Airway Flashcards
<p>The nasal pages (nasopharanx) includes</p>
<p>septum, turbinates, adenoids</p>
<p>The functions of the nasopharanyx (4)</p>
<p>2/3 upper aw resistance, humidify, filter, warm air</p>
<p>Nasopharanyx innervated by</p>
<p>trigeminal nerve</p>
<p>Oropharnyx includes (4)</p>
<p>teeth, tongue, hard and soft palate</p>
<p>Predominate cause of aw resistance in oropharynx</p>
<p>tongue</p>
<p>Oropharynx innervated by (2)</p>
<p>Trigeminal Nerve (hard and soft palate, ant. 2/3 tongue)
Glossopharyngeal (post. 1/3 tongue, soft palate, oropharynx)</p>
<p>Border of nasopharynx</p>
<p>soft palate</p>
<p>Border of oropharynx</p>
<p>epiglottis, tonsils, uvula</p>
<p>Primary cause of upper aw obstruction during anesthesia</p>
<p>loss of pharyngeal muscle tone</p>
<p>Pharynx innervated by</p>
<p>glossopharyngeal and vagus nerves</p>
<p>Larynx is located at</p>
<p>C4-C6</p>
<p>Functions of the larynx (3)</p>
<p>phonation, respiration, aw protection</p>
<p>The function of the epiglottis</p>
<p>cartilaginous anterior border of laryngeal inlet, blocks food from entering larynx when swallowing</p>
<p>Larynx has 9 cartilages, name them.</p>
<p>3 paired (Corniculate, Cuneiform, Arytenoid)
3 unpaired (epiglottis, thyroid, cricoid)</p>
<p>Anterior attachment for vocal cords</p>
<p>Thyroid cartilage, large/most prominent</p>
<p>Cricoid cartilage is the only</p>
<p>complete cartilaginous ring</p>
<p>Narrowest part of pediatric aw</p>
<p>cricoid cartilage</p>
<p>Narrowest part of adult aiw</p>
<p>glottic opening between cords</p>
<p>Posterior attachment for vocal cords</p>
<p>arytenoid cartilage</p>
<p>Often cartilage that is falsely identified in DL</p>
<p>arytenoid</p>
<p>Corniculate cartilages are located</p>
<p>on posterior portion of aryepiglottic fold</p>
<p>Cuneiform cartilages are located</p>
<p>lateral to corniculate cartilages on aryepiglottic fold, sometimes missing*</p>
<p>vocal cords are formed by</p>
<p>thyroartenoid ligaments, are pearly white in color</p>
<p>the portion of the laryngeal cavity above the glottis is the 1
and the portion inferior to vocal cords is 2</p>
<p>1 vestibule
| 2 subglottis</p>
<p>Name intrinsic laryngeal muscles</p>
<p>cricothyroid, vocalis, thyroarytenoid, lateral cricoarytenoid, arytenoid, posterior cricoarytenoid</p>
<p>Lateral cricoarytenoid muscle functions by 1 and is innervated by 2</p>
<p>1 adduct (lets close aw)
| 2 recurrent laryngeal nerve (branch of vagus)</p>
<p>arytenoid muscles function 1 and innervated by 2</p>
<p>1 adducts vocal cords (oblique and transverse)
| 2 recurrent laryngeal nerve (branch of vagus)</p>
<p>posterior cricoarytenoid muscle function 1 and innervated 2</p>
<p>1 abduct (pull cord apart)
| 2 recurrent laryngeal nerve (branch of vagus)</p>
<p>cricothyroid muscle function 1 and innervated 2</p>
<p>1 elongates/tenses vocal cords
| 2 superior laryngeal nerve, external branch of vagus</p>
<p>thyroarytenoid muscle functions 1, innervated by 2</p>
<p>1 shortens/relaxes
| 2 recurrent laryngeal nerve (branch of vagus)</p>
<p>Vocalis muscle functions 1, innervated by 2</p>
<p>1 relaxes/shortens
| 2 recurrent laryngeal nerve (branch of vagus)</p>
<p>Function of intrinsic laryngeal muscles</p>
<p>Control length and tension of vocal cords/size of glottic opening</p>
From superior to inferior name parts of vagus nerve
superior laryngeal, internal laryngeal, external laryngeal, recurrent laryngeal
extrinsic laryngeal muscles function (2)
suprahyoid - move larynx cephalad
infrahyoid - move larynx caudad
Suprahyoid group of muscles
digastric, geniohyoid, mylohyoid, stylohyoid
Infrahyoid group of muscles
thyrohyoid, omohyoid, sternohyoid, sternothyroid
List parts of lower airway from largest to smallest (7)
tranchea > carina > bronchi > bronchioles > term. bronchioles > resp. bronchioles > alveoli
Describe traits of trachea
fibromuscular tube, 10-20 cm long, 22 mm diameter in adult, 16-20 u shaped cartilages, no cart on post side, bifurcates at T4 (carina)
Describe traits of carina
divides intro R and L main stem bronchi, at T4
Right bronchi length and angle and special fact
2.5cm, 25 degrees, more common intubate and ge t foreign body due to angle
Left bronchi length and angle
5cm, 45 degrees
AW assessment is done when?
preoperatively
Goal of AW assessment
identify potential aw problems, identify diff. aw
What ?’s to ask during AW assessment (9)
radiation or burn to head/neck, cspine pain ROM, TMJ pain, RA, ankylosing spondylitis, abscess/tumor, prior intubation or trach, snoring/sleep apnea, dysphagia/stridor
What to assess in aw assessment? (12)
1 general appearance (head neck size >43cm/17in and fullness) 2 ROM 3 dentition 4 mouth - tongue lips gums 5 mouth opening - 2-3 fingers, > 3cm/30-40mm 6 body habitus 7 mallampati 8 thyromental distance 9 mandibular protrusion (overbite) 10 hx diff aw 11 diagnosis 12 planned surgery
Mallampati Classification - what is it, how is it done, describe structures
Correlation of oropharyngeal space w/ ease of DL and intubation
Pt sits upright, sticks tongue out (no ah) as far as possible and mouth open as wide as possible, head neutral
Class 0: tip of epiglottis + class 1
Class 1: pillars, uvula, soft palate, hard palate
Class 2: uvula, soft palate, hard palate
Class 3: soft and hard palate
Class 4: hard palate
Cormack-Lehane score what is it, how is it done, describe structures.
DL view of glottis, correlated to Mallampati.
Grade 1: most of glottis
Grade 2: post. portion of glottis (most common)
Grade 3: only epiglottis visible
Grade 4: no aw structures seen
Normal thyromental distance and anatomical landmarks to measure it
Lower border of mandible to thyroid notch w/ neck fully extended. Normal is 6cm, 4 fingers. Difficult intubation is < 3 fingers
Mandibular protrusion test describe it
Class A: lower incisor protrudes anterior to upper
Class B: lower incisor brought to edge w/ upper
Class C: lower incisor cant be brought to edge w/ upper
How to prepare for induction?
MSMAIDS Monitors on and settings appropriate Suction on and at head of bed Machine checked w/ means of positive pressure vent aw IV drugs special equipment
An airway set up includes 12
1 appropriate sized mask 2 PPV - ambu, machine circuit 3 suction on and accessible 4 tongue depressor 5 appropriate oral and nasal aws 6 laryngoscope handle 7 2 different blades (Mac, Miller) 8 2 ETT sizes 9 stylet 10 syringe 11 LMA 12 tape
Sizing for ETT is as follows:
F 6.5-7mm M 7.5-8mm
Describe mask ventilation
Mask in Left Hand and reservoir bag in Right Hand, C grip on mask and 4th/5th fingers under chin and lift/jaw thrust
Goal of preoxygenation is
to increase O2 concentration of FRC by washing out N2 (79% RA)
FRC is
volume of air left in lung at end of passive expiration
3-5 min tight mask fit during normal tidal breathing w/ 100% FiO2 > 6L is _____minutes of safe apnea time
10
4 vital capacity breaths over 30 sec at 100 FiO2 >6L/min is _____ minutes of safe apnea time
5
Preoxygenation is less effective for what types of pts
obese, pregnant pts bc they have decreased FRC
What things to look for effective mask ventilation (4)
chest rise and fall, exhaled Tv, pulse oximetry, capnography
Adequate Tv should be achieved w/ peak inspiratory pressures (PIP) < than
20 cm H2O
Higher PIPs should be avoided bc of
gastric insufflation and therefore aspiration risk
If PIPs are inadequate at 20 cmH2O what should you assess
aw patency, pulm compliance
Predictors of difficult mask ventilation (7):
obstructive sleep apnea/hx of snoring, age > 55, male gender, BMI >30, Mallampati > III, beard, edentulousness
Relaxation of the genioglossus muscle during anesthesia can cause
aw obstruction d/t tongue and epiglottis
What are two types of oral airways?
Berman/BOA and Guedel
How do you size oral airways?
Center of mouth to angle of jaw OR from corner of mouth to earlobe
Complications of oral airways (3)
laryngospasm, bleeding, soft tissue damage
What are oral airway sizes for both BOA and Guedel?
small BOA 80mm = Guedel 3
medium BOA 90mm = Guedel 4
large BOA 100mm = Guedel 5
What happens if oral aw is improperly sized?
too big - obstructs
too small - tongue obstructs
How are nasal trumpets sized?
24 Fr, 26, ….36
Measure from nares to meatus of ear.
If a pt is lightly sedated which type of aw do they tolerate better- nasal or oral aw?
Nasal
Complications of nasal airway? (4)
epistaxis, nasal/basal skull fx, adenoid hypertrophy, anticoagulants
What should be checked on laryngoscope handle?
battery
What should be checked on laryngoscope blade?
light
Macintosh blade is (shape)
curved
Miller blade is (shape)
straight
Macintosh blades come in sizes _____
Miller blades come in sizes _____
1-4, Adults 3
0-4, Adult 3
When DL’ing pt what technique is used to open mouth?
scissor technique
Describe scissor technique
RIGHT Thumb on upper molars moving them cephalad, pointer finger on lower molars moving moving them caudad
Ideal position for ETT
4 cm above carina, 2 cm below cords
How do you estimate ideal ETT depth?
ETT size x 3
How to confirm good placement of ETT? (3)
etCO2*, bilateral breath sounds, chest rise/fall
Absolute indications of ETT placement (12)
1 full stomach (pt didnt fast),
2 high asp. risk dt gastric or bloody secretions
3 critically ill
4 sig. lung abnorm. (poor compliance, aw resistance, impaired O2)
5 lung isolation surgery
6 ENT/otorhinolaryngologic surgery where SGA not possible
7 post op vent support needed
8 failed SGA
9 NMBD
10 positioning w/out quick access to aw (prone)
11 predicted diff. aw
12 prolonged procedure
Features of an ETT (5)
15 mm adapter,
high volume/low pressure cuff - prevents gastric asp., ensures Tv goes to lungs, helps prevent mucosal injury d/t increased surface area, inflate w/ 4-5cc (or min. air to achieve leak of 20-25 cmH2O)
beveled tip - makes it easier for tube to pass thru vocal cords,
murphy eye - side wall opening, back up hole for ventilation in case of obstruction of distal lumen
pilot balloon w/ one way valve
Describe the difference between high pressure/low volume and high volume/low pressure ETT cuffs?
High pressure/low volume - good at preventing aspiration, but exerts high pressure on tracheal wall, if left for long periods, causes injury
High volume, low pressure not as good at preventing aspiration but exerts minimal pressure on tracheal wall
What position needed for intubation and WHY?
Sniffing position, optimally visualized vocal cords
What 3 axis need to be aligned for intubation?
oral, pharyngeal, and laryngeal (OPL)
When should the stylet be removed from ETT during intubation and WHY?
At the level of the cords, just before passing thru glottis, prevents trauma to tracheal mucosa.
Describe the features of a stylet (2)
malleable, form 60 degree angle 4-5cm distal end - hockey stick shape
What is the ideal position for mask ventilation and WHY?
Sniffing position, aligns OPL axis
How is sniffing position achieved w/ obese pts?
ramp shoulders w/ pillows and blankets
Predictors of a difficult airway? (8)
1 long upper incisors, 2 prominent overbite 3 inability to protrude mandible 4 small mouth opening (2-3 fingers, > 3cm/30-40mm) 5 mallampati > III 6 high arched palate 7 short thyromental distance 8 short thick neck limited cervical mobility
What are the sizes of LMAs?
30-50 kg - LMA 3
50-70kg - LMA 4
70-100kg LMA 5
>100 kg LMA 6
What to inflate LMA cuff to?
Normal: 40 to 60 cm H2O, w/ a 18-20 cm H2O audible air leak
Proseal/Supreme: 40-60 cm H20, w/ 20 cm H2O air leak
Complications of improperly sized LMA (2)?
too small - cuff inflated too large to achieve seal, r/o nerve damage
too large - sore throat
Features of a supreme LMA that differ from LMA classic?
integrated bite block, drain tube for stomach, can achieve PIP of up to 30 cm H2O (vs 20 cm H2O on classic)
Advantages (5) and disadvantages of LMA?
A: 1 increase speed and ease of placement, 2 improved hemodynamics at inductions/emergence d/t less anesthesia required, 3 lower freq. coughing, 4 lower freq. sore throats, 5 avoids foreign body in trachea (ex. asthmatics have rxtive aws and do better w/ less invasive aws)
D: 1 not a definitive aw, 2 lower seal pressure, 3 higher freq. of gastric insufflation, 4 esophageal reflux, 5 mech ventilation limited - pressure support
Hazards of AW management (8)
1 dental damage 2 soft tissue/mech injury 3 laryngospasm 4 bronchospasm 5 vomitting/aspiration 6hypoxemia/hypercarbia 7 SNS stimulation (tachy adults, brady kids) 8 esophageal/endobronchial intubation
Describe MAC case
complete aw set up, nasal cannula - everyone gets O2, spont. breathing pt, nasal aw if snoring
Describe GA mask case
no diff aw, no need to access head/neck for surg, no aw bleeding/secretions, short surg., no position changes, pt spont. breathing
Describe GA LMA case
no difficult aw, access head/neck for surg, no aw bleeding/secretions, short surg., more reliable than mask, want free hands
Describe GA tracheal intubation case
used for aw compromised, aw inaccessible, long surg, changing surgical positions, surgery of head/neck,abdomen, need for controlled vent./PEEP, inability to maintain aw w/ mask/LMA, aspiration risk, aw/lung disease, NMBD
