bi-pap trying to over-ride my natural breathing?

Recently had a bi-pap titration study; high component of my apneas were central (14 of 18).

Early on, the study machine was trying to over-ride my inhale/exhale cycles. Specifically, well before my natural exhale cycle ended the machine would increase the pressure trying to get me to inhale. Similarly, well before my natural inhale cycle had ended the machine would decrease the pressure trying to get me to exhale. Made it impossible for me to sleep.

Described what I was feeling; tech changed some parameters and we completed the study at pressures of 6/17, sleeping like a baby.

Two questions: 1) Do both the Resmed and Phillips bi-pap machines have adjustable settings will reduce/eliminate their machine over-riding my non-apnea breathing pattern?

2) If YOU had a choice, which machine would you want to have, and why?

Central apnea is difficult to treat. Generally CPAP machines use pressure to hold the airway open to prevent obstructive apnea. However with central apnea the airway is already open, so more pressure does not help and in many cases it makes it worse. There are at least a couple of different types of central apnea. One is where you have mixed apnea and when you use the CPAP to treat the obstructive apnea then the central apnea becomes worse. Generally that is what is being done in a titration test. They start with a lower pressure and then increase it to the point where obstructive apnea is controlled, but central apnea is not aggravated. This can be called pressure emergent CA. The other possibility is that central apnea is high and dominant even without pressure. That is more difficult again. About the only way you can help with a BiPAP machine is to cycle the pressure up and down to try and assist breathing. I have a ResMed APAP and I am in the first category. I have found that if I do not use the EPR (difference between inhale and exhale) and keep the pressure low, I can control the CA's. After much testing I ended up with a fixed 11 cm of pressure and EPR during the ramp only. But, if you have excessive CA with no pressure that is unlikely to work.

I do not have any experience with BiPAP machines, and the tuning of them to do what you say can be tricky. I think the most I can do for you is give you links to each specific type of machine and you can try and compare them. The link to the ResMed is for the BiLevel machines only and it explains how they work a little better. The DreamStation manuals cover everything from fixed CPAP's to BiLevels. Much harder to read, but the adjustments available should be in there somewhere.

ResMed AirCurve Technical Manual

DreamStation Technical Manual

Studies have shown that BiLevel machines do sometimes work, but not always for difficult CA cases. The next step in dealing with CA is the ASV machines (Adaptive Servo-Ventilation). They basically follow each breath and adjust the pressure to keep you breathing. The BiLevel is more of a broad brush approach, and not breath by breath. My thoughts would be to try and get one of the BiLevel machines on a trial to find out if it controls the CA well. And if not, then you may want to investigate the ASV option. It requires a special heart function test before it will be prescribed.