Oxygen Therapy Flashcards
Difference between high flow and low flow?
You know exactly how much FiO2 is being delivered.
Hypoxia vs. hypoxemia?
Hypoxia: low O2 in tissue
Hypoxemia: low O2 in blood
Cause of peripheral cyanosis?
Peripheral ⬆️ O2 intake
Areas of central cyanosis?
Skin, mucous membranes, lips, tongue, and nail beds (associated with arterial desaturation)
Mild hypoxemia PaO2 range?
60-79 mmHg
Mild Hypoxemia SaO2 values?
90-94%
Moderate hypoxemia PaO2 range?
40-59 mmHg
Moderate Hypoxemia SaO2 values?
75-89%
Severe hypoxemia PaO2 range?
<40 mmHg
Severe Hypoxemia SaO2 values
<75%
Mild hypoxemia symptoms?
Tachycardia
Tachypnea
Headache
SOB
Coughing
Wheezing
Confusion
Cyanosis:
Skin
Fingernails
Lips
Early stage: severe hypoxia/hypoxemia
Skin color change:
Blue-cherry red
Confusion
Cough
⬆️ HR
Rapid breathing
Later stage: Severe hypoxia/hypoxemia
Sweating
Severe SOB
Bradycardia
Bradypnea
Lethargic
Chronic Response to Hypoxia?
Pulmonary vasoconstriction
Pulmonary hypertension ⬆️ work of the right side of the heart (JVD)
O2 can reverse
Condition for Medical Oxygen Use
Anesthesia
COPD
Cyanosis
Shock
Severe Hemorrhage
Carbon monoxide poisoning
Major trauma
Cardiac/respiratory arrest
Nasal catheter flow?
1/4-6L/min
FiO2 for nasal catheter?
0.22-0.45
How often should nasal catheter be replaced?
Every 8 hours
Nasal cannula flow rate?
1/4-6L/min
Nasal cannula FiO2 delivery factor?
How much the patient inhales and mouth breathing
At what flow rate for the nasal cannula should a bubbler be used?
4L/min and up
FiO2 delivery for the nasal cannula?
22-45%
How many FiO2 increases per 1L/min?
4%
Advantage of nasal cannula?
Used on adults ➡️ infants
Easy to apply
Disposable
Low cost
Well tolerated under 6L/min
Disadvantages of nasal cannula
Unstable FiO2
Easily dislodged
Flow ⬆️ 6L/min may be uncomfortable
Can dry nose and cause bleeding
Polys or deviated septum can block flow
Best use for the nasal cannula?
Stable pt. Who need low FiO2
Home care needing long term O2 therapy
Flow rate for salter high flow NC
1-15L/min
When should a humidifier be used with a salter high flow NC?
Above 4L/min
Flow rate for the Transtracheal catheter
1/4-4L/min
Transtracheal catheter FiO2 delivery difference compared to NC?
Uses 40-60% less O2 to oxygenate the same amount
Complication and task for Transtracheal catheter?
Careful maintenance and cleaning
Infection is a possibility
Advantages of Trans tracheal catheter?
Reduce O2 flow required for saturation
Improves activity and mobility
Improves physical, social, and psychological function
Improves compliance (daily duration of O2 use)
Trans tracheal catheter disadvantages
Requires mandatory outpatient surgical procedure
Potential for infection
Tracheal irritation
Mucus accumulation
By what percent can reservoir cannulas reduce O2 use
50-75%
Is humidification used with reservoir cannula?
Not usually (can’t be used)
How much O2 does reservoir cannula hold?
20ml during exhale
How much is the flow reduced with the reservoir cannula?
50%
Does pt. need to take breaths through the nose?
Yes
Disadvantages of pendent reservoir cannulas?
Can be heavy
Disadvantages of reservoir cannula?
Pt. Object appearance
Liters for simple mask?
5-10L/min
FiO2 of simple mask?
35-50%
What causes FiO2 variability in simple mask?
Air dilution through mask ports
Input flow
mask volume
Extent of leakage
Breathing patterns
Advantages of simple mask?
Infants-adults
Quick and easy application
Disposable
Low cost
Disadvantages of simple mask?
Uncomfortable/ claustrophobia
Must be removed to eat or drink
Prevents heat loss
Blocks vomit
Best use of the simple mask?
Emergencies
Short term therapy requiring moderate FiO2
Partial rebreather FiO2 delivery?
40-70%
Minimum L/min of partial rebreather?
6-10L/min
Partial rebreather advantages?
Moderately high FiO2
Infants-adults
Quick, easy application
Disposable
Low cost
Disadvantages of partial rebreather?
Potential of suffocation
Uncomfortable/claustrophobia
Must be removed for eating and drinking
Prevents heat loss
Blocks vomit
Best use for the partial rebreathing mask?
Emergencies
Short term moderate FiO2
Non-rebreathing mask FiO2?
60-80%
Minimum non-rebreathing flow?
10L/min to flush
Which is more used between the partial and non rebreathing?
Non-rebreathing
How does Non-rebreathing work?
Has one-way valves that prevents rebreathing
Slightly negative pressure closes expiratory valves while opening inspiratory valves
Advantages of non-rebreathing mask?
High FiO2
Infants to adults
Quick and easy application
Disposable
Low cost
Disadvantages on non-rebreathing
Potential of suffocation
Uncomfortable/claustrophobia
Must be removed to eat or drink
Prevents heat loss
Blocks vomit
Best use for non-rebreathing mask?
Emergencies
Short term high FiO2
Heliox therapy
Guidelines for low flow assembly?
Use bubbler above 4L/min
Line up threads
With heated humidifier or Neb use large-bore corrugated tubing with water traps/drain to avoid blockage by condensation
Liters for flush?
40-60
Interface for entrainment?
Mask
T-piece
Trachea collar
Tent
What principle does entrainment use?
Bernoulli principal
Principal of operation for air entrainment
Direct high pressure through a small nozzle or jet surrounded by air entrainment ports
Amount entrained depends on size of port and velocity of O2 at jet
Bigger ports and jets = less FiO2 and more flow.
Cause for variability in FiO2 delivery from entrainment?
Air to O2 ratio
Amount of flow resistance downstream from the mixing site
FiO2 range for air entrainment?
24-50%
Air entrainment liter range?
2-15L/min
Can you deliver less liters than in the air entrainment piece?
No, FiO2 is no longer guaranteed
Inspiratory peak flow need formula?
Minute ventilation (3)
Delivered flow calculations?
100-FiO2/FiO2-21 (add one)
Multiple by liters on piece or ideal
Can you deliver 100% FiO2 with entrainment?
No. Not able to meet the patients inspiratory flow needs.
Advantages of Venturi
Easy to apply
Disposable
Inexpensive
Stable precise FiO2
Disadvantages of Venturi
Limited to adults use
Uncomfortable
Noisy
Must be removed for eating
FiO2 greater than or equal to 35% not assured
Best use for Venturi?
Unstable patient requiring a precise FiO2
Types of bland aerosolize delivery devices?
Jet Nebulizers
Cool
Heated
Ultrasonic Nebulizer
Principal of Operation of cool large volume jet Nebulizers
Pneumatic
Liquid aerosols generate by passing through small jet
Low pressure at the jet draws fluid up reservoir to top of the siphon tube where it sheared off and shattered into liquid particles
Largest unstable particles fall out of suspension
Remaining particles leave thru outlet port carried away by gas stream
Assessment of adequate aerosol delivery
Delivered relative humidity is 100% if condensate is seen in tubing near airway
Must see mist befit putting interface on patient
No mist indicates air dilution/ not enough flow
This turns a high flow to a low flow
Indications for cool, bland aerosol therapy?
Upper airway edema
Laryngotracheobronchitis
Subglottic edema
Post-op upper Aw management
Presence of a by-passed upper Aw
Need for sputum or mobilize secretions
Flow for Oxymask?
1-flush
FiO2 for OxyMask?
24-90%
Cause for variation in FiO2 from OxyMask?
Respiration rate
Depth of breathes
Distance of diffuser
How does Virtual reservoir system work?
Virtual reservoir formed by a vortex of O2 flow to patients pt. nose and mouth through pin and diffuser
Open design allows CO2 to escape
Advantages of OxyMask?
Higher humidity room air is brought in negating humidification
Feels less confining
Allows: communication, drinking, and talking
Blending-system HHFNC principal of operations?
Two 50 psi pass through dual pressure regulator that matches pressures
Gas flows to a precision proportioning valve
Proportional size allow control over relative concentration of each gas
Devices that use O2 blender?
Heated high flow O2
NIV
Ventilator
Hoods
Temperatures capable with heated humidifier?
30-39 degrees Celsius
Relative humidity delivered from heated humidifier?
Up to 100%
What is the point of the heated wire in the heated humidifier?
Reduce condensation in tubing
Hazards for heated humidity?
Electrical shock
IF NOT SET PROPERLY:
Hypothermia
Hyperthermia
Burns to clinician and patient
Tubing melt down
Pooled contamination can result in:
Pt./ventilator asynchrony
Tracheal lavage
Nosocomial infection
Types of HHFNC
Vapotherm precision flow system
Airvo
Fisher and paykel’s optiflow
FiO2 range for HHFNC
24-95%
Adult-infant HHFNC flow range?
Adults 1-60L/min
Children 1-20L/min
Infant 1-8L/min
PEEP and flow purpose with HHFNC?
Generates a distending positive airway pressure
The higher flows washout anatomical deadspace
Advantages of the HHFNC?
Easy to apply
Provides gas at BTPS without condensation
Meets/exceeds non-rebreather performance
Decreases anatomical deadspace (CO2 washout)
Disadvantages of HHFNC?
Stable precise FiO2 requires special cannula and humidification
Can create CPAP
Potential electrical risk
Some units associated with contamination/infection
Best use for the HHFNC?
An alternative for the non-rebreather
An alternative for nasal CPAP
To facilitate weaning from mechanical ventilation
PATIENTS WITH:
Claustrophobia
Facial burns
Hypothermia
Why we choose nasal cannula?
Comfortable so preferred by patients
Even though they aren’t as effective we are more ensured compliance
Tracheotomy patient is on a LVN but is on his way to an X-ray?
Patient must be switched to a venti-trach collar
Pt. has a low SpO2 <85: initial and target device?
Non-rebreather or oxymask (emergency mask)
Eventually HHFNC
Oxygen hazards
Oxygen toxicity
Absorption atelectasis
Abolition of hypoxia drive
Retinopathy of prematurity
What is oxygen toxicity?
Over production releases free radicals by cellular metabolism
This can overwhelm the body’s antioxidant system and kill cells
This will trigger MAC and Neutrophils which will release inflammatory mediators that worsen injury
Signs of oxygen toxicity?
Pleuritic chest pain
Sub-sternal heaviness
Coughing
Dyspnea
What is Absorption atelectasis?
High O2 will prevent nitrogen which usually keeps alveoli’s open
Also, since no diffusion of N2 into capillaries, venous pressure drops.
Greater than what FiO2 is a risk of absorption atelectasis?
Any FiO2 greater then 50%
What is Abolition of hypoxic drive?
Small amount of COPD patients will not be able be triggered by high CO2 decreasing ventilation by 20% increasing CO2 20-23mmHg
They rely on low O2 for ventilation
Broncho-pulmonary dysplasia
Affects newborns (premature) and infants
Results from damage of lungs from vent and supp O2
Most babies recover, but some have long term breathing difficulties
Intraventricular hemorrhage in infants
Concentration of O2 can cause vasodilation in premature infants which can altar cerebral blood flow
Retinopathy of prematurity/Retrolental Fibroplasia?
Causes retinal vasoconstriction leading to necrosis of the blood vessels
New vessels form
Hemorrhage of vessels causes scarring behind retina
Scarring can lead to retinal detachment and blindness
Infants up to one month
How to prevent O2 hazards?
Monitoring close
Weaning
Accept low O2 in pop. (Infants and COPD)
Capacity of bulk systems?
Greater than 20,000 cubic feet
Alternative names of bulk supply containers?
Stand tanks, vessels, or dewars
Bulk gas delivery?
Liquid O2 passes through vaporizer
Now gas goes through reducing valve dropping pressure to 50 psi
Bodies/agencies in charge of design, construction, and delivery?
National Fire Protection Association
The American Society of Mechanical Engineers
Bureau of Explosives
The Joint Commission
Where is the bulk primary shut off valve?
Exit at the point where the main distribution pipe leaves the bulk supply
Description and Function of Bulk System?
Generally backup or reserve systems
Alternating or manifold cylinder supply system (“H” cylinders together in series)
Once empty, replaced with full
Bulk Gas Delivery System regulating body ?
Regulated by NFPA
Piping distribution systems include?
Pipes
Pressure relief valves
Zone valves
Alarms
Station outlets or terminal units
What pipes are used for distribution systems
Seamless “K” or “L” copper or brass pipes
Labels on piping
Labeled with type and flow direction every 20’
Pipes?
Main line:
Connects to operating supply
Risers:
Connect to main line
Branch lines:
Travel from risers to individual rooms
What are pressure relief valve set at?
50% greater than normal line pressure
Safety features/ test done for O2 piping Systems?
Pressure tested, checked for leaks, and checked for cross connections
Test on primary and reserve systems and their switch over mechanisms conducted
Pressure valves, zone valves and terminal units are monitored
What does the National Fire Protection Association regulate?
Where system can be located in relationship to buildings surrounding structures
What Does The American Society of Mechanical Engineers Regulate?
How systems are designed and construction of the storage containers
What Does The Bureau of Explosives Regulate?
Regulates the pressure relief valves used in the system
What is The Joint Commissions Job?
Ensures that hospitals are complaint with regulations
Thorpe Tube Function and Structure?
Attach to 50 psi source
Measures true flow. Involves fluid and gravity dynamics
1-40 or 60 L/min (flush)
Diameter increases from bottom to top
When flowmeter is on follow pushes against float
As float rises flow around it increases due to wider diameter beneath
Compensated Thorpe Tube
Have a needle valve downstream from float
Gas moves through float so density remains constant regardless of back pressure (kink)
What are cylinders made of?
Steels, aluminum, or chrome molybdenum
How much pressure does a cylinder hold?
Excess of 2,000 psi
Most frequently used tank size?
E tank
Helium tank color?
Brown
Hydrogen tank color?
Red
Nitrogen tank color?
Black
Carbon dioxide tank color?
Grey
Air tank color?
Yellow or black and white
Carbon dioxide and oxygen tank color?
Grey shoulders and green body
Nitric Oxide Tank Color?
Silver cylinder or teal and black
Nitrous Oxide Tank Color?
Light Blue
Oxygen Tank Color
Green or White
What does the cylinder labeling tell us?
Industrial or medical
Hazards associated and how to prevent them
Proper handling, storage and first aid
Company that filled
UN number and pictogram
Cylinder testing?
Hydrostatic testing every 5-10 years
Pressure testing at 3,000 psi
Dates of testing are engraved
What must be Done Prior to Cylinder filling?
Cleanliness and safety must be ensured prior to filling
Four Step Process of Filling Cylinder?
Prefilled inspection
Filling cylinder with gas
Check valve for leaks
Check purity standards
Cylinder valves details?
Needed to attach equipment for delivery
To ensure no leak
For small cylinders attached to yoke
Made of chrome, brass and made to resist mechanical, chemical, and thermal effects of gas
Three Types of Pressure Relief Valves?
Rupture disk:
Thin metal disc for certain pressure and breaks apart
Fusible disk:
Metal alloy that melts at 208-220 degrees Fahrenheit (97.8-104 Celsius)
Spring-loaded devices:
When pressure exceeds pressure pushes up on the spring and causes valve to be unseated
Use of The American Standard Safety System?
Prevent wrong gas delivery
H or K tanks
ASSS connection differences
Thread type and size
Right and left-handed threading
Internal and External threading
Nipple-seated design
Use for Diameter Index Safety System?
Cylinders with pressure lower then 2000 psig
Safety features for the DISSS
Contains a body, nipple, and a nut assembly
The shoulders of nipple allow nipple to unite
Pin Index Safety System
Smaller cylinders(A through E)
Each gas has a specific pin index
Pressure above 2000psig
Safety feature for PISS
Yoke not thread
Where yoke attaches to cylinder, has corresponding pins
2-5 for Oxygen
1-5 for Air
“D“ cylinder conversion factor?
0.16
“E” Cylinder Conversion Factor?
0.28
“G” Cylinder Conversion Factor?
2.39
“H or K” Cylinder Conversion Factor?
3.14
Duration for Cylinder Formula?
Tank psi(factor)/liters
Duration for Liquid Oxygen System Formula?
Convert pounds to volume by multiplying by 344 liters for each pound
Divide by liters
Bulk system ideal conditions?
Either bank of high-pressure cylinders or industrial compressors (can be both)
At least two compressors needed on site
Compressed air cooled for vapor rain-out
How Many Bulk Compressors on site?
At least two compressors needed on site
How Many Valves Does a Direct Cylinder Valve Have?
A 3 port valve
Direct Cylinder Valve in the normal position is?
Closed
Direct Cylinder Valve Has a Button that?
Must be held down for as long as the cylinder is outstroked
Rules for Handling Cylinders?
Secure
Do not use flammable material on regulators, cylinders, fittings, or valves
Crack or open slightly to remove dust before attaching regulator
Post no smoking
Store flammables separately from gas as that support combustion
Reason for alteration of AW muscle tone?
CNS depression (drug O.D.)
Anesthesia
Cardiac arrest
Loss of consciousness
Sleep apnea
Loss of consciousness diminishes what reflex’s?
Swallow
Gag
Laryngeal
Tracheal
Carinal
Causes of partial or complete blockage of breathing passage?
Posterior displacement of tongue (most common)
Presence of foreign matter
Allergic reaction
Infection
Anatomical abnormalities
Trauma
How can you assess patients patency?
Awake patients will let you know
Not awake listen for lack of breath sounds, or chest rise
First step for AW management?
Airway positioning
Will basic airway management protect against aspiration, vomit?
No it does not. Keep suction at hand
What is the gold standard for securing the airway?
Intubation
By what percent does CO2 increase with abolition of hypoxia drive
20%
20-25 mmHg
