Oxygen TherapyRhonda Contant, BScH, RRT

Let’s Start with the Basics! How much O2 is in room air?

How much O2 comes out of a flowmeter?

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Oxygen TherapyO2 delivery systems: design and

performance

Three basic designs exist1. 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?

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

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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

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Nasal Prongs / Cannula

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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

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Reservoir SystemsReservoir 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

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Reservoir SystemsReservoir masks Most commonly used reservoir systems

Three types Simple mask Partial rebreathing mask Nonrebreathing mask

Inc.

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Simple Mask

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Partial and Non - Rebreathers

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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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

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Air Entrainment or Venti Mask

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High Flow Jet Nebs

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Equipment for Aerosol Therapy

Airway appliances Aerosol mask Face tent T-tube Tracheostomy mask

All used with large-bore tubing

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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: 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!!

Questions?