exam 3 part 1 Flashcards
ANESTHESIA BREATHING MACHINE and SUPPLY
WHAT IS THE COMMON USE OF AN E CYLINDER
as a portable oxygen tank, particularly as a backup supply on the anesthesia machine, during patient transport, and in emergency situations
Size values of general E cylinder
height, diameter, weight
26 inches tall and 4.25 inches in diameter. When empty this cylinder weighs 14 lbs
WHAT IS THE COMMON USE OF AN H CYLINDER
is most commonly used to store and deliver a large volume of medical oxygen, serving as a central oxygen supply for patients
Size values of general H cylinder
height, diameter, weight
51 in tall, 9.25 inches in diameter, When empty this cylinder weighs 119lbs
ORGANIZATIONS THAT REGULATE MEDICAL COMPRESSED GASES
DOT - department of transportation
FDA - food and drug administration
CGA - the compressed gas association
NFPA - national fire protection association
ASME - american society of mechanical engineers
what does the DOT regulate
the manufacture, filling, labeling, inspection, storage, and transportation of cylinders
what does the FDA regulate
the quality and purity of the medical gas contents
DOT standards that must be met
need to find this
FDA standards that must be met
need to find this
OXYGEN E CYLINDER FACTS
color, PISS, capacity, psig, critical temp
green
2,5
660L
1900 psig
-119
NITROUS OXIDE E CYLINDER FACTS
color, PISS, capacity, psig, critical temp
blue
3,5
1590 L
745psig
36.5
AIR E CYLINDER FACTS
color, PISS, capacity, psig, critical temp
yellow
1,5
625L
1900 psig
-140
CARBON DIOXIDE COLOR
grey
NITROGEN E CYLINDER COLOR
black
HELIUM COLOR
brown
relationship between pressure and volume with gas (oxygen and air)
varies directly
relationship between pressure and volume when stored as gas and liquid (N2O)
pressure remains constant until liquid all vaporized
what law/formula is used to calculate pressure and volume changes for an oxygen tank at a constant temperature
Boyle’s Law
P1V1=P2V2
if N2O tank is partially full at 1000L what is the psig
745psig
How to determine volume of nitrous in the E cylinder
you have to weigh it and subtract the current weight from the ‘tare weight’ (empty cylinder weight) that is stamped on the outside of the tank
critical temperature
The critical temperature of a substance is the temperature at and above which vapor of the substance cannot be liquefied, no matter how much pressure is applied
structure and function of cylinder valves
designed to control the flow of gas from a pressurized cylinder, typically featuring a threaded stem with a hand-wheel to open and close the valve, a pressure seal to prevent leaks, and often incorporating safety features like pin index connections to ensure proper equipment compatibility; its primary function is to allow controlled release of a gas from the cylinder while preventing accidental mixing with other gases due to its unique design and connection type
structure and function of cylinder outlet ports
allows for the secure attachment of oxygen delivery devices, such as nasal cannulas or oxygen masks, to an oxygen source. These ports typically come in standardized sizes and shapes to ensure compatibility with various oxygen delivery systems.
structure and function of cylinder pressure relief devices
(3 types)
frangible disc - bursts
fusible plug - melts
valve - opens
yoke connectors for cylinders
The yoke assembly is made up of a yoke block, yoke screw, and pin index system. The yoke block is attached to the regulator or device and contains a hole with a specific number of pins arranged in a specific pattern. The yoke screw is used to secure the gas cylinder to the yoke block.
6 rules for cylinder handling
do not oil valves
protect the valve when transporting
turn valve off with no more force than necessary to seal
no temperature above 125 F or below 20F
never stand upright without support
never drop, drag or roll
rules for storage of cylinders
do not store multiple cylinders in a small closed space in case of a leak
- combustion and suffocation risk
separate full and empty cylinders clearly
MRI SAFE OXYGEN CYLINDERS ARE
silver body and green top
how is medical Air sourced
by air compressors that dry, filter, and compress ambient air to fill medical air pipeline (location of this compressor is important)
COMPONENTS OF A MEDICAL GAS PIPELINE FOLLOW THE ______MODEL
SPDD MODEL
S - SUPPLY
site- back of the machine
pipeline: wall outlets, connecting valves and hoses, filters and check valves, pressure gauges
cylinder: hanger yokes, filters and check valves, pressure gauge, pressure regulators
P-PROCESSING
site- within machine proximal to common gas outlet
fail-safe, flowmeters, oxygen flush, low oxygen pressure alarms, ventilator-driving gas, hypoxic guard, oxygen second-stage regulator, vaporizer, check valve distal to vaporizer, common gas outlet
D- DELIVERY
site- breathing circuit
gas delivery hose connecting CGO to breathing circuit, breathing circuits (circle and nonrebreathing), CO2 absorption, ventilators, monitors (oxygen analysis, disconnection, spirometry), ventilator alarms, addition of PEEP, means of humidification
D-DISPOSAL
site- scavenger
scavenger systems:
Interface (closed or open, active or passive)
scavenger flowmeter
components of the high pressure pneumatic system
hanger yoke, yoke block with check valve, cylinder pressure gauge, cylinder pressure regulator
components of the intermediate pressure pneumatic system
pipeline inlets, check valves, pressure gauges, ventilator power inlet, oxygen pressure-failure devices, flowmeter valve, oxygen second stage regulator, flush valve
components of low pressure pneumatic system
flowmeter tubes, oxygen proportioning system, vaporizers, vaporizer mannifold, check valves, common gas outlet
who published guidelines for pipeline systems
NFPA
CGA
PIPELINE SYSTEMS DELIVER GAS AT INTERMEDIATE PRESSURE WHICH IS ______PSIG
50-55 PSIG
PIPELINES SAFETY SYSTEMS INVOLVE THE _________ AND ________
DISS (diameter index safety system) and quick coupler system
high pressure system psig
above intermediate, example is psig of the cylinders 45-2200psig
Low pressure ssytem psig
below intermediate 14.7 (1 atm) (760mmHg)
a group of gas cylinders connected together to act as a central storage unit, supplying pipeline gas by feeding the gas from the cylinders through a manifold system into a pipeline network, which then distributes the gas to various points of use, essentially acting as a backup or supplemental source of gas when the main pipeline supply might be insufficient or unavailable
cylinder bank
advantages to storing oxygen as a liquid
greater storage capacity in a smaller space, easier transportation due to lower weight, longer duration of supply compared to gas cylinders, and often a higher purity level; making it a cost-effective and efficient option for high oxygen demand situations within healthcare facilities
disadvantages of storing liquid oxygen
liquid oxygen is stored at what temp
-150 to -175 C in a large flask
proportioning systems
mixes O2 and N2
each anesthetizing location must have a ________ for each gas
ICU and PACU have zone specific ones as well
shut off valve
shut off valves in OR
typically individual, color-coded, manually operated valves located within a recessed panel usually near patients head or where gases are delivered to system, accessible by removing a cover plate
An on/off switch in a pneumatic system …
acts as a primary control to manually start or stop the flow of compressed air within the system, essentially turning the system on or off by allowing or blocking air supply to the pneumatic components, like actuators or cylinders, depending on the switch position; essentially acting like a tap to control the air flow.
All the possible upstream entry points of compressed gas into the high pressure systems
the connections on the gas cylinders at the central gas supply manifold and the backup O2 supply on the back of the anesthesia machine
function of check valves
prevents reverse flow of gases from machine to pipeline or cylinder
location of check valves
in the anesthesia machine downstream from the pipeline and cylinder inlets and down stream from vaporizer upstream from CGO or internal to vaporizer
what do the first-stage pressure regulators do to the gas pressure from the cylinders entering the anesthesia machine
takes the very high, variable pressure from a gas cylinder and reduces it to a significantly lower, intermediate pressure, essentially acting as a first step to deliver a consistent, usable pressure to the machine, even as the cylinder depletes
gas pressure at the pipeline inlet compared to the pressure leaving the first stage regulator
reduced to a much lower level like going from 500psi to 20 psi
describe the second-stage pressure regulator
the intermediate pressure is then further reduced to reach the desired working pressure for the anesthesia machine
(from 45psig to 14psig for O2 and 26psig for N2O)
provides further precision
can be adjustable whereas first-stage is not
most upstream and most downstream components of a high pressure system
The cylinder is the most upstream component, and the pressure regulator that reduces the pressure to a lower level is the most downstream component.
most upstream and most downstream components of an intermediate pressure system
The pipeline inlet connection is the entry point for the gas, making it the most upstream component. The flowmeter, where the gas flow is controlled, is usually considered the most downstream component in this system
what allows for a rapid delivery of a high volume of pure oxygen directly to the patient’s breathing circuit by bypassing the vaporizer, used primarily during critical situations like mask ventilation when a quick oxygen boost is needed, or when establishing an airway; it delivers a large flow of oxygen at high pressure when activated by a button or lever
oxygen flush valve
When the oxygen flush valve is activated, it provides a direct connection to the high-pressure oxygen supply, bypassing flowmeters and vaporizers, delivering a large volume of oxygen at a high flow rate of _____
35-75L/min
Improper use of the oxygen flush valve can lead to ________ due to the high pressure of the delivered oxygen
barotrauma
barotrauma
tissue damage caused by a difference in pressure between the body and the surrounding gas or fluid. It can occur when there is a sudden change in air or water pressure, it can affect many parts of the body, including the lungs, ears, eyes, sinuses, and gastrointestinal tract. Symptoms vary depending on the affected area
Think about barotrauma and scuba divers
Barotrauma can be prevented by equalizing pressures. For example, divers can equalize pressures to avoid being crushed or squeezed on descent, or stretching and bursting on ascent.
oxygen supply failure alarm is based on
pressure of oxygen supply
explain the O2 supply failure alarm
when
what does it indicate
safety feature designed to alert medical professionals when the pressure of the oxygen supply drops below a safe level (50psig), typically by sounding an audible alarm, indicating a potential lack of oxygen available for patients and prompting immediate action to address the issue
how to address the O2 supply failure alarm
switch from pipeline supply to O2 tank
what automatically happens when there is an O2 supply failure
N2O is shut off and patient gets medical air instead (remember this only has 21% O2)
automatically shut off the flow of all other gases (like nitrous oxide) if the oxygen supply pressure drops below a certain level, preventing the delivery of a hypoxic gas mixture to the patient in case of an oxygen supply failure; essentially, it prioritizes oxygen delivery and cuts off other gases when oxygen pressure becomes critically low
fail-safe valve aka pressure sensor shut off aka oxygen failure protection device
The rate of flow to the common gas outlet on an anesthesia machine is determined by
by the setting on the flowmeter, which is manually adjusted allowing for precise regulation of the gas delivery based on the patient’s needs
common gas outlet
This is the point on the machine where the combined gas mixture exits and connects to the breathing circuit
Thorpe tubes (TT)
a device used to measure the flow rate of a gas, such as oxygen. It’s a type of variable-area flowmeter, also known as a rotameter, and is a key instrument in medical gas delivery systems.
4 components of a thorpe tube
Gas source connection: Connects to the gas source
Needle valve: Controls the flow rate by opening and closing with an attached dial
Float: Rests in a clear, tapered tube
Outlet port: Allows the gas to exit
low flow in thorpe tube
small annular space, flow is laminar and is a function of gas viscosity
high flow in thorpe tube
large annular space, flow is turbulent and a function of gas density
low pressure manifold is the
common gas outlet –> where the different anesthetic gases mix together after passing through their respective flowmeters and vaporizers
with a ball float in a flow meter you should read it in the
middle of the ball
with a bobbin float in a flow meter you should read it at the
top of the bobbin
the most upstream components of the low pressure system
Flowmeter control valve - This is where the gas flow is regulated before entering the flowmeters
the most downstream component of the low pressure system
Vaporizers, check valves (if present), and the common gas outlet.
On an anesthesia machine, flowmeters are typically arranged as
individual, vertical glass tubes with a visible bobbin inside, each controlled by a separate knob, where the oxygen flowmeter is easily identifiable by its larger size and often a distinct color (usually green)
O2 flow meter should be ______ from all other gases to prevent a hypoxic mixture
downstream
minimum oxygen flow is
200-300ml/min
proportioning device maintains O2 to N2O ration of
1:3
hypoxic mixtures will occur despite proportioning device if (4 things)
wrong gas to pipeline or cylinder
defective pneumatic or mechanical components
leaks downstream of flow control valve
3rd inert gas is used
oxygen ration monitor controller shuts N2O off if O2 ratio falls below
30%
high pressure-cylinder pressure(1900psig)-begins @ _______- ends @ __________
cylinder
cylinder regulators
intermediate pressure- pipeline(50psig) or tank(45psig)- begins @ _______- ends @ __________
pipeline
flowmeter valves
low pressure- slightly above atmospheric but varies- begins @_______- ends @ ________
flow meter tubes
common gas outlet
if a cylinder is left open, the first alarm you would here for oxygen supply fail would be when _____
the cylinder loses pressure, not the pipeline
if there are two oxygen yokes present, they both feed into one
first stage pressure regulator
if your primary O2 source is from an E cylinder and not the pipeline then you must have
2 hanger yokes and a second O2 cylinder
cracking the O2 tank serves what purpose
to confirm it is closed when you do, confirm the adequate pressure of the cylinder to and to remove any dust or debrie
what is the most fragile part of the cylinder
cylinder valve
yoke plug must be placed when
yoke is empty
5 tasks of oxygen
power the
oxygen flush valve
oxygen supply failure alarm
oxygen pressure failure safety device
oxygen flowmeters
ventilator driving of pneumatic bellows
devices that do not rely on wall outlet electrical power
spontaneous or manually assisted ventilation
mechanical flowmeters
scavenging
variable bypass vaporizers
after 30 min has passed and you still don’t have power for anesthesia system then you would no longer have
NO LONGER HAVE VOLATILES
if check valves malfunctioned it would cause transfiling which can cause
heat production and explosions
the bodock seal refers to the
1 washer on the hanger yoke system
electronic pressure indicators for cylinders have light emitting diodes what colors and what do they indicate
dark - closed
green - open and adequate pressure
red - open and inadequate pressure
what must be on to allow flow to flow meters
master switch
what is independent of the master switch being on and is always available
O2 flush valve and auxiliary flowmeter
gas will always flow from wherever there is _______pressure
higher
fail-safe device is great but it will not recognize a ________mix-up
pipeline
Ohmeda uses the _______ for O2 supply fail
pressure sensor shut off
Drager uses the _______ for O2 supply fail
oxygen failure protection device
O2 supply failure alarm sounds when pipeline reaches below_____, can be silenced but not deactivated
30psig
both fail-safe and pressure alarm measure pressure of O2, NOT
flow or concentration of O2
