OXYGEN DEVICES HTTP:// HTTP:// RT 210A.

OXYGEN DEVICESHTTP://WWW.YOUTUBE.COM/WATCH?V=1T7TGKQCIGI

RT 210A

http://www.youtube.com/watch?v=1T7TGkQcIGI

Oxygen Therapy – Indications*

• Documented hypoxemia (PaO2 and/or SaO2

decreased below patients baseline)

• An acute care situation in which hypoxemia is

suspected (cardiopulmonary arrest, stroke,

Pneumo…)

• Severe trauma*From the AARC Clinical Practice Guideline

Oxygen Therapy – Indications*

• Acute myocardial infarction

• Short term therapy or surgical intervention

*From the AARC Clinical Practice Guideline

Indications• When a patient exhibits signs, symptoms or situations that indicate

oxygen therapy there are very few contradictions.

A patient may need oxygen to keep the workload of the heart and lungs at a normal level. If an asthmatic patient has an asthma attack and their airways are becoming restrictive they won't be able to bring in as much air to their lungs. In this case you want the air that they are able to bring into their lungs to have higher levels of oxygen than what room air alone can provide.

One indication for oxygen is short-term therapy. In many of these situations a patient may have normal SaO2 values but are in a situation where hypoxia may be common. Some of these may be postoperative patients, CO2 poisoning, cyanide poisoning, shock, trauma, acute MI or some premature babies. Oxygen can sometimes be better used as a preventative than a treatment.

Hypoxemia• When the a patient develops hypoxemia their breathing rate

will begin to rise proportionally along with their heart rate to compensate for the demand of oxygen.

• Pulmonary vasoconstriction and hypotension develop. This in turn will increase the workload on the right side of the heart and over time can lead to heart failure.

• Tachypnea, tachycardia, dyspnea, lethargy/confusion develop with severe hypoxemia

• Other visual symptoms include restlessness and headaches.

Oxygen Therapy – Contraindications*

• There are no specific contraindications to

oxygen therapy when indications are judged to

be present


Oxygen Therapy – Hazards and Complications*

• Ventilatory depression (if you supersede a

patients need)

• Absorption atelectasis

• Oxygen toxicity


Oxygen Therapy – Hazards and Complications*

• Fire hazard (combustible)

• Retinopathy of prematurity

• Bacterial contamination (when using humidity

or aerosol)


Ventilatory Depression

• Patients at risk:

• COPD patients with hypercapnea, again only if the

patient receives more PaO2 than they require, the

FIO2 does not necessarily matter during an

exacerbation, always give them enough to support

appropriate tissue oxygenation.


• Mechanism of action

• Patient has “normal” PaCO2 > 60 mmHg (chronic

hypercapnea)

• Response of central chemoreceptors blunted

• PaO2 decreases to < 55 mmHg



• Decrease in oxygen level triggers response by

peripheral chemoreceptors, if they

• Rate and depth of breathing increase



• When supplemental oxygen administered, PaO2 can

rise to > 55 mmHg, removing stimulus to

peripheral receptors

• Hypoventilation results

Absorption Atelectasis

• Two contributing factors

• FIO2 > 0.50

• Air trapping

What are the types of atelectasis?

• Passive• From hypoventilation, typically post surgical pain, weakness,

diaphragm weakness• Resorptive

• When there is endobronchial obstruction, there is no more ventilation and air gets absorbed from alveoli. Alveoli collapse with significant loss of lung volume. Example: Lobar atelectasis from endobronchial lung cancer.

• Relaxation • Normally lungs are held close to chest wall by the negative pressure in

pleura. In pneumothorax or pleural effusion the negative pressure in pleura is lost. Lung relaxes to its resting position.

• Adhesive • Surfactant is necessary for keeping the alveoli open. In ARDS and

Pulmonary embolism there is loss of surfactant and alveoli collapse.



• At higher FIO2, nitrogen in alveolus is replaced by

oxygen

• With obstruction of the airway, oxygen is rapidly

absorbed into the capillary without replacement

in the alveolus



• Removal of oxygen causes decrease in volume of

alveolus, resulting in alveolar collapse or atelectasis



• May also occur in patients with low tidal volumes as a

result of sedation, pain, or CNS dysfunction

• Oxygen is absorbed faster than it can be replaced

• Alveoli gradually decrease in volume

• May eventually lead to complete collapse

• May occur even without supplemental oxygen

Oxygen Toxicity

• Two contributing factors

• FIO2 > 0.50

• Time of exposure

Oxygen Toxicity

• Pathophysiological changes

• Damage to capillary epithelium

• Interstitial edema

• Thickening of alveolar capillary membrane

Oxygen Toxicity


• Destruction of type I alveolar cells

• Proliferation of type II alveolar cells

• Formation of exudate

Oxygen Toxicity


• Decrease in ventilation/perfusion ratio

• Physiologic shunting

• Hypoxemia

Oxygen Toxicity


• Overproduction of free radicals

• Safe level: FIO2 ≤ 0.50

Oxygen Toxicity

Fire Hazard

• Risk increases as oxygen level increases

• Greatest risks include operating rooms and

selected procedures

• Laser bronchoscopy may cause intratracheal

ignition in presence of increased FIO2

Retinopathy of Prematurity (ROP)

• Occurs in premature and low birth weight infants

• Causative factor

• Increased PaO2 usually greater than 80 mmHg

• Covered in neonatal section of curriculum

• http://www.youtube.com/watch?v=BVYwo-RmDNE

http://www.youtube.com/watch?v=BVYwo-RmDNE

Bacterial Contamination

• Associated with equipment

Assessment of the Hypoxemic Patient

• Clinical signs of hypoxemia

• Tachypnea

• Tachycardia

• Anxiety



• Cyanosis

• Present when there are 5 grams of desaturated

hemoglobin

• May not be present in instances of severe anemia

• May be present in absence of hypoxemia in presence of

polycythemia



• Confusion

• Lethargy

• Coma


• Laboratory data

• Arterial blood gas results (PaO2)

• Saturation (SpO2)

• Increased levels of lactic acid may indicate hypoxia

• O2 delivery in COPD patients:

• http://www.youtube.com/watch?v=XFieSB3

TzK4

http://www.youtube.com/watch?v=XFieSB3TzK4

http://www.youtube.com/watch?v=XFieSB3TzK4


• Specific clinical conditions

• Myocardial infarction

• Generally given 100% oxygen, especially in ED

• Recent research may show that high FIO2 may cause

vasoconstriction of the coronary arteries, contributing to

cardiac ischemia


• Specific clinical conditions

• Trauma

• Overdose

Monitoring the Physiologic Effects of Oxygen• The symptoms of hypoxia are cognitive

impairment, cardiac rhythm and conduction dysfunction, and renal dysfunction.

• Monitoring arterial blood gas analysis is standard for documenting oxygenation, ventilation, and acid–base balance.

• Pulse oximetry is the most common form of continuously monitoring oxygen saturation.

• Oxygen analyzers are used to measure the concentration of oxygen administered to patients.

Oxygen Devices• http://www.youtube.com/watch?v=OW-LkJv61eo&feature=rel

ated• Low flow systems• High flow systems• Positive pressure (vents, IPPB, resuscitation bags)• Hyperbaric chamber

http://www.youtube.com/watch?v=OW-LkJv61eo&feature=related


Low Flow Oxygen Systems

• Deliver flows at less than the patient’s

inspiratory flow rate, diluting the inspired

oxygen with room air

• FIO2 varies dependent upon the specific

device and the patient’s inspiratory flow

Low Flow Oxygen Systems

• Conditions required for low flow systems

• VT between 300 and 700 mL

• f < 25 breaths per minute

• Regular breathing pattern

Nasal Cannula• Used on adults pediatrics and neonates• Adult flows: 0.5-6L• Infant/neonatal flows: typically less than 1 L• Typically a low flow device but may be high flow if given as a

high flow nasal cannula• Add humidity for flows over 4L or anytime a infant/neonate or

pediatric is on any amount of O2

Delivery Devices – Nasal Cannula

• Advantages

• Economical

• Comfortable – better patient compliance

• Patient able to eat, speak, and cough with cannula

in place

• Mouth breathing not a significant factor

Estimating FiO2Nasal Cannula flow rate FIO2

1 L .24

2 L .28

3 L .32

4 L .36

5 L .40

6 L .44

O2 mask flow rate FIO2

5-6 L 0.4

6-7 L 0.5

7-8 L 0.6

NC• 0.5 LPM = 22% • 1 LPM = 24%• 2 LPM = 28%• 3 LPM = 32%• 4 LPM = 36% starting at 4 LPM a bubble humidifier is

required to prevent • 5 LPM = 40% irritating the nasal mucosa which can cause

nose bleeds or• 6 LPM = 44% drying of mucus.


• Disadvantages

• Imprecise concentration of oxygen delivered

• May fluctuate according to patient’s

breathing pattern

• May cause irritation to nares, nasal airway, or

ears (around ear), may use cushion around ear

• Easily dislodged


• Flows generally not greater than 6 L/min

• May use with very low flows, less than ¼

L/min

• Flows ≤ 4 L/min do not require use of

humidifier

Figure 16-9A: Nasal cannula with elastic strap. (A) Adapted from Scanlan CL, et al. Egan’s Fundamentals of Respiratory Care. 7th ed. Mosby; 1999.

Figure 16-9B: Over-the-ear style nasal cannula.

Figure 16-9C: Various styles of nasal prongs.

Courtesy of Teleflex Incorporated. Unauthorized use prohibited

Nasal Cannula

Keep flange against upper lip

NC should be adjusted below chin, do not place behind head, choking risk; unless applying to neonates/small peds. On infants, tape to face

Nasal Cannula• Insert the nasal cannula into your nose and breathe through

your nose normally.• If you’re not sure whether oxygen is flowing, place the cannula

in a glass of water. Bubbles mean that oxygen is flowing.• Patients may use extension tubing for increased mobility

Simple Mask/O2 mask

Figure 16-10B: Simple O2 mask.© Corbis/age fotostock

Simple Oxygen Mask

• Typically given for short term use, during deliveries, in the ER

• Flows begin at 5-6L at least to prevent rebreathing exhaled CO2

• Max flow is around 10-12L• DO not add a bubble humidifier• Not used regularly by RT’s

Simple Mask• Used for patients in need of oxygen in the range of 35% to

50%. • Again this is a estimation since it is a low flow device. This

mask is used on children through adults but not neonates. The mask can be uncomfortable and needs to be removed to eat. Used for short term or emergency use requiring moderate O2 use such as CHF, Pulmonary Emboli, Pulmonary Fibrosis, Labor, Surgery, Heart attack, and a multitude of other diseases. Not for CO2 retainers.

Delivery Devices – Simple Oxygen Mask

• Advantages

• Can deliver moderate concentrations (FIO2

between 0.35 and 0.55 at flows of 5 to 10 L/min)

• Economical

• Mouth breathing not a factor


• Disadvantages

• Uncomfortable for most patients

• Must be removed for eating, speaking,

expectorating

• May allow vomitus to be aspirated


• Disadvantages

• May allow accumulation of CO2 and rebreathing if

flow is inadequate

• Can irritate skin and cause pressure sores

• http://www.youtube.com/watch?v=tBUjR5HDqNs&feature

=related

http://www.youtube.com/watch?v=tBUjR5HDqNs&feature=related

http://www.youtube.com/watch?v=tBUjR5HDqNs&feature=related

Aerosol Mask

• Used for the delivery of aerosol. Either by:• Small volume nebulizer or Large volume

nebulizer• Can be a face or trach mask• FIO2 dependent on device in • it is used

Partial Rebreathing Mask• No one way valves• Otherwise looks identical to a non rebreathing mask

Partial Rebreathing Mask

• Originally used in anesthesia; currently used for short-term therapy

requiring moderate to high FIO2, Not a commonly used mask

• Has a reservoir bag that fills with oxygen but also exhaled CO2.

Delivers up to 60% O2 with flows of 10-15 LPM. The bag should not

deflate on inspiration, if it does INCREASE THE FLOW. Used for the

delivery of moderately high FIO2’s and is given for the same reasons

a simple mask is given. Usually seen in emergency rooms. Not for

CO2 retainers. This is a low flow oxygen device, the patient should

be breathing adequately and simply need an increased FIO2.


• Advantages

• Able to deliver moderate concentrations of oxygen

(FIO2 between 0.40 And 0.70)

• Economical

• Mouth breathing not a factor


• Disadvantages

• Uncomfortable for many patients


expectorating


• Disadvantages


• Possible suffocation hazard if anti-entrainment

valves in place and the oxygen source fails

Non Rebreathing mask (NRB)• Looks similar to the partial rebreathing mask except this one

has 3 one way valves that prevents the patient from exhaling CO2 into the reservoir bag.

• Instead the bag is filled with 100% O2 that the patient inhales. This device is set at flows of 10-15 LPM and is similar to the partial rebreathing mask in that the bag should not deflate on inspiration.

• This device can deliver 55% to 95% oxygen depending on how many one way valves are present. This mask is given in all emergencies, for nitrogen washout, ARDS, heart attack, pulmonary embolism, CHF, pnemothorax, pneumonia, and a multitude of other diseases in which the patient is spontaneously breathing but requires high FIO2’s. This is not for CO2 retainers unless it is an emergency situation.

Non-Rebreathing Mask

• Used primarily in emergencies and for short-

term administration of high concentrations of

oxygen

One way valves


• Differentiated from partial rebreathing

mask by presence of valve between mask

And reservoir bag

• http://www.youtube.com/watch?v=VV5w4

qerBDg

• http://www.youtube.com/watch?v=fyg5FnG

k0zA

http://www.youtube.com/watch?v=VV5w4qerBDg

http://www.youtube.com/watch?v=VV5w4qerBDg

http://www.youtube.com/watch?v=fyg5FnGk0zA

http://www.youtube.com/watch?v=fyg5FnGk0zA


• Sufficient flow must be maintained;

evidenced by reservoir bag always being at

least partially inflated

• Usually has anti-entrainment valve on only

one side of mask; precaution against

suffocation in the event of oxygen source

failure


• Advantages

• Able to deliver relatively high concentrations of

oxygen (FIO2 between 0.60 and 0.80)

• Theoretically able to deliver up to FIO2 of 1.00

• Economical

• Easy to apply


• Disadvantages

• Uncomfortable for many patients


expectorating


• Disadvantages


• Possible suffocation hazard if anti-entrainment

valves in place and the oxygen source fails

Reservoir (Oxygen Conserving) Cannula

• Uses a reservoir to trap and build up oxygen that the patient inspires. Uses up to 4 LPM of oxygen, and is worn in the same manor as a nasal cannula.

• There are two types: pendant and nasal pillow. The pendant cannula hangs down to chest and forms a pendant reservoir for oxygen. The nasal pillow is a mustache reservoir the sits on the upper lip. Both types are unattractive for the patient but saves money by using less flows 0.25 LPM to 4 LPM.

• Primary use in home care and/or ambulatory patients

Reservoir Cannula• Oxymizer and Oxymizer Pendant brand reservoir cannulas

store oxygen in a reservoir during exhalation and deliver a bolus of 100% oxygen upon the next inhalation. These devices were originally designed for portable home oxygen therapy. However, they are finding increasing use in acute care settings for patients who are difficult to supply oxygen via standard nasal cannulas and as high-delivery alternatives to oxygen delivery via a face mask

Nasal Pillow and Pendant

Reservoir Cannula

• Reservoir cannula • Pendant reservoir cannula


• Advantages

• Lowers oxygen usage, thereby lowering cost

• Allows greater mobility secondary to longer duration of cylinder


• Disadvantages

• Unattractive (many home care cannulas are now

hidden into hats, visors…)

• Must be replaced regularly (See manufacturer’s

specifications), increasing cost

• Breathing pattern affects performance

Transtracheal Catheter

• Teflon catheter surgically inserted between

second and third trachea rings

• Increases the anatomic reservoir during

expiration providing greater bolus of oxygen

to be inspired


• Used primarily in home care and for ambulatory

patients who will not accept nasal oxygen

• Not commonly used. Surgically inserted into the

trachea by MD. Uses less flow than a nasal cannula or a

nasal catheter. Good for long term oxygen use on

patients that do not tolerate nasal cannulas and need

increased mobility. Needs a humidifier at any flow.

Needs to be changed and clean periodically to prevent

mucus plugs.


• Advantages

• Able to deliver very low flows of oxygen (1/4 to

4 L/min.)

• Uses less oxygen, lowering costs


• Advantages

• Improvement in compliance with therapy

• Humidification not required because of low flows


• Disadvantages

• High initial cost (surgical procedure)

• Possibility of infection


• Disadvantages

• Easily plugged by mucus

• If removed for replacement, tract may close

Nasal Catheter• Less commonly used. Long term nasal cannula that bypasses

the upper airway.• Used during bronchoscopys and for long term use in children.

Soft and smooth open distal end facilitates non-traumatic insertion, Proximal end is fitted with color coded funnel shape connector for easy connection to oxygen source. Uses less flow than a nasal cannula but delivers the same oxygen concentration. Requires a humidifier at any flow. Hard to insert and may cause gagging and aspiration if inserted to deeply. Changed every 8 hours!

Nasal Catheter

Figure 16-8: Nasal catheter for oxygen administration.Adapted from Scanlan CL, et al. Egan’s Fundamentals of Respiratory Care. 7th ed. Mosby; 1999.

OxyMask• Developed in 2005• Open mask design, FIO2 based on flow inputted into mask as

indicated on package. • Not considered a high flow device, as the % may vary• Ranges from 25-90% O2

Oxygen Devices

• Venturi Mask Setup• http://www.youtube.com/watch?v=qJ9ZIAYAKBY&feature=rela

ted• Large Volume Nebulizer• http://www.youtube.com/watch?v=0HUJs0FgkoY&feature=rel

ated• Simple Mask• http://www.youtube.com/watch?v=fIdioyC4Bjc&feature=relat

ed• • Overall: • http://www.youtube.com/watch?v=OW-LkJv61eo&feature=rel

ated

http://www.youtube.com/watch?v=qJ9ZIAYAKBY&feature=related

http://www.youtube.com/watch?v=qJ9ZIAYAKBY&feature=related

http://www.youtube.com/watch?v=0HUJs0FgkoY&feature=related

http://www.youtube.com/watch?v=0HUJs0FgkoY&feature=related

http://www.youtube.com/watch?v=fIdioyC4Bjc&feature=related

http://www.youtube.com/watch?v=fIdioyC4Bjc&feature=related



High Flow Oxygen Systems

• Provide a flow of oxygen equal to or

exceeding the patient’s peak inspiratory

flow

• Use either air entrainment or blending to

provide precise concentrations of oxygen


• Conditions that may require high flow systems

• VT > 700 ml

• f > 25 breaths per minute

• Irregular breathing pattern

• Need for delivery of precise concentration of

oxygen


• Delivery devices

• Air entrainment (Venturi) mask

• Air entrainment nebulizer

• Blending systems

Venturi Mask

• Set flow dependent upon final concentration of

oxygen desired

• Concentrations available between 24% and 50%

• As the FIO2 is increased the total flow decreases

• The device depends on the venturi entrainment

size, the input flow and obstructions

• http://www.youtube.com/watch?v=zdIXQVVuLs4

http://www.youtube.com/watch?v=zdIXQVVuLs4

3 designs. Two change the entrainment window size to increase/decrease FIO2, the other has colored adapters. The flow required is indicated on the device

Venturi Mask

• Calculation of total flow to the patient

• 2 ways (memorizing ratios or magic box)

• Both methods give you the ratio. Add the ratio

together then multiply by the flow the patient is set on.

To determine if you are meeting a patients total flow

take this total flow and compare it to a patients (Ve x3)

Figure 16-12: Magic box to determine oxygen-to-air ratio when mixing O2 and air. Examples are shown for 40% and 60% O2.

Magic Box• Set up magic box with given % O2 in the middle of box• Place 100 and 21 and subtract from 40. This gives you the

ratio.

Memorizing ratios:.28.30.35.40.50.60Primary ratios

Venturi Mask

• Advantages

• Inexpensive

• Easy to apply

• Stable, precise concentration

• Ideal for COPD, as it gives high flow and also

precise FIO2

• Maybe adapter for Trach use

Venturi Mask

• Disadvantages

• Generally limited to adult use

• Uncomfortable, noisy

Venturi Mask

• Disadvantages


expectorating

• FIO2 varies if entrainment port occluded or in the

presence of back pressure, or water in tubing if

using a LVN

• If port occluded FIO2 increases

Air Entrainment Nebulizer

• Generally no more than 15 L/min. input;

should maintain output of at least 60 L/min

• Used when aerosol is desired, e.g., patients

with artificial airways

Venturi Mask

Color adaptor type- Orifice size changes

Venturi valve Flow rate Oxygen delivered

color (l/min) (%)

Blue 2 24

White 4 28

Yellow 6 35

Red 8 40

Green 12 60

Treatment with oxygen 60% or/>101 rebreathing 90-94

Figure 16-18C: Changes in air entrainment by changing jet size or changing size of the entrainment port.


• Advantages

• Stable, precise concentration when FIO2 > 0.28 And

< 0.40

• Provides aerosol

• Inexpensive

• Easy to apply

LVN

• Used when upper airway is bypassed (ETT, Trach)

• Used for croup, stridor• Not used for Asthmatics• Typically given- Bland aerosol with sterile

water

Figure 16-14B: Large-volume nebulizers.Courtesy of Teleflex Incorporated. Unauthorized use prohibited

Figure 16-15A: Aerosol mask

(A) Adapted from Fink JR, Hunt GE. Clinical Practice of Respiratory Care. Lippincott Williams & Wilkins; 1999.

Figure 16-15B: Briggs T piece


Figure 16-15C: Face tent


Figure 16-15D: Tracheostomy collar


Figure 16-17: Injection nebulizer, in which additional flow is injected at the outlet of the nebulizer.

Courtesy Jeffrey J. Ward, R.R.T.

Figure 16-26: Equipment for heliox administration to spontaneously breathing patients.

Figure 16-20: High-flow oxygen delivery system using two flow meters.

Courtesy of Dr. Dean Hess


• Disadvantages

• Increased risk of infection

• FIO2 varies if entrainment port occluded or in the

presence of back pressure

Components of an Air Entrainment Device

Aerosol Mask

Large Volume Nebulizer• http://www.youtube.com/watch?v=0HUJs0FgkoY• This also uses Bernoullis principle and has an adjustable FIO2.

The nebulizer provides cool mist to patients with stridor or upper airway edema. Also used for patients with artificial airways in need of humidification. It is also utilized for patients with thick tenacious secretions. The flow is set between 8 and 15 LPM. The concentration of O2 is 28% to 100%. The higher the concentration the lower the total flow due to the closing of the venturi which adds or takes away air dilution. The nebulizer sometimes requires two flow meters when using higher FIO2 in order to achieve proper misting.

http://www.youtube.com/watch?v=0HUJs0FgkoY

Blending Systems

• Generally used when high flows (> 60 L/min.)

required

• Separate pressurized air and oxygen sources

required

Blending Systems

• Manually blended system

• Each gas manually set with flowmeter

• Total flow and desired FIO2 must be calculated

Blending Systems• To confirm proper operation of an O2 blending system there

are three major steps. 1.) Make sure that the inlet pressures of the air and O2 are within the specifications of the manufacturer. 2.) Test the alarms for low air and O2 by disconnecting the sources seperately. Make sure that the safety bypass system is working correctly. 3.) Make sure to analyze the O2 concentration at levels of 100%, 21% and at desired FIO2.

The use of a blender is for when O2 concentrations need to be provided at a higher rate or flow. Flow meters have limitations and therefore cannot provide these higher rates like a blender can do.

Blending Systems

• Manually blended system

• Will deliver precise FIO2 if calculated correctly

• Deviation of either flow changes FIO2 and total

flow

Blending Systems

• Oxygen blender

• Able to deliver very precise concentrations

• Able to deliver high flows across a wide range of

concentrations

Blending Systems

• Oxygen blender

• Must check with analyzer periodically to confirm

proper operation and eliminate possibility of

blender failure

Oxygen Blending Device

Enclosure Systems

• One of the oldest approaches to oxygen

administration

• Provides patient with controlled

atmosphere

• Used primarily with infants and children

Enclosure Systems• Oxyhood• Used for neonates and infants that requires oxygen from

21% up to 100%. Flows must be set at a minimum of 7 LPM to prevent CO2 build up. A hood covers the infants head without directly attaching to the patient. The hood is comfortable but difficult to clean. The FIO2 is measured at the bottom near the patients face with an O2 analyzer due to layering affects of oxygen. The hood amplifies sound, so minimize noise around the babies sensitive ears. A humidifier is used instead of a nebulizer due to the noise factor. Used for Nitrogen washout for pneumothorax or as a weaning tool off nasal CPAP

Oxygen Hood

• Used with infants

• Minimum flow normally of 7 L/min

Oxygen Hood

• Disadvantages

• Noise level can cause auditory damage

• Difficult to clean and/or disinfect

Oxygen Hood

• Disadvantages

• Need to ensure neutral thermal environment is

maintained by using warmed gas, especially

with premature infants

Oxygen Hood

Enclosure Systems

• Delivery devices

• Oxygen tent

• Oxygen hood

• Incubator (isolette)

Oxygen Tent

• Generally uses 12 – 15 L/min

• Can produce FIO2 of 0.40 to 0.50

• Used with children/rare, Croup

Oxygen Tent

Oxygen Tent

• Advantage

• Simultaneously produces aerosol

• Allows child movement while maintaining FIO2

Oxygen Tent

• Disadvantages

• Expensive

• Cumbersome to use

• Limits access to patient

Oxygen Tent

• Disadvantages

• Fire hazard

• Difficult to clean and/or disinfect

Incubator

Incubator (Isolette)

• Used with infants to provide complete

control of environment

• Able to provide maximum FIO2 of 0.50 at 8 to

15 L/min


• Advantages

• Provides complete environment

• Stable FIO2


• Disadvantages

• Limited access to infant

• Expensive

• Difficult to clean and disinfect


• Disadvantages

• Fire hazard

• Noise level can cause auditory damage

Hyperbaric Oxygen Therapy

• Therapeutic use of oxygen at pressures

greater than 1 atmosphere (expressed as

ATA or atmospheric pressure absolute)


• Physiologic effects

• Hyperoxygenation of blood plasma and tissue

• Reduction in bubble size

• Vasoconstriction

• May be helpful in decreasing edema


• Physiologic effects

• Neovascularization

• Creation of new capillary beds

• Enhanced immune function

• Aids in white blood cell function


• Indications

• Air embolism

• Carbon monoxide poisoning

• Decompression sickness

• Acute traumatic ischemia


• Indications

• Necrotizing soft tissue infection (gangrene)

• Ischemic skin graft

• Intracranial abscess

• Acute peripheral arterial insufficiency


• Complications and hazards

• Barotrauma

• Pneumothorax

• Tympanic membrane rupture

• Gas embolism



• Oxygen toxicity

• Fire

• Decrease in cardiac output



• Sudden decompression

• Claustrophobia


• Methods of administration

• Fixed hyperbaric chamber

• Capable of holding caregivers and patients

• Has airlock to allow entry and egress of

caregivers



• Fixed hyperbaric chamber

• May be large enough to allow multiple patients

• Only patient receives supplemental oxygen

Fixed Hyperbaric Chamber



• Monoplace chamber

• Large enough for single patient only

• Chamber kept at FIO2 of 1.0 during patient

treatment

Monoplace Chamber

Nitric Oxide (NO) Therapy

• Normally produced in the body

Figure 16-28A: INOmax delivery system.

Courtesy of IKARIA

Figure 16-28B: (B) INOvent delivery system.

Courtesy of IKARIA



• Activates guanylate cyclase which catalyzes

production of cGMP, leading to vascular smooth

muscle relaxation



• Improves blood flow to ventilated alveoli,

reducing intrapulmonary shunting

• Results in decrease in pulmonary vascular

resistance


• Indications

• Treatment of neonates with hypoxic respiratory

failure with associated pulmonary

hypertension


• Indications

• Potential uses

• RDS

• Primary pulmonary hypertension

• Cardiac transplantation, including pulmonary

hypertension following surgery


• Indications

• Potential uses

• Acute pulmonary embolism

• COPD

• Sickle cell disease

• Pulmonary hypertension related to congenital

heart disease


• Adverse effects

• In high concentrations (5000 to 20,000 ppm),

causes pulmonary edema that can be fatal

• Direct damage to cells


• Adverse effects

• Impaired surfactant production

• Increase in left ventricular filling pressure

• Paradoxical response

• Methemoglobinemia


• Dosage

• In neonates, initial dose is 20 ppm; continued

for up to 14 days or until underlying oxygen

desaturation is resolved

• Frequently can be reduced to 6 ppm at the end

of 4 hours

Administration of NO

• Patient preparation

• Stabilize the patient as much as possible

• Possibly sedate or paralyze patient

• Support blood pressure as needed


• System features

• Delivery of precise, stable level of nitric oxide

• Capable of scavenging of nitric oxide

• Limited production of nitrogen dioxide (NO2)


• Monitoring therapy

• Inhaled levels of NO and NO2

• Ventilatory status


• Discontinuing therapy

• Monitor for rebound effect

• Patient must be able to maintain adequate

oxygenation

• Patient must be able to maintain hemodynamic

stability

Figure 16-28A: INOmax delivery system.

Courtesy of IKARIA

Figure 16-28B: (B) INOvent delivery system.

Courtesy of IKARIA

INOvent Delivery System

• For administration of

nitrous oxide to

mechanically

ventilated patients

Helium-Oxygen (Heliox) Therapy

• Used to decrease the work of breathing in

the presence of turbulent gas flow in the

large airways


• Used with bronchodilator therapy to treat

acute obstructive disorders (e.g., status

asthmaticus); must use correction factor

(multiply observed flow by 1.8) for

flowmeter



• Generally cannulas are not effective because of

high rate of diffusion

• Best method – snug fitting, non-disposable non-

rebreathing mask

• May be administered through cuffed tracheal

airway with positive pressure


• Hazards

• Elevation of vocal pitch caused by low density gas

passing through vocal cords

• Cough less effective

• Hypoxemia secondary to using too low an oxygen

concentration

Oxygen Monitoring – Polarographic Analyzer

• Under ideal conditions of temperature,

pressure, and humidity, accurate to ± 2%

• Has a response time of 10 to 30 seconds

Oxygen Monitoring – Polarographic Analyzer

• Utilizes an electrochemical principle for

operation

• Blood or gas sample is separated from electrode

sample by oxygen permeable membrane

Polarographic Analyzer

Electrochemical Principle for Operation

• Oxygen diffuses through the membrane

into the electrolyte solution where a

polarizing voltage causes electron flow

• Silver in the anode is oxidized and the flow

of electrons reduces oxygen and water of

the electrolyte to hydroxyl ions at the

platinum cathode

Figure 16-23: Oxygen analyzer.Courtesy of Amvex Corporation

Electrochemical Principle for Operation

• The greater the number of oxygen

molecules reduced, the greater the

electron flow between the anode and the

cathode

• The current generated is equivalent to the

partial pressure of oxygen and is displayed

as a percentage

Galvanic Analyzer

• Under ideal conditions of temperature,

pressure, and humidity, accurate to ± 2%

• Has a response time as long as 60 seconds

Galvanic Analyzer

• Utilizes an electrochemical principle for

operation

• Has a gold anode and lead cathode

• Current flow is generated by the chemical reaction

itself resulting in slower response time

Galvanic Analyzer

• When the chemicals in the sensor are

depleted, the sensor must be replaced

Galvanic Analyzer

Oximetry

• Utilizes the principle of spectrophotometry

• Every substance has a unique pattern of light

absorption which varies predictably with the

amount of the substance present

Oximetry

• Each form of hemoglobin, e.g.,

oxyhemoglobin, carboxyhemoglobin,

methemoglobin, has a unique pattern

Oximetry

• Comparison of light transmitted through a blood

sample at two or more specific wavelengths

allows the measurement of two or more forms

of hemoglobin

• Oxyhemoglobin absorbs less red light and more

infrared light than reduced hemoglobin

• Comparison of light absorption yields %HbO2 and %Hb

CO-Oximetry

• Uses three different wavelengths of light

• Able to distinguish and measure Hb, HbO2,

HbCO, and metHb

• Results reported as SaO2 to distinguish from

pulse oximetry

CO-Oximeter

Pulse Oximetry

• Utilizes principle of spectrophotometry with

the principle of photoplethysmography

(utilization of light to detect tiny volume

changes in tissue during pulsatile blood flow)

• Uses only two wavelengths of light compared

to CO-oximeter

Pulse Oximetry

• Red and infrared LEDs alternately transmit

light through tissue to a receiver

Pulse Oximetry

• Does not distinguish between different forms

of hemoglobin, so can be inaccurate in cases

of carbon monoxide poisoning or with higher

levels of methemoglobin

• Results reported as SpO2

Pulse Oximetry

Transcutaneous Monitoring

• Used primarily with neonatal and pediatric

patients; changes in skin composition make

results less reliable for adults

• Skin sensor containing oxygen and carbon

dioxide electrodes is attached to the skin,

usually in the abdominal area


• Sensor contains a heating element to heat

the skin

• Increases perfusion in the area of the sensor

• Allows diffusion of oxygen and carbon dioxide

more readily


• Oxygen and carbon dioxide diffuse through

the skin into the electrolyte solution and are

analyzed by the two electrodes and reported

as mm Hg

• Results reported as PtcO2

Correlation of PtcO2 With PaO2

Age Group PtcO2/PaO2 Ratio

Premature infants 1.14:1

Neonates 1.00:1

Children 0.84:1

Adults 0.79:1

Older adults 0.68:1

Factors Affecting Accuracy

• Poor perfusion

• Improper sensor application

• Use of vasodilator drugs

• Variation in skin characteristics

Factors Affecting Accuracy

• Hyperoxemia

• Inadequate heating of sensor

• Lack of contact between sensor and skin

Transcutaneous Monitor

Carbon Dioxide Monitoring – Severinghaus Electrode

• Variation of Sanz electrode

• Used to measure pH

• Consists of two electrodes or half cells

• Measuring half cell contains silver-silver chloride

rod surrounded by solution of constant pH and

enclosed by pH-sensitive glass membrane



• Sample passes over glass membrane, changing

electrical potential of the measuring electrode

• Reference half cell of mercury-mercurous

chloride produces constant potential



• Difference in potential between electrodes is

proportional to H+ concentration and is

displayed as pH


• Severinghaus electrode is Sanz electrode

that is exposed to an electrolyte solution in

equilibrium with the sample through a CO2

permeable membrane


• CO2 diffuses through the membrane and

dissociates into H+ and HCO3- ions.

• The greater the concentration of CO2, the

greater the number of H+ ions


• Change in pH of the solution proportional

to change in PCO2

• Used primarily in blood gas analyzer and

transcutaneous monitor

Carbon Dioxide Monitoring – Capnometry

• Used during mechanical ventilation and

general anesthesia

• Placed inline between ventilator circuit and

endotracheal or tracheostomy tube

• Infrared light is passed through a sample

chamber


• Carbon dioxide absorbs infrared light

• The amount of infrared light passing through

the sample chamber is compared to a

reference chamber


• The less infrared light, the greater the

concentration of carbon dioxide

• Result read out as PETCO2

Capnometry

Colorimetric Carbon Dioxide Analysis

• Uses an indicator that changes color when

exposed to different levels of carbon

dioxide

• Most units are either blue or purple in the

absence of carbon dioxide and change to

yellow when exposed to carbon dioxide


• Unit is disposable

• Placed on endotracheal tube following

intubation to confirm placement of ET tube

• May give false negative readings in states of

very low pulmonary perfusion


• May give false positive readings if large

volumes of carbonated drinks were

consumed prior to intubation

• Does not give a numeric result

Colorimetric Carbon Dioxide Analyzer

Nebulizers• Hand Held Nebulizers/ also know as small volume nebulizers

may be given via aerosol mask, blow by, inline on the vent/bipap or by mouth piece, given on air or oxygen

• Small volume nebulizers contain less than 200 ml of fluid• Set flow 6-8 L, a typical treatment lasts 10-15 minutes, when

the neb starts to sputter, shake contents

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