Session 6: Ventilation Under Anesthesia Flashcards
3 types of ventilation
bag mask
LMA
ETT
most common situation for mask ventilation
mask induction
after IV induction but before intubation
over-sedated pts who go apneaic
failed itubation
any other unexpected apnea
advantage of mask ventilation
non-invasive
non-traumatic
disadvantages of mask ventilation
hands are not free
airway not protected
difficult on certain pts
limited to 20cmH2O
difficult in field avoidance cases
predictors of difficult mask ventilation
Obesity (can cause airway obstruct)
Overbite (prominent)
Facial hair/beard
Facial/neck trauma
Foreign body
Edentulous
Pharyngeal abscess or mass
Airway swelling
types of airway swelling
airway trauma
epiglottitis
burn pts
ludwig’s angina
anaphylaxis
Ludwig’s Angina
bacterial infection in the mouth that causes airway swelling
causes of ineffective mask ventilation
- poor mask seal/not enough pressure
- soft tissue airway obstruction
- too much pressure in circuit
- APL valve closed too much = hard to inflate lungs
how to improve mask ventilation
- use oral/nasal airway
- doing jaw thrust w/double handed masking technique
difficult mask ventilation protocol step 1
- properly positioned w/airway aligned
difficult mask ventilation protocol step 2
- if you cant mask, place oral/nasal airway
difficult mask ventilation protocol step 3
- perform double handed technique w/oral airway
- need additional person to squeeze bag
- if you dont have additional person, use ventilator
difficult mask ventilation protocol step 4
- if 2 hand mask fail, place LMA
Difficult mask ventilation protocol step 5
- if LMA doesnt work, 2 options
- if paralyzed w/Roc, try to intubate while assitant draws up reversing dose of sugammadex (16mg/kg)
- if not paralyzed, wake them up (let propofol wear off)
Ventilator setup during difficult mask protocol
pressure control ventilation
stay under 20cmH2O
Options for potential difficult mask ventilation and intubation
- awake intubation w/bronchoscope
- CPAP preoxygenation w/RSI
- emergency tracheotomy
LMA relieves
all airway obstruction
creates effective seal in pharynx
LMA vs Mask ventilation
LMA more effective and efficient
LMA accomplishes everything a mask can do but anesthetist has free hands
LMA advantages
- more effective ventilation
- great backup ventilation for difficult pts (rescue device)
LMA disadvantages
- doesnt protect airway
- limited to 20cmH2O
- cannot use volume control vent setting
Using ventilator w/LMA risks
higher risk for atelectasis
reduce risk by using pressure support ventilation or assist ventilation
LMA vs Intubation
- LMA is less traumatic
- LMA does not require muscle relaxants
- LMA lowers risk of laryngospasm
when do you place an LMA
for every general anesthetic unless LMA placement is contraindicated
Absolute contraindications for LMA
(FGPLVHDN)
Full stomach
GERD/Hiatal Hernia/pregnancy/neonates
Paralysis needed
Laparoscopic Surgery
Ventilator needed (pt not spontaneously breathing)
Higher airway pressure needed
Difficult intubation suspected
Neck/pharyngeal pathology
Full stomach pt examples
not NPO
gastroparesis (delayed emptying)
- narcotics, diabetes, ozempic, intense pain
bowel obstruction
types of pts w/decreased lower esophageal tone
GERD
hiatal hernia
pregnant
neonates
surgery types that require muscle paralysis
inner abdominal
laparoscopic
hip replacement
cardiothoracic
when is the ventilator required
Muscle relaxants used
Brain surgery
Cardiothoracic surgery
Clear liquid NPO
2 hrs
non-clear liquid NPO
4 hrs