Nasal Cannulas & Nasal Catheters |
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 nasal 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 of greater than 4
l/min. |
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