Philips DreamStation CPAP: Continuous air through nose or not

All

Since last week I have a Philips DreamStation which I got via the hospital. I use it with a nose cap. The first night I had to stay in hospital and I clearly felt a continuous airflow through my nose. There was also some air which flew away via the top front. According the nurse this was normal as it was "over pressured air".

The second night I felt the same continuous airflow through my nose. But after then, I had two nights in which I did not feel anything and all air seemed directly to flow away through the over-pressure exits. I tried to tighten/straighten the mask, put it higher/lower in my face, ... without result except the air also flew away via other sides of the cap meaning it is not put on straightened enough. The following night was the same as during the first two nights. During last night, I felt nothing and all of the air once again seems to flow directly away through the over-pressure exits.

So I called to customer support and they said it is normal and - in my case - my nose already got used of the airflow and I don't feel it anymore. According them, if no air escapes via other parts than the over-pressure exits all is fine. I do not agree with this answer as regarding the situation, I feel the air through my nose as soon I put on the machine, or I don't feel anything at all at least during the time I'm still awake. Even if I breathe I do not feel the pressured air. If a open my mouth there is a huge flow going through my nose and even exits via my mouth due to the pressure.

So I called my hospital but they were not willing to help as all kind of support and technical issues are outsourced to the customer support of the supplier.

So my question: should I always feel a continuous airflow through my nose or not? If yes, what could I do wrong? I put my mask on in the correct way so I have no idea what's the root cause of this issue.

What is the brand name and model of the nasal mask? That would help to understand better what you are describing.

Some things that may help you understand what is going on would be the normal air flow. The CPAP machine always maintains a positive pressure at the mask. The pressure will depend on how the machine is set up, but it is never less than 4 cm. The machine may reduce the pressure a little when you exhale but never to anything less than 4 cm. When you don't breathe at all air escapes out the vents in the mask. When you breathe out all your exhaled air goes out the same vents. Even when you breathe in air will be escaping out the vents. This vented air is necessary to let you exhale and also to keep the air fresh in the mask.

Independent of the intentional venting you can have leaks. While ideally there is no leakage, some smaller amount can be tolerated. I wasn't clear from your description whether you were talking about leakage or the intentional venting air.