Oxygen Therapy

Do you know what is the properties of the Oxygen ?

Oxygen is a color less, odorless, transparent, and tasteless gas.
 Its density of 1.429 g/L , slightly heavier than air (1.29 g/L)

but not very soluble in water. At room temperature only 3.3 ml of O2 dissolves in 100 ml of water.

Do you know what is the oxygen therapy?

Oxygen therapy is a treatment that delivers oxygen gas for patients to breathe. When patients saturation of oxygen is below the normal range 95-100% it may produce hypoxia. To   maintain the level of oxygen  and treat the condition of  hypoxia we  use oxygen.

when we use oxygen for therapeutic purpose or for the purpose of oxygenation  is known as oxygen therapy.

Why oxygen required for survival?

Because it is essential for cell metabolism, to provide  better ventilation and oxygenation  for tissues in our body and also
to maintain  normal physiological process in our body. 

How oxygen is transport  in our body?

 following methods are used for O2 transport -

SIMPLE    PHYSICAL SOLUTION–

Because of  poor solubility of oxygen in water plasma  dissolves 

only 0.3 ml/100 ml of plasma and it is 3% of total oxygen in blood.

COMBINATION WITH  HEMOGLOBIN-

 About 97% 

 in the form of oxyhemoglobin.

 1 gram % of hemoglobin carry 1.34 ml of oxygen so 15 gram% 

Hb carries about 20.1 ml of oxygen.

Can you differentiate the type of oxygen gas?

OXYGEN GAS- stored in a portable tank  called compressed gas 

system.

LIQUID OXYGEN- also can be stored in a portable tank . more 

highly concentrated so more oxygen can fit in a smaller tank. 

OXYGEN CONCENTRATES- less portable and it is a device that 

takes oxygen from the room concentrates so it is less expensive.

HYPERBARIC OXYGEN THERAPY- pure oxygen in a 

pressurized room or chamber. 

Increases the amount of delivery to the body. This type of O2 is 

used to treat wounds, serious infections or bubbles of air in your 

blood vessels.

What are the goals of Oxygen therapy?

 To correct hypoxemia or hypoxia - O2 therapy corrects 

hypoxemia by increasing alveolar and blood levels of O2.

 Decreases work of breathing- in the  refractory hypoxia 

occurs increase work of breathing very well responding to 

O2 therapy.

 Minimizing cardiopulmonary work load- the cardio-

pulmonary system compensates for hypoxemia by 

increasing ventilation and cardiac output.

How to monitor Oxygenation Status in intensive care

unit?

Noninvasive monitoring- pulse oximetry

  

1. Spectrophotometry

2.Optical plethesmographyInvasive monitoring By –   

ABG and transcutaneous monitoring.

what are the indications for oxygen therapy?

• Acute respiratory failure

• Acute MI

• Cardiac failure

• Circulatory Shock

• Anemia

• CO poisoning

• During CPR

• During post operative anesthesia recovery

what are the contraindications for oxygen therapy?

some exception is there such as nasal cannulas and 

nasopharyngeal catheters in pediatrics and neonatal 

patients with nasal obstruction.                        

Acc.to AARC GUIDLIN

What are the complication of the supplimental 

oxygen therapy?

Acc. To AARC 31-1 guideline there is many


hazards but five hazard are common-

1. Oxygen toxicity-
2. Depression of ventilation-
3. Retinopathy of prematurity-
4. Absorption atelectasis-
5. Fire hazards-

Oxygen toxicity-

Two primary factors determine the harmful effect of O2  

(1) higher the Po2 (100% ) and 

(2) prolong the exposure time greater the damage 

 1.Effects on CNS- It may produce 

1.  Tremor 
2.  Twitching
3.  convulsions.

             2.Effects on pulmonary system -

          Damage capillary endothelium cell>Interstitial edema followed   by thickening of  alveolar capillary membrane>Type I alveolar       cell damage>type II alveolar cell are proliferate (Low V/Q ratio  ,Pulmonary shunting,Hypoxia)>Pulmonary fibrosis and                 hypertension occurs.

        Depression of ventilation-

         In COPD patients some patients are hypo-ventilated when  we  give O2 is most likely  suppression of the hypoxic drive-

COPD>Increases PCO2 level >Stimulus for breathe because of lack of O2 sensed by peripheral chemoreceptors >Increase blood O2, suppresses peripheral  chemoreceptors depress ventrilatory drive and increases Pco2>High blood O2 levels disrupts the normal V/Q balance  so increase dead space and tidal volume ratio in PCO2.

Retinopathy of prematurity-

In premature baby who receive supplemental O2 Excess blood O2 

level causes retinal vasoconstriction which leads to necrosis of 

blood vessels>In response new vessels form and increase in 

number, hemorrhage of these new vessels causes scarring>Retinal 

detachment and blindness.

Absorption atelectasis-

it is produce because

1.Alveolar region becomes obstructed 

2.O2 rapidly diffuses in the blood

3.No source of repletion

4.Total gas pressure  in the alveolus are progressively decreases until lung collapse.

Fire hazards-
some thimes there is the chances of fire hazards with oxygen therapy.

Oxygen Delivery System-

3 BASIC DESIGNS

A) LOW FLOW

B) HIGH  FLOW

C) ENCLOSER

Relation between Flow rate and FiO2

A) Low flow

Nasal Cannula


Flow  ¼-8L/min (adults),         fio2 range 22-40%

ADVANTAGE

Low cost, easy to use for children and adults and infant also, 

disposable, stability

DISADVANTAGES

unstable, high flow uncomfortable, dryness

Nasal Catheter 

Flow  ¼-8L/min (adults),         fio2 range 22-45%

ADVANTAGE

Low cost, easy to use for children and adults and infant also, 

disposable, stability

DISADVANTAGES

difficulty inserting, high flow increases back pressure

Trans-Tracheal Catheter

flow1/4- 4L/min                        fio2 range 22%-35%

ADVANTAGE

low O2 use, low skin irritation, increases exercises tolerance

DISADVANTAGES

high cost ,surgical complication, infection, mucus plugging

Reservoir Cannula

Flow  ¼-4L/min (adults),          fio2 range 22%-35%

ADVANTAGE

Lower O2 use and cost, less discomfort

DISADVANTAGE

un-attractive, must be regularly replaced

Simple Mask

Flow  5-10L/min (adults),         fio2 range 35%-50%

ADVANTAGE

Use adult, children, and infant, inexpensive, easy to use, disposable

DISADVANTAGES

uncomfortable, must be remove for eating, block vomitus for 

unconscious patients

Partial Rebreathing Mask

flow min  10L/min         fio2 range 40%-70%

ADVANTAGE 

same as simple mask
 

DISADVANTAGES

same as simple mask

Non-rebreathing Mask

Flow min  10L/min         fio2 range 60%-80%

ADVANTAGE

same as simple mask high fio2

DISADVANTAGES

potential suffocation hazard

Venturi Mask


1.Fixed Venturi Mask 

2.Adjustable venturi Mask

B) High Flow

High flow nasal cannula and other devices

Flow min  10-40L/min         fio2 range 35%-90%

ADVANTAGE

full range of fio2
 

DISADVANTAGES

depending on input flow and patient breathing

C) Enclosure

Oxyhood

Flow min  >7L/min         fio2 range 21-100%

ADVANTAGE

full range of fio2

DISADVANTAGES

difficulty to clean and disinfect

Isolette

flow-min  8-15L/min         fio2 range 40-50%

ADVANTAGE

provide temperature control
 

DISADVANTAGES

difficulty to clean and disinfect, expensive

Tent

Flow min  12-15L/min         fio2 range 40-50%

ADVANTAGES

provide concurrent aerosol therapy

DISADVANTAGES

same as isolette

Other Device

Mechanical ventilator

Recent devices are also used in hospital setup

1.AIRVO

2.PHONE OXIMETER

Refrences:

1. EGANS Fundamental of Respiratory Care 10th edition by 

Robert M., James k.stollar, Albert j.Heuer Chapter no 37, 38 

Page no. 888-937.

2.CLINICAL MENIFESTATION AND ASSESSMENT OF 

RESPIRATORY DISEASE 7th edition 2016 by Terry Dess 

Jardins Chapter no. 5 page no.70-78.

3.Hand Book of Blood Gas/Acid –Base Interpretation 2nd 

edition 2013 by Ashfaq Husan chapter no.2, page no. 53 -92

4.OXYGEN THERAPY 2nd edition 2008 by Jindal Agrwal

5. Essential of Medical Physiology 5th edition by  

k.sembulingam, prema sembulingam chapter 124

6.Relating oxygen partial pressure, saturation ad content :the 

hemoglobin oxygen dissociation curve September 2015, volume 

11, issue no 3