Airway Adjuncts/LMA Flashcards
When to use a supraglottic airway ventilation?
-Primary means of managing a difficult airway
-Rescue ventilation
-Failed intubation
-Alternative to ETT, in elective sx pts
-Conduit to facilitate endotracheal intubation
-Difficult facemask ventilation
Predictors for difficult SAD placement
-Restrictive mouth opening
-Distortion in the upper airway anatomy
-Both upper and lower airway obstruction
Which important assessment tool is considered when introducing any airway adjuncts in to the mouth?
Interincisor gap <4cm/three fingerbreadths
What physiological conditions may cause difficulty with some SAD placements?
-Reductions in atlanto-occipital joint movement d/t conditions such as anklyosing spondylitis and RA
-Obstructions at the larynx, trachea, or below can reduce or completely block ventilation from a SAD
What could cause the disruption and distortion in the upper airway anatomy and may make SAD placement difficult and lead to ineffective ventilation from a compromised “seat and seal?”
Upper airway lesions, such as oropharyngeal
____________________ or __________________ require higher ventilatory pressures to facilitate adequate gas exchange within the lungs.
Bronchospasm or Acute respiratory distress syndrome
Conditions affecting the _______________ airway results in decreases in pulmonary compliance or increases in airway ____________ can cause peak airway pressures to rise.
Lower; resistance
Which factors determine the selection of an airway adjunct for airway management?
1) The need for airway control
2) The ease of laryngoscopy
3) The ability to use supralaryngeal ventilation
4) Aspiration risk
5) The pt’s tolerance for apnea
Which 2 devices are truly supraglottic that sit above or surround the glottis?
LMA, facemask
Why are LMAs well tolerated?
They follow the same pathway as the airway, unlike laryngoscopy
Examples of LMA variations?
Flexible
ProSeal
Supreme
Fastrach
In what ways can the LMA be used in General anesthesia?
BMV
How is the LMA sized?
Pt’s Kg
Step 1 in LMA classic insertion technique
Deflating the cuff and placing a water soluble lubricant on its posterior surface
Step 2 in LMA classic insertion technique
Insert the LMA midline, with the posterior surface pressed flat against the palate of the mouth
Step 3 in LMA classic insertion technique
Then advance with the index finger along the palatopharyngeal curve
Success rate on the first attempt
88-95%
What should be done if the LMA encounters resistance when it reaches the posterior pharyngeal wall?
It is typically due to the distal tip folding back as a result of aggressive posterior pressure
——->
Retract the airway and advance again, applying more upward pressure toward the top of the patient’s head.
What should you do if the continued resistance occurs when placing LMA?
Place the R index finger b/w the superior portion of the LMA and the palate and “flip the tip” back in to the normal position while advancing the device with the opposite hand.
What is the position when the LMA is properly placed?
Final resistance denotes placement of the LMA’s tip in the hypopharynx, and the black line on the tubing will be even with the upper lip
Where is the LMA sealed after the cuff is inflated?
Over the larynx
What pressure should the LMA cuff not exceed?
60cmH20
The ______________ opening at the base of the hypopharynx has no seal
Esophageal
What happens if the LMA cuff is over inflated?
It can open the upper esophageal sphincter, or potentially cause posterior cricoarytenoid muscle fatigue
Alternative technique #1 for LMA placement
Introduced into the mouth with the opening initially facing the palate, advanced til it reaches the oropharynx, rotate 180 degrees counterclockwise, then advance to final position
Alternative technique #2 for LMA placement
Partial or fully inflate the LMA cuff with air before insertion
Alternative technique #3 for LMA placement
Guided technique using an Eschman stylet (bougie) or a laryngscope to facilitate placement
Which LMA is a variation of the LMA classic that utilizes a smaller diameter wire-inforced barre?
LMA Flexible
Indications of LMA Flexible
-Sx on the mouth, pharynx, face, or jaw, or any other procedure in which the head may be moved
-When drapes cover the patient’s face and head
-If the barrel cannot be secured at the midline
2nd gen SAD benefits
1) Attempts to reduce aspiration risk with additional channel
2) Reinforced tips that prevents folding
3) Better cuff seals with higher ventilation pressures
4) More rigid to prevent rotation and easier insertion
Examples of 2nd Gen SAD
LMA ProSeal (PLMA)
LMA Supreme
AuraGain
What is considered a 2nd Gen SAD, but is primarily used in the prehospital setting, and is not suitable as a conduit for TI?
King LTS-D
PLMA modifications compared to the LMA Classic
1) Large and deeper bowl w/ no grill
2) Posterior extension of the mask cuff
3) A gastric drainage tube, existing at the mask tip
4) Bite block
5) Anterior pocket for seating an introducer or finger during insertion
What is the benefit of the esophageal gastric drain tube on a PLMA?
Allows the practitioner to identify misplacement and decompress the patient’s stomach of air or solid contents, and may vent regurgitated stomach contents
In the PLMA, airway seal is improved by __________, allowing peak ventilation pressures up to ___________cmH20 (versus the 20cmH20 with the LMA Classic.
50%; 28-30cmH20
When has the PLMA been used?
Lap Sx (controversial)
Obese
ICU
Trauma
Difficult Airway populations
What SAD is a disposable version of the PLMA?
LMA Supreme
Peak ventilation pressures were slightly _________ in LMA Supreme when compared to PLMA.
Lower
This device occupies the entire hypopharynx and laryngopharynx
i-gel mask
T/F: The i-gel creates a noninflatable anatomical seal of the perilaryngeal structures while avoiding compression trauma, relies on contact with anatomical structures to create and effective seal for ventilation.
True
T/F: The channel of the i-gel CANNOT be used as a conduit for intubation under fiberoptic guidance.
False; It can be used
Proper placement of the i-gel provides what?
A good seal and effective ventilation
Benefits of the i-gel
Ease of insertion
High seal pressures
Lower incidence of sore throat
AuraGain key features
Gastric access port
Intubating capabilities
Bite block
AuraGain capabilities
Similar airway pressures
Ease of insertion
Successful insertion in children
What makes King LT different from other SADs?
It does not have a mask that covers the laryngeal opening.
One time use, with a double lumen tube with a large oropharyngeal balloon and a smaller esophageal balloon.
T/F: A single pilot balloon is used to inflate both balloons in the King LT when the device is situated in the airway.
True
What is the purpose of the large oropharyngeal balloon of the King LT?
-Isolates the oropharynx and nasopharynx from above
-Lifts the base of the tongue
What is the purpose of the distal esophageal balloon of the King LT?
It sits at the esophageal inlet and isolates the esophagus from below, providing a high-pressure esophageal seal
The King LT model has the capacity to achieve a ventilatory seal of _______cm H20 or higher.
30cmH20
