Airway Assessment Flashcards
Airway assessment: Should be conducted in a _______ and ______ fashion
thorough and systematic fashion
What does evidence say about airway exam techniques?
No single examination has emerged that has a consistently high sensitivity and specificity with minimal false positive or false negative reports
Research advocates for the use of __________
multiple airway tests
What does the mallampati classification allow us to determine? (2)
- Serves as a rough estimate of the tongue size relative to the oral cavity
- Provides an estimate of the relative visibility of the pharyngeal structures
Mallampati classification: A __________ may hinder the view of the larynx
disproportionately large tongue base
Describe how you should instruct the patient on how to preform the mallampati classification.
- Perform with patient in sitting position.
- Instruct patient to open mouth as wide as possible and stick their tongue out.
What should be avoided during the mallampati assessment?
Avoid phonation
What is the Intraclass Correlation Coefficient ICC?
Used to describe the degree to which individuals with a fixed degree of relatedness (e.g. siblings, anesthesia providers, etc.) resemble each other in terms of a quantitative trait.
What is sensitivity?
is the ability of a test to correctly identify those with the disease (true positive rate)
What is the specificity?
is the ability of the test to correctly identify those without the disease (true negative rate)
What is the Intraclass Correlation Coefficient (ICC) of the mallampatic?
0.31
Mallampati: Sensitivity _____%; Specificity _______%
Sensitivity 49%; Specificity 86%
When is the hard palate immobile?
Immobile during mastication, breathing and swallowing
What is the function of the soft palate? (3)
1) Prevents food from entering nasal passages; 2) With age the soft palate stretches and becomes more pliable; 3) the soft palate relaxes and may cause upper airway obstruction
What are the characteristics of the Mallampati Class I (3)?
Exposure of the:
- Soft palate
- Faucial pillars
- Entire uvula
What are the characteristics of the Mallampati Class II (3)?
Exposure of the:
- Soft palate
- -Faucial pillars
- Portion of the uvula
What are the characteristics of the Mallampati Class III (3)?
Exposure of the:
- Soft palate
- Base of the uvula
What are the characteristics of the Mallampati Class IV?
Exposure of the: Hard palate only
Practice examples
Slide 44
What is the airway opening assessment?
Defined as the maximal mouth opening and measured by the distance between upper and lower incisors
The airway opening should be at least __________.
3cm (2 full finger breadths)
What is the Intraclass Correlation Coefficient (ICC) of the oral opening?
0.93, excellent correlation
Oral opening: Sensitivity _____%; Specificity _______%
Sensitivity 46%; Specificity 89%
What is the thyromental distance assessment?
Defined as the distance from the mentum to the thyroid notch
What would be considered a challenging airway according to the thyromental distance?
- If less than 6cm (3 finger breadths) anticipate a challenging airway
- May also be challenging if >9cm
What is the Intraclass Correlation Coefficient (ICC) of the thyromental distance?
0.74
Thyromental distance: Sensitivity _____%; Specificity _______%
Sensitivity 20%; Specificity 94%
What is the Prognathism/Mandibular Protrusion Test?
Ability to protrude the lower jaw beyond the upper incisors (ULBT)
How many classifications of the Prognathism/Mandibular Protrusion Test
3
What is a normal Prognathism/Mandibular Protrusion Test?
Patient can protrude lower incisors anteriorly past the upper incisors and can bite the upper lip above the vermilion border
What is a intermediate Prognathism/Mandibular Protrusion Test?
Patient can move lower incisors in line with the upper incisors and bite the upper lip below the vermilion border, but cannot protrude lower incisors beyond
What is a abnormal Prognathism/Mandibular Protrusion Test?
Lower incisors cannot be moved in line with the upper incisors, and cannot bite the upper lip*
What is the Intraclass Correlation Coefficient (ICC) of the Prognathism/Mandibular Protrusion Test?
0.66
What is the Atlanto-Occipital Extension?
Measurement of patient angles in the sniffing position
What is the desirable result of Atlanto-Occipital Extension?
A greater degree of extension is desirable, normal head extension is 35 degrees
What is the Intraclass Correlation Coefficient (ICC) of Atlanto-Occipital Extension?
0.67
What does the Profile Classification/Mandibular Hypoplasia measure?
Measurement of retrognathia
What is the Intraclass Correlation Coefficient (ICC) of Profile Classification/Mandibular Hypoplasia?
0.58
What is ramus length?
Length of the jaw
What is the Intraclass Correlation Coefficient (ICC) of ramus length?
0.53
What is the oropharyngeal best view?
The best Mallampati view obtained using any and all means
What is the Intraclass Correlation Coefficient (ICC) of oropharyngeal best view?
0.49
What is the sternomental distance?
Less than 12.5cm my indicate difficults
What is sternomental distance reliability?
Poor indicator
Review additional factors:
Slide 50
What are some advantages of the artificial airways?
Creates a patent airway after loss of upper airway tone secondary to relaxation of the genioglossus muscle
What are the disadvantages to oral airways (2)?
- Awake or lightly anesthetized patient at risk for laryngospasm
- Nasal airways trauma may lead to epistaxis
What are some contraindications to artificial airway? (3)
- Contraindicated in anticoagulated patients
- Children with prominent adenoids
- Basilar skull fracture
What is an absolute contraindication to artificial airways?
Basal skull fracture, can end in brain
Nasal airway: How do you measure the device?
on the patient, Device should reach from the patient’s nostril to the earlobe or angle of the jaw
What should be done before inserting the nasal airway tube?
thoroughly lubricate the length of the device to minimize soft tissue trauma
How do you determine the appropriate diameter of the nasal airway device?
Examine patient’s nostrils
How is the nasal airway inserted?
Insert the airway perpendicular to the nostril with gentle pressure. If unable to pass, attempt placement through other nostril
How is an oral airway chosen?
Correct size is chosen by measuring the device against the patient’s head from the earlobe to the corner of the mouth
Why is measuring for the oral airway important?
Measuring is important. The flared ends of the airway must rest securely against the oral opening in order to remain secure
What are two methods for inserting an oral airway?
- Place oral airway in the mouth. Once contact is made with the back of the throat, rotate the airway 180 degrees.
- Use a tongue depressor to hold the tongue down and insert the airway right side up. This is the preferred method
What can happen with the 180 degree rotating airway method for inserting oral airway?
May cause trauma to roof of mouth
How does the head tilt and chin lift help with insertion?
Obtain an extended position
What is the components of the jaw thrust?
Grasp the angles of the lower jaw and lift with both hands on each side moving the jaw forward
Mastering the art of ________ is a hallmark of the anesthesia provider
mask ventilation
What is required for effective ventilation?
requires a tight seal and patent airway
What is the incidence of difficult BMV? Impossible BMV?
Incidence of difficult BMV has been described between 0.9% and 7.8% and the incidence of impossible BMV as 0.15%
What is the hand position for face mask ventilation?
C and E
What are some characteristics that can be indicative of a difficult BMV? (10)
- Mask seal impediments: facial hair, altered facial anatomy, edentulous, -NGT
- Upper airway obstructions
- Obesity: BMI >30kg/m2
- Pregnancy, esp. third trimester
- Elderly patients
- Mallampati scores of III or IV
- Short thyromental distance
- Snoring/OSA
- Poor lung compliance
What is the goal of the ASA closed claims projects?
The goal of the American Society of Anesthesiologists (ASA) Closed Claims Project is to identify major safety concerns, patterns of injury and strategies for prevention to improve patient safety.
The project consists of an in-depth investigation of approximately ______ closed insurance claims resulting from anesthetic mishaps
10,000
How is ASA data gathered for ASA closed claims?
Data is gathered in the form of detailed case summaries collected by ASA member anesthesiologists from insurance company claim files.
Most cases are from mishaps resulting in _______, as files in these cases contain the most extensive information
lawsuits
Review the database of the ASA closed claims.
Slide 68
What are the top three sentinel events associated with ASA closed claims?
Permanent brain damage (867), airway injury (581), difficult intubation (466)
Esophageal intubations have declined significantly since the adoption of _____________.
end tidal capnography
Inadequate oxygenation and ventilation have also declined with the adoption of _________ as a standard intra-operative monitor
pulse oximetry
ASA review: How many claims were reviewed
179 claims
ASA review: What was the setting of these claims?
87% of claims occurred in peri-operative setting; 13% occurred at outside locations
ASA review: Who was more likely to be subjects of claims outside the OR? (3)
more likely to be female, ASA I-II, and pts undergoing general, ortho or gyn/urologic surgery
________ or ________ occurred in more than half of the peri-op claims and ALL of the claims outside of the operating suite.
Death or brain damage
Review indications for intubation.
Slide 72
What are the characteristics of inability to oxygenate or ventilate?
SpO2 <90%, PaO2 <55mmHg, rising PaCO2, respiratory acidosis, mental status changes
What are the key steps to intubation preparation? (4)
- Assemble and check all equipment
- Calculate correct doses of medications and draw up medications
- Ensure appropriate IV access and flush fluid
- Optimize your intubating condition
What blade is most commonly used to learn intubation technique?
Macintosh
What blade had advantageous for anterior intubations?
Miller
What is the is the rule of thumb for determining ETT size in pedicatrics?
(Age/4) + 4 (uncuffed) OR (Age/4) + 3.5 (cuffed)
What is the equation for determining length of insertion of ETT?
Length of insertion = 3 x ID
What size ETT is appropriate for a premature neonate?
2.5-3.0 mm ID @ 8cm
What size ETT is appropriate for a FT neonate?
3.0 mm ID @ 10cm
What size ETT is appropriate for a 1-6 months?
3.5 mm ID @ 11cm
What size ETT is appropriate for a 6-12 months ?
4 mm ID @ 12cm
What size ETT is appropriate for a age 2 years old?
4.5 mm ID @ 13cm
What size ETT is appropriate for a 4 years old ?
5.0 mm ID @ 14cm
What size ETT is appropriate for a 6 years old ?
5.5 mm ID @ 15 cm
What size ETT is appropriate for a 8 years old ?
6.5 mm ID @ 16 cm
What size ETT is appropriate for an adults ?
7.0-8.0 mm ID
What is the optimal bed height for intubation?
Ensure bed is at a comfortable height – HOB at xiphoid process
What is the optimal patient position for intubation?
Patient aligned without lateral deviation of head or neck, Shoulders, head and neck supported, Extremities supported and secure
What does the sniffing position do?
Aligns the laryngeal, oral and pharyngeal axes
Most pediatric patients are, by virtue of their anatomy, already in the _______ .
sniffing position.
How do you preform the sniffing position?
- Neck flexed approximately 15 degrees
- Head hyperextended to maximum comfortable degree (may be done after induction)
- Elevate the patient’s head and extend the atlanto-occipital joint
- Allows for optimal visualization of the glottic opening
What is another name for sellick’s maneuver?
“cricoid pressure”
How do you instruct someone to preform the sellick maneuver?
Thumb and index finger of assistant apply downward pressure to the cricoid cartilage
“BURP (back upward right pressure)”
When do you apply cricoid pressure?
Begin applying pressure prior to administration of induction agents
When do you release cricoid pressure?
Do not release pressure until receiving confirmation that the airway has been secured
When is cricoid pressure usually used?
Used during rapid sequence induction (RSI)
What are the steps for RSI?
- Preoxygenate patient
- Assortment of blades and ETT prepared prior to induction
- Sellick’s maneuver applied by assistant
- Administration of induction agents, including rapid acting muscle relaxant (succinylcholine vs rocuronium)
Why is the sellick’s maneuver applied?
to avoid potential aspiration of gastric contents
RSI: Mask ventilation is ______
avoided
How are pts preoxygenated in RSI?
100% high flow (8-12 L) not bag mask
What is important to know about cricoid pressure in clinical practice?
literature suggest controversy over this benefits out weigh risks
What could happen if a patient vomits during cricoid pressure?
cricoid could rupture
In the pediatric population less than ________, the cricoid cartilage is the narrowest portion of the airway*
5 years
An ETT that passes thru the glottic opening may still have difficult passing the _________
cricoid cartilage
What can mucosal trauma from forcing the ETT lead to postop? 4
edema, stridor, croup or airway obstruction
Due to the chance of mucosal trauma from forcing the ETT into a pediatric patient, it is recommended for uncuffed ETTs or not inflating a cuffed ETT in peds ________.
< 5 years
What can external manipulation of the cricoid during intubation do the the vocal cords?
can alter the view of the vocal cords in both pediatrics patients and adults
