anesthesia machine Flashcards
anatomy of the cylinder valve
what to do if you open the cylinder and hear a hissing sound
- tighten connection
- if that doesn’t work, replace washer (gasket)
what happens if theres no cylinder or yoke plug present and check valve fails
gas that should be going to patient will exit anesthesia machine
MRI safe cylinder will have
two colors. most of tank is silver and top of tank is color of gas that it contains. has to be aluminum.
name 2 oxidizers
O2 and nitrous oxide
safety relief devices to prevent cylinder explosion include
-fusible plug that melts at elevated temperatures. typically made from woods metal (bismouth, lead, tin, cadmium- remember BLT with cheese)
-valve that opens at elevated pressurs
-frangible disc that ruptures under pressure
role of american society for testing and materials (ASTM)
sets standards for required components of anesthesia machine. standard document is ASTM F1850
role of FDA
created 1993 anesthesia machine pre use check out procedures
role of OSHA
sets standards for acceptable occupational exposure to volatile anesthetics
role of DOT
sets standards for compressed gas cylinders
(tests cylinder at 1.66 x PSI ex: O2 is 1900 PSI so is tested at 3,154 PSI)
USDOT requires the following info on the cylinder label (7)
- government agency (DOT)
- type of metal used to construct cylinder
- max filling pressure PSI
- serial number
- manufacturer
- owner
- date of last inspection
which pressure system does the O2 fail safe device reside in
intermediate pressure system
two components of the intermediate pressure system
- threshold alarm that sounds when O2 pipeline pressure falls between 28-30 PSI
- pneumatic device that reduces or stops the flow of N2O when the pressure in the O2 tank falls below 20 PSI (less O2 will put less pressure on the spring to keep it down and then it ultimately blocks flow of N2O)
2 types of O2 fail safe devices based on machine
- GE Datex Ohmeda- O2 falls below 20 PSI, N2O flow is not allowed
- Drager- as O2 pipeline pressure decreases, there is a proportionate decrease in N2O flow
How can you tell O2 pressure failure device is working?
If you d/c O2 when machine is on, N2O should stop before O2 goes to 0 and should be restored once O2 is re connected
can the O2 fail safe device detect a flow meter leak?
no, since it is up stream from the flow meters
the hypoxia prevention safety device on the gas machine will
limit the ratio of N2O to 3x O2 flow (O2 never drops below 25%)
compare and contrast O2 pressure failure device with hypoxia prevention safety device
describe link 25 (on GE datex ohmeda)
O2 and N2O flow meter are mechanically linked by a chain
-incorporates second stage regulator for N2O and O2 (pneumatic component)
-gear engages to ensure titrated gases adjust as needed
O2 ratio monitor controller (Drager)
-O2 and N2O are connected pneumatically
when can the proportioning devices not handle a hypoxic mixture?
- O2 pipeline cross over
- leaks distal to flow meter valves
- administration of a third gas (ex helium)
- defective mechanic or pneumatic components
describe annular space in flow meter
between indicator and flow meter wall
O2 flow meter is always furthest to the
right aka closest to the patient
4 types of flow meter floats and where to measure