[Diagnosis] Very weird AHI readings

[gilbo]

I began using a Bi-Pap machine April 19, 2011 (I = 12, E = 7). Between then and January 24, 2012, my daily AHI readings fell between 0.7 and 2.1, with a single day maximum of 2.5. On January 25, 2012, my AHI for that night was 10.6. Between January 25 and today (March 17, 2012) my AHI never fell below 8.8. The average for this period was 15.6, with several peaks in the 20+ range. The average has consistently been increasing throughout this period. This huge jump in AHI readings happened literally overnight, and I have no idea why. One thing that's interesting is that I stopped drinking January 24. I was a heavy drinker, drinking consistently throughout the day, everyday, as opposed to going out and getting drunk at night. My period of total abstinence from alcohol corresponds identically with the period of the huge increase in AHI readings. Is it possible that there is a connection? Drinking kept my AHI down, and not drinking caused it to increase significantly? I'd appreciate any ideas as to why this significant jump in AHI happened, and is still happening. Gilbo

[zonk]

Hi gilbo and welcome
I thought alcohol have the opposite effect on AHI it would higher not lower.
How is the leak. May be it,s time to replace the mask cushion.
If neither is applicable suggest see your doctor.

[Sleepster]

I'm not sure why the AHI changed like that, but congrats on getting off the alcohol. Do you know if that increase in AHI is composed mostly of clear-airway apneas (CA)?

Alcohol is a sedative so, according to that theory, getting off the alcohol would indicate a lower pressure might be needed. Too high of a pressure can cause excessive CA's. When I switched to a BiPAP I had to have my pressure lowered because my CA's went up.

[Netskier]

I began using a Bi-Pap machine April 19, 2011 (I = 12, E = 7). Between then and January 24, 2012, my daily AHI readings fell between 0.7 and 2.1, with a single day maximum of 2.5. On January 25, 2012, my AHI for that night was 10.6. Between January 25 and today (March 17, 2012) my AHI never fell below 8.8. The average for this period was 15.6, with several peaks in the 20+ range. The average has consistently been increasing throughout this period. This huge jump in AHI readings happened literally overnight, and I have no idea why. One thing that's interesting is that I stopped drinking January 24. I was a heavy drinker, drinking consistently throughout the day, everyday, as opposed to going out and getting drunk at night. My period of total abstinence from alcohol corresponds identically with the period of the huge increase in AHI readings. Is it possible that there is a connection? Drinking kept my AHI down, and not drinking caused it to increase significantly? I'd appreciate any ideas as to why this significant jump in AHI happened, and is still happening. Gilbo

I suggest installing Sleepyhead immediately, so you can begin to see what is happening. My learning rate went through the roof as soon as I installed it and began using it.

[zimlich]

I agree that now you may need a slightly lower pressure and would experiment with tritrating down a bit, giving it at least a week per change.
Good luck. Glad you stopped drinking. I don't mean there is anything wrong with a drink or three, but....

[zonk]

Excerpt from the article 'Intelligent CPAP systems: clinical experience'
H Teschlera, M Berthon-Jones
http://www.apneaboard.com/forums/Thread-...experience

Stability of titration pressure and breathing with alcohol
We argued that, since consumption of alcoholic beverages worsens snoring, a social amount of pure alcohol might worsen untreated OSA and, by further relaxing the upper airway, increase the titration pressure. To study the stability of titration pressure further 14 men with untreated uncomplicated OSA were studied with and without 1.5 ml/kg 40% vodka (blood alcohol 0.45 mg/ml). Surprisingly, without CPAP there was no significant or important change in AHI, arousal index, sleep architecture, or saturation with the exception of one subject who showed prolonged periods of hypoventilation without much desaturation after alcohol. There was a slight but non-significant decrease in the percentage of REM with alcohol on the non-CPAP night (11 (2)% versus 8 (1)%). The AutoSet titration pressure was 11.9 (0.9) cm H2O without alcohol and 12.5 cm H2O with alcohol. Again there were no important or significant changes in sleep or breathing with alcohol during CPAP therapy. These results are consistent with the notion that, unlike snorers, in subjects with OSA the upper airway is already completely floppy so that alcohol cannot make matters worse. Since the existing CPAP pressure adequately maintains airway patency, a modest dose of pure alcohol therefore has no important consequences for sleep and breathing during CPAP therapy. We hasten to point out that these results cannot be extrapolated to alcoholic beverages containing vasodilator substances (histamine, tyramine) which may lead to a large increase in nasal airway resistance, nor to higher doses of alcohol which may lead to a reduction in arousal response, particularly in subjects with overlap syndrome.

[Netskier]

I began using a Bi-Pap machine April 19, 2011 (I = 12, E = 7). Between then and January 24, 2012, my daily AHI readings fell between 0.7 and 2.1, with a single day maximum of 2.5. On January 25, 2012, my AHI for that night was 10.6. Between January 25 and today (March 17, 2012) my AHI never fell below 8.8. The average for this period was 15.6, with several peaks in the 20+ range. The average has consistently been increasing throughout this period. This huge jump in AHI readings happened literally overnight, and I have no idea why. One thing that's interesting is that I stopped drinking January 24. I was a heavy drinker, drinking consistently throughout the day, everyday, as opposed to going out and getting drunk at night. My period of total abstinence from alcohol corresponds identically with the period of the huge increase in AHI readings. Is it possible that there is a connection? Drinking kept my AHI down, and not drinking caused it to increase significantly? I'd appreciate any ideas as to why this significant jump in AHI happened, and is still happening. Gilbo

This is an interesting question. AHI is the composite of Obstructive Apnea, Open Airway Apnea, Hypopnea, and what Sleepyhead software calls something else, something like Unspecific Apnea. So I am wondering whether all of these components of the AHI are increasing, or just some of them, and if just some, then which ones? Sleepyhead will give you plots of all of them, and will answer these questions with one glance. So I strongly encourage you to install and run the Sleepyhead software.

I can hypothesize explanations, but they are all wild guesses. So here goes.

1.1. Aging causes apnea to increase, so perhaps your alcohol withdrawal has increased your aging.

1.2 You have gotten a little older just from the passage of time, perhaps you passed some sort of aging threshold for your throat.

2. Perhaps you have been exposed to some environmental toxin that causes apnea, such as mercury, or other heavy metal, coincidentally with stopping ethanol.

3. Ethanol increases apnea but only while sleeping. You drank during the day when it could not cause apnea. Every day, you stopped drinking when you went to bed, so your ethanol concentration would have been decreasing throughout the night, and obstructive apnea happens mainly during REM sleep every 90 minutes, and REM durations increase as the night goes on. Tolerance to ethanol is typically a rebound in the opposite direction of the effects of the ethanol, so these rebound effects would have been anti-apneaic, and would have increased exactly as untreated apnea would have been increasing. These ethanol tolerance rebounds could have been combining with your BIPAP therapy to suppress you AHI. But now that you have quit drinking, these rebounds are gone, so your BIPAP is left to treat the apnea alone. Therefore, the AHI is increasing.

4. Now that you have stopped drinking, your weight has changed, and your mask leaks more, causing an artifactual increase in your AHI. Has your weight changed? If you have lost weight, then perhaps your face has changed shape, leading to more leakage.

OK. There are five ideas. I am all guessed out for now.

The Sleepyhead software will show you all kinds of things, and you may see some of them start changing when you stopped drinking. I want to see these plots, or at least for you to see them. I suspect they will suggest more ideas.

I hope this helps.

Netskier

[Dreamcatcher]

Any change in routine will change your AHI from giving up coffee or Tea to alcohol. If you change your diet then you need to reset and change your pressure.

Your body will be in withdrawel wether you feel it or not, when you take something away from your normal routine your body will notice there is a difference and so will react differently just as though you added something. Ask a non drinker to drink a bottle of wine or take a few pints of beer before their bedtime and watch the AHI go through the roof. Try it. have a stimiulant before bedtime or dont take your last coffee and watch your AHI change. Simple rule

Change your diet, change your settings.

[Babs_Le_Grand]

Quiting Alcohol is definetly behind the Increase in the AHI = OAI+CAI. First analyse your machine data to know the nature of your apnea, is it obstructive? Central? or Complex? If you notice that most of the AHI is due to central apnea, then try to have a drink before you sleep and check the CAI the otehr day. Do this 3 times a week and monitor the variation in your AHI. If you are using Sleepyhead software which is highly useful, set the preferences to show the RDI = Respiratory disturbance Index = AHI + RERA. the RERA index must not be underestimated at all. So instead of reading the AHI read the RDI and monitor the effect of alcohol on the RERA and the CAI. I hate alcohol and don't drink, probably few times a year on occasions, so i advise you not to get back to the bad habit but for the sake of science do the experiment and see. I am saying this because i have noticed without a doubt that my RDI was utterly decreased when drinking wiskey. Most of my apnea is (central+RERA), even without CPAP i noticed a better sleep after drinking a bit. My guess is that alcohol worked as anti-stress drug and relaxed the brain tension, i am still investigating this phenomena which contradicts the medical litterature i read so far.

[Sleepster]

Many times these changes in our AHI are temporary, and are due to the change in our habits. For example, you could see a rise in the AHI when you stop drinking, but after a while the AHI will drop back down to where it was before. It's your body adjusting to the change in your drinking habits.