1. RSI Airway Assessment New Hampshire
Division of Fire Standards & Training and
Emergency Medical Services

2. Introduction Slide

3. Purpose of this Module Review Airway Anatomy
Learn Advanced Airway Assessment Techniques
3-3-2
Laryngoscope View Grading
Mallampati Classifications
BURP
During this module the student will review the airway anatomy.
The student will learn advanced airway assessment techniques not limited to Mallampati classification, Laryngosopic view grading, and the “3-3-2” airway grading method.

4. IF Endotracheal Intubation fails, you must have a back-up plan...
King-LTD
LMA
BVM
Combi-Tube
Cricothyrotomy

5. Upper Airway Upper Airway
The face and the facial skeleton and are considered components of upper the airway. The upper airway heats, humidifies and conducts air into the lower airways. Problems can arise from obstructions, fractures and soft tissue injuries.

6. Upper Airway

7. Middle Airway Middle Airway
The middle airway consists primarily of the larynx. It is fairly well protected but is susceptible to injury. The larynx is comprised of cartilage and contains the vocal cords. Because it is narrow, edema, secretions, or foreign bodies can quickly cause problems.
The rigid laryngeal structures are the hyoid bone, thyroid cartilage, cricoid cartilage and arytenoid cartilage. Inferior to the cricoid cartilage are tracheal cartilages. The cricoid cartilage is a complete ring and can be used to prevent passive reflux of stomach using cricoesophageal pressure (Sellick’s Maneuver)
Laryngeal Cartilages
The Cricothyroid artery is a small branch of the superior thyroid artery. It travels along the inferior border of the thyroid cartilage and becomes smaller as it reaches the midline. Cricothyroid puncture in the midline, inferior part of the membrane above the cricoid cartilage is least likely to produce bleeding.
The large superior and inferior thyroid arteries supply the thyroid gland. The gland is highly vascular. A pyramidal lobe may extend to the hyoid bone. Puncture below the cricoid cartilage has increased risk of bleeding. Palpate the puncture site carefully and avoid any masses (Engel et al, 2001).

8. Thyroid versus Cricothyroid Cartilage
Thyroid cartilage used in “BURP” maneuver. Does not form a complete ring around the trachea.
Cricothyroid Cartilage used in CricoidPressure, does form a full ring around the trachea allowing for the compression of the esophagus.

11. Lower Airway

12. 1. Preparation A two-part process: Assess the risks
Prepare the equipment

13. Assess the Risks

14. Difficult Airways - Assess the Risks
“The difficult airway is something one anticipates; the failed airway is something one experiences.”
-Walls 2002

15. How do you know if your patient is going to be difficult to intubate…
…and does it really matter? ?
In most pre-hospital cases the airway needs managing regardless of the level of difficulty, and the provider is expected to do that, regardless of difficulty ….so what is the benefit of knowing a fancy system?

16. Some Predictors of a Difficult Airway
Dentures
Limited jaw opening
Limited cervical mobility
Upper airway conditions
Face, neck, or oral trauma
Laryngeal trauma
Airway edema or obstruction
Morbidly obese
C-spine immobilized trauma patient
Protruding tongue
Short, thick neck
Prominent upper incisors (“buckteeth”)
Receding mandible
High, arched palate
Beard or facial hair
Trauma: immobilized – cannot align axis
Peds: anterior and cephalad airway, large tongue, large occiput, small mouth, stiff/floppy epiglottis (more horizontal)
Obesity or very small
Short Muscular neck
Large breasts
Prominent Upper Incisors (Buck Teeth)
Receding Jaw (Dentures)
Burns
Facial Trauma
S/S of Anaphylaxis
Stridor
FBAO
Blood
Vomitus
Epiglottis
Dentures
Tumors
Impaled Objects
Spinal Precautions
Lack of adequate access

17. Additional Predictors: Medical History
Joint disease
Acromegaly
Thyroid or major neck surgeries
Tumors, known abnormal structures
Genetic anomalies
Epiglottitis
Previous problems in surgery
Diabetes
Pregnancy
Obesity
Pain issues
Rheumatoid Arthritis
Ankylosing Spondylitis: Painful Stiffening of the joint
Cervical Fixation Devices
Klippel-Fiel Syndrome: Short wide neck, reduction in number of cervical vertebrae, and possible fusion of vertebrae.
Thyroid or major neck surgeries
Pierre Robin Syndrome: Small Jaw, cleft Palate, No Gag reflex, downward displacement of tongue
Acromegaly: Thickening of Jaw, Soft tissue structures of the face, associated with middle age

18. Assess the Risk
Identifying a potentially difficult airway is essential to preparing and developing a strategy for successful ETI and also preparing an alternate plan in the event of a failed ETI.
The American Society of Anesthesiology (AMA) has noted:
“… there is strong agreement among consultants that preparatory efforts enhance success and minimize risk.”
And “…the literature provides strong evidence that specific strategies facilitate the management of the difficult airway “
Well, many Anesthesiologists have the option to “Abort” induction, or to work through a problem with as much assistance as needed.
In the REAL WORLD of EMS that is seldom the case.
However many of the BASIC principles are valid in the clinical evaluation of patients, and thus valuable in our education as medics.
Knowing these principles will improve our decision making process and Patient Care;.

19. Objectives Identify 4 areas of airway difficulty
Predict a difficult airway using the following mnemonics:
MOANS
LEMONS
DOA

20. Airway Difficulties Difficult to ventilate with a BVM
Difficult laryngoscopy
Difficult to intubate
Difficult to perform cricothyrotomy
The four dimensions of difficult airways.

21. Difficult to Bag (MOANS)
Mask Seal
Obesity or Obstruction
Age > 55
No Teeth
Stiff

22. MOANS Mask Seal Small Hands Wrong Mask Size Oddly Shaped Face
Bushy Beard
Blood/Vomit
Facial Trauma

23. Obesity or Obstruction
MOANS
Obesity or Obstruction
Obesity
Heavy chest
Abdominal contents inhibit movement of the diaphragm
Increased supraglottic airway resistance
Billowing cheeks
Difficult mask seal
Quicker desaturation
More dead space in cheeks
Lower residual volumes

24. Obesity or Obstruction
MOANS
Obesity or Obstruction
3rd Trimester Pregnancy
Increased body mass
Quick desaturation
Increased Mallampati Score
Gravid uterus inhibits movement of the diaphragm

25. Obesity or Obstruction
MOANS
Obesity or Obstruction
Obstructions
Foreign Body
Angioedema
Abscesses
Epiglottitis
Cancer
Traumatic Disruption/Hematoma/Burns

26. MOANS
Age > 55
Associated with BVM difficulty, possibly due to loss of tone in the upper airway

27. MOANS No Teeth Face tends to “cave in”
Consider leaving dentures in for BVM and remove for intubation

28. MOANS Stiff Refers to Poor Compliance Reactive Airway Disease COPD
Pulmonary Edema/Advance Pneumonia
History of Snoring/Sleep Apnea
Also predicts a higher Mallampati score

29. Difficult Laryngoscopy & Intubation
LEMONS
Look Externally
Evaluate 3-3-2
Mallampati Score
Obstruction
Neck Mobility
Scene and Situation

30. LOOK Externally LEMONS Beards or facial hair Short, fat neck
Morbidly obese patients
Facial or neck trauma
Broken teeth (can lacerate balloons)
Dentures (should be removed)
Large teeth
Protruding tongue
A narrow or abnormally shaped face

31. Any single indicator has poor specificity
LEMONS
EVALUATE 3-3-2
Bottom of Jaw/Chin to Neck > 3 fingers
Jaw/Palate > 3 fingers wide
Mouth opens > 2 fingers wide
Thyromental Distance
Measure from upper edge of thyroid cartilage to chin with the head fully extended.
A short thyromental distance equates with an anterior larynx that is at a more acute angle and also results in less space for the tongue to be compressed into by the laryngoscope blade.
> 7 cm is usually a sign of an easy intubation
< 6 cm is an indicator of a difficult airway
Relatively unreliable unless combined with other tests
Any single indicator has poor specificity

32. LEMONS EVALUATE 3-3-2 Mouth Opens at least 3 finger widths.
Three finger widths thyromental distance.
Two finger widths mandibulohyoid distance.

33. LEMONS
EVALUATE 3-3-2
Will patients mouth open wide enough to accommodate 3 fingers?
Will 3 fingers fit between the mentum and hyoid bone?
Will 2 fingers fit between the hyoid and thyroid notch?
If not, expect a difficult intubation

34. Mouth opens at least 3 fingers width?
LEMONS
Mouth opens at least 3 fingers width?

35. LEMONS Thyromental Distance
Distance from the mentum to the thyroid notch.
Ideally done with the neck fully extended. Can be done in-line
Helps determine how readily the laryngeal axis will fall in line with the pharyngeal axis.

36. LEMONS Thyromental Distance
If the thyromental distance is short, <3 finger widths, the laryngeal axis makes a more acute angle with the pharyngeal axis and it will be difficult to achieve alignment.
Less space to displace the tongue.

37. Thyromental Distance-3 fingers?
LEMONS
Thyromental Distance-3 fingers?

38. Mandibulohyoid Distance- 2 fingers?
LEMONS
Mandibulohyoid Distance- 2 fingers?
Measured from the mentum to the top of the hyoid bone.
The epiglottis arises from the thyroid and remains dorsal to the hyoid bone.
Therefore, the position of the hyoid bone marks the entrance to the larynx.

39. Mandibulohyoid Distance
LEMONS
Mandibulohyoid Distance

40. Mandibulohyoid Distance
LEMONS
Mandibulohyoid Distance
When the position of the hyoid bone is caudal or relatively caudal, a large portion of the tongue is situated in the hypopharynx instead of the mouth.
During laryngoscopy, this large hypopharyngeal tongue mass further compromises the compliance needed for its displacement

41. Mandibulohyoid Distance
LEMONS
Mandibulohyoid Distance
Patients who have a longer mandibulohyoid distance, greater then 2 finger widths, tend to be more difficult to intubate.
A more caudal hyoid bone thus indicates a relatively caudal larynx.

42. LEMONS Upper & Lower Face
Measure the size of the upper face as compared to the lower face.
Should be roughly the same.
If the lower face is longer than the upper face then you should anticipate some degree of difficulty lining up the structures.

43. Upper and lower face equal?
LEMONS
Upper and lower face equal?

44. Upper and lower face equal?
LEMONS
Upper and lower face equal?

45. LEMONS Mallampati Score

46. LEMONS Mallampati Score
Have patient sit up, and stick out tongue without phonating
May be unable to properly assess this in an emergent field situation
Modified version is to use a laryngoscope blade like a tongue blade to visualize the oropharynx – (not as sensitive or specific)

47. Mallampati Classification
LEMONS
Mallampati Classification
Relates to tongue size to pharyngeal size.
Performed with patient in a sitting position, head neutral, mouth open wide and tongue protruding to the maximum.
The Subsequent Classification is assigned based upon the pharyngeal structures visible.

48. Mallampati Classification
LEMONS
Mallampati Classification
Class I: Visualization of the soft palate, fauces, uvula, and anterior & posterior pillars

49. Mallampati Classification
LEMONS
Mallampati Classification
Class II: Visualization of the Soft palate, fauces and uvula.

50. Mallampati Classification
LEMONS
Mallampati Classification
Grade III: Visualization of the soft palate and the base of the uvula.

51. Mallampati Classification
LEMONS
Mallampati Classification
Grade IV: The soft palate is not visible at all.

52. LEMONS
Pt should be sitting, head in neutral position, mouth wide open, and tongue extended out as far as possible. The number classification is based on the structures that are visible.
A Class I view is a Grade I Intubation 99% of the time
A Class IV view is a Grade III or IV intubation 99% of the time
Class IV: <1% prevalence (hard palate only visible) Severe Difficulty Intubating
Class III: <13% prevalance (soft palate, base of uvula visible) Moderate Difficulty Intubating
Class II: 40% prevalence (soft palate, uvula, fauces visible) No Difficulty Intubating
Class I: 46% prevalence (soft palate, uvula, fauces, pillars visible) No Difficulty Intubating

53. Mallampati Classification
LEMONS
Mallampati Classification

54. LEMONS
Obstruction
Laryngoscopy or intubation may be more difficult in the presence of an obstruction
Anatomy
Trauma
Foreign body obstruction
Edema (burns)

55. Obstructions Laryngoscopic View Grades
LEMONS
Obstructions Laryngoscopic View Grades
Grade 1: Full aperture visible
Grade 2: Lower part of cords visible
Grade 3: Only epiglottis visible
Grade 4: Epiglottis not visible

56. Obstructions Laryngoscopic View Grades
LEMONS
Obstructions Laryngoscopic View Grades
Graded in order from the best view to worst.
Grade 1: Visualization of the entire laryngeal apeture

57. Obstructions Laryngoscopic View Grades
LEMONS
Obstructions Laryngoscopic View Grades
Grade 2: Visualization of just the posterior portion of the laryngeal aperture.
Grade 3: Visualization of only the epiglottis
Grade 4: Visualization of the soft palate only.

58. Obstructions Laryngoscopic View Grades
LEMONS
Obstructions Laryngoscopic View Grades
A severe grade III or IV view with failed endotracheal intubation occurs in % of patients

60. Cormack & Lehane Grading
LEMONS
Cormack & Lehane Grading
Grade I =  success & ease of intubation
10-30%
Grade I: full aperture is visible
Grade II: Lower portion of cords visible
Grade III: Epiglottis only visible
Grade IV: Epiglottis not visible
Grades III & IV are rare. So, if you frequently see Grade III or IV – consider revisiting your technique.
<5%
<1%
% listed = incidence

61. LEMONS
Neck Mobility
Ideally the neck should be able to extend back approximately 35°
Problems:
Cervical Spine Immobilization
Ankylosing Spondylitis
Rheumatoid Arthritis
Halo fixation

62. Scene and Situation (SEE)
LEMONS
Scene and Situation (SEE)
Scene safety
Environment
Do you have a reasonable chance to get the tube?
Space, positioning, access
Egress
Will you be able to ventilate during egress?
A respiratory rate of 4 is better than a rate of 0!
Enough meds for a long extrication?

63. Difficult Cricothyrotomy
DOA
Difficult Cricothyrotomy
DOA
Disruption or Distortion
Obstruction
Access Problems
If you can’t bag and can’t cric, they’re DOA

64. Disruption / Distortion
DOA
Disruption / Distortion
Distortion
Surgeries
Radiation Therapy
Scarring
Burns

65. Disruption / Distortion
DOA
Disruption / Distortion
Disruption
Hanging
Crush Injuries
Penetrating Trauma
Other Soft Tissue Trauma
Burns
Laceration

66. DOA Obstructions Hematoma Abscess Tumor
Tumors can also create distortions & extra bleeding

67. DOA Access Issues Obesity Halo Short neck SC Emphysema Bushy beard
Flexion deformity of the spine

68. “BURP” – a.k.a. “External Laryngeal Manipulation”
Backward, Upward, Rightward Pressure: manipulation of the trachea
90% of the time the best view will be obtained by pressing over the thyroid cartilage
90% of the time the best view will be obtained by pressing over the thyroid cartilage – because, anatomically, the vocal cords are connected here.
“BURP”-backwards, upwards, right, pressure
May help with difficult intubation
Differs from the Sellick Maneuver

69. To Summarize Airway assessment is a critical part of the RSI process
The difficult airway assessment must be performed prior to ALL RSI attempts.
While this criteria helps identify difficult airways, it does not guarantee an easy intubation—Be Prepared!