oxygen therapy Flashcards
What is the goal of oxygen therapy
Maintain adequate tissue oxygenation
Decrease cardiopulmonary work
Define hypoxia
Abnormal condition in which the oxygen available to the body cells is inadequate to meet metabolic needs
An abnormal condition in which the oxygen available to the body in cells is inadequate to meet metabolic needs
Hypoxia
Define hypoxemia
Abnormal deficiency of oxygen in arterial blood
An abnormal deficiency of oxygen in the arterial blood is called
Hypoxemia
What are the signs of hypoxia/hypoxemia?
Tachypnea
Tachycardia
Headache
SOB
Coughing
Wheezing
Confusion
Cyanosis
What signs would you see in the early stages of severe hypoxia/hypoxemia?
Changes in the color of skin ranging from blue to cherry red
Confusion ‘
Cough
Tachycardia
Tachypnia
What signs would you see in the later stage of severe hypoxia/hypoxemia?
sweating/diaphoresis
Severe shortness of breath
Bradypnea
Bradycardia
Lethargy
Define cyanosis
abnormal bluish discoloration of the skin or mucus membranes
An abnormal bluish discoloration of the skin or mucus membranes
Cyanosis
Arterial desaturation and discoloration of the skin, mucous membranes, lips younger and nail beds is associated with what?
Central cyanosis
When does peripheral cyanosis occur?
Occurs when there is increased oxygen uptake in peripheral tissues and is not associated with arterial desaturation
What a chronic response to hypoxia?
Pulmonary vasoconstriction
Pulmonary hypertension
Pulmonary hypertension increases the workload on which side of the heart?
The right side/right ventricle
What is jugular vein distortion indicative if?
Right ventricular failure
Pulmonary hypertension
Pulmonary vasoconstriction
When would a nasal catheter be used?
Generally limited to short term oxygen administration during specialized procedures
Bronchoscopy
Surgery
What flow rate should you set a nasal catheter to?
¼ to 6 L/m
What is the FiO2 delivered by a nasal catheter?
.22-.45
How often should a nasal catheter be replaced and what should you be sure to do?
Replace every 8 hours
Place in opposite naris
What should the flow rate be set to for a low flow nasal cannula?
⅛-6 L/minute
When should a bubble bottle or humidifier be attached to a nasal cannula?
When flow is at 4 L/m or above
What FiO2 can a nasal cannula deliver?
24-40%
What is the rule of thumb for how flow correlates to FiO2?
Every increase of 1 liter of flow raises the FiO2 by 4%
What should the flow rate be set to for a salter high flow nasal cannula?
1-15 L/m
Describe trans tracheal oxygen therapy
A method of delivering oxygen directly into the lungs by a small flexible catheter which passes from the lower neck via stoma into the trachea or windpipe
Why would you use a salter high flow nasal cannula instead of a low flow nasal cannula?
When the situation requires flow rates greater than 6 L/m
What are the flow rates used with a transtracheal catheter?
¼-4 L/m
Why use a transtrachial catheter over a nasal cannula?
Uses 40%-60% less oxygen to achieve the same oxygenation via nasal cannula
What are the disadvantages and risks of a transtracheal catheter?
Requires careful maintenance and cleaning
Complications such as infections are possible
Tracheal irritation
Mucus accumulation
Requires mandatory outpatient surgical procedure
What are the advantages of a transtracheal catheter?
Reduces oxygen requirement to achieve desirable oxyhemoglobin saturation
Improves activity and mobility
Improves physical social and psychological function
Improves compliance (daily duration of oxygen use)
Which patient will receive a greater FiO2, a patient with small tidal volumes or a patient with large tidal volumes? Why? Note, both patients are on the same liter flow
Patients that take small tidal volumes will receive proportionally more FiO2 than patients with large tidal volumes
A patient with a larger tidal volume will have a greater minute ventilation than a patient with a smaller tidal volume. This results in the amount of inspired oxygen from the nasal cannula being proportionally smaller than the patient with a lower minute ventilation
How does respiratory rate impact the amount of FiO2 delivered?
High rates dilute the amount of FiO2 received
Low rates increase the amount of FiO2 received
Why do patients with a lower respiratory rate receive proportionally more 100% oxygen from an oxygen delivery device than patients with a higher respiratory rate? Assume same tidal volume
A higher respiratory rate will result in a greater minute ventilation. This will result in the amount of inspired 100% oxygen being proportionally smaller when compared to a patient with the same tidal volume but a lower respiratory rate
Humidification is …..
The act of adding water vapor to an anhydrous gas (a dry gas)
Define absolute humidity
Absolute humidity is the density of water in the air
It is usually measured in grams of water vapor per cubic meter of water
Define relative humidity
The absolute humidity in a volume of gas expressed as a PERCENTAGE of the water vapor capacity of the gas
During exhalation, the heat and humidity that our body has added to the inspired gas is deposited where?
The upper airways
The nasal mucosa
At what point should inspired gases be warmed to body temperature and fully saturated? Where is this located
Isothermic saturation boundary
Just below the carina
What are the characteristics of gas at the ISB?
100% relative humidity
97 degrees C
What is the absolute humidity of the inspired gas after it passes the isothermic saturation boundary?
44 mg per L
How does the ISB react to inhalation of dry gas
The ISB moves deeper into the respiratory tract
The effects of inadequate humidification include…
Increased risk of damage to the epithelial lining of the airways due to increased susceptibility to infection and inflamation
Disruption of the mucociliary escalator
Increase in mucus production
Thickening of secretions
Increased airway irritability
Structural damage to the lung
Cold dry air has what effect on secretions?
Increase in mucus production
Increase in secretion viscousity
T/F Decreases in air humidity will have minimal effect on the mucociliary escalator
False. The decrease in humidity will cause secretions to thicken resulting in decreased effectiveness of the mucociliary escalator
T/F Decreases in humidity will not cause structural damage to the lungs, although it may increase airway irritability.
False. A decrease in humidity can cause structural damage to the lungs as well as increase airway irritability
What effect does increased humidity have on secretions
Increased humidity can potentially decrease secretion viscosity and make them easier to expectorate
Intubated patients rely on us to humidify and warm the air that they are receiving. Why?
By intubating patients, we are bypassing the natural physiological processes that humidify and warm the air such as the nasal concha
What 3 factors affect the humidity output of a humidification device?
Temperature - warmer air can hold more water vapor
Surface area - by increasing the surface area, we can increase the amount of gas that is exposed to water and allow more water to be picked up
Exposure time - the longer amount of time that gas is exposed to water, the more water it can pick up
You have a patient on a 2 L low flow nasal canula. They are complaining of a dry nose. What can you do to make them more comfortable?
Attach a bubble passover humidifier to the oxygen output to humidify the air
You have a patient on 8 L of oxygen on a high flow nasal cannula. They need the air to be humidified. What device would you use for this?
High flow bubble bottle
Why should bubble bottles not be used with flow rates greater than 10 L a minute?
At flow rates over 10 L/min the bubble bottle can produce an aerosol which can overhydrate the patient or carry bacteria
How does a high flow bubble bottle work?
Conducts gas down a small tube submerged in water
Gas passes through a diffuser which breaks the gas down into smaller bubbles increasing the surface area
The bubbles float to the surface allowing the gas to be humidified and sent to the patient
What can happen to a bubble bottle with prolonged use?
The pressure relief valve may become dysfunctional and not alert staff when the flow has been blocked
If flow is blocked with a bubble humidifier bottle (the disposable kind) what can happen?
They can explode
How does a reservoir device work?
Incorporate a method for gathering and storing oxygen between patient breaths
Patient draws on the reservoir whenever inspiratory flow exceeds the oxygen flow into the device
Why are reservoir devices superior to standard oxygen delivery devices?
They are capable of delivering a higher FiO2 than low flow devices at the same flow rate
Nasal reservoirs and pendant reservoirs are found on what type of oxygen delivery devices?
Nasal cannulas
Nasal reservoirs and pendant reservoirs can reduce oxygen use by how much?
50-75%
Is humidification needed when used a nasal cannula with a reservoir?
No
How do reservoir cannula devices increase FiO2?
They store a small amount of oxygen in a small membrane reservoir during exhalation so when the patient inhales they receive an additional burst of oxygen
How much can a reservoir cannula reduce flow requirements by?
Low flow reservoir cannulas can reduce flow requirements by up to 50%
What are the types of reservoir mask?
Simple mask
Partial rebreathing mask
Non-rebreathing mask
What must a patient do when using a reservoir cannula?
Exhale through the nose ‘
What is the flow range for the simple mask?
The flow range for an adult simple mask is 5-10 L/m
What will happen if the flow rate on a simple mask is set to less than 5 liters a minute?
At flows less than 5 liters per minute the mask volume acts as dead space and causes carbon dioxide rebreathing
What is the FiO2 range for the simple mask?
0.35-.050
What can cause variable FiO2 delivery when using a simple mask?
Air dilution via the mask ports and leaks around where the mask makes contact with the face
FiO2 varies depending on the oxygen input flow, the mask volume, the extent of air leakage and the patients breathing pattern
Long term use of the simple mask can result in what?
Skin irritation and break down
What is the FiO2 range on a partial rebreather mask?
.40-.70
What is the minimum flow required when using a partial rebreather mask?
10 liters per minute
You walk into a patients room after a nurse has called because of a patients low oxygen saturation. The patient is on a partial rebreather mask and the bag is deflating completely every time the patient breaths. What is wrong?
The flow is too low
Why does a partial rebreather mask deliver a higher FiO2 than a reservoir nasal cannula or a simple mask?
The bag increases the reservoir volume which allows for a higher FiO2
How is a partial rebreather different from a non rebreather?
A non rebreather has a one way valve that closes off the reservoir during exhalation and prevents the patient from exhaling into the bag. When they inhale, the valve opens and they receive the pure oxygen from the reservoir. A partial rebreather does not have this valve and the patient will end up inhaling more carbon dioxide than with a non-rebreather.
What is the FiO2 range on a non-rebreathing mask?
The FiO2 range on a non rebreathing mask is .60-.80
What is the minimum flow required for a non rebreathing mask?
10 liters per minute
What are the advantages of a nasal cannula?
Can be used on adults, children and infants
Easy to apply
Cheap and disposable
Generally well tolerated at flows less than or equal to 6 L
What are the disadvantages of a nasal cannula?
Unstable, easily dislodged
FiO2 varies with rate, depth of breathing and inspiratory flow
Flows greater than 6 L per minute can be uncomfortable
Can cause dryness/bleeding
Polyps or deviated septum may block flow
What is the best use scenario for nasal cannulas?
Stable patient needing low FiO2
Home care patients requiring long term oxygen therapy
What are the advantages of the simple mask?
Can be used on adults, children and infants
Quick and easy to apply
Disposable
Low cost
What are the disadvantages of a simple mask?
Uncomfortable, some may find them claustrophobic
Must be removed for eating or taking oral meds
Prevents radiant heat loss
Blocks vomitus in unconscious patients
What is the best use scenario for the simple mask?
Emergencies
Short term therapy requiring moderate FiO2
What are the advantages of a partial rebreathing mask?
Can be used on adults, children, infants
Quick and easy to apply
Disposable
Low cost
Moderate to high FiO2
What are the disadvantages of the partial rebreathing mask?
Same as simple mask
Potential suffocation hazard
What is the best use scenario for partial rebreather masks?
Emergencies
Short term therapy requiring moderate to high FiO2
What are the advantages of a nonrebreathing mask?
Same as simple mask
High FiO2
What is the best use scenario for a non rebreather mask?
Emergencies
Short term therapy requiring high FiO2
Heliox therapy
A trach collar is what kind of oxygen therapy device?
Entrainement device
Entrainment devices can use what kind of interfaces?
Mask (venti mask)
Face tent
Trach collar
T-piece
How does an entrainment device work?
Utilizes the bernoulli principle by directing 100% oxygen through a flow restrictor adjacent to an entrainment port
Concentration of oxygen delivered is depended upon resistor size, not flow
Describe how the amount of air is related to the flow rate of the oxygen
The amount of air entrained at the ports varies directly with the size of the port and the velocity of oxygen at the jet
What does the fraction of inspired oxygen depend on?
The air to oxygen ratio
The amount of flow resistance downstream from the mixing site
The advantage of entrainment devices over low flow devices is
That we can set a fixed FiO2
T/F: Bigger ports and smaller jets cause less air dilution, low oxygen percentage and higher total flows
False. Bigger ports and smaller jets cause more air dilution, lower oxygen percentage and higher total flows
T/F: Smaller ports and smaller jets cause less air dilution and higher oxygen percentage but lower total flows
False. Smaller ports and bigger jets cause less air dilution, higher oxygen percentages but lower total flows
T/F: The higher the oxygen percentage from the entrainment device, the higher its total flow output
False. The higher the delivered oxygen percentage from an entrainment device, the lower its total output flow
T/F: Entrainment devices are incapable of delivering 100% oxygen
True. entrainment devices utilized the bernoulli principle to dilute oxygen with air to get a specific oxygen percentage delivered. They are incapable of delivering 100% oxygen
When setting up an entrainment device, we must ensure that the patient is receiving the proper amount of oxygen and we must also ensure that we are meeting the patients _________ requirement
Peak flow requirement
A jet for a venti mask gives what important information to the therapist?
Amount of oxygen delivered
Minimum flow requirement
If a patient is desatting and on a venti mask, what should the therapist do?
Change the venti port to increase the oxygen percentage delivered
How is an aerosol generated with cool large volume nebulizers?
Gas is passed through a small jet orifice
The resulting low pressure at the jet draws fluid up the reservoir to the top of the siphon tube where it is sheared off and shattered into liquid particles
Large unstable particles fall out of suspension
Remaining particles leave through the outlet port and are carried away in the gas stream
When using a cool large volume nebulizer, what must a therapist confirm before attaching the tubing to the patient interface?
That mist is coming out of the tubing near the patients airway
If you, a therapist (i know, unlikely, right?) do not see mist coming out of the tubing on a cool large volume jet neb, what does this indicate?
It indicates air dilution which means that there is not enough flow
In this situation, this high flow system becomes a low flow system delivering variable oxygen
List clinical use for heated nebulizers?
Increased humidification needs
Dry gas delivery
Artificial airways
Cold reactive airways
Hypothermia
Thick secretions
What can cool bland aerosol therapy be used for?
Upper airway edema
Laryngotracheobronchitis
Subglottic edema
Post operative management of the upper airway
Presence of a bypassed upper airway
Need for sputum specimens or secretion mobilizations
A viable therapy for increased humidification needs, dry gas delivery, artificial airways, cold reactive airways. Hypothermia and thick secretions is….?
A heated nebulizer
A gases vapor capacity can be increase how? By how much
Heating it
33-55 mg H2O/L
Gas delivered to the mouth needs to be at what temperature and have what water content? Relative humidity?
20-22 degrees celsius
10 mg/L water vapor
50% relative humidity
Gasses delivered to the trachea need to be at what temp? Water content? Relative humidity?
32-40 degrees celsius
36-40 mg/L
>90% relative humidity
What is the formula for peak inspiratory flow PIFN?
VE x 3
Minute ventilation x 3
What are the hazards and complications associated with large volume jet nebulizers?
Wheezing or bronchospasm
Bronchoconstriction when used with artificial airway
Infection
Overhydration leading to edema
Patient discomfort (suck it up, buttercup)
T/F: changing the flow on entrainment devices changes the FiO2
False. Changing the flow only affects the total output flow, not the FiO2
To change the FiO2, therapists need to adjust the port settings
What is the minimum amount of flow most patients need?
40 L/min
Determine PFIN to determine true flow need, but 40 L/min is a good place to start for adults
What are examples of large reservoir jet neb oxygen delivery devices that utilize enclosures?
Oxihood - best method for delivering oxygen to infants
Incubators - can be used in conjunction with oxihood
Oxygen tent
What are drawbacks of the oxygen tent?
Regulating, cooling and FiO2 can be difficult
What flows can you run an oxymask at?
1-flush
The oxymask is a high flow device, but…
Delivers a variable FiO2
What FiO2 can an oxymask deliver?
24-90%
What are the advantages of the oxymask?
Higher humidity room air is drawn in as patient inhales, negating the need for extra humidification
Large openings in the mask feel less confining and allow patient to
Communicate
Drink fluids
Talk
What are the parts of a HHFNC?
Blender - mixes air and oxygen
Flowmeter - capable of generating high flows
Heated humidification system
An oxygen analyzer to ensure FiO2
Heated delivery system to prevent condensation
Custom nasal cannula
How does the oxymask work?
It forms a virtual reservoir by making a vortex of oxygen flow directed at the patients nose and mouth though a pin and diffuser assembly
Open design allows carbon dioxide to escape mask on exhalation reduce carbon dioxide rebreathing
External blenders require what to be delivered at what pressure?
Oxygen and air
50 psi
What are the clinical applications for oxygen blenders?
Heated high flow oxygen
NIV
Ventilators
Hoods
How are water levels maintained with a HHFNC?
Maintained by a float system and disposable containers holding sterile water
What temperature range can HHFNC deliver gas at?
30-39 degrees celsius
What are the hazards associated with heated humidity?
Electrical shock
hypo/hyperthermia
Burns (caregiver/patient)
Tubing melt down
Pooled contaminated contaminated condensate
What could pooled contaminated condensate result in?
pt/vent asynchrony
Tracheal lavage (waterboarding)
Noscomial infections
If the inlet on a humidifier temperature is high, what could happen?
The water may not be warmed as a result and the gas may remain dry
What are the common types of HHFNC?
Vapotherm precision flow system
Airvo
Fisher and paylels optiflow
What can the FiO2 range be set to on a HHFNC?
21-100%’
What are the flow ranges for adults on a heated high flow nasal cannula?
1-40+ L/m
What are the hazards associated with administering too much oxygen?
Oxygen toxicity
Absorption atelectasis
Abolition of hypoxic drive
Retinopathy of prematurity
How much PEEP can a HHFNC generate?
0.8-1 cm H2O for every 10 liters of flow set
Likely much lower
Useful for deadspace circulation, not much else
How does oxygen toxicity cause damage?
Overproduction of free radicals overwhelms bodys normal antioxidant system and can severely damage or kill cells
Damage caused by free radicals can lead to what?
An immune response resulting in tissue infiltration by neutrophils and macrophages
What happens when neutrophils and macrophages infiltrate damaged tissue?
They release inflammatory mediators that worse the initial injury and cause more free radicals to be released
What effect can over oxygenation have on the eyes?
Visual field loss
Near sightedness
Cataract formation
Bleeding
Fibrosis
What effect can over oxygenation have on skeletal muscle?
Makes ya twitchy
What effect can over oxygenation have on the central nervous system?
Seizures
What effect can over oxygenation have on the respiratory system?
itation
Coughing
Pain
SOB
Tracheobronchitis
Acute respiratory distress syndrome
At what FiO2 can absorption atelectasis become a risk?
> 50% represents a significant risk
How does absorption atelectasis occur?
High levels of oxygen deplete body nitrogen levels
This causes blood nitrogen levels to decrease, causing the total pressure of the venous gasses to decrease
This creates a pressure gradient that causes atmospheric gasses to RAPIDLY diffuse into the venous blood
Rapid diffusion of atmospheric gasses into venous blood causes a pressure decrease in the alveoli which can lead to alveolar collapse
Can lead to total lung collapse
What patients are at a loss for abolition of hypoxic drive when receiving supplemental oxygen?
COPD
Patients with chronic hypercapnia
What population is generally most affected by bronchopulmonary dysplasia?
It is a chronic disease that affects newborns (mostly premature) and infants
What causes bronchopulmonary dysplasia?
It is the result of damage to the lungs caused by mechanical ventilation and long term use of oxygen
T/F: Most infants do not recover from bronchopulmonary dysplasia
False. Most recover, but some may have long term breathing difficulty
What is a risk associated with delivering high concentrations of oxygen to infants?
Intraventricular hemorrhage
What is interventricular hemorrhage in infants?
Result of high concentration oxygen delivery
Causes vasodilation in premature infants which can alter cerebral blood flow and cause hemorrhaging
What is another name for retinopathy of prematurity?
Retrolental fibroplasia
Describe what happens to the eyes of infants who require high concentrations of oxygen?
Excessive oxygen levels cause retinal vasoconstriction which leads to necrosis of the blood vessels
Excessive oxygen can also cause accelerated blood vessel growth in the eyes, resulting in delicate vessels that can easily hemorrhage and cause scarring behind the retina
What can we do to prevent or decrease the risks associated with oxygen?
Monitor patients closely
Wean oxygen when possible
Which patient populations do we accept lower PaO2 values?
Infants
Elderly
COPD
A system with the capacity to store >20,000 cubic feet of medical grade gas qualifies as what type of system?
Bulk gas delivery system
A bulk gas delivery system is a system with what medical grade delivery capacity?
> 20,000 cubic feet
Containers for the bulk supply of oxygen can be referred to as what?
Stand tanks
Vessels
Dewars
Oxygen storage systems have the potential to catastrophically fail causing massive damage, injury, and loss of life. What safety procedures are in place to help prevent catastrophic failure resulting from human error or mechanical failure?
Design and construction must meet specifications met by several regulatory bodies
Tanks are generally stored outside
Tanks are protected by physical barriers
Multiple layers of monitoring and alarms
Shut off valves
T/F: A central supply cannot be a high pressure cylinder system
False. A central supply can either be a bulk supply system or a high pressure cylinder system
What temperature must containers maintain to keep oxygen in a liquid state?
-181.4 degrees fahrenheit
Describe the pathway oxygen takes out of storage to the wall “outlets”
Liquid oxygen leaves bulk containers and passes through a vaporizer/heat exchanger
Liquid oxygen turns from a liquid to a gas
Oxygen gas goes through a reducing valve that drops the pressure to about 50 psi
What are the acronyms for some of the governing bodies that regulate the design, construction and delivery of oxygen?
NFPA
ASME
What must exist at the point at which the main distribution pipe leaves the bulk supply?
A primary shut off valve
What is the general function of cylinder gas bulk system in a healthcare facility?
Back up or reserve systems
Describe the layout of a cylinder gas bulk system
H cylinders banked together in series
How many compressors are needed on site for redundancy purposes in case of a failure or depletion of the main system?
At least 2
What type of pipes do the oxygen distribution systems use?
Seamless type K or L
Copper or brass pipes
How often are pipes labeled with flow or direction?
Every 20 feet
What agency regulates the piping distribution systems?
NFPA
What are risers in terms of oxygen distribution systems?
Vertical pipes that connect main line with branch lines on each floor of the building
What are branch lines in terms of oxygen distribution systems?
Travel from risers to individual rooms on the same floor
What is the main line in terms of oxygen distribution systems?
Connects the supply of oxygen to risers and branch lines
What is an overpressure event?
Any condition which would cause pressure in a vessel or system to increase beyond the specified design pressure or maximum allowable working pressure
How do systems account for a potential overpressure event?
By utilizing pressure relief valves
Describe what a pressure relief valve does
A pressure relief valve is a safety device designed to protect a pressurized vessel or system during an overpressure event
At what pressure are overpressure valves set to begin releasing pressure?
50% greater than normal line pressure
Where are pressure relief valves located?
Throughout the distribution system
A zone valve can also be called a what?
Shut off, isolation or section valve
Pressure gauges allow for visualization of gas pressure in the distribution lines. Describe how this is facilitated
The gauges must be correctly labeled, color coded, and readable from a standing position
What is the purpose of a zone valve?
Allow for isolation of zones from the main system
What is the pressure coming out at the terminal units?
50 psi
Station outlets can also be called what?
Terminal units
What kind of tests are performed to ensure that the oxygen system is being maintained?
Pressure tests
Checks for leaks
Checks for cross connections
What does the NFPA (national fire protection association) regulate?
Regulates where the system can be located in relationship to buildings and surrounding structures
What does the american society of mechanical engineers (ASME) regulate?
How system is designed and the construction of the storage containers
What does the Joint commission do?
Require hospitals to comply with all safety standards
What does the Bureau of explosives regulate?
The pressure relief valves used in the system
A Thorpe tube is what?
A variable orifice device
T/F: The diameter of a thorpe tube decreases from bottom to top
False. Diameter increases from bottom to top
What can affect the accuracy of a thorpe tube?
Its positioning, must be upright
T/F: Thorpe tubes are not gas specific
False. Thorpe tubes are calibrated for specific gasses
What is the advantage of a compensated thorpe tube?
The gas moves the float at the supply pressure regardless of back pressure from something like a kink in the hose
What are the two basic types of quick connect adapters?
National compressed gas (NCG)
Ohio Diamond
T/F: quick connect adapters are less prone to leaks
False. Quick connect adaptors are more prone to leaks because they are not threaded
Station outlets have DISS connections that are _____ specific
Gas specific
Each connector has a distinct shape and does not fit into an outlet for another gas
T/F: Cylinders are for liquified and non liquified gasses
False. Cylinders are for non liquified gasses only
What are the main materials that gas cylinders are made out of?
Steel
Aluminum
Chrome molybdenum
T/F: cylinders should hold less that 2000 psig
False. Cylinders should hold in excess of 2000 psig
In what situations would an aluminum cylinder be better than a steel cylinder?
Home care
Transport
MRI
What is the most frequently used cylinder size?
E
What color are oxygen tanks?
Green
What color are helium tanks?
Brown
What color are hydrogen tanks?
Red
Just like the hindenburg
What color are nitrogen tanks?
Black
What color are air tanks?
Yellow
What color are carbon dioxide tanks?
Gray
What color are nitrous oxide tanks?
Light blue
What color are heliox tanks?
Brown shoulder with a green body
What color are nitric oxide tanks?
Silver cylinder with teal and black
Labels on cylinders contain a lot of information. What information can you expect to find on them?
Hazards
Proper handling
Proper storage
First aid if in contact
Cylinder contents
Company that filled it
Safety warnings
UN number and pictogram
How can you know when a cylinder was tested?
Dates of testing should be engraved on the cylinders
T/F: the cylinder label will not inform you who filled the tank
False. The cylinder label will detail what company filled it
T/F: the cylinder label will not have details about hazards associated with the contents
False. The label will list hazards associated with the gas and how to prevent them ‘
What is the 4 step process to cylinder filling?
Prefill inspection (look at that shit)
Filling the cylinder (Fill that shit)
Check valves for leaks (inspect that shit)
Check for purity standards (test that shit)
How should a cylinder be tested and how often should a cylinder be tested?
Hydrostatic testing
Every 5-10 years
What is the purpose of cylinder valves?
They contain the high pressure gas and provide a way to attach equipment for delivery to the patient and ensure that gas does not accidentally escape or leak from the cylinder
When using a direct acting cylinder valve, what is the effect of the normal position produced by the spring?
The normal position produced by the spring closes the valve
In a direct active cylinder valve, what must be done in order to outstroke the cylinder?
The push button must be held down
I have no idea what this means, and i dont care
A single acting cylinder is usually controlled by what?
A 3 port valve that provides an inlet and an exhaust path
What are the 3 types of pressure relief valves used with cylinders?
Rupture disk (aka frangible disk)
Fusible plugs
Spring loaded devices
What are the tank sizes associated with each type of pressure relief system?
Rupture disc and fusible plugs = small cylinders
Spring loaded devices = large cylinders
Describe how a rupture disc works
A rupture disc is a thin metal disc that is rated for certain pressure and will break apart or rupture under pressure (much like the grand majority of this class) allowing gas to escape
Describe how a fusible plug works
The plug is made of a metal alloy that will melt when the temperature of the gas reaches 208-200 F or 97.8-104 C allowing gas to escape
Describe how a spring loaded pressure relief valve works
As pressure exceeds the predetermined level, pressure pushes up on the spring causing a valve to be unseated allowing gas to escape
What safety system prevents patients from having the wrong gas delivered via cylinder?
American Standard Cylinder Safety System (ASSS)
ASSS dictates that connections differ in
Thread size and type
Right and left handed threading
Internal and external threading
Nipple seat design
ASSS ensures that
Cylinders for different medical gases will not connect to equipment meant for a different type of gas
What cylinder size does ASSS regulate
Large capacity cylinders (H and K)
Pressures about 2000 psig
What safety features does DISS incorporate
DISS connections contain a body, a nipple and a nut assembly
The shoulders of the nipple only mount with a body that has the correct borings preventing the wrong gas from being connected
How does the Pin Index Safety System (PISS) prevent the wrong yoke from being attached to a specific cylinder?
Pins are layed out in a specific pattern that is dictated by the type of gas they are meant to work with
Exact positions of pins and pinholes vary for each gas
What are the pins and pin holes for oxygen?
2-5
What are the pins and pin holes for air?
1-5
T/F: use petroleum products on regulators, cylinders, fittings and valves to prevent rust or corrosion
False. Unless you want to explode.
What should you do to a cylinder valve before attaching a regulator?
Crack it open or slightly open the valve to remove any dust
Describe the rules for safe storage of cylinders
Store in racks or chain to wall
Do not store combustible material in vicinity of cylinders
Store away from sources of heat
Store flammable gases separately from gases that support combustion
Keep cylinder cap in place if cylinder is not in use
Store liquid oxygen containers in cool, well ventilated areas
What is the conversion factor for D cylinders?
.16
What is the conversion factor for E cylinders
.28
What is the conversion factor for G cylinders
2.39
What is the conversion factor for H or K cylinders?
3.14
How much LOX can a stationary home storage unit hold?
45-100 pounds of liquid oxygen
How can you convert pounds of LOX to liters of gaseous oxygen?
1 pound of LOX = about 344 liters of gaseous oxygen
Describe the calculation to determine how long a cylinder will last
(PSIG x conversion factor for tank size)/liter flow = minutes of oxygen at state flow
What are actions you can take if you hear a hissing noise and gas escaping from the cylinder?
Assess regulator to determine whether the plastic or teflon washer is missing or damaged
If washer is gone, replace washer and reseat regulator
What actions can you take if you hear a hissing noise and gas escaping from the cylinder but the teflon washer is present and intact?
reseat/reposition the regulator and tighter the connection with a wrench…which we totally carry around in our scrubs
You have just hooked up a patient to a tank of some form of gas. You turn on the flow meter but no gas comes out, what do you do?
Ensure the cylinder valve is turned to the fully on position
Assess tank pressure to determine if gas is present in the tank
Determine if cylinder valve is damaged and obtain another cylinder. Make a note that the previous cylinder is damaged.
Mr. V. is going to x-ray. He is on a 40% venturi mask at 10L/min. How long will his full E tank last?
56 min
he oxygen delivery device interfaces used to connect the air entrainment systems to the patient include:
Trach collars
T-pieces
Masks
Face tents
In health care facilities oxygen piping systems:
Have monitored pressure relief valves, zone valves, and terminal units.
Mr. A. is on a partial re breather mask with the flow set at 10 L/min. His oxygen saturation is 98% (SpO2). The respiratory therapist should:
Switch to a Salter high flow nasal cannula at 10 L/min. with a bubble bottle
The primary indication for oxygen therapy administration is
Hypoxia/Hypoxemia
Mr. C. is on a simple mask set at 10 L/min. His oxygen saturation (SpO2) is 86%. The respiratory therapist should:
Switch to a non-re breather mask with a flow of 12 L/min.
Ms. D. has trans tracheal oxygen. Her oxygen saturation (SpO2) is 86% on 4 L/min. The respiratory therapist should
Administer a nasal cannula at 4 L/min. and check to see if the transtracheal oxygen tube is obstructed
Mr. E. has an SpO2 of 100% on a simple mask at 5 L/min. The therapist should
Switch to a nasal cannula at 4 L/min. with a bubble bottle
Ms. B. is on a nasal cannula set at a flow of 3 L/min. Her oxygen saturation (SpO2) is 87%. The respiratory therapist should:
Increase the liter flow to 5 L/min. with a bubble bottle
T/F: Patients with large tidal volumes receive less FiO2.
True
Mr. C. is on a 60% tracheostomy collar through a heated large volume jet nebulizer. His total flow requirement is 40 L/min. How should the respiratory therapist set up Mr. C.’s heated jet nebulizer? The therapist should
Set up 2 heated jet nebulizers each set at 12 L/min on the oxygen flow meter.
Mr. A. is receiving 40% oxygen through a cool large volume jet nebulizer with a flow set on 12. What is the total flow output of this device on these settings
50 L/min.
Cylinder safety includes:
Cracking” cylinders before attaching the regulator.
Cylinder caps on cylinders when not in use.
Storing cylinders in stands or racks.
What are the two variables that determine the amount of entrained air in an oxygen entrainment device?
The size of the port on the air entrainment device.
The flow of the oxygen at the jet in the air entrainment device.
Ms. B. has a respiratory rate of 20 and an approximate tidal volume of 400 ml. What is Ms. B.’s approximate peak inspiratory flow need?
24 L/min.
