Oxygen
Therapy
Rhonda Contant, BScH, RRT
Let’s Start with the Basics!
 How
much O2 is in room air?
 How
much O2 comes out of a flowmeter?
3
Oxygen Therapy
O2 delivery systems: design and performance
Three basic designs exist
1.
Low-flow systems
2.
Reservoir systems
3.
High-flow systems
We need to answer 2 key
questions…
1.
How much O2 can the system deliver?

2.
What is the FiO2 or FiO2 range of the
device?
Does the FiO2 vary or remain fixed with
changing pt demands?
Fixed or Variable FiO2?
 Depends
on how much of the pt’s
inspired gas the device delivers
Fixed or Variable FiO2?
 Fixed

FiO2
The device is designed to deliver ALL the
pt’s inspired gas  FiO2 is constant or fixed
Fixed or Variable FiO2?
 Variable
FiO2

The device provides only SOME of the
inspired gas

The pt must draw the rest from the
surrounding environment (room air)

What happens if we mix O2 with room air?
 Dilutes

the delivered O2  lowers FiO2
The result = variable FiO2 from breath to
breath depending on pt demands
Low Flow Systems:
 Uses
 They
low flows (< 8 Lpm)
are variable systems therefore the
pts demands will affect the FiO2
9
Low Flow Systems:
Nasal cannula

Delivers an FIO2 of 0.24 to 0.40

Used with flow rates of ¼ to 8 L/min

FIO2 depends on how much room air the patient
inhales in addition to the O2.

Device is usually well tolerated.

Humidifier should be used with flows > 4 Lpm
10
Nasal Prongs / Cannula
Mosby items and derived items © 2009 by
Mosby, Inc., an affiliate of Elsevier Inc.
How to Estimate the FiO2 for
Nasal Cannula:
 FiO2
= 21% + (4 x #Lpm)
 Example:
What is the approximate FiO2
when the flow meter is set at 2 Lpm?



FiO2 = 21% + ( 4 x Lpm)
FiO2 = 21% + ( 4x 2)
FiO2 = 29%
Reservoir Systems
 Incorporate
a mechanism to gather and
store O2 between pt breaths
 Pts
draw from this reservoir when their
inspiratory flows exceed the oxygen flow
delivered by the device
 Instead
of diluting with room air, they
dilute with O2  results in a higher FiO2
13
Reservoir Systems
Reservoir cannula

Designed to conserve oxygen
 Nasal reservoir
 Pendant reservoir

Can reduce oxygen use as much as 50% to 75%

Humidification usually not needed
Moustache Reservoir Cannula
Pendant Reservoir Cannula
16
Reservoir Systems
Reservoir masks

Most commonly used reservoir systems

Three types
 Simple mask
 Partial rebreathing mask
 Nonrebreathing mask
I
n
c
.
17
Simple Mask
Mosby items and derived items © 2009 by
Mosby, Inc., an affiliate of Elsevier Inc.
18
Partial and Non - Rebreathers
Mosby items and derived items © 2009 by
Mosby, Inc., an affiliate of Elsevier Inc.
19
High Flow Systems

Supply a given (or fixed) O2 concentration at a
flow equaling or exceeding the patient’s peak
inspiratory flow

Use air-entrainment or blending system to mix air
and oxygen at very specific ratios to determine a
specific oxygen concentration

Can ensure a fixed FIO2
20
Air Entrainment or Venti Mask
Mosby items and derived items © 2009 by
Mosby, Inc., an affiliate of Elsevier Inc.
High Flow Jet Nebs
22
Equipment for Aerosol Therapy
Airway appliances




Aerosol mask
Face tent
T-tube
Tracheostomy mask
All used with large-bore tubing
23
Equipment for Bland
Aerosol Therapy
Equipment for Bland
Aerosol Therapy
How do we know what to use?
 Nasal

Cannula
Uses:
 Stable
pts requiring low FiO2
 Home care pts requiring long term O2

Advantages
 Adults,
peds and infants
 Easy to apply
 Disposable, inexpensive
 Well tolerated
 Can eat with them in place
How do we know what to use?
 Nasal

Cannula
Disadvantages
 Easily
dislodged
 High flows uncomfortable
 Can cause dryness and bleeding
 Variable FiO2s
How do we know what to use?
 Reservoir

(NRBR)
Uses
 Emergencies
 Unstable
pts (MI)
 Acute hypoxemia
 Smoke inhalation / CO poisoning
 CHF
How do we know what to use?

Reservoir (NRBR)

Advantages
High FiO2
 Adults and peds
 Quick and easy to apply
 Disposable and inexpensive


Disadvantages
Uncomfortable
 Can’t eat with mask on
 Risk of aspiration if pt vomits
 Potential suffocation hazard

How do we know what to use?

Venti mask

Uses:



Advantages:




Unstable pts requiring precise low FiO2
Pts with variable RR and Tidal Volume
Easy to apply
Disposable and inexpensive
Stable, precise FiO2
Disadvantages:




Uncomfortable
Can’t eat with mask on
Noisy
Risk of aspiration if pt vomits
How do we know what to use?

Large Volume (Jet) Nebulizers

Uses:




Advantages:



Pts with artificial airways
Pts with supraglottic swelling
To help mobilize secretions
Provides humidification
Provides fixed FiO2
Disadvantages:


FiO2 varies with back pressure (ie condensation in
tubing)
Increased risk for infection
FYIs

O2 is a prescribed drug

For every connection there is a possibility for a
leak

Vasoline and O2 don’t mix  use a water
based lubricant to treat nasal and lip dryness

When in doubt, call RT, we are there to help!!
Questions?