Hi AfibApnea, welcome to the forum
Sleepyhead doesn't do a lot of interpretation - it basically decodes and displays the data captured by your machine. The key things that I look for are:
- AHI (just the number, not the graph)
- Mask pressure
- Flow limitation
Some people will add or subtract from this list, but these are the ones I find useful. First, look at the leaks. On a Resmed machine, these should be below 24. Philips does it somewhat differently, so I don't know what the limiting number is for any given mask - I'm sure somebody will chime in. If your leaks are out of control, all the other data is suspect, so taking care of leaks is the first priority.
The AHI score gives you a potted summary of apneas and hypopneas over the night. AHI = (total apnea + total hypopnea) / hours. The target is five or below.
"Events" will show you the individual apneas and hypopneas. It should also distinguish between central and obstructive apneas. A lot of people get hypopneas and central apneas during the transition in /out of sleep. These can be pretty much ignored. Events once you are properly asleep need to be treated. Central apneas are just as important as obstructive - they are a cessation of breathing. (There is a tendency for people to write off centrals as unimportant - this is not the case).
The flow graph shows your breathing pattern on a breath by breath basis. Zoom in and you can readily see times with nice smooth regular breathing and times of irregular breathing. Apneas will show up as flatlines, and hypopneas as periods of reduced flow.
Pressure and mask pressure show how the machine is responding to events in your breathing. Depending on your settings, pressure should start to increase when an event occurs, and drop down again once stable breathing is resumed. Different machines have different algorithms for handling this process.
Flow limitations occur when the shape of your airway changes - ie when it's starting to collapse but isn't yet obstructed. This will normally trigger an increase in pressure to maintain the patency of the airway.
Having got all this data, the trick is to look at how the traces interact with each other. You can often see ragged breathing and flow limitation as a precursor to an obstructive apnea. You can also see that centrals usually occur with no precursor - they just happen. But see if these events are occuring with major leaks - in that case you can't really trust the data.
More important than the nightly detailed readings are the trends. In your case you have a pretty negative trend going on, so it's necessary to identify the underlying problem. Perhaps you could do a screen dump of some of your graphs and we'll be able to advise you further.