Flow Rate/Flow limit

[ovmeadows]

I would conclude from the attached screenshot for 8 Dec 2024 that it takes very little flow limitation to cause some level of sleep disturbance or at least graph anomalies.   How does a PAP user find the cause of irregular but small flow rate?  Does it even matter?

   

[G. Szabo]

Your 0.15 flow limit is higher than the accepted threshold, indicating your setting is not optimal. I suggest increasing both the minimum and maximum pressure by 1 cm.

As for the wavy pattern and its relation to flow limits, my understanding is that the flow limit is primarily deducted from the shape of the individual inhalation peaks, and it is not strongly correlated with the actual height of the peak. Suppose the peaks are smooth and close to sinusoidal. In that case, the flow limit (FL) figure is low. The FL figure cannot warn the user when nice inhalation peaks appear, but the inhalation is restricted (i.e., insufficient air intake). For instance, this is the case when someone starts showing the symptoms of nasal congestion. In the initial period,  the height of these nice inhalation peaks starts to decrease, and simultaneously, the oxygen saturation drops. But there is no FL increase reported. Because of the lack of oxygen, the patient eventually uses higher inhalation effort to compensate, which leads to this wavy pattern. NB the congestion is only an example I experienced,  but there can be other causes of the reduced airflow with seemingly perfect inhalation peak shapes.