07oxygen admin dev student3 - Amarillo College · 2017. 3. 27. · • Tents are used primarily to...
Transcript of 07oxygen admin dev student3 - Amarillo College · 2017. 3. 27. · • Tents are used primarily to...
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RSPT 1410 Oxygen Administration Devices Part 3
Cairo: Chapter 3, p. 64-78 Wilkins: Chapter 38, p. 872-891
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High-flow Devices
• High-flow Nasal Cannula – AquinOx, Comfort Flo, Vapotherm
• Delivery of high flow oxygen via facemasks creates compliance issues – Facemasks cover the entire mouth and nose
preventing eating and talking and removing them can lower oxygen saturation levels
– Facemasks can be difficult to fit, can become dislodged during sleep, and cause undue stress
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High-flow Devices
• A better way to administer high flow oxygen therapy is through a nasal cannula – The nares can typically only tolerate up to
______ L/min due to the cold and dry composition of oxygen
– Flows higher than 6 L/min can be too uncomfortable to endure and could possibly cause trauma over long periods of time
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High-flow Devices
• With the newer high-flow cannulas, patients can tolerate high flow oxygen therapy directly through the nose, due to the systems’ ability to provide ______________ and ______________ oxygen
• For example, the AquinOx provides – High flow oxygen delivery from ____ to ____ L/min – A flow rate dependent temp range of 33°C to 40°C – Relative humidity of ____% to _____% – Single patient therapy per unit
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HFNC - What It Does
• In the past, it was thought that FiO2 would plateau at 6-8 L/min
• Recent studies show FiO2 increase over the tested range of 10-30 L/min
• The gas must be ______________ – Body core temperature – 100% relative humidity
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HFNC - What It Does
• Possible Benefits – Increased FiO2
– Oxygen at BTPS can add significant moisture to the airways • Stabilizing and protecting effect • Enhances ciliary movement & mucus clearance
– May flush anatomic deadspace
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HFNC - What It Does
• Possible Benefits – Creation of low levels of ______________
• Useful in treating neonates and in some cases of adult sleep apnea
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HFNC – How is it Used?
• In place of NRB masks – Clinical report: CHF pts in the ED had higher SaO2s
with a 20 L/min HFNC
• A method to avoid CMV – Clinical report: pts with mean SaO2s of 88% and with
mean RR of 25 avoided CMV – Clinical report: one hospital had a 51% decrease in
CMV
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HFNC – How is it Used?
• To deliver ______________ and ______________
• To improve exercise tolerance in asthmatics and COPD pts
• Traumatic and post-op ______________ • To treat AOP • To help lung transplant pts exercise and tolerate
pre-conditioning prior to surgery
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HFNC – Set-Up
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HFNC – How It Works
• Breathing gases are introduced at the gas input port on the AquinOx™ Humidification Chamber
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HFNC – How It Works
• The pressurized gas flows over two orifices – The first, causes a
suction that siphons sterile water from the reservoir through the up tube into the AquinOx™ Humidification Chamber
– The second, causes a suction through the secondary tube that is connected to the center lumen of the Delivery Tube
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HFNC – How It Works
• As the sterile water is aerosolized, some particles collect in a shallow layer at the base of the chamber
• The layer of water is kept warm as aerosolization continues
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HFNC – How It Works
• Aerosolized molecules circulate over the layer of warmed water, pick up heat, and are delivered down the Delivery Tube through the two outer lumens
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HFNC – How It Works
• The warmed molecular and particulate humidification flow over a hollow porous media
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HFNC – How It Works
• The suction caused by the secondary tube in the chamber, captures rainout, and suctions particulate back into the chamber initially through the porous media and then through the center lumen
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HFNC – How It Works
• Only molecular humidification is delivered to the patient through the high flow nasal cannula.
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High-flow Devices
• Air-entrainment masks – also known as ______________ masks or Venti-
masks – consist of mask, O2 jet and air entrainment ports – due to a pressure drop and “drag”, O2 pulls in air
through entrainment ports – amount of air drawn in, and therefore FiO2,
depends on O2 flowrate, the size of the O2 jet and the size of the entrainment ports
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High-flow Devices
Venturi Principle
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High-flow Devices
• Two methods – fixed O2 jet size; variable entrainment port size – fixed entrainment port size; variable O2 jet size – both methods use known air:O2 ratios to deliver a
______________ FiO2
– air:O2 ratios can also be estimated – If the air:O2 ratio is known, total _____________
can be estimated
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Approximate Air:O2 Ratios
FiO2 Air:O2 Total Parts*
1.0 0:1 1
.70 .6:1 1.6
.60 1:1 2
.50 1.7:1 2.7
.40 3:1 4
.35 5:1 6
.30 8:1 9
.28 10:1 11
.24 25:1 26
*Total parts X O2 flow = Total flow estimate
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Air:O2 Ratios
O2
100
Air
20
60%
O2
100
Air
20
air:O2 = 40:40 or 1:1
40 40
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Total Flow
If the air:O2 ratio is known, total flow can be estimated:
total parts X O2 flow = total flow estimate
Ex: FiO2 = 0.4; air:O2 = 3:1; O2 flow = 12 L/min
Ex: FiO2 = 0.6; air:O2 = 1:1; O2 flow = 8 L/min
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Enclosures
• One of the oldest approaches to oxygen therapy
• Create a controlled O2 ______________ • Some enclosures can create an entire
controlled environment: O2, temperature, humidity
• Now used mainly with infants and children
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Tents
• Once, common method for adults and children
• Today, used almost exclusively with children, who, in most cases, will not wear a facial appliance
• Used to provide a controlled ______________ inside a ______________
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Tents
• Most common type is the “______________ ” tent which also provides cooling and high humidity
• Cooling is provided by a refrigeration unit that is capable of temperatures approximately 10 degrees F below room temperature
• ______________ is provided by an aerosol generator
• Tents are used primarily to provide pediatric aerosol therapy to children with croup or cystic fibrosis
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Tents
• Major problem with tents is that frequent opening and closing of the canopy can cause wide fluctuations in ______________ concentration and ______________
• In larger tents, O2 flows of _________ L/min can only provide approximately _________% oxygen
• Other hazards include fire if certain items are allowed in the tent
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Tents
• Devices that are electrically powered should not be allowed in the tent; and of course, no open flames, etc.
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Hoods
• Best method of providing controlled O2 therapy to ______________
• The “oxyhood” covers only the infant’s head, leaving the body free for nursing care
• Oxygen is delivered to the hood by either a heated nebulizer or a blending system with a heated humidifier
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Hoods
• O2 flow should be set at a minimum of _____ L/min to prevent accumulation of CO2 and depending on the size of the hood, O2 flows of 10-15 L/min may be needed to maintain stable oxygen concentrations
• Higher flows should not be used because they are not necessary and may create harmful ______________ levels
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Hoods
• With premature infants, gas should be warmed and not directed over the infant’s face as low temperatures or convection cooling can cause heat loss and cold stress
• Gas temperature should be set to maintain a neutral thermal environment (N ���TE)
• NTE for newborns over 2500 gm is 30oC • NTE for newborns under 1200 gm is 35oC
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Incubators
• Incubators are clear, usually Plexiglas, enclosures used to create a total environment, O2, temperature and humidity
• Humidity is provided usually by an aerosol generator
• O2 can be provided through a heated humidifier or by direct connection to a flowmeter which can limit delivered oxygen concentration to ________%
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Incubators
• However, the best way to control delivered O2 is with a hood
• Incubators are not as popular as they once were, but are still one of the best methods of providing a neutral thermal environment for stable infants
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Which Delivery Device?
• A wide variety of devices is available and there is usually not just one best approach
• Physicians may not always know what devices are available or what they can do - RCPs should be involved from the initial set-up and consultation and be responsible for oversight of the therapy
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Which Delivery Device?
• Use the three Ps – purpose – patient – performance
• Purpose – general purpose is to raise the FiO2 sufficiently to
correct hypoxemia – some patients may have specific problems to be
addressed
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Which Delivery Device?
• Patient - assess key factors – severity and cause of hypoxemia – patient age – level of consciousness – presence of artificial airway – stability of ventilation
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Which Delivery Device?
• Performance – look at categories, i.e. fixed/variable performance,
low/high flow, etc. – pair that with patient acuity – critically ill patients generally need stable, more
precise FiO2 control – less acutely ill generally will need lower, less exact
FiO2s