بسم الله الرحمن الرحیم

Dr jarahzadeh MD.Intensivist Oxygen Therapy Dr jarahzadeh MD.Intensivist

Oxygen Therapy Administration of oxygen at an FIO2 > 21%

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. 4

Indications for Oxygen Therapy Hypoxemia Inadequate amount of oxygen in the blood SPO2 < 90% PaO2 < 60 mmHg Excessive work of breathing Excessive myocardial workload 5

Factors Influencing Oxygen Transport Cardiac output Arterial oxygen content Concentration of Hgb Metabolic requirements

Hypoxemia Hypoxia decrease in the arterial oxygen content in the blood decreased oxygen supply to the tissues.

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 8

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 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% 6 lito2=Fio2 24% 21%+24%=Fio2 45%

Simple 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% 6 lito2=Fio2 36% 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 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 Infant

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

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 29

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? 30

Optimization cont. Check my source! Is the flow set high enough? Ensure the O2 delivery device is attached to oxygen not medical air. Follow tubing back to source and ensure patency Are all connections tight? Is the flow set high enough? All nebs especially high flow large volume nebs need to be run at the highest rate. Turn flow meter to maximum for large volume nebs. 31

Optimization cont. Reposition patient. Listen to chest. 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? 32

optimization cont. Can I improve the mechanics of breathing? Patient position Pursed lip breathing Abdominal breathing. Anxiety relief? 33

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. 34

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 35

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 36

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 37

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 38

Questions? Thank you for attention !