BRTP 05 Oxygen Therapy Equipment Flashcards
Nasal cannula
(LPM)- 1-6
(Oxygen %) 24-44%
Simple mask
(LPM) 5-10
(Oxygen %) 35-50%
Partial rebreathing mask
LPM 8 or greater
Oxygen %- up to 60%
Non rebreathing mask
LPM 8 or greater
Oxygen %- up to 70%
Air entrainment mask (Venturi mask)
LPM varies
% is constant 24, 28, 35, 50%
Oxyhood with heater humidifier
7 LPM or greater
21-100%
Briggs or T tube assembly
8-12 LPM (can go higher)
SaO2
% if hemoglobin saturated with oxygen
Mid 90s
96-99
Found in Blood test- very accurate
SpO2
Found with skin test- fairly accurate
Pulse oximetry
Composed of a photodetector sensor, a microprocessor, an infrared light emitter
Non invasive, transcutaneous technique for periodically or continuously monitoring the oxygen saturation of blood (SpO2)
PaO2
80-100 mmHg
3 types of oxygen delivery systems
Low flow systems
High flow systems
Reservoir systems
Low flow devices
Provide supplemental O2 directly to the airway at a flow of 8 L/ min or less.
O2 provided by a low flow device is always diluted with room air. The result is a low and variable FiO2.
Example: 8 L of flow + 22 L of room air is 30 L of flow
Normal inspiratory flow rate
30-40 L
Low flow explanation
Low flow is a minor assistance/ the patient will breathe but low flow helps add more flow.
Example: nasal cannula
What factors determine FiO2 delivered by a low flow system?
Patients ventilatory pattern
The flow going to the device
The patients tidal volume
Low flow O2 delivery systems include
Nasal cannula, nasal catheters, simple mask, tracheostomy collar
What is the determinant if the adequacy of a low flow 02 delivery system?
Patient observation and ABG assessment
What is the most commonly used low flow O2 delivery device
Nasal cannula
When is a humidifier used with a nasal cannula?
When the patient complains of nasal irritation/ drying or if flow rate exceeds 3-4 L/ min
Nasal cannula flow
1 L. 24% O2 2 L. 28% O2 3 L. 32% O2 4 L. 36% O2 5 L. 40% O2 6 L. 44% O2
Desired FiO2 formula
Desired FiO2=(desired PaO2 x current FiO2)/ Current PaO2
Desired PaO2 for normal person
80
Diaries PaO2 for COPD
60
Simple mask
O2 delivered at no less than 5L/ min
5-10 L/ min
O2 35-50%
Simple mask description
Fits over the nose and mouth and allows atmospheric air to enter and exit through side ports
Allows for higher level of O2
Used on patients who breath through the mouth
Allows some CO2 to be re-inhaled
Partial rebreather mask description
Patient inhales O2 from both the O2 source and O2 contained in the reservoir bag along with atmospheric air. Inhales higher concentration of O2 than a simple mask
Used in emergencies and short term
Sources of O2 are tubing, reservoir and room air
Partial rebreather flow rates
Minimum of 8-10 L/ min to prevent reservoir bag from collapsing more than 1/2 way.
If reservoir bag collapses more than 1/2 way, increase flow.
O2 variable at approximately 60%
Non rebreather mask description
Look similar to partial rebreather except they have 2 valves attached to device
This mask provides more O2 without the patient breathing their own CO2.
Flow rates for no breather mask
Flow 8-10 L/ min to prevent bag from closing more than halfway. If bag collapses more than halfway increase flow.
O2 70%
When is partial rebreather used
In emergencies, short-term therapy requiring MODERATE TO HIGH FiO2
When non rebreather is used and what affects performance
Emergencies, short term therapy requiring high FiO2
Affecting performance: liter flow into mask, size of reservoir bag, the fit of the mask
Nasal cannula flow
1-6 LPM
24-44% FiO2
add 4 for every liter
Simple mask flow
5-10 LPM
35-50%
Trach mask
8-12 LPM
FiO2 varies
Partial rebreather
8 or greater LPM
up to 60%
Non rebreather
8 or greater
Up to 70%
Dead space (VD)
Volume of gas that does not participate in diffusion across the alveolar capillary membrane
Air no blood flow
4 types of dead space
- Anatomical (normal)
- Alveolar
- Physiological
- Mechanical
Anatomical dead space
Dead space in airways that does not participate in gas exchange. (Also known as normal)
Alveolar dead space
Volume of gas ventilating unperfused alveoli
Physiological dead space
a combination of anatomical and alveolar dead space
Mechanical
Volume of expired air that is rebreathed through connecting apparatus or tubing
Rebreathing your own CO2
This will be with machine assistance (anything outside the body)
High flow O2 systems facts
Supplies a given O2 concentration at flow rates equaling or exceeding a patients peak Inspiratory flow (meets patients needs)
No room air will be used with high flow systems
This will have fixed and precise settings.
What kind of patient is high flow good for?
Good for patients with “marked” variation in minute ventilation
Marked means significant
Types of high flow?
Air entrainment masks (AEM) aka Venturi mask / or blending system
Both systems ensure a fixed or precise FiO2
How does a Venturi mask work
Mixes O2 and atmospheric air with color coded adapters that are regulated by a dial system allow specific amounts of room air to mix with O2z
EXACT AMOUNT OF O2 prescribed
Flow rates for Venturi mask (AEM)
Flow rates set to a varying range for constant O2 %: 24-50% (sometimes higher). (24,28,35,50)
What patient is a Venturi mask best for?
COPD Patients
Most appropriate O2 device for chronic CO2 patients in mild to moderate respiratory distress.
Bernoullis principle
As O2 from the outlet port is driven through the small jet hole, it’s velocity increases, the pressure around it drops and it entrains(draws in) air through the holes in the body of the device
Calculating total flow for high flow devices
Use tic tac toe
100 on top
20 on bottom
Given Fi02 in middle
Take the differences of 100 and 20 from the middle number
Have a fraction
Add numerator and denominator of fraction
Multiple product by initial prescribed flow
What would happen if the entrainment port was cover of occluded?
Flow goes down, O2 goes up
Something to remember about high flow
Increasing flow will never affect or create an increase in O2 concentration
CPAP (continuous positive airway pressure) devices
When a patient has a decreased functional residual capacity (FRC)
-sleep apnea, COPD, cardiogenix pulmonary edema. Immunosuppressed patients with pulmonary infiltrates, and hypoxia or atelectasis.
In order to use CPAP a patient needs to show what
That they can ventilate on their own.
CPAP Only helps with oxygenation, not ventilation
Advantages of CPAP?
Increases FRC (function residual capacity)
Increases lung compliance Can open collapsed alveoli Improve distribution of breath High total flows and FiO2 Increase removal of secretions
Disadvantages of CPAP
First 3 most important
- Barotrauma (excessive amounts of pressure)
- Gastric insufflation (stomach filled with air)
- Decreased venous return to the heart
Vomiting on aspiration
Requires adequate ventilation from patient
What kind of device does CPAP fall under
High flow O2 device
Aerosol delivery devices
Face shield Tracheostomy collar Aerosol mask Briggs or T tube assembly Oxyhood
Face shield (tent) description
Open on top, fits around lower face, used to avoid claustrophobia
Used for patients with facial trauma, facial/ nasal surgery or facial burns
If used with humidifier it will be COOL mist
Disadvantage of face shield (tent)
O2 can actually be inconsistent due to wide opening, may need tandem devices (2 nebulizers) to increase total flow
Tracheostomy collar
O2 deliver near artificial opening in neck (blow by or flow by O2)
Provides oxygenation and humidification because it bypasses the nose( the bodies nature humidifier)
Warm aerosol used.
Aerosol mask
Looks similar to simple mask but has larger holes in mask.
Heated or cooled, usually heated.
Used after surgery to help with swelling of throat or to administer drugs
Needs enough flow to flush out CO2
Briggs or T-Tube
Flow rates of 8-15 L/ min
“50 ml reservoir tubing to maintain FiO2”
“Adequate flow is demonstrated by visible mist”
Disadvantages of Briggs or t-tube assembly
Moisture accumulates, could go down patients lung
Weight of t tube could yank on trach and cause irritation and coughing
Maybe need double the devices to keep up flow
If reservoir detaches, the amount of inspired O2 will decrease
When you don’t know someone’s inspiratory flow rate what do you set it at?
60 will meet or exceed needs
Oxyhood
Usually set up with a heated humidifier for perspire infants, not a nebulizer
“Delivers precise amount of oxygen that is heated and humidified”
7 lpm or greater -21-100%
Oxygen (croup) tent
Large tent like device used to deliver high levels of oxygen to a bedridden patient requiring a cool environment.
Tent will cover entire head.
Recommended flow rate of 12-15 L/min to flush exhaled CO2 from the enclosure.
VARIABLE oxygen from 21-40%, up to 50%.
Incubator
Keeps babies heated, stable, and can add oxygen but it will be separate from incubator.
For infants in stable condition
premature infants/ infants use these.
NICU can add O2 if needed but will be from separate device.
Humidified High Flow Nasal Cannula (HFNC)
An oxygen delivery system which blends oxygen/ air from 21-100%.
Can be administered via wide bore nasal cannula or trach adapter from 1 Lpm to 60 Lpm.
Provides humidity enriched oxygen therapy for patients in mild to moderate respiratory distress.
Doesn’t augment tidal volume nor does it facilitate CO2 removal.
5 Key benefits to Humidified high flow nasal cannula (HFNC)
- Delivers a high FiO2 accurately
- Meets the patients ventilatory demands (inspiratory flow rate)
- Provides patient comfort and decreases work of breathing.
- May provide positive airway pressure.
- Optimizes mucociliary clearance.
Humidified HFNC benefits
Flow rate that exceeds patients inspiratory flow rate at various minute ventilation.
Can be used as a bridge from a more invasive O2 device to a noninvasive O2 device
Types of HFNC systems
Optiflow
Airvo 2
Vapotherm
Comfort flow
Optiflow and Airvo System
Flow rate ranges from 1 L/min to 60 L/min
Oxygen deliverey 21-100%
Delivered via nasal cannula or trach adaptor
4 cannula sizes
Vapotherm
Flow rates 1 L/min to 40 L/min
O2 delivery 21-100%
Delivery only by nasal cannula
7 different sizes
CAN BE USED FOR IN HOSPITAL TRANSIT
REMEMBER THIS SYSTEM HAS LESS FLOW CAPPING AT 40 L/MIN
Comfort flow
Flow rates 1 L/min to 60 L/min O2 delivery 21-100% Heated/humidified using conchatherm or conchasmart tech Delivered via nasal cannula 4 different sizes
How should you wean from HFNC?
It is recommended that oxygen be weaned to 30% as tolerated, THEN begin to decrease the flow.
Adult- 10 L/min then change to conventional cannula
Pediatric- 6 L/min then change to conventional cannula
Neonate- 2 L/min then change to conventional cannula
Oxygen toxicity
Lung damage that develops when O2 concentrations of more than 50% are administered for longer than 48-72 hours.
TWO PRIMARY FACTORS DETERMINE THE HARMFUL EFFECTS OF O2 TOXICITY
- FiO2
- EXPOSURE TIME
COPD AND HYPOXIC DRIVE
Normal PaO2 for COPD patient is 60 mmHg
Raising PaO2 above 70 mmHg with supplemental O2 may “knock out” the COPD patients hypoxic drive and cause hypoventilation. (PATIENT WILL BECOME DROWSY OR SOMNOLENT)
What devices and FiO2 do you want to stick to for COPD patients?
We want O2 devices that are low in FiO2 less than 30% FiO2
We want low flow nasal cannulas and venturi masks
1-2 lpm nasal cannulas
24-28% AEM (venturi mask)
With what exception would you give a COPD patient high FiO2?
One exception is during resuscitation (CPR)
Use 100% FiO2
With what exception would you give a COPD patient high FiO2?
One exception is during resuscitation (CPR)
Use 100% FiO2
With what exception would you give a COPD patient high FiO2
One exception is during resuscitation (CPR)
Use 100% FiO2
Pulse Oximetry
Oximetry utilizes a probe that transmits two wavelengths of light, red and infrared, from a light emitting diode to a photo detector through a capillary bed.
Capillary beds commonly utilized are those found in the finger, toe, or earlobe
Red light associated with deoxygenated
Infrared is associated with oxygenated
What oxygen saturations are pulse oximeters accurate for?
Accurate for oxygen saturations higher than 80%.
lower than 80% indicates its not accurate
What is the minimum value acceptable for O2 saturation?
90%
What does an oxygen saturation less than 90% warrant?
Warrants an increase in delivered oxygen percent to the patient and a physician should be contacted.
What is SaO2?
The amount of oxygen bound to hemoglobin
Found with an ABG
What is SpO2?
Oxygen saturation measured by a pulse
The % of Hb that is fully saturated
PaO2
Amount of oxygen dissolved in the blood plasma
Found with ABG
With normal pH and temp, This O2 correlates to PaO2 via ABG analysis
90% O2 saturation to a PaO2 of 60 mmHg
Normal SpO2
Normal is 98-99%
Other ranges in SpO2
Acceptable for normal people: anything greater than 95%
Acceptable for a COPD patient: 88%
Acceptable in a sick patient: anything less than less than 90%
(A really sick patient may have a SpO2 in the 80’s)
What are some indications for Pulse oximetery
When receiving supplemental O2
When weaning patients patients from mechanical ventilation
During sleep apnea studies
During cardiopulmonary stress studies
To determine if an arterial blood gas sample is arterial or mixed venous blood by comparison of saturations
(IF ABG IS DRAWN IT VERIFIES IF NEEDLE POKE ACTUALLY HIT ARTERY)
Factors that affect accuracy of pulse oximeter?
External bright Patients with weak or absent peripheral pulses, low perfusion states Motion artifact (moving around too much) Artificial or painted nails Skin pigmentation Injection of radiographic dyes
What is Methemoglobin?
Oxidized hemoglobin
Saturations read around 85%
(falsely low at high SpO2, falsely high at low SpO2)
What Carboxyhemoglobin?
Carbon monoxide poisoning
CO bind to O2 with 250 times the affinity of O2
Readings are artificially high
percentages related to Carboxyhemoglobin
Normally less than 5%
Smokers will be 9% or less
Symptoms of CO poisoning start at 15-25% (headache, nausea, fatigue)
Above 30%: dizziness, mental confusion, sever headache, fainting
50% unconscious or death
Treatment for CO poisoning is 100% O2
How to ensure accuracy of pulse oximeter?
Compare actual counted heart or ECG rate to the displayed heart rate on the oximeter.
Also look at pleth ( mountain like outline that goes up and down for heart beat)
Irregular pleth or straight line (you can’t trust the reading)
Probe placement for pulse oximeter?
Adults: fingers, toes, earlobe
(preferred: non dominate hand)
Children: hand, wrist, foot
What does pnuematically powered mean?
Powered by a compressed gas
How do you know if you patient needs humidity?
Dry cough aka a nonproductive cough nose bleeds increased work of breath increased incidence of infections thick secretions
Atelectasis
What are the four factors that effect the efficiency of humidifiers?
- Temperature
- Time expose
- surface area
- Depth of water in reservior
What does inpissated mean
Thickened, dried, or made less fluid by evaporation.
Humidity deficit results in?
impairs ciliary activity atelectasis pneumonia inflammation retention of tenacious secretions
What is a servo controlled humidifier?
Heated humidifier that regulates the delivery temperature
shuts down heater if theres no water in it
Like a heater in a house it comes on/off when needed
What does inpissated mean?
Thickened, dried, made less fluid by evaporation
What are four factors that effect humidification?
contact time, temperature, surface area, depth of water reservoir
Humidity is water in what form?
Molecular form
Less chance of carrying germs
will be invisible
What is bland aerosol?
- sterile water
- hypertonic saline (has extra salt)
- isotonic saline (this is normal saline in body)
- hypotonic saline (thick secretion)
Why would we want to heat the nebulizer?
Increasing the temperature will carry moisture
What is the purpose of a baffle?
Makes particles smaller
What should you do if your nebulizer is not producing mist?
Make sure jet is inside
What does pneumonic mean
Powered by compressed gas
What type of matter do aerosols produce?
Particulates
What type of matter do aerosols produce?
Particulates
How do you add humidity to an AEM( venti) mask?
Large volume nebulizer
How do you estimate inspiratory flow?
Inspiratory flow aka minute ventilation
VE= Tidal volume x Respiratory rate
When do you need an analyzer?
When FiO2 needs to be known:
COPD patient oxyhood briggs adaptor mist tent trach collar
What does a whistling bubble humidifier mean?
Bubble humidifiers have a safety pressure relief or pop off valve
It will whistle and pop up to RELEASE EXCESSIVE PRESSURE
(can be caused by high flow or kinked tube)
what is an aerosol?
Aerosol is the suspension of solid or liquid particles in a gas
Medical aerosols generated by nebulizers, inhalers, and atomizers
REMEMBER AEROSOLS AND NEBULIZERS DELIVER PARTICULATE MOISTURE
FACTORS AFFECTING PARTICLE DEPOSITION?
intertial impaction (tend to follow same path)
sedimentation (larger particles are deposited)
size (larger particles deposit faster)
diffusion (movement from an area of higher concentration to an area of lower concentration)
inertial impaction
Inspiratory flow rates greater than 30 L/min associated with increased inertial impaction
Larger the particle the more likely to move alone in a set path.
turbulent flow
Larger particles are deposited
Sedimentation
Particles are deposited due to gravity
Sedimentation is main reason for deposition of particles
diffusion
most aerosol particles reach the lungs by diffusion
Increased deposition factors
Patient factors: larger Vt, Longer inhalation, breath hold
Other:
Flow- higher the flow the smaller the particle size
Jet orifice: larger the orifice, larger the particle size
Humidity increases particle size
Bernoulli’s principle
A fall in pressure in a flowing fluid must always be accompanied by an increase in the speed
How to avoid contaminating reservoir
Change water, wash hands, avoid touching inside of reservoir
How do jets work?
compressed air expands, and increases velocity
expanding air causes an under pressure and liquid is sucked up to the air orifice
liquid meets rapidly expanding air, forming droplets
the droplets are carried on the air to the baffle system
How are large volume nebulizers powered and what about their flow rates?
Pneumatically powered ( powered by compressed gas)
Flow rates meet or exceed patients inspiratory demand
How do do you determine total flow?
Use magic box
(tic tac toe)
100 on top
20 on bottom
current Fio2 in middle
Heated large volume nebulizers
Used to humidify( add water content) to gas delivered to patients
( this was large container of liquid that screwed into flowmeter)
Flow rates for small volume nebulizer
Most effective flow rate is 7-8 L
5 L for infants only
The higher the flow the smaller the particle size
Flow for Large volume nebulizers
Typical flows 10-15 L
Need to see mist on inspiration
May need to “t” another flowmeter to provide adequate flow
Electrochemical analzyers
calibrate at both 100% O2 and 21% room air before using.
Galvanic analyzers have fuel cells
Polarographic analyzers use batterys
PRN
SB
DC
PRN (as needed)
SB (standby)
DC (discontinued)
