Oxygen therapy involves administering oxygen at concentrations greater than in ambient air to treat hypoxia and reduce work of breathing and myocardial work. It can be delivered via low-flow nasal cannulas or high-flow face masks, hoods, and tents. Precautions must be taken when using oxygen to avoid drying tissues, hypoventilation, absorption atelectasis, oxygen toxicity, and fire hazards. Clinical assessment and arterial blood gases are used to monitor patients and determine appropriate oxygen concentrations and durations of therapy.

2. Oxygen therapy
“Oxygen Therapy is defined as the
administration of oxygen at concentrations
greater than those found in ambient air”
Goals: 3 clinical goals of O2 therapy
* Treat Hypoxia
* Decrease work of breathing
* Decrease myocardial work

3. Physical properties of oxygen
 It was first recognized as a distinct gas by Joseph
Priestley in 1774 .
 Is a colourless , odourless non-flammable gas.
 Molecular weight 32 & specific gravity 1.105
 Makes up 20.9% of air by volume and 23% air by
weight.
 Boiling point -183 C
 Melting point –216.6C
 Critical temp. –118.4C , Critical pressure 736.9psi

4. Preparation & storage
 O2 manufactured by fractional distillation of
liquid air .
 Before liquefaction ,co2 removed by filter.
 O2 & N2 separated by means of their
boiling points. O2 = -183 C, N2= -195 C

5. O2 can be store either
1) Cylinder
 Oxygen can be stored under pressure in cylinders
made of molybdenum steel.
 Cylinders are black with white shoulders.
 The pressure inside at 15°C is 137 bar.
 Pin index 2,5
 Oxygen cylinder content estimated Boyle’s law
 Capacity: E cylinder =643.9L/1900 psi
M cylinder = 3450L/2200psi
H cyinder= 6900L/2200 psi
2) Oxygen concentrators
3)Vacuum Insulated Evaporator (VIE).

6. INDICATION FOR OXYGEN
THERAPY
For Adult :
PaO2 < 60 mmHg(8KPa), SpO2< 90% .
For Neonate :
paO2 < 50mmHg (6.7KPa), SpO2< 88%.
In general the indication are:-
Hypoxemia/hypoxia
Excessive work of breathing
Excessive myocardial work
Improvement of oxygenation in patient with
decreased O2 carrying capacity ( anaemia)

7. INDICATION
HYPOVENTILATION INTRAPULMONAR
Y SHUNT
WASTED
VENTILATION
DIFFUSION
DEFECTS
INCREASED
DEMAND
*CEREBRAL INJURY
CHEST INJURY
*INADEQUATE
REVERSAL OF NMBA
*POST OPERATIVE PAIN
*PULMONARY EMBOLISM
*UPPER AIRWAY
OBSTRUCTION
*COPD
*ENDOBRONCHEAL
INTUBATION
* CONGENITAL
HEART DISEASE
* ATELECTASIS
* PNEUMO THORAX
*CARDIAC
FAILURE
*PULMONARY
HTN
*PULMONARY
OBSTRUCTION
*SHOCK
*RETAINED
SECRATION
*PULMONARY
OEDEMA
*POSTOPERATIV
E SHIEVERING
*CONVULSION
HYPERTHERMIA

8. HYPOXIA
Inadequate delivery of O2 to the tissue
Type of hypoxia :
1. Hypoxic hypoxia
 low inspired FiO2 eg. High altitude .
 Hypoventilation : COPD.
 Diffusion impairment eg. Pulmonary edema .
 V/Q inequalities eg , Asthma , Pulmonary
emboli .
 Right to left shunt(cardiac anomalies)eg.
Cyanotic congenital heart disease .

9. 2. Stagnant hypoxia/ischemic :
 Heart failure , Shock , dehydration , sepsis .
3 Anaemic hypoxia
 Anaemia
 Carbon monoxide poisoning
 Methemoglobinemia
4. Histotoxic hypoxia
* Cyanide poisoning
HYPOXEMIA
Reduced O2 concentration/tension in the blood
PaO2<80mmhg.

10. Benefit of O2 therapy in
Hypoxia
 Hypoxic Hypoxia (100%) +++
 Anaemic Hypoxia (75%) +
 Stagnant Hypoxia (50%) +
 Histotoxic Hypoxia -

12. Oxygen cascade

13. Oxygen Transport in the body
1. Diffusion of O2 from alveolar air to pulmonary
capillary
PO2 in alveolus = 105 mm Hg
PO2 in pulmonary capillaries at arterial end = 40
mm Hg
The pressure difference of O2 = 65 mm Hg
2. Transport of O2 in Blood :
Dissolved state :
Approximatly (0.27-0.3) mL/100 mL of Blood .
In the form of O2-Hb complex :
About 97% of O2 is arrived in the form of O2-Hb .

14. 3. Diffusion of O2 from Blood to the Tissue :

15. Oxygen content
 Arterial Oxygen content(CaO2)= SpO2 x Hb%
x 1.34 mL/dL + 0.003 x PaO2~20ml
 Venous Oxygen content(CvO2)= SpO2 xHb%
x 1.34 mL/dL + 0.003 x PvO2 ~15ml
 O2 delivery = CaO2 x cardiac output
 O2 consumption = (CaO2-CvO2) x cardiac
output 25%

16. OXYGEN DELIVERY SYSTEM
Classification
1. Low-Flow Systems/Variable performance
2. High Flow / fixed performance equipment .
Low flow/variable
performance devices
High flow /fixed
performance devices
* Flow rate less than
patients inspiratory flow
rate.
* FiO2 varies with
RR&TV
* FiO2 not predictable
*Flow rate more than patients
inspiratory flow rate
* Not influenced by RR/TV
* FiO2 fixed & accurate

17. Low-Flow Systems/Variable performance :
Is adequate for patients with
Minute ventilation < ~8-10L/min
Breathing frequencies < 20 breath/min
Tidal volumes(VT)< ~0.8L
Normal inspiratory flow (10-30L/min)
Low flow devices:
No capacity system : Nasal cannula , Nasal catheter
Low capacity system(<100ml) : Simple mask of children
Medium capacity system(100-250ml) : Adult Simple face
mask
nebulizer mask
High capacity system(250-1500ml): facemask with reservoir
bag
*Partial rebreathing
* Non rebreathing
Very high capacity system(>1500ml): oxygen hood ,oxygen
tents

18. Nasal cannula (prongs)
Capable to deliver an FiO2 ranging from 0.24-0.44
Maximum of 6LPM : causes crusting of the secretion ,
drying of the nasal mucosa & epistaxis
Advantages – inexpensive , well tolerated, comfortable
patient can eat and drink
Disadvantages – pressure sore, irritant to the mucosal
Flow L/M FiO2
LPM, 1 0.24
LPM , 2 0.28
LPM, 3 0.34
LPM, 4 0.38
LPM, 5-6 0.44

20. Simple face mask
Usual flow rate -6-10 l/min
Fio2 : 35-65 %
O2 flow must be more than 5LPM to prevent
rebreathing
Flow ` FiO2
5-6LPM 0.30-0.45
7-8LPM 0.40-0.60
Advantages – simple, light, deliver higher FiO2
Disadvantages – need to remove for eat, drink,
speak
- uncomfortable for facial trauma

22. MASK WITH GAS RESERVOIR
Partial rebreathing :-
Simple mask with addition of reservoir bag.
Low flow, medium concentration, 8-12 LPM
Allow the mixture or oxygen and carbon dioxide in the mask
Deliver ~ 60% O2.
Advantages
Client can inhale room air if oxygen supply is iterrupted .
Disadvantages
Requires tight seal (eating and talking difficult,
uncomfortable)
Partial rebreathing
Flow FiO2
7 LPM 0.35-0.75
15LPM 0.65- 1.0

23. Non rebreathing mask :–
one way valve to prevent rebreathing
Advantages
Delivers the highest possible oxygen Conc (95-100%)
at a
flow rate 8-15 L/min.
Disadvantages
1.Impractical for long term Therapy
2.suffocation
3.Expensive 4.Uncomfortable
Non rebreathing
Flow FiO2
7-15 0.40-1.0

26. Oxygen Hood
 An oxygen hood is used for babies
who can breathe on their own but still
need extra oxygen.
 A hood is a plastic dome or box with
warm, moist oxygen inside.
 The hood is placed over the baby's
head

28. Oxygen tents
An oxygen tent is a bendable piece of
clear
plastic held over the child's bed or crib
by a
frame.

29. Oxygen tents
An oxygen tent is a bendable piece of clear plastic held
over the child's bed or crib by a frame.
Oxygen tents

30. High-Flow Systems/Fixed
performance
 Air Entrainment Mask (Venturi);
 Air Entrainment Nebulizer: T-piece , Tracheostomy
collar .
 Mechanical Ventilators (invasive Non-invasive);
 CPAP Machines;
 Resuscitation Bags
 Hyperbaric Oxygen Chambers.

31. Venturi mask
• Operate on Bernoulli principle
• Is designed with wide- bore tubing and various color -
coded jet adapters
• Each color code correspond to a precise .
• The amount of air determined by the size of the orifice
(jet adapter).
• Oxygen from 24 - 50% . flow of 4 to 15 L/min.

32. Venturi mask
Advantages –
Delivers most precise oxygen Conc.
Doesn’t dry mucous membranes
Disadvantages –
Uncomfortable
Risk for skin irritation
produce respiratory depression in COPD

34. AMBU BAG
AMBU- Artificial Manual Breathing Unit
(or)
Bag Valve Mask Ventilation is a hand-
held device commonly used to provide
positive pressure ventilation to patients
who are not breathing or not breathing
adequately.

36. T-PIECE
 Used on end of ET tube when
weaning from ventilator
 Provides accurate FIO2
 Provides good humidity

37. T-PIECE

38. Tracheostomy Collar/ Mask
 Inserted directed into trachea
 Is indicated for chronic O2 therapy
need
 O2 flow rate 8 to 10L
 Provides accurate FIO2
 Provides good humidity.
 Comfortable ,more efficient .

40. Hyperbaric Oxygen Therapy
(HBOT)
Hyperbaric O2 therapy use a pressurized
chamber greater than one atmosphere combined
with the delivery of 100% oxygen (FiO2 = 1.0),
drives the diffusion of oxygen into the blood
plasma at up to 10 times normal concentration.

41. HBOT

42. Indication
1. Air or Gas Embolism
2. Carbon Monoxide Poisoning
3. Gas Gangrene
4. Crush Injury, Compartment Syndrome and
Other Acute Traumatic Ischemias
5. Decompression Sickness
6. Arterial Insufficiencies: • Central Retinal
Artery Occlusion
7. Severe Anemia
8. Intracranial Abscess
9. Necrotizing Soft Tissue Infections

43. Problems with HBOT
1. Barotrauma .
• Air / Sinus trauma
• Tympanic membrane rupture
• Pneumothorax
2. Oxygen toxicity
3. Fire hazards
4. Sudden decompression
5. Calutrophobia

44. Assessment of Oxygen
Therapy
• Clinical assessment
• Arterial blood gas analysis.
• Pulse Oximetry
How much O2 is safe ?
100% - not more than 12 hours
80% - not more than 24 hours
60 % - not more than 36 hours

45. COMPLICATION OF OXYGEN
THERAPY
Drying of mucus membrane
Oxygen induced hypoventilation
Absorption atelectasis
Oxygen toxicity/narcosis
Retinopathy of prematurity
Hyperbaric O2 hazards
Depression of hematopoesis
Fire hazards

46. Hypoventilation
The increased PO2, decreased and eliminates
the hypoxic drive ( esp. in pt. with chronic CO2
retention )
Hypoventilation occures and apnea developed
Under this circumstances O2 must be given at
low concentration <30%

47. Absorption Atelectasis
During 100% oxygen delivery, nitrogen in
alveoli is washed out and replaced by
oxygen. In contrast to nitrogen, oxygen is
extremely soluble in blood and diffuses
very quickly into the pulmonary
vasculature, so that not enough gas is left
in the alveoli to maintain patency, and the
alveolus collapses; this is known as
absorption atelectasis .

49. Pulmonary Oxygen Toxicity
High FiO2 for prolonged time
Generation of free radical
React with cellular DNA
Cytotoxicity ,damage capillary endothelium , Interstitial
edema
Thickened alveolar capillary membrane
Pulmonary fibrosis and hypertension

51. Retrolental Fibroplasia
Excessive O2 to pre-mature infants may
result in constriction of immature retinal
vessels, endothelial damage, retinal
detachment and possible blindness
Recommended that PO2 be maintained
between 60-90 mmHg range in neonate

52. Oxygen safety
Safety precautions when using oxygen
 Never use oxygen near an open flame
cigarettes
 Never use grease or oil with O2 equipment
 Oxygen promotes combustion
 Do not tamper with oxygen equipment
 Store in a cool place
 Store oxygen bottles lying flat, or security
fastened if upright
 Use only medical oxygen.
 Do not use when delivering a shock via a
defibrillator.
 Used oxygen failure warning device