E2 - Breathing System I Flashcards
What are the six functions/definitions of the breathing system?
- Receives gas mixture from machine
- Removes CO2
- Delivers gas to the patient
- Provides heating and humidification of the gas mixture
- Provides gas sampling, measures airway pressure, and monitors the volume
- Allows spontaneous, assisted, or controlled respiration
What is considered apparatus dead space?
A. y piece to the patient + inspiratory limb
B. y piece and distal (towards patient)
C. y piece to the patient + insp and exp limbs
D. y piece and proximal (away from patient)
B. Y piece and distal
decrease apparatus DS by having y piece as close to pt as possible
what are the most distensible components of the breathing circuit? select 2.
A. reservoir bags
B. face mask
C. scavenging system
D. breathing tubes
A. reservoir bags
D. breathing tubes
compliance/distensibility helps determine Vt
What are the six desirable characteristics of a breathing circuit?
- Low resistance to gas flow
- Minimal rebreathing
- Removal of CO2 at rate of production
- Rapid changes in delivered gas when required
- Warmed humidification of inspired gas
- Safe disposal of waste gases
Name and Describe the four classifications of breathing circuits.
- Open - No reservoir bag and no rebreathing (nasal cannula)
- Semi-Open - Reservoir bag but no rebreathing d/t FGF > minute ventilation.
- Semi-Closed - Reservoir bag w/ partial rebreathing
- Closed- Reservoir bag and complete rebreathing, FGF equivalent to patient uptake
When would you want a closed breathing circuit?
- Conserve patient’s temperature
- Trying to be economical and not waste any gas
- Trying to perform low flow anesthesia
Name the components of the breathing system.
- Facemask, LMA, ETT
- Y-piece with mask/ tube connectors
- Breathing tube (corrugated tubing)
- Respiratory Valves (unidirectional)
- Fresh gas inflow site
- APL (Pop-off) Valve leading to scavenger
- CO2 absorption canister
- Reservoir Bag
The facemask needs to fit between the ____ and in the groove between the ____ and alveolar ridge.
- interpupillary line
- mental process
The facemask will connect to the Y-piece/connector, how big is the female connection?
- 22 mm
A fitting that joins together 2 or more components.
- Connectors/ Adapters
What are the benefits of connectors and adaptors?
- Extends the distance b/w patient and breathing system
- Change the angle of the connection
- Allow more flexibility/ less kinking (The accordion will give you the most flexibility)
What are the disadvantages of connectors and adaptors? select 2.
A. more distance between patient and breathing system
B. increases resistance and deadspace
C. more kinking of tubing
D. add’l locations for disconnections
E. less flexibility of tubing
B. Increased resistance + Increased dead space
D. Additional locations for disconnections
How long is the breathing tubing?
What is the internal volume of the breathing tubing?
- 1 meter in length
- 400-500 mL/meter of length
Flow is always ___ due to corrugation.
A. laminar
B. generalized laminar
C. turbulent
D. slow
C. Turbulent Flow
True/False: Breathing tubes connected together to increase tube length will increase dead space.
False; Longer tubes do not create deadspace
* Dead space is only from Y-piece and distal (towards patient) due to unidirectional gas flow
Pressure check the circuit before use. What value should this be?
- 30 cm H2O
How much of a normal Vt is anatomical deadspace?
150 mL
That is why we deliver at least 300 mL of tidal volume in simulation for adequate ventilation.
What directs respiratory gas flow in the correct direction?
Unidirectional valves
These unidirectional valves must open widely with very little pressure. Low resistance, high competence. Open/Close rapidly with no backflow.
The inspiratory valve opens on ____.
The inspiratory valve close on ____.
What does the inspiratory valve prevent?
- The inspiratory valve opens on inspiration.
- The inspiratory valve close on exhalation.
- Prevents backflow of exhaled gas
The expiratory valve opens on ___________.
The expiratory valve close on _________.
What does the expiratory valve prevent?
- The expiratory valve opens on exhalation.
- The expiratory valve close on inspiration.
- Prevents rebreathing
What composes the apparatus dead space?
- Distal limb of Y-connector
- Tube/mask/LMA
The unidirectional valves are located near what parts of the breathing system? select 3
A. CO2 absorber
B. O2 flush
C. fresh gas inflow site
D. flowmeters
E. APL valve
F. mask
A. CO2 absorber canister
C. Fresh gas inflow site
E. APL Valve
What are the 5 requirements of unidirectional valves?
- Arrows/ Directional words
- Hydrophobic - needs to repel water/moisture!!!
- Must open and close appropriately
- Clear dome - to visualize if valves are working
- Must be placed between patient and reservoir bag
Which unidirectional valve is more likely to be stuck? Inspiratory or Expiratory?
left from last years class
- The expiratory valve is more vulnerable because it is subject to greater moisture exposure.
Miller pg. 605
What are the 4 functions of the reservoir/breathing bag?
(1) Reservoir for anesthetic gases/oxygen
(2) A means of delivering manual ventilation or assisting spontaneous breathing
(3) Serving as a visual or tactile means of monitoring a patient’s spontaneous breathing efforts
(4) Partially protecting patient from excessive positive pressure in the breathing system.
What is the shape of the reservoir bag which makes it helpful for 1 hand ventilation?
A. ellipsoidal
B. circular
C. conical
D. spherical
A. ellipsoidal
How much volume is in a traditional reservoir bag for adults?
3 L
Can range from 0.5 to 6 L
All reservoir bags must have ___ mm female connector on the neck.
22 mm