Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

[Equipment] AHI on my cpap auto machine.
#1
Why do cpap auto machines (and other such machines) quote  AHI stats? I thought my using a machine meant that all the air going up my nostrils would put a stop to my having theses breathing problems?  Should the stats show 0.0 AHI ? ( I've seen readings of from 6.3 to 12.2.on my machine) Thanks for any info.
Post Reply Post Reply
#2
(02-02-2017, 08:03 AM)gola321 Wrote: Why do cpap auto machines (and other such machines) quote  AHI stats? I thought my using a machine meant that all the air going up my nostrils would put a stop to my having theses breathing problems?  Should the stats show 0.0 AHI ? ( I've seen readings of from 6.3 to 12.2.on my machine) Thanks for any info.

Welcome!

They report AHI to show the effectiveness of the treatment.  Normal AHI is considered to be <5.  I don't think many folks on an xPAP machine experience 0.0 very often if ever.  I don't expect my AHI to be 0, I expect it to be <5 to be treated effectively.  

Since you said your AHI ranges from 6.3-12.2 you should download sleepyhead and post some charts and the fine folks on this board can help you optimize your treatment.  There is a link at the top of the board for the software.  Good luck!
Post Reply Post Reply
#3
Many thanks for responding COmbe. So am I right in thinking that my machine will not spot and stop a breathing "event" before it starts, but will stop me from waking before things get to that stage? Thanks
Post Reply Post Reply


#4
gola321,
What was your AHI when you had your Sleep Test?  Probably much higher than you are seeing now.
The AHI readings you see on your machine (if not under 5) indicate that your pressure settings are not optimal to treat your apnea.  

Cpap therapy is not a cure, but a treatment.  The goal is to have an AHI below 5.

Here is a small excerpt from the Beginners guide to SleepyHead, which explains how the machines respond to apnea events.  

How APAP machines respond to events

New CPAP users are sometimes surprised by the fact that their CPAP did nothing when an apnea was in progress. There's an assumption that the positive air pressure provided by the CPAP is supposed to "blast" through the obstruction and restart the breathing. But pressure is not used to try to "end" an on-going event. It's not even clear that 20cmH20, the maximum pressure delivered by a CPAP, would even be effective at trying to "blow" a collapsed airway open: 20cmH20 is not enough pressure to effectively blow up an ordinary balloon. In fact, 20 cmH20 is about the difference in atmospheric pressure between a very stormy, low pressure day, and a bright sunny high pressure day.

The basic idea in CPAP therapy is to provide (a small bit of) positive air pressure through the entire breath cycle to make it more difficult for your airway to collapse. This system is very good at preventing apneas and hypopneas from occurring, but it is not perfect: A few events will likely occur each night, but the overall number of events will be low enough to keep your treated AHI under 5.0, and probably well under 5.0, each night you use the machine. In other words, a well-adjusted CPAP makes it difficult, but not impossible for your airway to collapse.

CPAPs, of course, cannot respond to OAs and Hs by increasing pressure since they have one fixed pressure setting. APAPs do respond to OAs and Hs, but it's important to realize that an APAP will wait until the apnea or hypopnea is over before it increases the pressure. And even then, a typical APAP won't raise the pressure after each and every OA or H. Rather, APAPs will only raise the pressure in response to OAs and Hs if two or more events occur in a relatively small amount of time like 5 minutes or so. The rationale for this behavior is based on the AASM Clinical Guidelines for Manual Titration Sleep Studies. Isolated OAs and Hs are not necessarily indicative of a badly compromised airway: Even normal people have the occasional (frank) OA or H during their sleep. But two or more OAs or Hs occurring close together indicates that the current pressure may not be sufficient to prevent the airway from collapsing in the (very near) future. And since more pressure is needed to prevent future events from happening, the machine increases the pressure after the second (or latest) event in the cluster ends.

APAPs also respond to snoring and flow limitations by increasing the pressure. Snoring and flow limitations are considered precursor events to OAs and Hs. In other words, snoring and flow limitations are thought to indicate that the airway is compromised: It may be partially collapsed (but not far enough to score an H) or it may be just barely beginning to collapse. More pressure at this point will help hold the airway open and prevent further collapse, and hence, prevent OAs and Hs from occurring. It's worth noting that some brands of APAPs are very aggressive in how fast and how far they increase pressure in response to snoring or flow limitations.

So the overall goal in every manufacturer's Auto-algorithm is to increase the pressure just enough to prevent more events from happening in next few minutes and allow the breathing to stabilize. The idea is to avoid jacking up the pressure unnecessarily: That can lead to more unstable breathing, discomfort, and more pressure than is needed to keep the airway open most of the time. And once the machine is satisfied the breathing is indeed stable, the Auto-algorithm will decrease the pressure until there is evidence that the airway is once again in some danger of collapsing.


The next step for you is to download the free SleepyHead software and start to track your therapy.  

Once we can see some data from you, we can help to make sure your machine and pressure is set up properly to give you the best outcome.
Post Reply Post Reply
#5
Many thanks OpalRose.  I'm afraid I don't know what my sleep report said about the AHI Thanks . And yes I will install the Sleepyhead app you mentioned.
Post Reply Post Reply
#6
(02-02-2017, 08:46 AM)gola321 Wrote: Many thanks for responding COmbe. So am I right in thinking that my machine will not spot and stop a breathing "event" before it starts, but will stop me from waking before things get to that stage? Thanks

It isn't that it stops all events, nor wakes you up so one doesn't happen.
It provides support to help you breathe, which reduces the number of times you can't, so you don't need to wake up to breathe.
                                                                                                                                                                                  
Please organize your SleeyHead screenshots like this.
I'm an epidemiologist, not a medical provider. 
Post Reply Post Reply


#7
Hi gola321,
WELCOME! to the forum.!
I wish you good luck with your CPAP therapy,
hang in there for more responses to your post.
trish6hundred
Post Reply Post Reply
#8
Many thanks Beej  Thanks

Thanks
Post Reply Post Reply
#9
I am new to all of this myself and have found I have to learn. Hang in there!
Post Reply Post Reply


#10
thanks 4Speed. Yes and there is a lot to learn, but I feel I'm getting there slowly. Thanks
Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
Money Just Bought an Apex Medical XT Auto CPAP System Heated Humidifier TimtheEnchanter 4 109 7 hours ago
Last Post: trish6hundred
  Hi! I have a CPAP machine, but do I need it? Sleep study attached Grazi 12 263 9 hours ago
Last Post: trish6hundred
Exclaimation CPAP Machine Choices - read this before you accept a new machine SuperSleeper 59 25,729 Yesterday, 01:49 PM
Last Post: VernonBill
Question AirStart 10 CPAP as a backup machine TimtheEnchanter 13 273 12-15-2017, 12:43 AM
Last Post: DeepBreathing
  Just got my first CPAP machine....YIKES!!! dumbusername 12 612 12-08-2017, 06:19 PM
Last Post: Sleeprider
  [Equipment] Quebec Insurance for CPAP machine and supplies sonicboom 7 264 12-02-2017, 01:10 PM
Last Post: sonicboom
  COPD with OSA and obtaining CPAP machine silversnore 9 247 11-28-2017, 08:25 AM
Last Post: silversnore

Forum Jump:

New Posts   Today's Posts




About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.

For any more information, please use our contact form.