Since I started on cpap therapy in March I have been keeping a daily log of my results.This log includes data from the lcd display on my machine, data downloaded to my computer and analysed by the Sandman 1.4 software, Also data on mask, beard getting longer, how I feel in the morning, the world situation and what I want for Christmas.
When I first started I was too brain frazzled to write a Microsoft Access program, which is why I chose to do a hand written log. I now think I would prefer my log because writing makes me pay more attention to the figures, and I can easily change the criteria.
I use a ledger type analysis book. On the left page is my lcd data, the most important of which is the duration of using the machine. The AHi on the lcd does not include centrals, but the software analysis does include centrals. The night is divided into machine usage sessions, and I note the start time, the end time, and the duration. And then the total for the night. This is a total of machine usage, not how long I have been asleep.
The left side is mainly used by me to keep track of my sleep hygiene; when I put the mask on and start the machine, and for how long. I need to get to bed earlier, and possibly sleep longer. AHi is not a concern, as you will see.
The right side I have 90% pressure, maximum pressure, average pressure, average leaks, obstructive AHi, central AHi and total AHi. This would differ from most machines, as the Sandman gives a value for centrals. For me the most important values are average pressure, average leaks, and obstructive and central AHi. Average leaks tells me when I need to trim my beard. Average pressure (over many different pressure settings) gives me a good idea for working out the best starting pressure for apap.
Now there are a fair number of variables in all this, but each pressure or range of pressures was tested between 7 and 10 days. The figures below reflect the average taken from those 7-10 (sometimes 20) days. Average mask time over the last 50 days has been 6 hours 32 minutes. I do not use Pressure Command on IFL. I was titrated at 11cms.
I cannot show all the variables, so have restricted myself to the following - pressure, obstructive AHi, central AHi and total AHi which with the Sandman includes centrals.
I did have a close look at clusters, but decided it was not necessary because I test each pressure at least once with a night on my oximeter. I have never desaturated whilst on the machine. So although I sometimes see events (2 or 3 within a 5 minute period) the machine is stopping further events which would lead to desaturation.
The fact that I know I never desaturate is a source of great satisfaction to me. I love my oximeter.
So here is my analysis of the last 8 months, with different pressure settings. Some pressures have been tested more than once.
I will start with cpap -
Code: Select all
Pressure Obs AHi Cnt AHi Total AHi
11.0 1.3 1.2 2.5
11.5 1.2 1.3 2.5
12.0 1.6 0.8 2.4
12.0 1.6 1.7 3.3
then we move to apap -
Pressure Obs AHi Cnt AHi Total AHi
09.0 to 13.0 1.3 1.3 2.6
09.5 to 13.0 1.5 1.5 3.0
10.0 to 13.0 1.5 1.3 2.8
10/5 to 12.5 1.6 1.4 3.0
10.5 to 13.5 1.1 1.5 2.6
11.0 to 12.5 1.3 0.9 2.2
11.0 to 13.0 1.2 1.0 2.2
11.0 to 13.0 1.5 1.3 2.8
11.0 to 13.5 0.9 1.1 2.0
11.0 to 14.0 1.2 1.6 2.8
11.0 to 14.5 1.4 1.7 3.1
11.5 to 13.5 1.6 1.4 3.0
11.5 to 14.0 1.4 1.6 3.0
As you can see, the higher the highest pressure, the more centrals I get. So finding the balance between low obstructive AHi and not initiating a higher central AHi is probably a good idea, but within the above wide range just about every combination is good.
Yes, I will go for the best. But for a backup machine I will probably get myself a cpap, and save myself some money. And I may experiment further. The lowest obstructive AHi I have recorded was 0.3 over 6.5 hours on 29/30 November with 11.0 to 13.5 pressure.
I am not claiming any ultimate truths in all this. It is really just me messing about. However, feedback would be welcome.
And I hope it will give some confidence to those who are unnecessarily wary of changing their pressure.
cheers
Mars
