Dfficult Airway

Question 1

What should you check before you administer a neuromuscular blockade

Answer 1

One should not administer a neuromuscular blocking medication to a patient unless one has a measure of certainty that oxygenation can be maintained if laryngoscopy and intubation fail

This is why it is so important to determine whether or not an airway will be difficult

Question 2

CICO=Cant Intubate Cant Oxygenate

Answer 2

Failure to maintain acceptable oxygen saturation during or after one or more failed laryngoscope attempt

Question 3

A failed airway exists when any of the following conditions is met:

Answer 3

Failure to maintain acceptable oxygen saturation during or after one or more failed laryngoscopic attempts (CICO) or

Three failed attempts at orotracheal intubation by an experienced intubator, even when oxygen saturation can be maintained or

The single “best attempt” at intubation fails in the “Forced to Act” situation

Question 4

Forced to Act Scenario

Answer 4

Airway difficulty is apparent, but the clinical conditions (e.g., combative, hypoxic, and deteriorating patient) force the operator’s hand, requiring administration of RSI drugs in an attempt to create the best possible circumstances for tracheal intubation, with immediate progression to failed airway management if that one best attempt is not successful

Question 5

Clinically, the failed airway presents itself in two ways, dictating the urgency created by the situation:

Answer 5

1. Can’t Intubate, Can’t Oxygenate: There is not sufficient time to evaluate or attempt a series of rescue options, and the airway must be secured immediately because of an inability to maintain oxygen saturation by BMV or with an EGD.
2. Can’t Intubate, Can Oxygenate: There is time to evaluate and execute various options because the patient is oxygenated.

Question 6

Specificity and Sensitivity in Regards to Difficult Airways

Answer 6

We value sensitivity (i.e., identifying all those who might be difficult) more than specificity (i.e., always being correct when identifying a patient as difficult).

Just because you have anticipated that an airway will be difficult to manage does not mean that it actually will be

Conversely just because you think an airway will be easy to manage does not mean that it will be

Question 7

BMV-Golden Rules

Answer 7

Manual ventilation skill with proper equipment is a fundamental premise of advanced airway management

Anybody (almost) can be oxygenated and ventilated with a bag and a mask

The art of bagging should be mastered before the art of intubation

Question 8

Acroymn for Difficult BMV

Answer 8

MOANS

Mask Seal

Obesity/Obstruction

Age

No Teeth

Stiff/Snoring

Question 9

MOANS

M-Mask Seal

Answer 9

Bushy beards, trauma (blood/debris on the face) are the most common examples of conditions that will make mask seal difficult

KY Jelly can be used to help, however it may only makes it worse as the face may become more slippery

Both male sex and a Mallampati class 3 or 4 airway appear also to be independent predictors of difficult BMV.

Question 10

MOANS

O-Obesity

Answer 10

If a patient has a BMI > 26 or are pregnant they can be hard to BMV due to the increased weight of the chest which will decrease diaphragmatic excursion

Obese patient will have redundant tissue which will increase resistance and affect patency of airway

Pregnant or obese patients also desaturate more quickly, making the bag ventilation difficulty of even greater import

Question 11

MOANS

O-Obstruction

Answer 11

Obstruction can also be caused through angioedema, Ludwig angina, upper airway abscesses, epiglottitis

In general, soft tissue lesions (e.g., angioedema, croup, and epiglottis) are amenable to bag and mask rescue if obstruction occurs, but not with 100% certainty.

Similarly, laryngospasm can usually be overcome with good bag and mask technique.

Firm, immobile lesions such as hematomas, cancers, and foreign bodies are less amenable to rescue by BMV, which is unlikely to provide adequate ventilation or oxygenation if total obstruction arises in this context.

Question 12

MOANS

N-No Teeth

Answer 12

Try to start with teeth in unless they are loose

Without teeth/dentures the face (cheeks) tend to cave in making it harder to get a seal

Gauze dressings may be inserted into the cheek areas through the mouth to puff them out in an attempt to improve the seal.

Question 13

MOANS

S-Stiff/Snoring

Answer 13

Patients with reactive airway diseases with medium and small airway obstructions (asthma and COPD) and those with pulmonary edema, ARDS, advanced pneumonia, or other conditions that reduce pulmonary compliance or increase resistance

These patients will require high ventilation pressures

A history of snoring and sleep apnea predicts difficult BMV

This may not be detectable in the emergency setting as it requires historical information

Question 14

Difficult Laryngoscopy and Intubation Algorithm

Answer 14

LEMON

Look Externally

Evaluate 3-3-2

Mallanpati Score

Obstruction/Obesity

Neck Mobility

Question 15

LEMON

Look Externally

Answer 15

DCAP BLS TIC

If the airway looks difficult then it probably is

Question 16

DCAP BLS TIC

Answer 16

Deformities, contusions, abrasions, penetrations, burns, lacerations, swelling, tenderness, instability, crepitus

Question 17

LEMON

Evaluate 3-3-2: What is the 1st three assessing

Answer 17

Assessing Adequacy of Mouth Opening

The mouth must open adequately to permit visualization past the tongue when both the laryngoscope blade and the endotracheal tube are within the oral cavity.

A normal patient can open his or her mouth sufficiently to accommodate three of his or her own fingers between the upper and lower incisors

The mandible must be large enough to allow for the tongue to be displaced

The glottis must be located a sufficient distance to the base of the tongue in order to create a direct line of sight from the outside of the mouth to the vocal cords

Question 18

LEMON

Evaluate 3-3-2: What is the 2nd three assessing

Answer 18

The second 3 looks at the length of the mandibular space by seeing if the patient can place three of their fingers between the tip of the mentum and chin neck junction (hyoid bone)

A thyomental distance of <6 cm is consider to be associated with a difficult intubation

Assess the dimensions of the mandibular space to accommodate the tongue on laryngoscopy

The mandible must be of sufficient size (length) to allow the tongue to be displaced fully into the submandibular space.

Encroachment on the submandibular space by infiltrative condition such as Ludwig Angina will be identified during this evaluation

Question 19

LEMON

Evaluate 3-3-2: What is the 2nd three assessing

Can Accomdate more then 3 fingers

Answer 19

If can accommodate more than three fingers it means that the oral axis is elongated

Question 20

LEMON

Evaluate 3-3-2: What is the 2nd three assessing

Can Accomdate less then 3 fingers

Answer 20

If can accommodate less than three fingers then the mandibular space may be too small to accommodate the tongue requiring it to remain in the oral cavity or move posteriorly obstructing the view of the glottis

Question 21

Ludwig Angina

Answer 21

Ludwig angina is a type of bacterial infection that occurs in the floor of the mouth, under the tongue. It often develops after an infection of the roots of the teeth (such as tooth abscess) or a mouth injury

Question 22

LEMON

Evaluate 3-3-2: What is the 2 assessing

Answer 22

The “2” assesses the position of the glottis in relation to the base of the tongue. The space between the chin–neck junction

The glottis must be located a sufficient distance caudad to the base of the tongue that a direct line of sight can be created from outside the mouth to the vocal cords as the tongue is displaced inferiorly into the submandibular space.

Question 23

LEMON

Evaluate 3-3-2: What is the 2 assessing

If more than 2 fingers

Answer 23

If significantly more than two fingers are accommodated, meaning the larynx is distant from the base of the tongue, it may be difficult to reach or visualize the glottis on direct laryngoscopy.

Question 24

LEMON

Evaluate 3-3-2: What is the 2 assessing

If less than 2 fingers

Answer 24

Fewer than two fingers may mean that the larynx is tucked up under the base of the tongue and may be difficult to expose. This condition is often imprecisely called “anterior larynx.”

Question 25

LEMON

Mallampati Score

Answer 25

Reflects the relationships among mouth opening, the size of the tongue, and the size of the oral pharynx, which defines access through the oral cavity for intubation, and that these relationships are associated with intubation difficulty.

By itself, the scale is neither sensitive nor specific; however, when used in conjunction with the other difficult airway assessments, it provides valuable information about access to the glottis through the oral cavity.

Question 26

Measureing Mallampati Score

Answer 26

Mallampati determined that the degree to which the posterior oropharyngeal structures are visible when the mouth is fully open and the tongue is extruded as far as possible, without phonating

In emergency situations it tends to not be possible to have the patient sit up and follow instructions

A crude mallampati score can be taken by examining the patient in a supine, obtunded patient mouth with a tongue blade and light, or by using a lighted laryngoscope blade as a tongue depressor to gain an appreciation of how much mouth opening is present (at least in the pre-paralyzed state) and the relationship between the size of the tongue and that of the oral cavity.

Although not validated in the supine position using this approach, there is no reason to expect that the assessment would be significantly less reliable than the original method with the patient sitting and performing the maneuver actively.

Question 27

Mallampati Score

Grade Two

Answer 27

Can see the soft palate, uvula faucets, the uvula is closer to the tongue

Pillars are not visible

No difficultly anticipated

Question 28

Mallampati Score

Grade One

Answer 28

Can see the soft palate, uvula faucets, and pillars

No difficulty anticipated

Question 29

Ludwig Angina

Answer 29

Bacterial infection that occurs in the floor of the mouth, under the tongue.

It often develops after an infection of the roots of the teeth (such as tooth abscess) or a mouth injury

Question 30

4 Cardinal Signs of Airway Obstruction

Answer 30

The above 4 signs should always be considered when you are extubating a patient

1. Muffled (hot potato voice)
2. Difficulty swallowing secretions- May be due to pain or obstruction
3. Stridor
4. Sensation of dyspnea

The first two signs do not ordinarily herald imminent total upper airway obstruction in adults, but critical obstruction is much more imminent when the sensation of dyspnea occurs

Question 31

Stridor

Answer 31

Particularly inspiratory

Ominous sign

The presence of stridor is generally considered to indicate that the airway has been reduced to <50% of its normal calibre, or to a diameter of 4.5 mm or less.

Question 32

LEMON

O-Obesity/Obstruction

Answer 32

Upper airway obstruction is a marker for difficult laryngoscopy

Although it is controversial whether obesity per se is an independent marker for difficult laryngoscopy or whether obesity simply is associated with various difficult airway attributes, such as high Mallampati score or failure of the 3-3-2 rule

Question 33

LEMON

N-Neck Mobility

Answer 33

• C-spine mobility is assessed through measuring distance from the lower border of mandible to thyroid notch at full neck extension
  
  • Distance should be 4 fingers in adults
• Cervical spine immobilization by itself may not create a degree of difficult, but it can compound the effects of other identified difficult airway markers
• Intrinsic cervical spine immobility (ankylosing spondylitis or rheumatoid arthritis) can make direct laryngoscopy very difficult or impossible and is more difficult than a cervical collar

Question 34

Way to Deal Neck Mobility with Direct Laryngoscopy

Answer 34

Video laryngoscopy requires much less (or no) head extension, and provides a glottic view superior to that by direct laryngoscopy when head extension or neck flexion is restricted.

Other devices, such as the Airtraq or the Shikani optical stylet, also may require less cervical spine movement than direct laryngoscopy.

Question 35

Difficuly Extraglottic Device Acroynm

Answer 35

RODS

Restricted Mouth Opening

Obstruction

Disruption or Distorted Airway

Stiff Lungs OR Cervical Spine Precautions

Question 36

RODS

Restricted Mouth Opening

Answer 36

Adequate mouth opening is required for insertion of the EGD.

This requirement varies, depending on the particular EGD to be used.

Question 37

RODS

O-Obesity/Obstruction

Answer 37

Upper airways obstruction may make EGD impossible to insert and seat properly as it may not be able to bypass the obstruction to achieve ventilation and oxygenation

Redundant tissues in the pharynx may make placement and seating difficult (this is usually not a significant problem)

Higher ventilation pressures are needed due to the weight of chest wall and abdominal contents

Question 38

How does obesity affect manual ventilation

Answer 38

Higher ventilation pressures are needed due to the weight of chest wall and abdominal contents

This will cause resistance to ventilation by increasing the pressures that are needed to expand the chest

The abdominal contents will affect the ability of the diaphragm to descend

Question 39

What position should you place an obese patient in for ventilation

Answer 39

It is better to attempt ventilation with the patient 30° head up or in reverse Trendelenberg position

Question 40

RODS

Disruption or Distorted Airway

Answer 40

The key question here is, “If I insert this EGD into the pharynx of this patient, will the device be able to seat itself and seal properly within relatively normal anatomy?”

For example, fixed flexion deformity of the spine, penetrating neck injury with hematoma, epiglottitis, and pharyngeal abscess each may distort the anatomy sufficiently to prevent proper positioning of the device.

Question 41

RODS

S-Stiff Neck or Cervical Spine Precautions

Answer 41

Stiff lungs are the same as in MOANS mnemonic and is the intrinsic resistance to ventilation

Ventilation with an EGD may be difficult or impossible in the face of substantial increases in airway resistance (e.g., asthma) or decreases in pulmonary compliance (e.g., pulmonary edema).

Question 42

Difficult Cricothyrotomy

Mneumonic

Answer 42

S.H.O.R.T

Surgery

Hematoma

Obesity/Access

Radiation Distortion

Tumors

Question 43

Difficult Cricothyrotomy

Absolute Contraindications

Answer 43

There are no absolute contraindications to performing an emergency cricothyrotomy

Question 44

SHORT

S-Surgery

Answer 44

Can be recent or remote

The anatomy may be subtly or obviously distorted, making the airway landmarks difficult to identify

Scarring may fuse tissue planes and make the procedure more difficult.

Recent surgery may have associated edema or bleeding, complicating performance of the procedure.

Question 45

SHORT

H-Hematoma

Answer 45

A hematoma, abscess, infection, or other mass may make the procedure difficult to locate landmarks for the operation

Question 46

SHORT

O-Obesity

Answer 46

Obesity, Subcutaneous emphysema, soft tissue infection, or edema can make surgical access challenging

A patient with a short neck or overlaying mandibular pannus will present a challenge in identifying landmarks and access

Question 47

SHORT

R-Radiation Distortion

Answer 47

May result in distortion and scar tissue which will make the procedure difficult as normally separate tissues will bond together distorting tissue planes and relationships

Question 48

SHORT

T-Tumors

Answer 48

Tumor, either inside the airway (beware of the chronically hoarse patient) or encroaching on the airway, may present difficulty, both from access and bleeding perspectives.

Will be highly vascular so if you cut it then it may lead to hemorrhage

Question 49

What are some ways to get a better view of larynx

Answer 49

Elevate the head

Apply Cric Pressure

Question 50

Cormack and Lehane Laryngeal View

Answer 50

Provides a view of the larynx during a laryngscopy

Grade 1 is the best and grade 4 is the worst

Question 51

Cormack and Lehane Laryngeal View

Grading

Answer 51

Grade 1: Visualization of entire glottic aperture

Grade 2: Visualization of posterior portion of the cords or arytenoids. Can be further divided into Grade 2a/2b

Grade 3: Only the epiglottis is visible

Grade 4: No glottic structure are visible

Question 52

What is the most important question when intubation is indicated

Answer 52

When intubation is indicated, the most important question is, “Is this airway difficult?”

The decision to perform RSI, for example, is based on thorough assessment for difficulty (LEMON, MOANS, RODS, and SMART) and appropriate use of the main or difficult airway algorithms.

Question 53

What order difficult airway mneumonic should be assessed

Answer 53

If LEMON and MOANS are performed first, in order, then each component of RODS also has been assessed, with the exception of the D: distorted anatomy.

In other words, if LEMON and MOANS have identified no difficulties, then all that remains for RODS is the question: “If I insert this EGD into the pharynx of this patient, will the device be able to seat itself and seal properly within relatively normal anatomy?”

Question 54

Assessment and Guarantee of Airway Success

Answer 54

No single indicator, combination of indicators, or even weighted scoring system of indicators can be relied on to guarantee success or predict inevitable failure for oral intubation.

Application of a systematic method to identify the difficult airway and then analysis of the situation to identify the best approach, given the anticipated degree of difficulty and the skill, experience, and judgment of the individual performing the intubation, will lead to the best decisions regarding how to manage the particular clinical situation.

In general, it is better to err by identifying an airway as potentially difficult, only to subsequently find this not to be the case, than the other way around.

Question 55

MOANS

A-Age

Answer 55

>55 years old can increase difficult BMV, which is thought to be a result of loss of elasticicty and muscle tone in the upper airway