ENT Anesthesia Flashcards
Hyoid Bone
attached to epiglottis and strap muscles
Thyroid cartilage
anterior attachment to vocal cords, posterior articulation with cricoid
Cricoid cartilage
complete ring, articulates with thyroid and arytenoids
Arytenoids
paired, attach to posterior to vocal cords
Anatomy of larynx
Superior Laryngeal Nerve
Branch of Vagus (CN X)
Sensory laryngeal mucosa above VC, inferior glottis
Motor to Cricothyroid muscle: tenses the vocal cords
Injury results in loss of high register , vocal change
Recurrent Laryngeal Nerve
Branch of Vagus
Sensation to Sub-glottis (mucosa below VC)
Motor to intrinsic muscles of the larynx
Injury may result in stridor because of intrinsic muscle paralysis (unilateral v bilateral)
Muscles of Larynx
Posterior Cricoarytenoid muscle
When the PCA muscles contract, they swivel the arytenoids around on their axes, causing the vocal cords to ABDUCT (pull apart laterally). It is the only muscle that abducts the cords.
Lateral Cricoarytenoid Muscle
Because of its different orientation compared to the posterior cricoarytenoid muscle, it will internally rotate the arytenoids and cause ADDUCTION (bring together) the vocal cords.
Intrinsic Muscles Actions
Thyroarytenoids relax the VC
Cricothyroid adduct and tense the VC
Lateral Cricoarytenoid Adduct the VC
Posterior Cricoarytenoid Abduct the VC
Upper Airway Muscles and their function
Tensor Palatine: Opens the nasopharynx
Genioglossus: Opens the oropharynx
Hyoid Muscles: Opens the hypopharynx
Laryngospasm
Exaggeration of the normal glottis closure reflex that persists long after removal of the stimulus
Reflex glottis closure is produced by the superior laryngeal nerve
Risk factors for Laryngospasm
Pre op: Active or recent URI (<2wk)
Second hand smoke, Reactive airway disease, GERD, Age < 1 year
Intraoperative: light anesthesia, FB in airway, Hyperventilation/ hypocapnea, procedures on the airway.
Strategies to prevent Laryngospasm
IV or topical Lidocaine
Avoid stimulation during light anesthesia
Suction oropharynx prior to extubation
Tracheal extubation when fully awake
Administer 100% oxygen for 3-5 minutes prior to extubation
Step by step management of laryngospasm
A. Immediate suction and removal of debris
B. Application of 100% O2 with jaw thrust using bilateral digital pressure on the mandible
C. When A and B fail and O2 Sat continues to fall increase anesthesia depth with iv propofol and/or a small dose of succinylcholine 0.1-0.05mg/kg
Airway maneuvers
Larsen’s
Valsalva: Exhalation against a closed glottis
Muller’s: Inhalation against a closed glottis
Boarders of Larsen’s Maneuver
Posterior: Mastoid process
Anterior: Ramus of Mandible
Superior: Skull base
What is stridor? Management?
Noisy inspiration related to turbulent gas flow
MANAGEMENT
O2 by facemask, head up 45-90 degrees
Nebulized racemic epinephrine
Dexamethasone 4-8mg q 8-12 hours
Heliox (70% he 30% O2)
What is stridor? Management?
Noisy inspiration related to turbulent gas flow
MANAGEMENT
O2 by facemask, head up 45-90 degrees
Nebulized racemic epinephrine
Dexamethasone 4-8mg q 8-12 hours
Heliox (70% he 30% O2)
PEARLS of parotid surgery
Patients can have inflammatory disorders or lesions of the parotid
Facial nerve preservation
Short term muscle relaxation or none
Return of train of four or full return before dissection
Facial Nerve Branches
quick facts about head and neck cancer
Represents 5% of all human cancers
Most patients are between 50-80 years old
Men outnumber women 2:1
Examples of head and neck surgeries and common comorbidities among these patients
Includes laryngectomy, radical neck dissection, hemimandibulectomy and radical sinus surgery
Considerations
Heavy smokers and users of alcohol
Pulmonary disease
Malnutrition
Anemia
Difficult Intubation
anesthesia considerations for head and neck surgery
Vagal response from carotid artery manipulation
Open neck veins may create air emboli
May require tracheostomy as a part of the procedure or to avoid airway edema from extensive surgical manipulation
Tracheostomy is ____
an airway that is inserted subglottically through neck tissues directly into the trachea.
Surgical Tracheostomy involves _____
dissection and incision of trachea under direct vision.
Percutaneous Tracheostomy involves _____
Seldinger technique and dilatation of trachea.
For the first two weeks, all tracheostomy changes should be done _____
in OR with anesthesia provider present
Neck Dissection
To remove cancer that has spread to lymph nodes in the neck
Radical vs. Modified Radical Neck Dissection
Radical: lymph nodes of the neck, sternocleidomastoid muscle, internal jugular vein, and spinal accessary nerve are removed.
Flap Reconstruction
Where is the donor site?
Common pedicle flaps include; cervicothoracic, pectoralis major, sternocleidomastoid, and temporoparietal
A free flap is removed from a distant site
Microsurgery is required to reconstruct vascular supply
Anesthesia Considerations for Flap Reconstructions
Long procedures
Fluid and temperature management
Arterial line and two large IV’s
Tracheostomy is usually performed
Muscle relaxants are avoided
Vasoconstrictors are avoided (? dobutamine)
Transfusions are avoided to minimize micro thrombosis
Panendoscopy PEARLS
Anticipate difficult intubation
Communicate with surgeon
Techniques:
Mask with volatile agent when deep surgeon preforms endoscopies
Conventional GETA
Remifentanil a short acting mu-opioid analgesic
Microlaryngoscopy
Goal to provide the surgeon with a clear view an immobile field and room to work
The anesthetist must protect the trachea, ensure good ventilation and oxygenation minimize secretions and reflexes and promote rapid awaking and return of protective airway reflexes
Fire Triangle =
Laser Safety
Use < 30% FIO2 Air/Oxygen. NOT N2O
H2O or saline available
Most ETT are flammable
Laser resistant ETT are not laser proof
The cuff is most vulnerable to damage
Laser ETT cuff filled with water +/- dye
Laser ETT do not protect against electrocautry
Eye care: taped close no petroleum lube, covering with saline soaked gauze, and protective glasses
CO2 laser
wavelength: 10,600 um
type of surgery: Oropharyngeal, Vocal Cord
structure damaged: Cornea
eye protection: clear lenses
Nd:YAG laser
wavelength: 1064 um
type of surgery: Tumor Debulking, Tracheal
structure damaged: retina
eye protection: green goggles
Ruby laser
wavelength: 694 um
type of surgery: retinal
structure damaged: retina
eye protection: red goggles
Argon laser
wavelength: 515 um
type of surgery: vascular lesions
structure damaged: retina
eye protection: amber goggles
Anesthesia for nasal and sinus surgery
GETA is usually preferred for procedures such as endoscopic sinus surgery
Considerations
Blood in the oropharynx at the time of extubation may lead to coughing or laryngospasm
Throat pack can reduce the amount of blood entering the glottis
Blood collections can occlude the glottis after extubation and result in airway obstruction
Pre-op eval and technique for tonsillectomy
Preoperative evaluation: loose teeth and checking coagulation variables
Standard technique: Deep GA that prevents reflex induced hypertension tachycardia and arrhythmias. Muscle relaxation??. Rapid recovery and return of protective airway reflexes.
LMA (reinforced flexible)
Pediatric “tonsil position”
Tonsillectomy Complication: bleeding
BLEEDING
Incidence requiring surgery 0.3-0.6%
Usually occur within 6 hours of surgery
Blood loss is underestimated
Anesthesia
Check coagulation, type and cross, good IV access, adequate hydration before induction, RSI with cricoid pressure, slight head down, and extubate when patient is awake
Tonsillectomy Complication: PONV
Incidence as high as 70% during the first 24 hours after tonsillectomy
Dexamethasone
Metoclopramide
Ondansetron
N2O
Decompress the stomach
Tonsillectomy in Children
More than 289000 preformed on children younger than 15
Recommendations important to anesthesia
IV Dexamethasone
Against perioperative antibiotics
Importance of pain management after tonsillectomy
Cleft Lip and Palate Surgery
A common craniofacial abnormality occurring in 1:700 births, bones of the face develop in the fifth and ninth weeks, and the palatal development in the sixth to eleventh weeks
Up to 30% of these newborns have other congenital anomalies such as Downs syndrome, Pierre Robin and Treacher Collins syndrome
Pierre Robin
Small mandible = micrognathia or mandibular hypoplasia
Glossoptosis: A tongue that falls back and downward
Cleft Palate
Neonate often requires intubation
Main Characters of Pierre Robin Syndrome
Treacher Collins
A genetic condition caused by changes in gene on chromosome 5 which affects facial development
Downward slanted eyes small jaw and chin unusually formed or absent ears hearing loss and cleft palate
May present for plastic surgery
Small mouth, small underdeveloped mandible
Nasal airway is blocked by tissue (choanal atresia)
Ocular and auricular anomalies
Trisomy 21
John Langdon Down published in 1866 the first accurate description of a person afflicted with the syndrome
In Down’s syndrome the cell contains 47 chromosomes with an extra chromosome linked to chromosome 21, resulting in trisomy 21
Small mouth
Large tongue
Atlantoaxial instability
Small subglottic diameter (subglottic stenosis)
Timing of Cleft Lip Closure
Cleft lip usually at 3 mm of age to allow to feed and demonstrate facial expressions
Closure of the hard and soft palate 5-8mm age for speech development
Anesthesia Considerations for CleftLip and Palate
PREOP Guidelines: Rule of 10’s
Weight 10 lbs, hemoglobin10 mg/dl, white cell count < 10,000/mm3, and more than 10 weeks
Laryngoscope may slip into cleft
Oral RAE ETT taped to lower lip
Eye care
Tongue suture to avoid oral airway
Cleft lip may have a Logan Bow placed at the end of procedure, this makes mask ventilation difficult to impossible
Dingman-Dott Retractor
Can reduce venous drainage and cause tongue swelling
Post op airway obstruction
Anesthesia for ear surgery
Anesthesia can be by infiltration of local anesthetic or by general anesthesia
Premeatal operations, stapedectomy, and uncomplicated middle ear surgery can be preformed with local anesthesia
General anesthesia for ear surgery
Positioning of the the patient
Preservation of the facial nerve
N2O and middle ear pressure
Nausea and vomiting
Myringotomy
Commonly preformed pediatric surgical procedure
Short surgical procedure under GA by face mask
Treat postoperative discomfort by: acetaminophen 40/kg PR, intranasal fentanyl 2mcg/kg
