Transcript Oxygen Therapy
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 3.
2.
Oxygen Therapy O 2 delivery systems: design and performance Three basic designs exist 1.
Low-flow systems Reservoir systems High-flow systems
We need to answer 2 key questions… 1.
How much O2 can the system deliver?
What is the FiO2 or FiO2 range of the device?
2.
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 low flows (< 8 Lpm) They are variable systems therefore the pts demands will affect the FiO2
9 Low Flow Systems: Nasal cannula Delivers an F IO 2 of 0.24 to 0.40
Used with flow rates of ¼ to 8 L/min F IO 2 depends on how much room air the patient 2 .
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 .
Simple Mask 17 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) O flow equaling or exceeding the patient’s peak inspiratory flow 2 concentration at a 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 F IO 2
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
Equipment for Bland Aerosol Therapy 23
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:
Unstable pts requiring precise low FiO2 Pts with variable RR and Tidal Volume
Advantages:
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:
Pts with artificial airways Pts with supraglottic swelling To help mobilize secretions
Advantages:
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!!