I want to share a salient feature of my initial CPAP data. Most nights I tend to fall into a periodic breathing pattern despite clear airways. The frequent complete cessation of flow on these occasions (for up to half the time for periods of minutes) appears quite alarming. Yet I am not obviously symptomatic. Interestingly the oximeter data (CSM50D+) are also somewhat reassuring. In the attached screenshot, the oxygen saturation drops only from 96% to 95% after 2.5 min of apnea in a 4.5 minute window. (The slowish and very irregular pulse is characteristic of my atrial fibrillation, which has been continuous for the past decade or so but still supports a fairly high level of aerobic fitness with no suggestion of congestive heart failure. Pressure from the Airsense 10 CPAP device here was 7 mm inspiration, 5 mm expiration)
With an AHI over 20 prior to CPAP, I am ready to believe that CPAP can improve my quality of life even though I am not markedly symptomatic to begin with. But results like these raise a general question: is apnea necessarily damaging even if it doesn’t much affect oxygen saturation, pulse rate or quality of sleep? I see many reports of bad health conditions associated with apnea, but those reports usually include disclaimers to the effect that the nature and direction of the causal influence is not clear. So: how much apnea is compatible with good health? If there is no general answer, that is itself an answer that might allay some apnea anxieties.
A relevant discussion of CSA without heart failure --Manzhukani and others, ‘primary central sleep apnea’: doi:10.1016/j.jsmc.2013.10.006