Sleep Apnea Returns Rapidly When CPAP Stopped

From MedPage Today

By Charles Bankhead, Staff Writer, MedPage Today
Published: August 13, 2011
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco.

Obstructive sleep apnea (OSA) and its associated complications recurred rapidly after discontinuation of continuous positive airway pressure (CPAP), results of a small randomized trial showed.

After two weeks without CPAP, the number of arousal events per hour had more than tripled, and apnea-hypopnea events had increased 17-fold. Both measures remained unchanged in patients who continued CPAP.

OSA returned within days after stopping CPAP, as did subjective sleepiness, but objective measures of sleepiness did not change significantly.

By the end of the study, endothelial function had decreased significantly, and morning blood pressure, heart rate, and urinary catecholamines all increased significantly compared with patients who remained on CPAP.

"We found that CPAP withdrawal was associated with a return of OSA by the first night," Malcolm Kohler, MD, of University Hospital Zurich in Switzerland, and coauthors reported online in the American Journal of Respiratory and Critical Care Medicine.

The principal implications of the findings relate to clinical research in OSA, including studies of the physiologic effects of OSA and response to novel therapies, the authors added. The effect of CPAP withdrawal on sleep-disordered breathing and cardiovascular risk factors requires further study.

The effects of CPAP withdrawal on patients with diagnosed OSA previously have been evaluated only in uncontrolled trials, limiting the ability to draw definitive conclusions. The authors sought to clarify the effects in a randomized, controlled trial to examine a two-week trial of CPAP discontinuation.

Investigators queried a database of patients with OSA treated with CPAP and a sleep disorders center. Eligible adult patients had an oxygen desaturation index (ODI) >10/h in their initial sleep study and after four nights without CPAP, had used CPAP for more than 12 months, and had an average compliance of at least four hours per night.

After enrollment, all patients resumed CPAP for at least seven days and then were randomized to continue CPAP or switch to subtherapeutic CPAP for two weeks.

Investigators assessed patients' pulse oximetry nightly throughout the study period. Subjective sleepiness was evaluated at baseline and two weeks by means of the Epworth sleepiness score, and objective sleepiness was determined by a sleep resistance challenge at baseline and two weeks.

Patients completed a simulated driving test and a reaction-time task at baseline and two weeks to assess psychomotor performance at baseline and after two weeks.

Flow-mediated dilation was measured by ultrasound to assess endothelial function. Blood pressure and heart rate were measured three times daily through the study. Blood samples obtained at baseline and after two weeks were used to measure markers of systemic inflammation, insulin resistance, and lipids.

Patients provided 12-hour urine specimens at baseline and after two weeks for assessment of urinary catecholamines.

Investigators randomized 41 patients, 40 of whom completed the study. One patient in the subtherapeutic group dropped out after four days because of intolerable daytime symptoms.

Baseline characteristics, including sleep characteristics, did not differ significantly between groups.

When the study ended, patients in the subtherapeutic group had significant changes in multiple parameters compared with patients on continuous CPAP, including:

•Average arousal incidents - +20.7/h versus -0.6/h, P<0.001
•Apnea-hypopnea events - +33.8/h versus 0.4/h, P<0.001
•ODI events - +26.3/h versus -0.2, P<0.001
•Epworth score - +2.0 versus -0.7, P=0.001
•Morning blood pressure - +6.2/+4.4 versus -2.3/-2.5 mmHg, P=0.016, P=0.008
•Morning heart rate - +6.3 versus 0.0 bpm, P=0.035
•Flow-mediated dilation - -3.2% versus -1.7%, P<0.001
•Norepinephrine - +11.5 versus +0.9 nmol/mmol, P=0.012

Psychomotor performance did not change significantly in response to CPAP withdrawal, nor did markers of systemic inflammation, insulin resistance, or cholesterol.

The study was supported by the Swiss National Science Foundation and the Swiss Society of Pneumology.

The authors had no relevant disclosures.

http://www.medpagetoday.com/Pulmonology ... erid=53898

Should this be surprising? CPAP doesn't cure apnea, it just responds to clear it when it happens or prevents it by keeping the airway open to prevent it.

"Headache returns when you quit taking NSAIDS" Yawn ...

While I agree that the conclusion is obvious, the point of the study was to prove it scientifically. Insurance companies don't support treatments that can't be proven (by scientific experimentation) to be medically necessary.

So, this study will end up forcing insurers to continue to subsidize CPAP no matter how long a person uses it =)

I'm ok with a little redundant science if it help keep hoseheads attached to their blowers when they need them long-term.

TalonNYC wrote:While I agree that the conclusion is obvious, the point of the study was to prove it scientifically. Insurance companies don't support treatments that can't be proven (by scientific experimentation) to be medically necessary.

So, this study will end up forcing insurers to continue to subsidize CPAP no matter how long a person uses it =)

I'm ok with a little redundant science if it help keep hoseheads attached to their blowers when they need them long-term.

I can see the value in a supported scientific position, I just chuckled at the thought of science proving common knowledge at a price. It didn't occur to me that this is necessary to support medical insurance payments.

Maybe the government research on 3 wheel tricycles being dangerously unbalanced was really necessary to achieve legislation outlawing their continued production. We all got a chuckle out of that one, too.

I guess mine will return today then since I am not able to use my cpap tonight. I have a summer cold with some lung congestion so I called my sleep doctor and spoke with his nurse about the cold. My doctor called back shortly afterwards and told me not to use the cpap until my pulmonologist tells me it is all right; I will be seeing him this Thursday. I guess there is no way to tell myself about any returning OSA symptoms.

Roger

My husband was in the hospital and rehab for about 2wks without cpap and he's now been home for almost 2months and we're still working on getting his data back to previous excellent numbers. All his blood work and other tests have returned to normal and Drs say he's doing "great"! And he seems OK in general. But last night his AHI was 5.5 which was unusual but it's now almost 3-3.5 most nights when before it was between 0.5-1.5. Is it possible that 2wks without cpap can screw things up so much?

a little positive reinforcement can never hurt, especially for those who are newbies, and struggling to stay on therapy.

I'm sure we've all read an occasional post in this or another forum where someone's sleep doctor has told them to STOP CPAP therapy for anywhere from 2 days to a week before a new sleep study because of the "residual effect" of CPAP therapy on OSA.

Not too often we will see a post like that but ... I'd venture a guess I've seen 2-3 posts like that over the last 5 years.

Roger, hope your cold/congestion clears up quickly so you can resume therapy. I know my husband felt more "normal" when he was able to sleep with his "girlfriend" again and I "try" not to look at the numbers as much as how he's feeling. The higher AHI doesn't seem to be having an impact at all. I also know with a little more tweaking we'll get the numbers down again. It's good to be in control of our own therapy.