Breathing Circuits and Airway Flashcards
breathing systems
-
circle system
- rebreathing system (recycled)
- non-rebreathing system
circle system
-
unidirectional valves
- inspiratory
- expiratory
- canister with absorber
- breathing bag
- rebreathing tube
- pressure gauge
- pop off valve
most common type of failure in circle system
- failure of expiratory valve
- air from expiratory limb will be breathed in too-rebreathing
unidirectional valves
- allow flow only in one direction
- no rebreathing of CO2
- may stick with moisture (esp expiratory)
- may dislodge from housing
breathing tubes
- corrugated-prevent kinking
- transparent plastic
- light (less drag)
-
adult and pediatric size
-
two limbs
- expiratory and inspiratory
-
coaxial (F system)
- inside-inspiratory
- outside-expiratory
-
two limbs
breathing bag in circle system
- used as a reservoir
- 6x the Vt
- used to deliver breaths manually
- can be used to count RR
- some protection against excessive pressure
checking for leaks in circle system
- canister
- unidirectional valves
- reservoir bag
- hoses
- connections
**close pop off valve to check**
advantages of circle system
- rebreathing of expired gas after elimination
- keep heat and moisture
- more economic
- less O2 and inhalant
-
lower O2 flows
- less environmental contamination
disadvantages of circle system
- lots of parts
- more likely to leak
- difficult to clean
- not easily moved
-
controlled ventilation
- hypocarbia
non-rebreathing systems
- elimination of CO2 by high O2 flow
- usually patient <3kg
-
high O2 flows
- 100-200 mLs/kg (very wasteful)
- different systems
- Bain system (most used)
check for leaks in non-rebreathing system
- close pop-off valve
- put thumb on the patients end of the breathing hose (prevents dust from going into bag)
- press flush valve until pressure gauge reads 30 cmH2O
- pressure should hold
- press flush valve
- patient’s end of breathing hose open
-
reservoir bag
- will deflate (inspiratory hose intact)
- if inflates = leak in inspiratory hose
advantages of non-rebreathing system
- light
- simple
- low resistance
- no need for absorber
- fast change in depth (very little volume)
- inexpensive
disadvantages of non-rebreathing system
- wasteful
- loss of heat and moisture
- pollution
-
changes in EtCO2 and gas analyzer readings
- lower than it should be
PEEP
positive end expiratory pressure
doesn’t let lung collapse at end of expiration
anti-PEEP valve
anything over 20, valve releases into environment
safety mechanism
laryngoscope
allows you to visualize the throat
can push tongue down to exposure epiglottis and trachea
light source
endotracheal tube
cm size = diameter
radiopaque-visualized on xrays
laryngeal anatomy
- epiglottis
- arytenoids
- soft palate
verify that the endotracheal tube is in
- see it pass the vocal folds
- arytenoids bilaterally
- capnography (CO2 in stomach)
- auscultation of both lungs
- palpate neck: two tubes?
- air movement (or reservois bag movement)
complications of endotracheal intubation
-
esophageal intubation
- gastric distention
- no delivery of gas to lungs (hypoxia)
- patient will wake up
- occluded tubes
- bitten and inhaled tubes
- bronchial intubation
laryngospasm
- can occur at intubation or extubation
- humans, cats, pigs
- use local anesthetic before intubation
cuff inflation steps
- place tube on the trachea
- tip at inlet of chest
- connect syringe to pilot balloon
- place your ear close to animals mouth
- close pop off valve and hold pressure
- 10-15 cmH2O in cats
- 15-20 cmH2O in dogs
- add as little air as possible
- just enough to stop air leak
- open pop off valve
