoperative anesthetic considerations for thyroid surgery?
euthyroid
thyroid and beta blocker
What are regional anesthetic considerations for thyroid surgery?
combined deep and superifical cervical plexus block
What vasopressor is best?
phenylephrine
What position is best for thyroid surgery?
rose position eye protection (googles, padding)
Where is your NIMBs tube placed?
electrodes contact right and left vocal cords
What are postoperative considerations for thyroid surgery?
hypocalcemia (perioral numbness and tingling), tetany, chvostek sign, laryngospasm, QT prolongations, mental status chagnes and seizures RLN damage (unilateral >bilateral) hematoma
What are signs of bilateral RLN injury?
biphasic stridor
dyspnea
respiratory distress
aphonia
What are anesthetic considerations for dental surgery?
standard indution nasal intubation (oxymethazoline spray, warmed RAE, nasal trumpet dilation, red rubber catheter) throat pack OG suction deep extubation
How can you intubate with severe face or neck trauma?
retrograde intubation
jet ventilation via cricothyrotomy
emergent tracheostomy
What is a leforte 1 fracture?
horizontal fracture extending from the floor to of the nose and hard palate through the nasal septum
Leforte 2
triangular fracture running from the bridge of the nose, through the medial and inferior wall of the orbit, beneath the zygoma and through the lateral wall of the maxilla
Leforte 3
separates the midfacial skeleton from the cranial base, transversing the root of the nose, ethmoid bone, eye orbits and sphenopalatine fossa
Anesthetic considerations for trauma ENT
avoid naso-tracheal intubation
consider other trauma (cervical, thoracic and abdominal)
correct ABCs before addressing facial trauma
anticipate extensive blood loss (T&C, deliberate hypotension if tolerated)
consider remaining intubated
awake intubation (maintain airway reflexes)
cutting tools attached to patient or available at the bedside if jaw wired
Anesthetic considerations for radical neck dissection
Airway management
CT results, consult surgeon, preoperative exam
Pre-operative labs: T&C
IVs x2
arterial line (tight BP control), lab analysis
muscle paralysis
controlled hypotension
minimize vasoconstrictors (flap perfusion)
intake and output (colloid vs crystalloid)
vagal response (anticholinergic)
hyperoxygenate patient
Postoperative anesthesia considerations for radical neck dissection
trach care controlled ventilation chest radiography monitor for laryngeal edema ICU for potential edema, fluid shifts, altered ventilation, extensive anesthesia time
