Final exam review part II- preop evaluation & airway anatomy Flashcards
Describe the AANA standards of care.
- Patient’s Rights
- Preanesthesia Patient Assessment and Evaluation
- Plan for Anesthesia care
- informed consent for anesthesia care and related services
- documentation
- equipment
- anesthesia Plan implementation and management
- patient positioning
- monitoring, alarms
- transfer of care
What is the calculation for BMI?
(weight (lbs)/ height (in)^2 x 703
kg/m2
Essential components of the anesthesia interview include:
BMI allergies NPO instructions medications Previous anesthetics/complications family history of malignant hyperthermia possibility of pregnancy systems review baseline level of cognition airway assessment
Describe the NPO guidelines.
Clear liquid (water, black coffee, tea, pulp-free juice, carbonated beverages)- 2 hours
breast milk- 4 hours
formula or cow’s milk, light meal- 6 hours
full meal, fried or fatty food- 8 hours
Emergency cases are considered to have
a full stomach
Patients with longer stomach emptying times include
diabetes, recent injuries, obesity, abdominal complaints, GERD, pregnant or recently delivered
How much force needs to be applied when doing Selleck’s maneuver?
3 lbs to start
progress to 6-8 lbs
Describe the mallampati classes.
Class 1: PUSH- pillars, uvula, hard and soft palate
Class 2: PUS- pillars, part of uvula, soft palate
Class 3: US- soft palate and base of uvula
Class 4: hard palate only
Thryomental distance is
the mandibular space or Patil’s test
head full extended from the mentum to the thyroid notch (upper edge of thyroid cartilage to chin)
Short TM distance implies more difficult intubation because less space for the tongue
7 cm is ideal
Describe the prayer sign.
indicative of decreased joint and cartilage mobility
positive prayer sign is limited atlanto-occipital joint motion
Airway assessments include:
Mallampati, thyromental distance, cervical range of motion, prayer sign, dentition, upper lip bite test, mouth opening, neck circumference
A neck circumference of ______ is indicative of a difficult intubation.
40 cm.
What needs to be assessed in female patients?
Female patients of child-bearing age need to be assessed for possible pregnancy
What medications should be taken the day of surgery?
beta-blockers, GERD medications, Ca+ channel blockers, bronchodilators, antiarrhythmics, steroids, diuretics (if history of CHF) antipsychotics, thyroid medications
What medications should be held on the day of surgery?
oral hypoglycemics, ACE-I, ARBs, diuretics, herbal supplements
The system review includes:
CV, respiratory, neurological, GI, endocrine, musculoskeletal, hepatic, renal, alcohol/drugs, hematologic/coagulation, autoimmune
Patients over age _____ need an EKG
50-60
Important cardiac considerations include
hypertension, angina, coronary artery disease, myocardial infarction, valvular disease, syncope, congestive heart failure, edema and/or dyspnea of cardiac origin, cardiac arrhythmias
Patients with angina, CAD, or hx. of MI should have
EKG, echo, possible cardiac cath and cardiac clearance
Important respiratory considerations include
asthma, chronic bronchitis, emphysema, recent URI, pneumonia, tuberculosis, obstructive sleep apnea, & tobacco use
Describe how to calculate pack years.
number of years smoked x packs/day
Neurological consideratios include:
stroke, TIA, HAs, seizures, neuropathy
With any GI diseases, there is concern for
aspiration
think GERD, hiatal hernia/bowel obstruction
What endocrine considerations are there?
diabetes, thyroid disease
Autoimmune disorders such as
rheumatoid arthritis can cause difficulty due to decreased cervical spine mobility
Musculoskeletal disorders include
muscular dystrophies, MS, myasthenia gravis, myopathy, fibromyalgia, myotonias, obesity, Sjogrens syndrome
For patients with hepatic disease, consider (studies)
PT/PTT, liver panel, and EKG
For patients with ESRD consider (studies)
electrolytes, CBC, PT/PTT, LFTs, and EKG
Describe the ASA classes.
Class 1- normal healthy patient
Class 2- patient with mild systemic disease
Class 3- patient with severe systemic disease
Class 4- patient with severe systemic disease that is a constant threat to life
Class 5- moribund patient not expected to survive without surgery
Class 6- declared brain-dead; anticipating organ procurement (donor)
E- emergency surgery
What leads detect arrhythmias and which leads detect ischemia?
arrhythmias- II
Ischemia- V
The pharynx is composed of the
nasopharynx, oropharynx, and hypopharynx
The cricoid cartilage is at the level of
C6
What is the significance of Waldeyer’s Tonsillar Ring?
lymphoid tissue ring in the pharynx that is at high risk for bleeding, especially with nasal intubation- highly vascular area
The Waldeyer’s Tonsillar ring is made up of:
pharyngeal tonsils (adenoids) Palatine tonsils (located in oropharynx) Lingual tonsils (located at base of tongue)
Where is the larynx in adults vs. children?
Larynx: C3-C6 in adults
C2-C4 in infants and children
Describe the 9 cartilages of the upper airway.
Single: thyroid, cricoid, epiglottic
Paired: arytenoid, corniculate, cuneiform
Describe the significance of the epiglottis.
broad/leaf shaped
VASCULAR area
can be traumatized and swell incredibly
protects against aspiration by covering the glottis during swallowing
The _____ attaches to the cords
arytenoids- most commonly seen paired cartilages on laryngoscopy
The vestibular folds are known as
the false vocal cords; they are a narrow band of fibrous tissue on each side of the larynx
The only complete cartilage is
the cricoid cartilage
it sits at C6
The narrowest portion of an adult airway vs. a children’s airway is
glottic opening is the narrowest portion of an adult airway
in children, the narrowest portion of the airway lies just below the cords at the cricoid ring
Describe the cricothyroid membrane.
relatively AVASCULAR
site of emergency airway
The trachea is composed of
16-20 cartilaginous rings that sit anteriorly
Describe the differences between the adult & infant/pediatric airways is:
Pediatrics have larynx positioned higher in the neck, tongue larger relative to mouth size, epiglottis larger, stiffer, angled more posteriorly; head and occiput larger relative to body size; short neck; narrow nares; cricoid ring is narrowest region
The intrinsic muscles of the larynx include:
posterior cricoarytenoid lateral cricoarytenoid arytenoids cricothyroid thyroarytenoid
What adducts the vocal cords:
lateral cricoarytenoid
arytenoids
What abducts the vocal cords:
posterior cricoarytenoid
The cricothyroid produces
cord tension, closure and elongates the vocal cords
can result in laryngospasm
The thyroarytenoids
shorten and relax the vocal cords
What muscles elevate the larynx?
stylohyoid
mylohyoid
What muscles draw the hyoid bone inferiorly?
sternohyoid, thyrohyoid
What muscle draws the thyroid cartilage caudad?
sternothyroid
What muscles draws the hyoid bone caudad?
omohyoid
Describe the nerve innervation of the airway.
the superior laryngeal nerve innervates above the vocal cords- internal branch provides sensation above and external branch is a motor nerve (SIS & SEM)
the recurrent laryngeal nerve provides sensation below the vocal cords
Describe the innervation of the tongue.
Anterior 2/3rds is cranial nerve 5
Posterior 1/3rd is cranial nerve 9
Damage to the hypoglossal nerve can cause
the tongue to relax and fall back leading to an obstruction
Innervation for all muscles of the larynx is provided by:
superior laryngeal nerve- external branch provides motor innervation to cricothyroid muscle
recurrent laryngeal nerve- innervates all muscles of the larynx EXCEPT for the cricothyroid
What nerve is responsible for laryngospasm?
superior laryngeal nerve
-specifically external since it is motor
Describe a unilateral vs. bilateral superior laryngeal nerve damage.
unilateral- minimal effects
bilateral- hoarseness, vocal tiring
Describe a unilateral vs. bilateral recurrent laryngeal nerve damage.
unilateral hoarseness
bilateral- acute stridor, respiratory distress from unopposed tension of the cricothyroid muscle
chronic will cause aphonia
A vagus nerve injury will
affect both the SLN and RLN
producing flaccid, malpositioned cords resulting in aphonia
What axes are we aligning when we place the patient in ‘sniffing’ position?
the oral, pharyngeal, and laryngeal axis
OPL
How do you align the different axes?
PiLlow- pharyngeal and laryngeal
head extension will align the oral axis
What is the normal atlanto-occipital joint mobility?
35 degrees
greater than 2/3rds decrease is associated with a grade III or IV
A short thyromental distance creates
difficulty in aligning pharyngeal and laryngeal axes
Describe the different laryngoscopic view:
grade 1 view: full view of the glottic opening
grade 2 view: posterior portion of the glottic opening and arytenoid cartilage visible
grade 3: only tip of epiglottis is visible
grade 4: soft palate visible; no recognizable laryngeal structures
How do we treat a laryngospasm?
remove the stimulus
positive pressure
deepen anesthetic
muscle relaxants
A soft tissue obstruction is treated by
head-tilt, chin-lift maneuver or by jaw thrust. this moves the hyoid bone anteriorly and lifts the epiglottis to clear the obstruction
Describe MOANS & BONEs
beard, BMI >25, age >55, edentulous, snores
mask seal, obesity, age, no teeth, snores
What is the “lemon” rule?
look externally, evaluate the mandibular space, mallampati classification, obstructions, neck mobility
Oral airways are not well tolerated in
lightly anesthetized patients- may provoke, gag reflex, cough, vomiting, laryngospasm or bronchospasm
Describe LMA size 3
used for patients 30-50 kg
cuff volume test 30 cc
max cuff volume 20 cc
Describe LMA size 4
used for patients 50-70 kg
cuff volume test 45
max cuff volume 30 cc
Describe LMA size 5
used for patients 70-99 kg
cuff volume test 60 cc
maximum cuff volume 40 cc
What is the maximum airway pressure when using an LMA?
<20cmH2O
Describe the size and depth of insertion for ETT for men & women
men: 8 or 9; 24-26 cm at lip
women: 7-8; 20-22 cm at lip
Describe the size ad depth of insertion of ETT for children
size 4+ age/4
depth: 12 + age/2
The cuff pressure of the ETT should be
20-25 mmHg
tracheal mucosal perfusion pressure= 25-30 mmHg
Describe how the ETT can move with head flexion, extension & rotation
flexion 1.9 cm down
extension 1.9 cm up
rotation 0.7 cm
Describe the subjective criteria for “awake” extubation:
follows commands clear oropharynx intact gag reflex sustained head lift for 5 seconds sustained hand grasp adequate pain control minimal end expiratory concentration of inhaled anesthetics
Describe the objective criteria for “awake” extubation:
vital capacity >15 mL/kg peak voluntary negative inspiratory pressure >25 cmH20 tidal volume >6 mL/kg sustained tetanic contraction SPO2 >90% RR <35 PaCO2 <45
