User Review: Respironics REMstar C-Flex Auto CPAP

cpaptalk Nickname: wading thru the muck!


In the relatively short time that I've been diagnosed with obstructive sleep apnea (OSA) and using CPAP therapy, I've learned that the most important feature for any XPAP machine is an ability to be all things to all people. I say this with all sincerity, though it may sound like an impossibility, this is what the auto-pap (APAP) strives to do. The acceptance of CPAP therapy is subject to many personal preferences and proclivities. The success or failure of a machine depends on its ability to adapt to these idiosyncrasies. The REMstar Auto with C-Flex comes closer to this mark than any other machine on the market.

Four Machines In One

This machine is able to operate in four independent modes of operation:

  • Fixed pressure CPAP mode
  • Fixed pressure CPAP mode with C-Flex
  • Auto Adjusting APAP mode
  • Auto Adjusting APAP mode with C-Flex

These four modes will satisfy a wider variety of personal preferences than any other machine on the market.

Versatility Beyond The Basics

The features that make this machine more versatile than the standard CPAP machine are the auto-adjusting feature and the C-Flex feature.

With the auto-adjusting feature, the machine uses an algorithm to detect and proactively prevent most occurences of OSA. The benefit of this feature is two-fold. Firstly, it compensates for variations in pressure requirements that may have been missed during one's Polysomnography (PSG). This can be caused by the inherent inaccuracies in utilizing a snapshot of one's sleep profile during the sleep study and also due to changes in health or weight since the study. Secondly, because the machine can adjust pressure to resolve OSA events, it is able to keep the pressure low between events which can minimize the potential for pressure associated problems such as mask leaks, aerophasia and pressure related arousals.

C-Flex is a feature unique to the REMstar line of CPAPs. Most recently added to the Auto machine, it now creates this most versatile machine. The effect of C-Flex is similar to what is achieved with a more expensive Bi-level machine. Many find it uncomfortable if not difficult to exhale against continuous pressure. C-Flex provides the affect of relieving the pressure against exhalation for all but the end of the exhalation cycle. With this unique feature, the user is able to experience the luxury of easier exhalation without the risk of leaving OSA events untreated. Further variability is allowed by adjusting C-Flex to three levels of relief.

Lastly, to satisfy users for which some or none of these features are of benefit, they all can be turned on or off independently.

What We Have Come To Expect

Additional features of this machine that one would expect on any high quality machine are as follows:

  • Integrated heated humidifier, fully integrated with power supply and operation controlled by the machine. The removable chamber holds enough water for one night at the highest heat setting.
  • Auto on/off triggered by breathing into the mask or taking off the mask. One deficiency of this feature is that the humidifier is not also turned on (resulting in this user occasionally neglecting to turn on the heater).
  • Easy to operate lighted buttons. The backlit buttons are easy to see in the dark (the backlight can be turned off if desired). One deficiency is the lack of a backlight for the LCD display.
  • Encore Pro software with reporting of all compliance, pressure, leak and AHI parameters. The software is geared toward use by a sleep professional, but is very easy to use. Up to six months of data is stored on the removable smart card. Downloading the data with the required card reader provides data outputs in PDF format and is very professional and easy to read.

Sizing Things Up and A Summary

Though bigger than some of the small portable units currently on the market, the combination unit comprised of the flow generator and the integrated heated humidifier fit together securely and is relatively compact. The unit should fit very comfortably at your bedside. With the included padded nylon travel case, it should also comfortably tag along on whatever journey you find yourself.

Ultimately individual preference and results will dictate what machine is best for you, but the REMstar Auto with C-Flex is worthy of the status as one of the top two or three machines to consider.

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