CPAP usage the night before a PSG/Titration study?

Dave M. · Post by **Dave M.** » Fri Apr 11, 2008 11:08 am

My wife is going in for a split-night study in a couple of days. The last time I had a split-night study, the tech asked if I had used my CPAP the night (or two) before the study. I had used it and he said my doctor should have told me not to use my CPAP before the study. Their thought was that CPAP usage may have some effect on the airway for a day or two after discontinuing the CPAP therapy. This in turn could cause the baseline OSA tests to be inaccurate.

Has anyone else every been told this or have a reference to what the standard practice should be? Any feedback will be appreciated.

Regards,
Dave M.

Goofproof · Post by **Goofproof** » Fri Apr 11, 2008 11:35 am

Sounds like "Nuts" to me. I'd have a APAP and software so I didn't have to go back for a study. Jim

rested gal · Post by **rested gal** » Fri Apr 11, 2008 11:48 am

Dave, I've seen a few (very few) people on the message board say they were told not to use their machine for anywhere from the night before, up to a week ( ) when going in for another study.

Seems I've read that heavy snorers get ridges or roughness or thickening (something) in their soft palate, presumably from the friction; and, that after regular cpap use eliminates the snoring, the soft palate gets smoother.

I also seem to recall a few people saying they were told that with regular cpap use, their O2 levels will stay up better the next day or for a couple of days, even if cpap is discontinued.

I don't know if any of those things are so...or if so, would they even apply to all cpap-using people.

Most people who post on here about going in for another sleep study after months or a year or more of using cpap have NOT mentioned being told to not use their machine before the next study.

Wulfman · Post by **Wulfman** » Fri Apr 11, 2008 11:59 am

Goofproof wrote:Sounds like "Nuts" to me. I'd have a APAP and software so I didn't have to go back for a study. Jim

Ditto......or ANY data-capable CPAP/APAP and software would be more cost-effective than periodic sleep studies.

Yeah, I've read the same things that rested gal has, too. I can't imagine trying to sleep without it for a full night......if I could sleep at all.

Den

Slinky · Post by **Slinky** » Fri Apr 11, 2008 5:23 pm

I wasn't told to discontue using my CPAP prior to this recent sleep evaluation nor prior to my recent bi-level titration. Like RG, I've read one or two posts where people have been told not to use their CPAP prior to a new sleep evaluation or titration.

Frankly, my response would have been WHY and if the WHY didn't make sense to me I would have ignored the recommendation and slept w/my CPAP and would have truthfully told them no way in h*ll am I sleeping w/o my CPAP, the reason you gave wasn't good enough, or I didn't buy the reason or whatever but it ain't a gonna and didn't happen. I slept w/my CPAP last night. If you want, I'm perfectly willing to go home and forget doing another evaluation/titration. At least until you come up w/a better reason that makes sense to me.

roster · Post by **roster** » Fri Apr 11, 2008 7:10 pm

.........I've seen a few (very few) people on the message board say they were told not to use their machine for anywhere from the night before, up to a week ( ) when going in for another study.

........

When you come in for the study, they want you totally worn down and submissive. It makes for a more peaceful night (for the technicians).

Snoredog · Post by **Snoredog** » Fri Apr 11, 2008 7:22 pm

my guess why:

They want to get a better idea what your baseline SAO2 levels are untreated and treated, possibly leg twitches etc.

you are more likely to see dips to those levels and increased leg activity if you have been off the machine for a few days. Most people can make it a night or two without cpap but go down hill after that so latency may even play a part.

Guest · Post by **Guest** » Fri Apr 11, 2008 7:47 pm

Not many sleep labs ask their patients who are comming for a second split night to stop using their CPAP/BiPAP. However at a lab I used to Manage which did alot of sleep research and had an active Fellowship program they DID ask the patient to stop using their CPAP/BiPAP for 48-72 hours prior to a second split night study OR an Oral appliance study.

One of the Fellows asked WHY we do that, his preceptor said "Because people will many times retain a normal AHI for up too 72 hours after comming off CPAP/BiPAP therapy". The Fellow, like many other people, was skeptical of this reasoning and decided that he would do his Fellowship paper on the subject. Of the 48 patients (Yes I know some of you are going to say this is hardly a large enough sample) he studied who were either 2nd split night studies or Oral appliance studies, only 3 of they rebounded above and AHI of 5 before 48 hours. All 48 patients had been using CPAP/BiPAP for longer than 2 years, and they were all studied with a full attended PSG for 5 nights in a row. Many of them DID complain of daytime sleepiness, and a few (not sure on the number, but I think it was around 9) showed mild hypertension. His findings were not published since it was only a fellowship paper, and he didn't speculate as to WHY the situation presented this way. I know that he did put in an application for a research grant to study the causes for this though, I unfortunately left before he got the funding to do that research.

So there IS a possibity that you could show as a negative split study if you wore you CPAP/BiPAP right up until the night before your split night. Infact about a month ago I had a gentleman who wanted a new CPAP and his insurance said they needed a more recent sleep study since his was 11 years old. He went to a local sleep lab for his study and came to me 2 days later and was very happy because his AHI was 3.6 during his 8 hour study and they didn't have to split him, his original AHI 11 years ago was 58. He said the Doctor told him, "Good news you don't need CPAP anymore".

I called the sleep lab and asked them their policy about patients who are currently using CPAP/BiPAP comming in for repeat split studies. They said that the patient was advised to use their equipment right up until the night before the study. I wanted to call the Lab Manager, but figured it was pointless since I really had NO hard copy data to give her to make my point.

rested gal · Post by **rested gal** » Fri Apr 11, 2008 8:15 pm

Extremely interesting, akcpapguy. Thanks. Sounds like it would be better for people going in for another study to put the cpap away for a couple of nights beforehand.

akcpapguy · Post by **akcpapguy** » Fri Apr 11, 2008 8:30 pm

I agree RG, from the data I have seen it may be helpful. I wanted to add also, ALL of the patients in the above mentioned study were relatively healthy individuals who had no other major health problems (ie. COPD, Hypertension, Diabetes, etc.), so if you have other factors I would consult your Dr. if you are concerned about the effects it would have on those health issues.

Snoredog is also correct, PLM's, SPO2, etc. were also decreased right after CPAP/BiPAP use.

Goofproof · Post by **Goofproof** » Fri Apr 11, 2008 9:51 pm

rooster wrote:
.........I've seen a few (very few) people on the message board say they were told not to use their machine for anywhere from the night before, up to a week ( ) when going in for another study.

........
When you come in for the study, they want you totally worn down and submissive. It makes for a more peaceful night (for the technicians).

That answer I'll buy into. They need to record the worst to show you need XPAP, for INs and GOV. By feeling run down or over, you will be more ready get a nights rest. Jim

sleeptech tito · Post by **sleeptech tito** » Fri Apr 11, 2008 11:06 pm

Asking someone not to wear his/her CPAP for 1 or a few nights is courting trouble. First, talking about the patient's health - it would not make any difference if the patient is on CPAP the night before... during the baseline study of the split his apnea/hypopneas would still appear. and he/she would still be retitrated properly. As a sleep practitioner I never really liked to do split studies - since you lose out on the essential data that is generated from the latter REM periods (Which is usually the worst)

second, the liability issue - If something happens to the patient on the day of the Sleep Study due to excessive daytime sleepiness the lab or MD could be held liable.

roster · Post by **roster** » Sat Apr 12, 2008 5:26 am

sleeptech tito wrote:Asking someone not to wear his/her CPAP for 1 or a few nights is courting trouble. First, talking about the patient's health - it would not make any difference if the patient is on CPAP the night before... during the baseline study of the split his apnea/hypopneas would still appear. and he/she would still be retitrated properly. As a sleep practitioner I never really liked to do split studies - since you lose out on the essential data that is generated from the latter REM periods (Which is usually the worst)

second, the liability issue - If something happens to the patient on the day of the Sleep Study due to excessive daytime sleepiness the lab or MD could be held liable.

I am glad Dave brought up this topic and I appreciated everyone's input as there are several different but good points made. I agree with Tito's post.

There is an additional point of logic that needs to be considered. Think well beyond a follow-up titration. It is some weeks or months later and you are going to bed each night and you have expectations that your pressure settings will be correct for that night. Since you are compliant, if there is any carryover effect, it is with you that night.

So, would it not be better to titrate under the conditions you will be using cpap long term? That is, titrate after several straight nights of compliant cpap use?

BTW, I would have a very sharp discussion with any doctor who asked me to cease cpap for even one night. I had that double septoplasty and turbinate reduction in November and totally ignored the instructions of the sleep doc and surgeon to lay off the cpap mask for a few weeks. I wore a full face mask from night one. The first three nights there was a mustache bandage under the mask catching (most of) the dripping blood. .

akcpapguy · Post by **akcpapguy** » Sat Apr 12, 2008 12:51 pm

Yes Rooster I agree, if you are simply coming in for a retitration, than it would be fine to use you CPAP up until the night of the study. The problem arises when you have someone like the gentle in my post a couple above where his insurance is requiring him to have another spilt night study to recertify his OSA diagnosis. His AHI on a full nights diagnostic study wasn't even enough to qualify him for a diagnosis of mild OSA. This gentleman is now convinced that he doesn't have OSA and doesn't need CPAP. This gentleman's disease processes related to his OSA will now be allowed to continue unchecked until they eventually kill him. Where in this scenario are we putting the patients health first??!!

roster · Post by **roster** » Sat Apr 12, 2008 2:35 pm

akcpapguy wrote:... The problem arises when you have someone like the gentle in my post a couple above where his insurance is requiring him to have another spilt night study to recertify his OSA diagnosis. His AHI on a full nights diagnostic study wasn't even enough to qualify him for a diagnosis of mild OSA. .........

Could I lie awake and squeeze the hose tight for 90 seconds over and over? .

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