why are flowmeter valves linked mechanically or pneumatically
so that O2 cannot be set below 25% with to the use of N2O
- ensures adequate % of O2 delivery
- No more than 70% N2O can be used
how does the flowmeter interlink mechanism function
- O2 spindle is connected to N2O spindle
- if you incres. N2O flow, O2 incre
- if incres. O2 flow; N2O wil not increas
- if decre N2O flow; O2 flow will not decr.
teeth: O2=29, N2O=14
- N2O knob spins 2.07 x’s per 1 O2 knob spin
what is Heat of Vaporization
the number of calories required at a specific temperature to convert 1 G of liquid to vapor
Describe the vaporizer flow pattern
FGF enters the vaporizer and pass through a filter
-a temp relief valve exist which will open is gas flow exceeds that which is required for trhe delivery of gas conc on dial
why do temperature compensating bypass valve exist
- they exist because temp changes are constant
- bypass valve will open and allow gas to bypass vaporizer chamber
Color coded Vaporizers
Halothane-red Isoflurane- purple Enflurane- orange Sevoflurane-yellow Desflurane- blue
What happens if the wrong agent is put in a Vaporizer
- HLH : higher VP agent in lower VP vaporizer chamber will deliver a higher conc
- LHL :lower VP agent in higher VP vaporizer chamber will deliver a lower conc
*if occur, must flush with 100% O2 and dry
what is a TEC 6 Vaporizer and how does it work
- made specifically for desflurane
- electrically heats to approx 39 degrees C
- pressurizes to approx 2atm
- controls amt desflurane output
Why is Desflurane different from most other gases
- VP is 3-4x’s that of other gases
- boils at approx 22.8 degrees C
- VP at room temp ( 20 deg C) is near 1 atm
- if not heated, the large amt required would cause excess cooling of vaporizer making conventional temp compensation mechanisim ineffective
How is CO2 eliminated from a breathing circuit
- high FGF
- or chemical neutralization
what are some Advantages of the Circle system
- help avoid anesthetic pollution in the OR
- avoid anesthetic wasting
- helps prevent loss of patient heat and humidity by the high FGFrequired by the mapleson circuits
What is an APL or Pop Off valve
- Allowable Pressure Limiting valve
- Valve that limits the amount of pressure inside the pts lungs during manuel/spontaneous ventilation.
how does an APL valve function
- turning the knob to the right (closing) increases the pressure going into pt
- turning to left decreases pressure
- if pressure reaches the setting of the APL knob, the valve opens and allows excess gas to escape to the scavenging system
- pressure gauge amt = PIP
- not used for mechanical vent (bypassed)
- leave open when not in use
What is the final product of CO2 neutralization
- carbonate
- water
- heat
what is Soda Lime and Baralyme absorbant Mess size
4 -8
what is Soda Lime method of hardness
- silica added
- minimizes dust formation
what is Baralyme method of hardness
bound water of crystalization
What is the Indicating dye for Soda Lime and Baralyme
Ethyl Violet
What is the Absorptive Capacity for soda lime
14- 23 L of CO2/ 100G granules
What is the Absorptive Capacity for Baralyme
9 - 18 L of CO2/ 100G granules
What are the Contents of Soda Lime
- sodium hydroxyde
- potassium hydroxide
- calcium hydroxide
What are the Contents of Baralyme
- calcium hydroxide
- barium hydroxide
what are the contents of Amsorb absorbent
- calcium hydroxide
- calcium chloride
- does not form compound A
How are Toxic compounds formed
- Sevoflurane interacts with strong bases in soda lime and baralyme
- it forms degradation products that are toxic in high conc.
- Compound A
