The document outlines the principles and practices of oxygen therapy, including its definitions, goals, indications, contraindications, delivery systems, and potential adverse effects. It details various oxygen delivery devices, their mechanisms, and calculations for use in clinical settings, along with the physiological aspects of oxygen transport and gas exchange. The document also highlights special considerations for pediatrics, high-flow systems, and complications related to oxygen therapy.

1. presented by
Dr sapan kumar jena
2nd yr p.g
Guided by
Dr. C.R.Panigrahi
Asst Professor
Dept of Anaesthesiology & critical
care ,VIMSAR

2. Oxygen therapy
 “Oxygen Therapy is usually defined as
the administration of oxygen at
concentrations greater than those found
in ambient air”

3. Goal
 “To treat or prevent hypoxemia thereby
preventing tissue hypoxia which may result
in tissue injury or even cell death”

4. Indications
Hypoventilation Intrapulmonary
shunt
Wasted
ventilation
Diffusion
defects
Increased
demand
•Cerebral injury
•Chest injury
•Inadequate
reversal of
NMBA
•Post opertive
pain
•Pulmonary
embolism
•Upper airway
obstruction
•COPD
•Endobroncheal
intubation
•Congenital
heart disease
•Atelectasis
•Pneumothorax
•Pulm HTN
•Cardiac
failure
•Pulmonary
obstruction
•shock
•Retained
secretions
•Pulmonary
edema
•Postopertive
shievering
•Convulsions
•Hyperthermia

5. Absolute Contraindications &
Possible Adverse Effects
 Absolute Contraindications
• Patient/Client does not consent to receiving the
oxygen
• The use of some O2 delivery devices (e.g., nasal
cannulas and nasopharyngeal catheters in neonates
and pediatric patients that have nasal obstructions)
 Potential Adverse Effects
• Oxygen toxicity
• Oxidative stress
• Depression of ventilation in a select population with
chronic hypercarbia
• Retinopathy of prematurity
• Absorption atelectasis

7. Physical properties of
oxygen Oxygen (O2) is the eighth element on the periodic table.
 Molecular weight 32 & specific gravity 1.105
 Makes up 20.9% of air by volume and 23% air by weight.
 Can combine with all other elements except other inert gases
to form oxides.
 Oxygen is therefore characterized as an oxidizer.
 Is a colourless,odourless non-flammable gas.
 Accelerates combustion.
 Its critical temperature is -118.4 C (above this critical
temperature oxygen can only exist as a gas regardless of the
pressure).
 An oxygen enriched environment is considered to have 23%
oxygen in the air and is a fire hazard.

8. Preparation & storage

9.  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

10. Types of Oxygen Delivery
Systems
 There are three main types of oxygen
delivery systems:
 • Compressed gas cylinders;
 • Liquid oxygen in cryogenic containers;
and
 • Oxygen concentrators for medical use.

11. Compressed Gas
Cylinders
 Black with white shoulders in india
 Pin index = 2,5
 Capacity
 E cylinder =660L/1900 psi
 M cylinder = 3450L/2200psi
 H cyinder= 6900L/2200 psi

13. Calculation of duration of
flow
 To calculate how long a cylinder will last based
on the size of the cylinder and continuous flow
rate, the following formula can be used:
 Duration of Flow in minutes =
[current gauge pressure in psi x cylinder
factor]/ Flow rate in liters per minute
 Some examples of cylinder factors for different
sized cylinders are:
 D cylinder 0.16
 E cylinder 0.28
 M cylinder 1.56

14.  Bulk Oxygen
 in a manifold system, large sized
cylinders are linked together to supply
medical oxygen to medical gas pipelines
which then lead directly to the bedside in
hospitals.
 Pressure at pipe line /circuit= 4bar/60 psi

15. Manifold System

16. Liquid Oxygen in Cryogenic
Containers
 cryogenic containers (also known as
reservoirs) can be used in various settings
such as long-term care facilities, homes,
and hospital wards to fill smaller portable
cryogenic liquid systems that patients can
ambulate with.
 Portable liquid oxygen units offer
continuous flow or intermittent flow of
oxygen to the patient.

17. Oxygen Concentrators for
Medical Use

18.  A concentrator is an electrically
powered, electronically controlled device
that does not store oxygen when not in
operation.
 It produces oxygen from ambient air by
absorption of nitrogen onto some type of
alumina silicates.

19. How Does Oxygen Therapy
Work?
 Oxygen Transport
 The majority of oxygen carried in the blood is
transported bound to hemoglobin.
 = SpO2 x Hb% x 1.39 mL/dL
 A very small amount of oxygen gas is transported
dissolved in the plasma.
 Dissolved O2 = 0.003ml/dL/mm Hg x PO2

20.  Arterial Oxygen content(CaO2)= SpO2 x Hb%
x 1.39 mL/dL + 0.003ml/dL/mm Hg x PaO2
~20ml
 Venous Oxygen content(CvO2)= SpO2 x
Hb% x 1.31 mL/dL + 0.003ml/dL/mm Hg x
PvO2 ~15ml
 O2 delivery = CaO2 x cardiac output
 O2 consumption = (CaO2-CvO2) x cardiac
output
 Extraction fraction= (CaO2-CvO2)/CaO2 ~
25%

21. Oxygen Hemoglobin Dissociation
Curve

22. Gas exchange
 Oxygen cascade: steps by which partial
pressure of O2 decreases from higher level
in inspired gas to a lower level in
mitochondria.

24.  The movement of oxygen at the level of the
microcirculation occurs mainly by passive
diffusion.
 Fick’s Law of Diffusion
 R = A x D (P1 - P2)/T
 Where the factors affecting gas exchange are:
 R = rate of diffusion
 A = cross sectional area available for diffusion
 D = diffusion coefficient
 P1 - P2 = the partial pressure gradient
 P1 = partial pressure of oxygen in the alveolus (PAO2)
 P2 = partial pressure of oxygen in the blood (PaO2)
 T = thickness of the membrane (alveolar-capillary
membrane)

25. Oxygen Therapy Equipment
and Adjuncts

26. Low flow /variable
performance devices
High flow /fixed
performance devices
•Flow rate less than
patients inspiratory flow
rate leading to air
entrainment.
•FiO2 varies with RR &
TV.
•FiO2 not predictable
•Flow rate more than
patients inspiratory flow
rate
•Not influenced by
RR/TV
•FiO2 fixed and
accurate

27. 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,nebuliser mask
• High capacity system(250-1500ml):
facemask with resoirvior bag
• Partial rebreathing
• Non rebreathing
• Very high capacity system(>1500ml):
oxygen hood ,oxygen tents

28. Low flow oxygen delivery
devices
Nasal cannula
 Disposable
 Plastic device with two prongs for insertion into
the nostrils.
 Delivers 24 to 44 % of oxygen at 1 to 6 L/min
 Formula FiO2 = 20%+(4x oxygen litre flow)
 Advantages :
 easy to use
 Patients are able to talk &eat with oxygen in place
 Disadvantages :
 Cause irritation of nasal & pharyngeal mucosa

29. Nasal cannula

30. Nasopharyngeal catheter
 Like suction catheter with multiple openings
 Size 8-14 Fr
 Inserted upto fold of soft palate
 Need to be changed from 1 nostril to other
every 8 hrly.
 Upto 40 % FiO2 delivered
 Advantages : gas flow does not impinge on
one area
 Disadvanages : nasal irritation,drying of
mucasa

32. Face mask
 Simple face mask
 Made up of clear ,flexible plastic
 Held to head with elastic bands
 Has metal clip that can be bent over bridge of nose
for a comfortable fit
 Open ports for exhaled gas
 Minimum flow rate of 4l/min to avoid rebreathing
 Usual flow rate -6-10 l/min
 Fio2 : 35-65 % depnding on flow rate , mask size,
breathing pattern

33.  Advantages :
 Provide increased delivery of oxygen for short
period of time
 Useful for strict mouth breathers
 Disadvantages :
 Has to be removed while eating &drinking
 Muffles communication, obstruct coughing
 Uncomfortable & can’t be used for prolong time

35. PARTIAL REBREATHING
MASK
 Mask is a simple mask with a reservoir bag.
 Same as the Non re-breathing bag but
without a one way valve.
 Low flow, medium concentration
 8 – 12 liters per minute
 Bag should remain at least 1/3 full during
inspiration
 Allow the mixture or oxygen and carbon
dioxide in the mask.

36.  O2 directed into
reservoir
 Insp: draw gas from
bag & room air
 Exp: first 1/3 of exhaled
gas goes into bag
(dead space)
 Dead space gas mixes
with ‘new’ O2 going into
bag
 Deliver ~60% O2

37.  ADVANTAGES
 - Can inhale room air through
 openings in mask if oxygen supply is briefly
interrupted.
 Not as drying to mucous membranes
 DISADVANTAGES
 Requires tight seal
 Eating and talking difficult,
 uncomfortable

38.  Caution:
 Set flow rate so mask remains twothirds
full during inspiration
 Keep reservoir bag free of twists or kinks
 Prevents the reservoir bag to collapse or
be empty
 Prevents anyone to squeeze the bag while
on the patient.

39. NON REBREATHING
MASK
 It is similar to the partial rebreather
mask except two one-way valves
prevent conservation of exhaled air.
 the one-way valve closes and all of the
expired air is deposited into the
atmosphere, not the reservoir bag.
 This mask provides the highest
concentration of oxygen(95-100%) at a
flow rate 8-15 L/min.

41.  Valve prevents exhaled gas flow into
reservoir Bag
 Valve over exhalation ports prevents air
entrainment
 Delivers ~100% O2, if bag does not
completely collapse during inhalation
 Maintain flow rate so reservoir bag
collapses only slightly during inspiration

42.  ADVANTAGES
 Delivers the highest possible oxygen
Concentration
 Suitable for pt breathing spontaneous with
severe hypoxemia
 DISADVANTAGES
 Impractical for long term Therapy
 Malfunction can cause CO2 buildup suffocation
 Expensive
 Feeling of suffocation
 Uncomfortable

44. Calculation of FiO2 in variable
performance devices
 Flow = 6L/min
 RR= 20 /min
 TV =500 ml

45. Special consideration in
paediatric patients
 Oxygen hood
 A hood is a plastic dome or box with warm, moist
oxygen inside. The hood is placed over the baby's
head.
 Oxygen enters the hood
through gas inlet
 Exhaled gas exits
through opening in
the neck .

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

47. HIGH FLOW Or FIXED DELIVERY
SYSTEMS
 provide a fixed FiO2 (0.24 - 1.0) regardless
of the patient’s/client’s inspiratory demands.
 Air Entrainment Mask (Venturi);
 Air Entrainment Nebulizer;
 Nasal High Flow Oxygen Therapy;
 Mechanical Ventilators (invasive Non-
invasive);
 CPAP Machines;
 Resuscitation Bags; and
 Hyperbaric Oxygen Chambers.

48. The Venturi System
 Room air dilutes the oxygen entering the
tubing to a certain concentration
 The amount of air drawn in is
determined by the size of the orifice (jet
adapter).
 Applying the Bernoulli principle

49.  Oxygen from 24 - 50%
 At liters flow of 4 to 15 L/min.
 The mask is so constructed that there is a
 constant flow of room air blended with a
fixed concentration of oxygen
 Is designed with wide- bore tubing and
 various color - coded jet adapters.
 Each color code corresponds to a precise
Oxygen concentration and a specific liter
flow.

52. Calculation of total gas flow
 Total gas flow = oxygen flow in L/min+
entrained air flow
 Entrained air flow =
oxygen flow x (1-FiO2)
FiO2-0.2

53.  ADVANTAGES
 Delivers most precise oxygen Concentration
 Doesn’t dry mucous membranes
 DISADVANTAGES
 Uncomfortable
 Risk for skin irritation
 produce respiratory depression in COPD
patient with high oxygen concentration 50%

54. TRACHEOSTOMY MASK
 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
 Less expensive

56.  ADVANTAGES
 Delivers high concentrations of oxygen
directly to the lungs.
 Stable and not moved when the patient is
moved or cleaned.
 Maintains saturation levels.
 DISADVANTAGES
 uncomfortable

57.  Nasal High Flow Oxygen Therapy (NHF)
 alternative to standard high-flow face mask
(HFFM)oxygen therapy.
 It provides delivery of up to 60 L/min of
heated and humidified, blended air and
oxygen via wide-bore nasal cannula

58. Hyperbaric Oxygen Therapy
(HBOT)
 The Basic Principles of Operation of
Hyperbaric Chambers
 The increased pressure inside the
chamber, 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. Patients are monitored at
all times during HBOT

60. Indications of HBOT
 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
 10. Delayed Radiation Injury (Soft Tissue and Bony
Necrosis)
 11. Compromised Grafts and Flaps
 12. Acute Thermal Burn Injury

61. Assessment of Oxygen
Therapy
 Hemoximetry (also called CO-oximetry)
– performed in arterial blood gas
analysis.
 Pulse Oximetry - portable, noninvasive
monitoring technique

62. Complications
 Drying of mucus membrane
 Oxygen induced hypoventilation
 Absorption atelectasis
 Oxygen toxicity/narcosis
 Retinopathy
 Myocardial depression( hyperbaric O2)
 Depression of hematopoesis
 Fire hazards

63. Oxygen induced hypoventilation
 Occures if respirtory drive is dependent
on hypoxic stimulus
 Inhaling high FiO2 causes
hypoventilation and hypercarbia
 Common in COPD patients

65.  O2 displaces all the N2 in airway
 Due solubility, gets absorbed causing
alveolar collapse in highly perfused and
poorly ventilated alveoli.
 Seen in COPD patients

66. Oxygen toxicity
 Due to overproduction of free radicals
from oxygen molecule
 Superoxide ion
 Hydrogen peroxide
 Singlet oxygen

68. Prevention of o2 toxicity
 Use lowest FiO2 for shortest time
 Air break- intermittent air breathing
periods
 Early use of PEEP to reduce shunts
 Maintain acid base balance
 Antioxydants like vitamin C & E

70. References
 Smith & aitkinhead test book of anaesthesia 6th
edition page no 33-35
 Wiley text book of anaesthesia p53-54,94-
96,168-175
 Miller anaesthesia
 Morgan clinical anaesthesiology p 511-519
 American Association of Respiratory Care.
(2002). AARC Guideline: Oxygen therapy for
adults in the acute care facility. Respiratory
Care, 47(6). Retrieved from:
www.rcjournal.com/cpgs/pdf/06.02.717.pdf
 Internet sources