– Oxygen therapy is the use of oxygen as a medical treatment.

• Indications

– SaO2 level below 90%
– Before and after suctioning
– Heart surgery
– during exercise
– Terminally ill patients
– Breathlessness on exercise.

• Complications

– Hypercapnia
– Oxygen toxicity
– Blindness
– Atelectasis
– Discomfort and irritation
– oxygen creates fire hazards.

• Delivery devices

1) Low – flow mask
2) High – flow mask
3) High concentration reservoir mask
4) Nasal cannula
5) Nasal catheter
6) Transtracheal catheter
7) Tent
8) Head box
9) T- piece circuit.

* Low flow mask

– Deliver a flow rate less than patients peak inspiratory flow , so that room air is sucked through mask.

* High flow mask

– Also known as Venturi mask
– Delivery prescribed gas mixture at flows intended to be greater than the demand.
– Reduces rebreathing expired air.
– Used for COPD patients, breathless patients and Hypercapnic patients.

* High concentration reservoir mask

– This incorporates one litre of reservoir bag and delivers high percentage of oxygen.
– During expiration , oxygen fills the bag instead of being wasted.
– A non – breathing system : It has a valve.
– A partial rebreathing system : It has a valve and here about 1/3 rd of expired carbon dioxide enters the bag and delivers 35-60% of oxygen.
– Bag must be filled with oxygen before fitting to the patient .

* Nasal cannula

– Delivers oxygen directly into the nostrils .
– patient can talk , cough, eat and drink unhindered.
– 80% of oxygen is wasted.
√ 1 L/m delivers 24 % of Oxygen
√ 2 L/m delivers 28% of oxygen
√ 3 L/m delivers 32% of oxygen
√ 4 L/m delivers 36% of oxygen.
– It is indicated for hypoxemic patients, confused patients and long term oxygen therapy.

* Nasal catheter

– It is inserted after the lubrication.
– A flow of 3-4 L/m usually delivers about 30-40 % of oxygen.

* Tracheal catheter

– Smaller plastic Transtracheal Catheter introduced surgically into Trachea.
– There is a risk of infection, surgical emphysema , haemoptysis , and dermatitis.

* Tent

– Used for children, but these are isolating, wet and delivers fluctuating levels of oxygen.

* Head box

– These are clear plastic boxes over the heads of babies
– Controls the delivery of humidified oxygen
– High flows are delivered .
– Care should be taken.

* T- piece circuit

– This delivers oxygen to intubated patient ( spontaneous breathing patient )
– It is a large bore non- rebreathing circuit that attaches to tracheal tube.
– Through one end humidified oxygen is delivered and then expired gases leave through the other end.

• Prescription and monitoring

– Prescription should take account of patient comfort and including a high enough flow rate for patient with Breathlessness with high peak inspiratory flow.
– Venturi mask is accurately titrated .
– To monitor the response pulse oximetry is required.
– For breathless patients : Monitoring of respiratory rate indicates if fatigue is severe or not.




Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top