5. Composition of Room AirComposition of Room Air
Nitrogen 78.08% ~78%
Oxygen 20.946% ~21%
Trace gases ~1%
6. Definition:Definition:
*Oxygen therapy is the administration of oxygen
at concentrations greater than room air ( 21%)
*With goal of treating or preventing the
symptoms and manifestations of hypoxia(a state
of oxygen deficiency reaching the tissues)
07/06/13 6
7. Topics of DiscussionTopics of Discussion
*Types of Hypoxia
*Signs and symptoms of Hypoxia
*Indications
*O2 delivery Systems
*Hazards o2 therapy
07/06/13 7
9. Types of HypoxiaTypes of Hypoxia
1-Hypoxic Hypoxia
2-Circulatory Hypoxia
3-Hemic Hypoxia
4-Demand Hypoxia
5-Histotoxic Hypoxia
07/06/13 9
10. Hypoxic HypoxiaHypoxic Hypoxia
*Low PaO2(arterial oxygen tension) which is
secondary to FiO2 < 21% or decreased
barometric pressure( high altitude )
*Impaired ventilation secondary to
neuromuscular weakness or narcotic
overdose
*Impaired oxygenation secondary to
Pulmonary Fibrosis, ARDS
07/06/13 10
11. Circulatory HypoxiaCirculatory Hypoxia
*Inadequate pumping of the blood from the
lungs to tissues , maybe secondary to
disorders causing decreased cardiac output
such as MI, low fluid volume, hypotension,
poor supply of arteries. If the patient has
myocardial ischemia supplemental O2 is
definitely indicated.
07/06/13 11
15. Signs and Symptoms of HypoxiaSigns and Symptoms of Hypoxia
Tachypnea, dyspnea
Tachycardia, dysrythmias, pulse change,
hypertension
Anemia,
Restlessness, disorientation, lethargy,
Cyanosis, clubbing
07/06/13 15
16. IndicationsIndications
1)PaO2 <60mmHg or SaO2 <90% in subjects breathing room
air.
PaO2=partial pressure of oxygen as measured in the arterial
blood, SaO2=hemoglobin’s saturation
2)Acute situation where hypoxemia is suspected
3)Severe trauma
4)Acute myocardial infarction
5)Short term, post operative
07/06/13 16
17. DefinitionsDefinitions
FiO2= Fraction of inspired oxygen, or
the percent of oxygen in the inspired
gas
Oxygen toxicity is cellular injury of the lung
parenchyma and airway epithelium due
to release of cytoxic free oxygen
radicals.
There is no exact threshold at which O2
toxicity occurs, however signs of gas
exchange abnormalities occur within 24-
48 hours if on 100% oxygen. Atelectasis
leading to drop in PO2, decreased lung
compliance, infiltrates on x-ray.
Breathing FiO2 up to 50 % for 2-7 days
usually does NOT result in toxicity.07/06/13 17
18. DEVICESDEVICES
The oxygen delivery devices can be
categorized as
Low flow systems
Reservoir systems
High flow systems
Enclosure systems
07/06/13 18
19. Oxygen TherapyOxygen Therapy
Design & PerformanceDesign & Performance
◦ Low flow Devices
Flow does not meet inspiratory demand
O2 is diluted with air on inspiration
Devices deliver Fio2 ranging from 22-60%
E.g
Nasal cannula
Transtracheal catheter
19
22. NASAL CANNULANASAL CANNULA
low oxygen devicelow oxygen device
This device delivers an unpredictable amount of
oxygen ranging from 25-45 % at 1 - 6 L/min
depending on how much the patient inhales through
the mouth
Higher flow rates are uncomfortable for the patient
A high flow rate can quickly dry out the nasal
mucosa and become rapidly uncomfortable
22
23. NASAL CANNULA Cont…NASAL CANNULA Cont…
low oxygen devicelow oxygen device
Delivers 25-45% FIO2 at 1-6 L/min flow
1. Flow 0 liters per minute: 21% (Room
Air)
2. Flow 1 liters per minute: 25%
3. Flow 2 liters per minute: 29%
4. Flow 3 liters per minute: 33%
5. Flow 4 liters per minute: 37%
6. Flow 5 liters per minute: 41%
7. Flow 6 liters per minute: 45%
23
25. SIMPLE FACEMASKSIMPLE FACEMASK
low oxygen devicelow oxygen device
The simple facemask at an oxygen flow of 6 L/min delivers
approximately 35-40 % oxygen
Increasing the flow to 10 L/min may increase oxygen
concentration to about 50 %
If the flow rate is less than 6 L/min (as cylinder nears
empty), the patient may re-breathe much of his own
exhalation and thus, the concentration of oxygen delivered
will be low, possibly severely hypoxic
25
27. Partial Rebreathing Mask with reservoirPartial Rebreathing Mask with reservoir
Moderate oxygen deviceModerate oxygen device
Delivers 35-60% Oxygen at 6-10 L/min flow
rate
Ω First third of exhaled gases mix with reservoir
Ω Exhaled gases from upper airway are oxygen
rich
27
Reservoir
28. Non-Rebreathing Mask with reservoirNon-Rebreathing Mask with reservoir
High oxygen deviceHigh oxygen device
Delivers 95% Oxygen at 10-12 L/min
Two valves added to Rebreathing mask
prevents:
◦ Entrainment of room air during inspiration
◦ Retention of exhaled gases during expiration
28
Valves
29. High Flow systemHigh Flow system
It provide oxygen at flow rates high
enough to satisfy patient’s inspiratory
demands.
Such high flows( i.e. 35-40 lit approx) are
possible by
1. Entrainment of room air
2. High flow rates and reservoirs
E.g
Venturi masks
07/06/13 29
32. VENTURI EFFECTVENTURI EFFECT
Oxygen is forced through a jet
orifice entering the mask. As there
is pressure drop across jet orifice,
room air entrainment occurs
through side ports
07/06/13 32
33. Venturi MasksVenturi Masks
Venti-MasksVenti-Masks
Can provide 24%-50% oxygen by mixing
room air with a precise amount of oxygen
thereby delivering a precise FiO2. The size
of the port and the oxygen liter flow
determine the FiO2. The mask should be
fitted to the patient as best as possible to
prevent entrainment of room air around
the mask which would alter the FiO2.
07/06/13 33
38. Oxygen HoodOxygen Hood
High oxygen deviceHigh oxygen device
Clear plastic shell encompasses the baby's head
Well tolerated by infants
Size of hood limits use to younger than age 1 year
Allows easy access to chest, trunk, and extremities
Allows control of Oxygen Delivery:
o Oxygen concentration
o Inspired oxygen temperature and humidity
Delivers 80-90% oxygen at 10-15 liter per minute
38
40. Nasal CPAPNasal CPAP::
Nasal CPAP: It consists of a single
nasopharyngeal tube that deliveries 2-8
cm of positive pressure with or without
o2.
Nursing care :
- Frequent suction .
- Tube care.
- Change the nasal tube.
07/06/13 40
41. Endotracheal CPAPEndotracheal CPAP
Endotracheal CPAP: Positive pressure
delivering via an ETT.
Nursing care :
- Use sterile suctioning techniques
- Mouth care
- Change the ETT every seven days .
07/06/13 41
42. Oxygen HazardsOxygen Hazards
Fire ( airway fires)
Tissue toxicity, pulmonary and retina
Decreased hypoxemic drive and
increased in COPD.
Seizures (hyperbaric)
Mucosal damage due to lack of humidity
43. Complications of oxygen adm…Complications of oxygen adm…
1- Air way obstruction(thickened
secretions, mechanical problems with
artificial airway or ventilator circutory.
2- Tracheal damage
3- pulmonary infection
4- Barotrauma (pneumothorax or tension
pneumothorax)
07/06/13 43
44. Cont….Cont….
5- Decrease cardiac output.
6- Atelectasis.
7- Alteration in GI(dilation,bleeding).
8- Alteration in renal function.
9- Alteration in cognitive perceptual
status
07/06/13 44
45. Take home messageTake home message
Acute empiric oxygen treatment is ok but hypoxemia
should be verified with pulse oximetry and /or ABG’s
when situation more stable.
Oxygen is a drug and should be administered keeping
following things in mind: mode of administration, flow
rate, FiO2 (venturi), treatment goal, monitoring, when
to stop.
