Airway Anatomy, Equip., & Mgmt Flashcards Preview

Intro to Anesthesia > Airway Anatomy, Equip., & Mgmt > Flashcards

Flashcards in Airway Anatomy, Equip., & Mgmt Deck (67):
1

What is airway management?

establishing and securing a patent airway

2

What structures are included in the UPPER airway?

nasal cavity
oral cavity
pharynx
larynx

3

Describe structures, function, and innervation of the nasal cavity

Includes:
Septum, Turbinates, Adenoids, Paranasal
sinuses

Function:
Accounts for 2/3 of total upper airway
resistance
Humidification and warmth
Filter

Innervation:
Branches of the trigeminal
nerve (CN V)

4

Describe structures and innervation of the oral cavity

Includes:
Teeth
Tongue **Predominate cause of airway
resistance in oral cavity**
Hard palate
Soft palate

Innervation:
◦ Trigeminal Nerve (CN V)
Hard and Soft palate
Anterior 2/3 tongue

◦ Glossopharyngeal (CN IX)
Posterior 1/3 tongue
Soft palate
Oropharynx

5

What is the pharynx?

muscular tube that extends from the base of the skull down to the level of the cricoid cartilage

6

How is the pharynx divided?

Nasopharynx
Border is the soft palate

Oropharynx
Border is the epiglottis, tonsils, uvula

Hypopharynx/
Laryngopharynx

7

What cranial nerves is the pharynx innervated by?

Innervation:
◦ Glossopharyngeal (CN IX)
◦ Vagus (CN X)

8

Where is the larynx located?

C4-C6 (adults)

9

Name the functions of the larynx

Airway protection (Epiglottis)
Phonation
Respiration

10

How many cartilages make-up the larynx?

9 cartilages total
3 unpaired and 3 paired

11

Name the cartilages of the larynx

Unpaired
Epiglottis, Thyroid cartilage, Cricoid cartilage

Paired
Arytenoid, corniculates, cuneiform

12

Describe the shapes of the Arytenoid, Corniculate, Cuneiform

Arytenoid are pyramidal/ triangular
Corniculates are horned shaped
Cuneiform are wedge/rod shaped

13

Describe the vocal cords

◦ Appear pearly white
◦ Formed by the thyroarytenoid ligaments
◦ Attached anteriorly to the thyroid cartilage and
posteriorly to the arytenoid cartilages

14

Describe the glottic opening

◦ triangular fissure between the cords
◦ narrowest portion of ADULT airway

15

Cricoid Cartilage

◦Signet ring shape
◦Unique complete cartilaginous ring
◦Narrowest point of Pediatric airway
◦Inferior to thyroid cartilage-cricothyroid membrane

16

What is the role of the intrinsic laryngeal muscles?

◦Control the movements of the laryngeal
cartilages
◦Control the length & tension of the vocal cords; size of the glottic opening

17

Cricothyroid muscle innervated by the...

external branch of superior laryngeal nerve
(a branch of the Vagus nerve -CN X)

18

With the exception of the cricothyroid muscle, all other laryngeal muscles are innervated by...

recurrent laryngeal nerve
(a branch of the Vagus nerve -CN X)

19

posterior cricoarytenoid

ABDUCTS vocal cords & opens glottis

20

lateral cricoarytenoid

ADDUCTS glottis

21

arytenoids

ADDUCTS glottis (especially posterior)

22

cricothyroid

vocal cord tension and elongation

23

thyroarytenoid

vocal cord shortening and relaxation

24

Name the structures of the lower airway

-Trachea
-Carina
-Bronchi
-Bronchioles
-Terminal bronchioles
-Respiratory bronchioles
-Alveoli

25

Describe the trachea

-Fibromuscular tube 10-20cm length & 22mm diameter (Adult)

-16-20 'U' shaped cartilages
Posterior side lacks cartilage

-Bifurcates lower border T4-carina

-At Carina
◦ Trachea divides Rt. & Lt. mainstem bronchi
◦ Rt bronchi 2.5cm long with 25 degree angle
◦ Lt bronchi 5cm with 45 degree angle

26

Pre-op Airway Assessment

General appearance- head, neck-size & fullness
Range of Motion in the Neck
Thyromental Distance
Mouth- lips, gums, tissues
Mallampati Classification
Mouth opening-usually 3-4cm or 2-3 fingerbreadths
Dentition-Teeth missing, protruding, overbite,
dentures/bridges out?
Size & mobility tongue
History of Previous Difficult Airway
Body Habitus/Physical Characteristics
Diagnosis
Surgery Planned

27

Purpose of oropharyngeal A/W Evaluation -Mallampati Score?

Correlates the oropharyngeal space with the ease of
direct laryngoscopy and tracheal intubation

28

What is the hypothesis of Mallampati?

When base of tongue is disproportionately
large, tongue overshadows the larynx resulting in
difficult exposure of vocal cords during
laryngoscopy

29

How do you assess the patient during the Mallampati assessment?

Sit upright
Head neutral
Mouth open as wide as possible
Tongue maximally protruded (No AAAH! -causes elevation of soft palate)

30

Mallampati I-IV

P-U-S-H
Class I: faucial Pillars, entire Uvula, Soft and
Hard palates

Class II: tip of Uvula masked by tongue, Soft and
Hard palates

Class III: Uvula base, Soft and Hard palates

Class IV: Hard palate only

31

Mallampati scores of _____ and _____ are considered difficult airways

Class III and Class IV

32

Thyromental distance

lower border of mandible to thyroid notch with neck fully extended

-Normal 6-6.5cm or 4 Fingerbreadths
-Difficult intubation < 3 fingers, receding mandible; “anterior airway”

33

Optimal intubation positioning

“Sniffing” position- aligns the 3 axis
◦ Oral axis
◦ Pharyngeal axis
◦ Laryngeal axis

-provides the most optimal visualization of the vocal cords
-Allows for the most effective mask ventilation
-Positioning is key for success especially for
the novice practitioner

34

Airway Setup

L laryngoscope w/ 2 types of blades
O oral/nasal airways
S stylet and syringe on cuff
T tongue depressor, tape
S suction on and easily accessible
E ETT 2 sizes
A mbu-bag and machine for PPV
L LMA & facemask

35

Face Masks

Patient characteristics may predict difficult
mask fit
◦ Examples: Beard, edentulous, short mandible

Head strap and potential nerve injuries

Technique:
◦ Hold mask in Left Hand and Reservoir Bag in Right. Thumb on upper aspect of mask, index and middle fingers on lower aspect, and 4th/5th fingers under chin for chin lift/jaw thrust

36

Relaxation of the genioglossus muscle during induction can cause...

tongue and epiglottis to obstruct the airway

37

Ensuring airway patency

1. Airway Maneuvers
◦Head tilt/chin lift
◦Jaw Thrust

2. Adjuncts
◦Nasopharyngeal Airway-lubricate
◦Oropharyngeal Airway-tongue blade

3. 2 handed mask with bagging assistance

38

Types/Sizes of oral airways

-Berman (BOA) & Guedel

-Adult sizes
◦ small BOA (80 mm) = Guedel #3
◦ medium BOA (90 mm) = Guedel #4
◦ large BOA (100 mm) = Guedel #5

Measure from the center of the mouth to the angle of
the jaw, or from the corner of the mouth to the earlobe

39

Complications/Precautions of oral airway

◦ Soft tissue damage
◦ Bleeding
◦ Laryngospasm

40

The nasal airway/ trumpet is used to

provide passageway from nose to pharynx, beneath relaxed and obstructing tongue

41

Describe the nasal airway/trumpet size, measurement, insertion

-Diameter-French sizes 24, 26,…36; used in series small to large to dilate prior to elective nasal intubation
-Measurement estimated as distance from nares to
meatus of ear
-Lubricate!
-Usually tolerated better than oral airway during
light anesthesia

42

Complications/Precautions of nasal airway

◦ epistaxis; anticoagulants
◦ nasal or basal skull fractures
◦ adenoid hypertrophy

43

What should always be checked on laryngoscope handles? What are the types of handles?

Handles-> check the battery!
◦ Adult
◦ Pediatric (penlight)
◦ Stubby (short)

44

What should always be checked on laryngoscope blades? What are the types of blades

Blades-> check the light!
◦ Macintosh (1-4)
◦ Miller (0-4)

45

Macintosh blade is _________ and goes into the ________

Curved, Valeculla

46

Miller blade is _________ and goes ___________

straight, under/posterior to epiglottis

47

What are the ETT sizes for male and female, ideal position of tube, and measurement for depth of tube?

Adult ETT want 2 sizes available
◦ Female: 6.5-7.0 mm id (approximately 21 cm)
◦ Male: 7.5-8.0 mm id (approximately 23 cm)

Ideal position:
◦ 4 cm above the carina and 2 cm below the vocal
cords
ID x 3 = approximate depth

48

How do you confirm placement of ETT?

- bilateral chest rise
- bilateral breath sounds
- ETCO2 colorimetric or Capnography w/ 3 waveforms

49

Murphy Eye on an ETT serves what purpose?

serves to provide an additional portal for ventilation should the distal end of the lumen become obstructed by either soft tissue or secretions

50

The black marking on the ETT should align with the ...?

vocal cords

51

Most cuffs are ______ volume, ______ pressure.

High volume, low pressure

52

Indications for tracheal intubation

◦ Airway compromise
◦ Airway inaccessible
◦ Long surgical time
◦ Surgery of head, neck, cheek, or abdomen
◦ Need for controlled ventilation and/or positive end
expiratory pressure
◦ Inability to maintain airway with mask/LMA
◦ Aspiration risk
◦ Airway/ lung disease

53

What is an LMA device?

A supraglottic airway device used for routine and difficult airway management

Can be used as a conduit for ETT placement

54

What are the appropriate sizes of LMA?

Weight based sizes
◦ Adult sizes
30-50 Kg - LMA 3
50-70 Kg - LMA 4
70-100 Kg -LMA 5
>100 Kg -LMA 6

55

What's required for LMA insertion?

Equipment: 20 or 50 cc syringe,lubricant, suction, stethoscope, tape
◦ (lubricate posterior side only!)

Position head - neck flexed and head extended
-Hold LMA with right hand like a pen with black line facing you
-Insert LUBRICATED LMA into mouth, follow palate centrally, push into oropharynx until resistance is felt, and then stop.
-Release right hand, grasp upper aspect of LMA, and attempt
further advancement of the LMA
-Inflate the cuff (LMA will move)
-Ventilate- observe, listen (stomach, lungs)
-Secure with tape

56

Advantages of LMA

-increased speed and ease of placement by inexperienced personnel
-improved hemodynamic stability at induction and during emergence
-reduced anesthetic requirements for airway tolerance
-lower frequency of coughing during emergence
-lower incidence of sore throats in adults (10% vs 30%)
-avoids “foreign body” in the trachea
-patient can be fully emerged prior
to removal of LMA (good for asthmatic patients)

57

Disadvantages of LMA

-lower seal pressure
-higher frequency of gastric insufflation
-esophageal reflux more likely
-inability to use mechanical ventilation*

58

Potential Hazards of airway management

-Dental damage
-Soft tissue/mechanical injury
-Laryngospasm
-Bronchospasm
-Vomiting/Aspiration
-SNS stimulation
-Hypoxemia/Hypercarbia
-Esophageal/Endobronchial intubation

59

Laryngoscopy injury complications

HTN, tachycardia, bradycardia, corneal abrasion, dental trauma, spinal cord trauma, aspiration

60

Laryngospasm

***RECOGNIZE THE EVENT!!!***
Severe, sudden, sustained contraction of the glottic
opening (vocal cords) in response to a stimulus (blood,
secretions, light anesthesia) characterized by complete
airway obstruction with retractions

61

Treatment of Laryngospasm

◦ Jaw-Lift Maneuver and placement of mask
◦ O2 w/ continuous Positive Pressure
◦Strong intermittent pressure applied manually to a bag full of oxygen can force gas effectively through the upper airway and adducted cords.

-Immediate removal of the offending stimulus
◦ Small dose of short acting Muscle Relaxant Succinylcholine
20-40 mg IV

62

MAC Case

- Complete Airway Setup Ready to go
- Nasal Cannula- EVERYONE GETS O2
- Spontaneously Breathing Patient
- Nasal airway if snoring (partially obstructed breathing)

63

General Anesthesia Mask Case

Use when:
-Difficult airway not present
-Surgeon does not need access to head/neck (BMT-ok)
-No airway bleeding/secretions
-Case of short duration
-No table position changes- head available
-Obstruction easily relieved with oral nasal airway/ chin lift
-Patient will spontaneously breathe-no neuromuscular blocker used

64

General Anesthesia LMA Case

Use when:
◦ Difficult airway not present
◦ Surgeon does not need access to head/neck (?)
◦ No airway bleeding/secretions
◦ Case of short duration
◦ More reliable patent airway than mask
◦ Want hands free

65

Induction of Anesthesia step 1

Goal = Increase O2 concentration in functional
residual capacity (FRC) by “washing out”
nitrogen (79% in RA) in the FRC with oxygen
FRC volume of air left in the lung at end of passive expiration

3-5 minutes of “tight” mask fit during normal tidal breathing w/ 100% FiO2 at> 6L/min flow
= 10 minutes of safe apnea time

4 vital capacity breaths within 30 seconds with
100% FiO2 at >6L/min= 5 minutes of safe
apnea time

66

Induction of Anesthesia

1. Position patient supine in sniffing position
2. Turn on oxygen flow
3. Begin preoxygenation
4. Monitors on and vital signs taken (O2 sat, BP, ECC, PNS)
5. Suction on and ready at head-of-bed
6. Induction agent
7. Test lash reflex
8. Give test mask ventilation
9. Check neuromuscular-blocking monitor (PNS) working
10. Paralytic drug
11. Continue mask/bag ventilation until twitches cease/loss of twitches
12. Tape eyes closed
13. Laryngoscopy and intubation
14. Confirm ETT placement—bilateral breath sounds, chest rise and fall,
presence of ETCO2 x 3stable waveforms
15. Continue ventilation by bag or ventilator
16. Begin maintenance anesthetic
17. Tape ETT
18. Begin maintenance anesthetic
19. Surgical case

67

Basic steps of Emergence of Anesthesia

1. Muscle relaxant must be fully reversed
2. Anesthetic medications, including anesthetic gases
and infusions, turned OFF
3. Oropharynx is suctioned.
4. Patient is self-maintaining an acceptable respiratory rate and depth

Respiratory Criteria*
TV >5 mL/kg
VC > 10 mL/kg
RR < 30 breaths/min
SaO2 > 90%
ETCO2 <50
5. Assess for responsiveness / purposeful movement and/or responding to commands/ sustained 5 sec. head-lift
6. ETT is removed while a positive-pressure breath is given with the anesthesia bag to allow subsequent expulsion or secretions out of the glottis