[Sleepnet.com's Homepage] [Sleep Disorders] [Sleep Links] [Search]

Re: Basic CPAP Questions

[ Follow Ups ] [ Post Followup ] [ Apnea Forum134 ] [ FAQ ]

Posted by Bird Watcher on July 26, 2009 at 05:55:21:

In Reply to: Basic CPAP Questions posted by millich on July 24, 2009 at 08:27:29:

A basic CPAP machine is one pressure all the time, one pressure inhale and exhale, set for the particular person by the provider, between a range of 4 to 20 cm, 4 on the low end because you couldn't exhaust the CO2 with any less pressure and people need more pressure than that anyways - and 20 on the high end because that is the mechanical limit of most machines and about the limit for most people too. Most of the obstructive apneas during sleep happen on the inhale - the throat and soft tissues have a way of collapsing then and most people seem to need between 8 and 15 cm.

When the discovery of CPAP came out, it soon followed that some people could not handle (breathe out comfortably) against the exhale part of the cycle at a pressure on the inhale that controlled apnea. So, they invented a Bi-level machine where the exhale pressure could be adjusted lower than the inhale and that seemed to work a lot better for some people. The only problem - it was a costly machine. The company Respironics which pioneered sleep apnea equipment called their Bi-level PAP machine a 'Bi-PAP', which is now a trademark. Many other companies make Bi-level machines, called things different like VPAP.

Speed ahead 20 or 30 years -

Respironics figured out how to make a relatively simple and inexpensive CPAP that has some adjustable exhale relief features without it being a complicated adjustment or an expensive machine like a Bi-PAP. They called this machine feature 'C-Flex' which is a way to get some exhale relief to the person using a basic CPAP who needs it without having to go through a whole bi-level titration in a lab. Other companies have exhale relief on their machines now.

Auto-adjust is completely different. The inhale and exhale pressure swings in a set range according to the needs of the person. Now they have Bi-level auto adjust, but it is really expensive.

Getting to your situation, you probably have a need for a machine that has some exhale relief, whether it be a CPAP with exhale relief or a full blown Bi-level machine, and I would think that should be tried before some study with an auto machine set between 4 and 20. You likely won't do well with that kind of study. Autos are for people who already do well on CPAP but are looking for better results- not your situation at the moment. You have bad results of 11.7 on CPAP.

The other question out there - is a pressure of 20 cm high? Yes.

It sounds like your doctor and insurance company are going to make you go through some rough period before you get what you need - what a shame!

Follow Ups:


Post a Followup

E-Mail  :  required - same address used when you registered (will not show up in posting)
Password:  required (sent to you when you registered)

Subject : Re: Basic CPAP Questions

Comments:....note: including your email address here will result in the removal of your posting (See removal policy)

PLEASE ONLY CLICK THE SUBMIT FOLLOW UP BUTTON ONCE!!. Thanks, Sandman

[ Follow Ups ] [ Post Followup ] [ Apnea Forum134 ] [ FAQ ]