The importance of comfort
For Oxypoint, ‘comfort’ is defined as “the easing or alleviation of a patient’s discomfort associated with the administering of oxygen over a sustained period of time”. The main discomfort associated with oxygen therapy is the drying of the nasal cavities and mucus that can lead to acute perceived coldness, (severe) irritation of the nose, bleeding and headaches, etc. This discomfort is the main reason why patients of oxygen therapy tend to have a low therapy loyalty profile (taking the nasal cannula out of the nose cavities, etc.). Increasing patient comfort therefore implies avoiding the drying of the nasal cavity.
Quantification of ‘comfort’
During the exhalation phase, air that comes out of the lungs is saturated with maximum water vapor content (indicated by around 100% relative humidity).
In this study, relative humidity is recorded in the nasal cavity with a humidity sensor in the nose and with an oxygen nasal cannula.
The “blanco” mark identifies the reference point of breathing ambient air without additional oxygen.
The “Continuous 1” to “Continuous 5” marks demonstrate the effect on relative humidity when the continuous oxygen flow is increased from 1 L/min to 5L/min.
Relative humidity in comfort mode versus continuous mode
A drying out of the nasal mucus, directly proportional to the augmenting oxygen flow, is observed. In between the continuous oxygen flows, the relative humidity during comfort therapy (1 to 5 oxygen equivalent) was also measured.
As can be seen, within one or two seconds, the relative humidity returns to normal. Therefore, it can be stated that the comfort mode is indeed more comfortable because the negative side effects observed during continuous oxygen administering (mucus dryness) are below the threshold of measurable significance.