AHI SLEEP STUDY VS CPAP NOT THE SAME

Hi,

In a sleep study my AIH was 3.5 on device and 9 in the sleep studied.

Why 3 times more ? sleep study was more accurate ?

The sleep study is without the cpap machine??? AHI is going to be higher without the cpap machine because nothing is stopping them from happening.
Lower AHI with cpap just means that the machine is preventing those other apneas from ever happening. You want a lower AHI when using the cpap machine because that means it's working.

The cpap machine flags apnea events that slipped past the defenses and doesn't flag the ones it prevented. You can't see what was prevented from happening...the machine only shows you what it didn't prevent.

The sleep study determines that you a) have apnea, and b) what pressure your machine should be set at to prevent apneas. The whole point of Cpap is to prevent them, but without a study (not wearing a Cpap) they won't know how bad your apnea is or how to treat it.

sorry yes i have done the study WITH CPAP on. i wonder why the AHI is 3 times more

sorry for my bad english but i'm not.

After one year and half of CPAP, i have always trouble with fatigue and fatigue worsen.

March 2013 :Before CPAP i have done a poly (sleep study) in hospital i have
- an iah of 24.8/h (whose hypopnea of 21.7/h)
-17 acrousals awakening/ h.
-No restleg syndrom (or periodic movement)
-I've been on 10 mg deroxat (an antidrepressant with paroxetine - paxil i mean in other country).

i have a remstar with autopilot beetween pression 4-14 .nothing wrong and good compliance with the night of 8h but don't see full effect.

July 2013 : deroxat - paxil 30 mg. i have to increase at this level and i'm since here.

August 2014 i have done a poly (sleep study) in hospital with Cpap : i have
- an iah of 9.3/h (whose hypopnea of 9/h)
-14.5 acrousals awakening/ h.
-I've been on 30 mg deroxat.
- restleg syndrom (or periodic movement of 7.1/h but only 1h

my doc change my device to resmed s9 because he think algorithm is better (my pneumo has first give me the remstar).autopilot 4-16
No improve since one week.

I ask me why acrousals awakening/ h has go down very few with cpap treatment and the same with IAH.

I would like the link with the increase of paxil : give paxil arousals awakening ? My doc say he give periodic movement.
Actually i go down with paxil by 5 mg step by step but really wondering if this is the cause or not.

can paxil and antidepressants in general give more 1/ hypopnea ? 2/ more awakening arousals ?

in which case do we have a fix pression ? with hypopnea ?

Furthermore this night of sleep study my cpap give a iah of 3.5/h whereas the sleep study is 9/h : why is iah 3 times more than cpap give ?

thanks very much

chris677 wrote:Furthermore this night of sleep study my cpap give a iah of 3.5/h whereas the sleep study is 9/h : why is iah 3 times more than cpap give ?

A sleep study with cpap being used with AHI of 9...is just one night and they likely varied the pressures to try to figure out the best pressure...it's one night and in a foreign environment and we just don't always sleep the same from night to night.
I wouldn't worry about this part...since the AHI is lower at home...it's working better than at the sleep lab.

Paxil and meds like it are known to mess with sleep in general but not for actually closing the airway and causing apneas.
Explained in your other thread where you asked this same question.
So Paxil can disturb your sleep...it doesn't cause the airway tissues to collapse and thus cause the sleep apnea obstructive events.
There are some meds than can make the collapse worse...but Paxil isn't known to do that.

Yes but i have check after the study night what said the AIH on cpap for this night.
So AIH is compare on the same base: 1 day
But perhaps i don't understand one day is : is this for one night 00:00 on the next morning 6 am and the next evening 22 pm to 00:00 or one night from the last evening until the morning ?

Yes thanks very much i have hard to work after be stopped for the fatigue 2 week and no médical or psychological issue.

Typically these machine do a 24 hour period starting at Noon 12:00 PM...either by a clock on the machine itself that you can set or an internal clock that you can't set..
It works for keeping the sleep sessions reported in one large block for most people. Doesn't work so great for shift or night workers who might sleep during the day at the 12 PM Noon cutoff period. Those people get weird looking reports. but hours slept is hours slept no matter if they get broken up into 2 sessions or not. It normally averages out in the long term.

AHI is a per hour average over the sleep session that is reported within that 24 hour period. A "new" "day" typically starts at 12 Noon.

ok thanks i understand why the AIH is not the same

You'll get a lot of variation in AHI under any circumstances, especially if you have a number of "borderline" apneas.

Two different technicians scoring the same sleep study results, or even the same technician doing it again.
The same CPAP machine on two different nights with no changes.
Sleeping in a different position, different supper time, different prescription drugs, different bed time, etc.
Two different model CPAP machines.

Which resmed s9 you have? There are two machines, the Autoset and the Escape. Its written in top of the on/off button. If you have the autoset then you can install the software and look at detailed data. Then you can post a screenshot to give us more idea.

tmr wrote:Which resmed s9 you have? There are two machines, the Autoset and the Escape. Its written in top of the on/off button. If you have the autoset then you can install the software and look at detailed data. Then you can post a screenshot to give us more idea.

there are thirteen basic resmed s9 machines, not two.

Actually, only four are "basic";
the Autoset, Elite, Escape, and Escape Auto. (The Escapes are the only ones without full data.)
The remaining nine are advanced algorithm and pressure machines, all of which record full data.

chunkyfrog wrote:Actually, only four are "basic";
the Autoset, Elite, Escape, and Escape Auto. (The Escapes are the only ones without full data.)
The remaining nine are advanced algorithm and pressure machines, all of which record full data.

by 'basic' I mean function class, not basic as in simple, I was avoiding the various names that resmed has given the same model in different countries, like the autoset cs, which is called the adapt here, or the autoset cs-a which is the later model adapt.

one could also debate whether a vpap s or vpap auto is all that much more 'advanced' than the elite and autoset, since all those add is essentially a larger EPR setting ability. (and some minor tweaks on how that behaves).