2. Indications of O2 therapy
1. Documented hypoxemia
In adults, children, and infants older than 28 days, arterial
oxygen tension (PaO2) of < 60 mmHg or arterial oxygen
saturation (SaO2) of < 90% in subjects breathing room air or
with PaO2 and/or SaO2 below desirable range for specific
clinical situation
In neonates, PaO2 < 50 mmHg and/or SaO2 < 88% or capillary
oxygen tension (PcO2) < 40 mmHg
3. 2 . An acute care situation in which hypoxemia is
suspected
Substantiation of hypoxemia is required
within an appropriate period of time following
initiation of therapy
3. Severe trauma
4. Acute myocardial infarction
5. Short-term therapy (e.g., post-anesthesia recovery)
6. Increased metabolic demands, i.e. burns, multiple injuries,
and severe infections.
4. Three clinical goals of O2 therapy
1. Treat hypoxemia
2. Decrease work of breathing (WOB)
3. Decrease myocardial Work
5. FACTORS THAT DETERMINE WHICH SYSTEM
TO USE
1. Patient comfort / acceptance by the Pt
2. The level of FiO2 that is needed
3. The requirement that the FiO2 be controlled
within a certain range
4. The level of humidification and /or
nebulization
5. Minimal resistance to breathing
6. Efficient & economical use of oxygen
6. O2 delivery methods
Low flow oxygen delivery system
(variable performance, Pt dependent )
High flow oxygen delivery system
(fixed performance, Pt independent )
8. Nasal cannula
Simple plastic tubing + prongs with an over the ear adjustments.
Sizing available for adults children and infants.
Fio2 increases app. 1-2% with every increase in o2 flow per litre.
Flow > 5lt/min is less tolerated due to flow jet in nasal cavity
1 - 24%
2 - 28%
3 - 32%
4 - 36%
5 - 40%
6 - 44%
9. Correct placement
No nasal obstruction
Advantages Disadvantages
Inexpensive Pressure sores
well tolerated, comfortable Crusting of secr.
easy to eat, drink Drying of mucosa
used in pt with long Epistaxis
term therapy(COPD) 80% of O2 gets wasted during
used with humidity expiration
10. Nasopharyngeal Catheter
Soft tubes with several distal holes.
Available in 8-14 FG sizes.
Catheter has to be well lubricated and inserted in to the pt’s
nose to the depth equal to the distance from ext nares to
tragus. and the tip should lie just above the uvula.
Oropharynx acts as a anatomical reservoir.
Limitations:
less popular due to complexity, limited use in ex. mucus
secretion, mucosal edema, DNS,
Pt’s incooperation due to gag or cough on insertion.
Nasal obstruction, sinusitis, skin irritation are potential
complications
11.
12. Nasal Mask
Hybrid of nasal cannula and a face mask
Applied by either an over the ear lariat ar a headband
strip
Lower end rests on upper lip covering the external nose
Adv.- comfortable , no air jetted in nares.
Disadv. – sores on long term use
13.
14. Simple face mask
Simple or non reservoir, oxigen free mask is a disposible plastic devise
that covers both nose and face.
The placing of mask over the patient’s face increases the size of the
oxygen reservoir beyond the limits of the anatomic reservoir ;therefore a
higher FiO2 can be delivered.
•The oxygen flow must be run at a
sufficient rate, usually 5 lpm or
more to prevent rebreathing of
exhaled gases.
•Best suited for those who require
more o2 than prongs.
•O2 therapy for short period like
post op in recovery room,transport
of patients.
15. Advantages: simple, lightweight, FiO2 upto 0.50, can be used
with humidity
Disadvantages: need to remove when speak, eat, drink,
vomiting, expectoration of secretions, drying / irritation of eyes,
uncomfortable when facial burns / trauma, application problem
when RT in situ, lack of seal proof borders so pure o2 gets
mixed with air.
16. Reservoir Mask
Two types are commonly used:
1) Partial rebreathing mask
2) Non rebreathing
Both are disposable, light wt.,transperent plastic under
the chin reservoirs.
Diff. between two is placement of a valve between mask
and bag and over mask.
“Partial rebreather” part of a patients expired air refilling
the bag.
“Non rebreather” same as above except for the position
of the valves.
Inboard leaking is common, lack of good facial seal
system can affect o2 conc.
17. Partial Rebreathing Mask
Simple mask with reservoir bag.
Oxygen flow to maintain the reservoir bag should be
at least 1/3 to ½ full on inspiration.
Oxygen conc. Of exhaled gas combined with supply
of fresh oxygen, permits the lower flow than non
rebreathing masks.
6-10L/min provides 40-70% of oxygen.
18.
19. Non rebreathing mask
•Sufficient flow of o2 is used so the
reservoir bag is at least partially full
during inspiration
•Minimum flow-10-15 l/min
•Fio2 – 35 to 60% may reach up
to 100% at 15 l/min.
•Either style of mask indicated for
pts suspected for significant
hypoxemia , with relatively normal
spont. Respiration.
20. Advantages:
FiO2 delivered >0.60 is delivered in mod. to severe hypoxia.
exhaled oxygen from anatomic dead space is conserved.
Disadvantages:
insufficient flow rate may lead to rebreathing of CO2.
Claustrophobia;drying and irritation of eyes, sometimes
uncomfortable to pt.
21. High flow O2 delivery system
Venturi mask
Face tent
Aerosol mask
Tracheostomy collar
T-piece
•Pt with variable ventilatory level
and breathig pattern
•Profoundly Dyspnoeic and
hypoximic pts
•For those who require consistent
high fio2
• and with late inspiratory flow of
gas(>40 lt/min)
22. Venturi effect
Based on bernoulli principle.
As the velocity of a fluid increases, the pressure
exerted by that fluid decreases.
Applied on both liquid and gases.
Venturi principle describes how a second fluid can
be entrained into the stream of first fluid.
24. Venturi Mask
Also called “Air entrainment venti masks” OR “High Air
Flow with Oxygen-Entrainment” (HAFOE).
Goal is to create an open system with high flow about the
nose and mouth, with a fixed FIo2.
O2 is directed by a small bore tubing to a mixing jet.
Final conc. depends on the ratio of air drawn in through
enrainment ports.
Due to high flow , excess gas flushes out the expired co2
through the holes on the sides of mask.
Good for those with hypoxemia cannot be controlled with
low fio2.
30. Fio2 can be increased if the entrainment ports are
obstructed by the patients hands, bed sheets or water
condensate.
Depending upon the pt’s clinical condition , respiratory
rate, pattern, o2 saturation, mask can be changed to
higher or lower range.
31. Bag Valve Mask systems
Self inflating bags are AMBU bags, with an oxygen inlet
reservoir
Anaesthesia bag is a non self inflating reservoirs with gas
inlet and valve.
Mask are designed to provide comfortable leak free seal
for manual ventilation.
Flow to the reservoirs should be kept high so bags do not
deflate substantially.
These devices have a potential for a constant FiO2 of
>90%.
Limitation: in spont. Breathing person flow has to be
adjusted with the valve, chances of aspiration, constant
adequate flow of gases has to be maintained.
32.
33. Air Entrainment Nebulizers
Large volume, High Output ,all purpose nebulizers
provide bland mist therapy with some control of FiO2.
Commonly placed on patients following extubation for
their aerosol produsing properties.
Nebulizer system can be applied with many devices:
aerosol,tracheostomy dome/colar,face tents,T piece
adapter.
If T-piece is used if visible mist disappear during
inspiration, the flow is inadequate.
Excess water may collect in tubing and may obstuct and
develop resistance to flow.
Sometimes Bronchospasm may occure due to irritant
nature of sterile water.
36. Pediatric oxygen delivery system
Oxygen hood
Covers only head allowing access to
the lower body.
Ideal for short term use for neonates
and infants.
O2 and air premixed passed through
heated humidifiers.
Nebulizers should be avoided.
Mini. Flow >7 lt/min. avg flow 10-15
lt/min results in 80-90% oxygen conc.
38. Oxygen tents
Transparent enclosures in larger sizes for adult pts.
Co2 is removed by soda lime and water vapour by
calcium chloride.
Temp.is regulated by flowing oxygen and air over
ice.
60-70% O2 conc. Achieved by flow rates of 10-
12L/min.
The air changes 20 times/hour.
Limitations:
Confining and isolating
Fio2 can vary from 0.21 to 1.0
Fungal infection risk.
40. Other devices
Face tent:
21% to 40% depending on nebulizer setting
Flow rates of 8 to 15 L/min
Used mainly for patients who can not
tolerate a mask
