Airway - LMA Flashcards
4 indications for LMA
- Use instead of mask
- Facilitate ventilation, intubation with difficult airway
- Ventilate for flexible bronchoscopy
- Avoidance of airway manipulation
what is important concept to know regarding LMAs and contraindications?
NOT an occlusive airway, will have leak so potential for aspiration
some advantages of LMA over mask?
hands free, better seal, easier to maintain, less facial nerve/eye injury
some disadvantages of LMA vs mask airway?
more invasive so more trauma, deeper anesthesia, TMJ has got to be mobile
5 potential complications of LMA?
Aspiration 1-2:10,000 Sore Throat (10%) Hypoglossal nerve injury Tongue cyanosis Vocal cord paralysis
what causes vocal chord paralysis with LMA use?
overinflating cuff, bad positioning
how much prop would you give for an LMA vs ETT
2.5 to 3, have to increase to surpress airway reflexes
what is obstruction after insertion of lma typically from?
down-folded epiglottis or transient laryngospasm
describe proper position of LMA
tip in esophagus, opening over trachea
the cuff occupies the entire hypopharynx and lies immediately behind the cricoid cartilage, anterior to the second to seventh cervical vertebrae
4 Complications of Malpositioned Supraglottic Airway Devices (LMAs)
ventilatory failure
airway trauma
nerve trauma
difficulties using LMA as intubation conduit
LMA size, cuff volume, ETT size for 30-50 kg pt
3
20 cc
6.0
LMA size, cuff volume, ETT size for 50-70 kg pt
4
30 cc
6.0
LMA size, cuff volume, ETT size for 70-100 kg pt
5
40 cc
7.0
LMA size, cuff volume, ETT size for >100 kg
6
50 cc
7.0
4 ways to intubate through LMA?
Use fiberoptic to visualize cords
Blindly insert smaller ETT (6.0) through LMA
Use intubating LMA (Fastrach) to insert larger ETT
Insert intubating stylet
Advanced LMA for tracheal intubation
Handle allows one hand insertion, removal
Comes in sizes 3, 4, 5 with max air volumes of 20, 30, and 40 ml respectively
Fastrach lma
[has the metal]
Has a separate lumen through which a gastric tube can be inserted to evacuate contents from the stomach
proseal lma
This lma allows for pos pressure ventilation and allows for lower PIP
Proseal lma
4 different ways to ventilate with LMA?
-spont ventilation
-cpap 3 cm
-pressure support with cpap
all showed no difference in sa02, map, bp
what does pressure support with cpap look like with lma
Lower ETCO2, slower respiratory rate, lower WOB, lower esophageal pressure, higher expired tidal volume
what should you avoid when cleaning lma’s?
basically everything but sodium bicarb solution and endozime
Two balloons, one 100cc in the oropharynx and one smaller (15cc) near the tip.
Two lumens – one straight used if tip in trachea; one with side perforations used if tip in the esophagus.
Esophageal-tracheal combitube
Alternative emergency airway
Allows ventilation whether the tip enters the esophagus or the trachea.
Esophageal-tracheal combitube
Considered Gold Standard for management of expected difficult airway
Fiberoptic intubation
why Fiberoptic intubation?
Airway tumors Infections Cervical spine fractures, instability Cervical spine fixation Conscious intubation Difficult intubation
what is an important step NOT to skip with fiberoptic intubation?
make sure to thread ETT over fiberoptic tube
why is nasal fiberoptic int better than oral?
straight shot to glottis
less gagging
cannot bite scope
compared to awake patients, asleep fiberoptic intubation patients
have greater chance of tongue and epiglottis blocking cords.
60o curvature
Can be used with patient in neutral position
Stylet needed
glidescope
Ideal when the 3 axis can’t be aligned.
glidescope
difference in inserting glidescope and mac/miller blade
insert glidescope at midline and others on right side
Rigid laryngoscope with fiberoptic capability
Can view cords without sniffing position.
Indicated for cervical immobility or instability
bullard laryngoscope
Lighted stylet which transilluminates the neck.
Used for routine and difficult intubations
light wand technique
Insertion of a guide wire through the cricothyroid membrane, through the mouth over which the ETT is inserted.
retrograde intubation
what is jet ventilation?
Temporary oxygenation
14g or larger IV catheter inserted through the cricothyroid membrane
what is important to remember with jet ventilation?
Ventilate 6-8 breaths/min; I:E 1:4 and long expiratory phase to allow emptying
describe oxygenation/ventilation with jet ventilation
good oxygenation, bad ventilation
what does increase in intrathoracic pressure with jet ventilation cause
decreased venous return, decreased cardiac output, increased intracranial pressure
Complications jet ventilation
air entrapment, pneumothorax, bleeding, thyroid gland puncture, esophageal perforation, subcutaneous emphysema
most important thing Dr C said to remember about difficult airway?
call for help, no more than 2 more passes
