Nasal Cannula & Nasal Catheter |
Nasal Cannulae are used for their simplicity and patient
convenience. There is entrainment of ambient air through the
nostrils. The FiO2 achieved is
proportional to a) the flow rate of oxygen (1-6 l/mni), b) the
patients tidal volume, inspiratory flow rate, and c) the volume of
the nasa pharynx.
At an oxygen flow rate of 2 l/min the oxygen concentration in
the hypopharynx of a resting person is 25% - 30%. Nasal Cannula
prevents rebreathing and are comfortable for long periods.
There is increased patient compliance with nasal cannula as
patients are able to speak, eat or drink. Local irritation and
dermatitis may occur with high flow rates. Use of humidified oxygen
is recommended to reduce dryness of the mucosal wall in the nasal
cavities, particularly when using flows greater than 4 l/min.