بسم الله الرحمن الرحیمبسم الله الرحمن الرحیم

Oxygen TherapyOxygen Therapy

Dr jarahzadehMD.Intensivist

Oxygen TherapyOxygen Therapy

Administration of oxygen at an FIO2 > 21%

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Introduction

• Oxygen is a drug– Has a Drug Identification Number (DIN)– Colorless, odorless, tasteless gas– Makes up 21% of room air– Is NOT flammable but does support

combustion.

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Indications for Oxygen Therapy

• Hypoxemia– Inadequate amount of oxygen in the blood

– SPO2 < 90%

– PaO2 < 60 mmHg

• Excessive work of breathing

• Excessive myocardial workload

Factors Influencing Oxygen Transport

• Cardiac output

• Arterial oxygen content

• Concentration of Hgb

• Metabolic requirements

• Hypoxemia • decrease in the arterial oxygen content in

the blood

• Hypoxia • decreased oxygen supply to the tissues.

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Causes of Hypoxemia

• Shunt• Hypoventilation

– As carbon dioxide increases oxygen falls

• V/Q mismatching (ventilation/perfusion)– Pneumonia– Pulmonary edema– ARDS

• Increased diffusion gradient– asbestosis– Early pulmonary edema

Clinical Manifestations of Hypoxia

• Impaired judgment, agitation (restlessness), disorientation, confusion, lethargy, coma

• Dyspnea• Tachypnea• Tachycardia, dysrhythmias• Elevated BP• Diaphoresis• Central cyanosis

Need For Oxygen Is Assessed By

• Clinical evaluation

• Pulse oximetry

• ABG

Cautions For Oxygen Therapy• Oxygen toxicity – can occur with

Fio2 > 60% longer than 36 hrs• Fio2>80%longer than 24 hrs

Fio2>100%longer than 12hrs• Suppression of ventilation – will

lead to increased CO2 and carbon dioxide narcosis

• Danger of fire • Absorbtion Atelectasia• Premature retrolental fibroplasia

Methods of Dispensing OxygenMethods of Dispensing Oxygen

• Piped in

• Cylinder

• Oxygen concentrator

Classification of Oxygen Delivery Systems

• Low flow systems – contribute partially to inspired gas client breathes– do not provide constant FIO2– Ex: nasal cannula, simple mask

• High flow systems– deliver specific and constant percent of oxygen

independent of client’s breathing– Ex: Venturi mask, non-rebreather mask, trach

collar, T-piece

Nasal Cannula• Used for low-medium concentrations

of O2• Simple• Can use continuously with meals and

activity• Flow rates in excess of 4L cause

drying and irritation• Depth and rate of breathing affect

amount of O2 reaching lungs• adults 6 LPM• infants/toddlers 2 LPM • children 3 LPM• FIO2 is not affected by mouth

breathing• 1lit o2=FIO2 4%1lit o2=FIO2 4%• 6 lito2=Fio2 24%6 lito2=Fio2 24%• 21%+24%=Fio2 45%21%+24%=Fio2 45%

Simple MaskSimple Mask

• Low to medium concentration of O2• Client exhales through ports on sides

of mask• Should not be used for controlled O2

levels• O2 flow rate- 6 to 8L• Can cause skin breakdown; must

remove to eat.• 1 lit o2=FIO2 6%1 lit o2=FIO2 6%• 6 lito2=Fio2 36%6 lito2=Fio2 36%• 21% + 36%=Fio2 57-60%21% + 36%=Fio2 57-60%

Partial Rebreather Mask

• Consists of mask with exhalation ports and reservoir bag

• Reservoir bag must remain inflated

• O2 flow rate - 6 to 10L FIO2=60%-80%• Client can inhale gas from

mask, bag, exhalation ports• Poorly fitting; must remove

to eat

Non-Rebreathing Mask

• Consists of mask, reservoir bag, 2 one-way valves at exhalation ports and bag

• Client can only inhale from reservoir bag

• Bag must remain inflated at all times

• O2 flow rate- 10 to 15L Fio2= 95-100%• Poorly fitting; must remove to

eat

Venturi MaskVenturi Mask• Most reliable and accurate method

for delivering a precise O2 concentration

• Consists of a mask with a jet• Excess gas leaves by exhalation

ports• O2 flow rate 4 to 15L & Narrowed

orifice• Fio2, 24%-60%• Can cause skin breakdown; must

remove to eat

Tracheostomy Collar/Mask

• O2 flow rate 8 to 10L• Provides accurate

FIO2• Provides good

humidity; comfortable

T-piece

• Used on end of ET tube when weaning from ventilator

• Provides accurate FIO2• Provides good humidity

Face Tent

• Low flow

• O2 wet

• O2 flow, 4-8 lit

• Fio2=40%

Oxygen Tent

InfantInfant

Oxygen by transetracheal catheter

• Fio2-30-50%

Pulse Oximetry

• Non-invasive monitoring technique that estimates the oxygen saturation of Hgb (SaO2)

• May be used continuously or intermittently• Must correlate values with physical

assessment findings• Normal SaO2 values – 95 to 100%

Pulse Oximetry

Pulse Oximetry

Factors Affecting SaO2 Measurements

• Low perfusion states

• Motion artifact

• Nail polish(Blue) when using a finger probe• Intravascular dyes(methylen blue,indocyanine

green,indigocarmine)

• Vasoconstrictor medications• Abnormal Hgb(met-CoHb)

• Too much light exposure

Nursing Interventions Related to Pulse Oximetry Monitoring

• Determine if strength of signal is adequate• Notify physician if SaO2 < 92% or outside

specific ordered limits• If continuously monitored, evaluate sensor site

every 8 hrs and move PRN• Document SaO2, O2 requirements, client’s

activity according to policy

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Oxygen Therapy

• Goal of therapy is an SPO2 of >90% or for documented COPD patients(Spo2 88–92%)-(Pao2=55-60)

• As SPO2 normalizes the patients vital signs should improve”– Heart rate should return to normal for patient– Respiratory rate should decrease to normal for patient– Blood pressure should normalize for patient

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Optimization

• My SpO2 is < 90%, what next?

– Is the pulse oximeter working/accurate• Do I have a good signal?• Heart rate plus/minus ?• Is there adequate perfusion at the probe site?• Can the probe be repositioned?• Do other vital signs or clinical manifestations give

evidence of hypoxemia?

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Optimization cont.

• Check my source!– Ensure the O2 delivery Ensure the O2 delivery

device is attached to device is attached to oxygen not medical air.oxygen not medical air.

– Follow tubing back to Follow tubing back to source and ensure source and ensure patencypatency

– Are all connections tight?Are all connections tight?

• Is the flow set high Is the flow set high enough?enough?– All nebs especially high All nebs especially high

flow large volume nebs flow large volume nebs need to be run at the need to be run at the highest rate.highest rate.

– Turn flow meter to Turn flow meter to maximum for large maximum for large volume nebs.volume nebs.

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Optimization cont.

• Reposition patient.– Avoid laying patient flat

on back.– Raise head of bed.– Encourage deep

breathing/coughing

• Listen to chest.– Wheezing?

• Do they need a bronchodilator?

– Crackles?• Encourage deep

breathing/cough.

• Are they fluid overloaded?

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optimization cont.

• Can I improve the mechanics of breathing?– Patient position

– Pursed lip breathing

– Abdominal breathing.

– Anxiety relief?

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Optimization cont.

• Increase the flow:– With nasal prongs, increase the flow rate by 1

-2 lpm increments until target SpO2 is reached.

– High flow nasal prongs can be maximally set at 15 lpm.

– Call for physician assessment Medical if high oxygen flows are required.

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Optimization cont.

• What do I do if my patient is really hypoxemic (on low flow oxygen)?– Assess patient to determine cause of increasing oxygen

requirements.– Best short term solution is non-rebreathe mask at 15 lpm.

(reservoir stays inflated)– Goal saturation is still 88 – 92%.– Increase flow as required until re-assessed by physician

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Optimization cont.

• What do I do if my patient is really hypoxemic (on high flow oxygen)?– Assess patient to determine cause of

increasing oxygen requirements.– Adjust FIO2 upwards in 10% increments

titrating for target SPO2.– Call physician for further assessment

H1N1 points of emphasis• H1N1 decompensation requiring ICU

admission usually begins with a systemic inflammatory response and pulmonary edema

• CXR may not correlate with degree of oxygenation impairment

• Gradually increasing oxygen requirement is a sentinel sign of impending respiratory failure

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H1N1 points of emphasis

• H1N1 Patients with escalating O2 needs warrant frequent monitoring for signs of impending respiratory failure

• If a critical care triage system is operative, know the patient’s classification and prepare equipment accordingly – endotracheal intubation may not be an option

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Questions?

Thank you for attention !