sleeptech

Any event reported by the machine is not being treated. If it were being treated it would not happen and therefore would not be reported. The occasional night with an elevated AHI is not panic time but is worth investigating. Does it correspond with an occasional change in your routine like having a few drinks or taking a medication? It may just be something like you OSA getting worse in supine REM (lying on your back while dreaming - generally the worst combo for OSA) which may only happen rarely. If the increase in AHI is becoming more frequent, it would be wise to have another study for some tweaking.

Hi,

I'm not sure where the people above are getting there information from but I have been treating people with CPAP, BiPAP, ASV etc for over a decade. BiPAP in ST mode certainly is good for treating central events. In fact it is the default treatment for central events. ASV, As I added above, is only for specific cases.

One of the resasons that ASV is less widely used than it used to be (which is a good thing as too may doctors would throw ASV at a patient without checking to see if it actually worked) is that there was a study which showed an increased risk of mortality if your left ejection fraction is less than 40%. To put it more simply, if your heart is dodgy (in a particular way) then ASV could kill you. This is yet another reason not to get carried away playing doctor with your own treatment.

BiPAPs are complex devices and setting them is equally complicated. Yours was set the way it is for a reason. Your doctor should know what that reason is, so make sure that they explain it to you. Ask question until you get answers and be very involved in your own therapy, but beware of changing stuff based on responses from a forum such as this or, indeed, anything but advice from a qualified medical practitioner.

Many of my patients who use BiPAP say, as you have, that they find it easier to fall asleep with BiPAP when they follow its rhythm. This is fine. It should be adjust to something quite similar to you normal breathing pattern in sleep so going with the flow should not be a big change.

Overall, BiPAP therapy of any kind is complicated and should not be mediated through an online forum, nor should you make random adjustments yourself. I have treated hundreds of people with BiPAP (possibly thousands, I lost count long ago) and it has to be done hands on with all of the data at your disposal. If all else fails, perhaps a different doctor would be better.

ASV was created specifically for treatment of Cheyne-Stokes ventilation in a setting of hypercapnoea. It can occasionally work in some other cases but it is far from being a magic bullet. It certainly is not effective in situations were ventilation is required to increase oxygen saturation or lower CO2. It should ALWAYS be set up by a qualified, experienced technician (as with any Bi-level ventilation) because it is quite complicated and the way every patient responds to it is different.

How long they last depends on what treatment is being used (CPAP, BiPAP etc) and what the pressure is set at. Even in the best case scenario it would need to be charged every day. They won't hold 2 full nights charge.

By the way, hi there fellow tech.

What he said.

Your oxygen level is assessed during your sleep study, but not otherwise as a rule. If your lungs work normally then there is no more reason to check you oxygen level every night than there is for someone who doesn't use CPAP. All the CPAP machine measures is whether your breathing is even or irregular. Your low oxygen level is essentially a separate problem and you did well to pick it up. It is really up to your doctor to be aware of any other problems with your lungs that could cause this, as well as the results from your sleep study.

You should NOT connect the oxygen between the tube the mask. It should always be connected at the machine end of the tubing, not the mask end. This allows time for the oxygen to become properly mixed with the air. If connected at the mask end it can result in areas of higher or lower oxygen concentration in the mask. We had a patient whose oxygen saturation kept dropping very low because it was incorrectly added to the mask end of the tube. As soon as we swapped it to the machine end, everything was fine.

This is not widely known but important to be aware of if you use oxygen.

Apnoeas and hypopnoeas only need to be 10 seconds in duration to be scored, not 1 minute. Usually they are less than a minute.

I also would expect that the Prozac would make things worse. Rather Odd.

I see that your AHI and your central apnoea index both decreased a little without EPR, although not a heap. You may get some value in persisting without it a bit longer, but I don't want you to be too uncomfortable.

Another confounding factor with EPR is that it effectively lowers your CPAP pressure. If you are on 12 cmH2O but have a EPR of 3, you are effectively only getting CPAP of 9 - 10 cmH2O. I have had patients who were being under treated because they were issued CPAP set at the appropriate pressure, but with EPR on they were in fact getting less than they needed. We only use EPR with patients who have had it in a formal overnight study so that we can be sure it's not messing things up. In your case it is possible that with EPR off you CPAP pressure became too high. I don't recommend that you mess with it because that can cause more problems, I mention it mainly for your education.

You stick with whatever is working for you. Really your medical team should be managing this for you. Hopefully they will look at BiPAP/ASV soon.