Sleep Apnea and Snoring Q&A Blog for Dentists and our Patients

In this blog, I try to answer questions relating to treating sleep disordered breathing, which includes both snoring and sleep apnea. These have come in to me for many years, so I have decided to begin posting them as they come in, so that you may find your answer to whatever question you might have in this blog. At times, the questions and or answers may stray a bit, but not to a great degree. If you need to search for a topic or question as this Q&A blog gets lengthy, the search feature on the home page could come in handy.

Q: My question is, why is there a difference in REM sleep with this patient?

A: Obstructive sleep apnea is almost always worse in REM, because they are paralyzed and can't compensate for an obstruction by thrusting their mandible and tongue forward. They just continue to be obstructed. When the REM AHI is at least twice the NREM AHI, the new term is REM-related OSA. Most common in women, and even more common in young women.

Q: I know somebody who is a pilot. They can not be diagnosed with sleep or it is immediate disability and they can't pilot the plane. MY question is have you ever done the MAD for this type of person without the diagnosis? What would the liability be if you said it was just for snoring?

A: This is one reason we have ambulatory (home) monitors, so we can rule out anything more severe. I would insist on at least this, and you can keep it away from insurance and any official diagnosis. The liability would be pretty heavy if he fell asleep at the controls, thinking he was cured, when in fact you had created a "silent apneic", so you really need to get at least a Level 4 study done on this patient.

Q: In one of your e-mails I thought you mentioned as well you should refer out for a PSG ideally.

A: This depends on many things, but one reason to refer for psgs is to gain a relationship with sleep doctors. I do refer initially for psgs, but when I get resistance, offer the Watch-PAT or ApneaLink. I have many husbands who will not go to a sleep center for their wife, but will take home a unit. I also have women who would never spend a night in a foreign place by themselves. So, we use these for those reasons, as well to verify success (or not) of the appliances. Add to that the fact last year the powers decided that these units can now be used to diagnose sleep apnea!

Q: I don't get it, thought in order to have sleep apnea you had to be old, over weight and ugly, not in that order...  I went to the Doc about restless leg syndrome and she said we need to do a sleep study and see just how bad you got it. Well I got it worst than I thought. I walked in to the waiting room at 8:45 pm and 5 other guys were sitting there cracking jokes about how their wife's don't put out any more and waiting to be escorted back to our rooms.

Well here I am 200lbs bodybuilder sitting there waiting my turn and the nurse walked out and said your father will be in good hands so you can go home now... Well, I'm here for a study, and this black lady towers over me and asked is this a joke, because I'm not in a joking mood, I thought to myself you're going to die.. She came back out to the waiting room and gave me a long look, "your with me".. So I'm sitting in this chair in my room and she walks in with a 1000 wires and starts gluing them on every inch of my body and talking about uncomfortable..

So at 1:45 she put me to bed and said I can see everything so not make a move unless I tell you too. This room is dark and so quiet that I can hear my ears ringing from the years of racing I guess... finally the adrenine level comes back down and I fall asleep. She comes running in, wakes me up and tells me we're putting this mask on you before you die,, OK.. I asked is this going to help my restless legs, she said "baby this going to save your life". So here I am, can't stand to have anything touching me while I sleep and I'm told I have to have it.. can you help me with any advice on how I'm going to live with a mask on my face..... Poor Poor pitiful me...

A: First of all, 60% of sleep apneics are NOT obese. I have treated many slim females, and in fact, had 2 come in today with sleep-disordered breathing. I always tell them it's nothing they have done at all, it's just the luck of their genetics. It's why I take a "uvula shot" with all my new patient photos.

Secondly, put to bed at 1:45??? That place is very poorly run. I have never heard of that kind of delay. Anyway, each sleep center has their protocol for placing a PAP machine during a study, regardless of what the orders were from the MD. You received what we call a "split study", and they decide on this sometimes due to your insurance, but most times due to a drop in your SpO2 below a certain level (usually 80%) for a given amount of time (usually 10 minutes).

However, some centers are less than scrupulous, and all they want to do is sell you a PAP machine, so without knowing your center, it's hard to say. This is the reason I have written letters to the sleep centers I send patients to, stating "Under no circumstance are you to place a PAP machine on my patient". So, my name and about 4 ENTs in the area are on the walls in the sleep centers, warning the techs not to do this to our patients. They have been sleeping in their own beds for quite some time with their disorder, and the chances of them dying on their watch are not real good, especially since they are connected to 18-24 wires, and everyone would know if they are about to code.

Now to your specific study. It is now accepted that you will be sold a PAP (and insurance will cover), if your AHI (or RDI) is 15 or higher OR if it is 5 or higher, with accompanying comorbidities, such as hypertension, sleepiness, etc.. Be sure to ask them for a copy of your analysis. If you would like me to take a look at it and give you some advice, I do this regularly, so you can fax it to 972.255.5693, and I will gladly discuss your results with you.

Q: Do you have any studies that validate 90% as the minimum safe desat level for everyone?

A: That is an excellent and thought-provoking (for me) question that has me wondering who came up with the 90% rule and how did that become the standard CMCP (conventional morbidity cut point) accepted in the field of sleep. It is oft quoted, and almost all sleep software talks about the time spent under 90%, but after some surfing, I have not yet been able to find out why they chose this many years ago. When they study hypoxemia , they use the time under 90% to define nocturnal hypoxemia.

In a P < 0.05), a lower forced expiratory volume in one second % predicted (P = 0.01), lower daytime SaO2 (P = 0.01) and higher levels of mental fatigue (difficulty concentrating) (P = 0.02), compared to those without nocturnal hypoxemia.

In a study on pulmonary hypertension,, they quote "Patients who spent > 10% of the total sleep time with oxygen saturation by pulse oximetry (Spo2) at < 90% or who needed oxygen to maintain their Spo2 level at > 90% were classified as nocturnal desaturators."

Basically, it is well accepted that 90% is the cut point, but I am still unaware of the original source. I will continue to search, and thanks for the question!

Q: Hi Kent,  just for my info, where is the information printed as to the PSG no longer being the gold standard and the WP is all right?  Is this in regards to the Medicare now paying for ambulatory studies?

A: You can read the entire medicare document here

About 35% of the way down the page, you will read this:

There is no anatomic or physiologic "gold standard" for the diagnosis of obstructive sleep apnea, in contrast to conditions such as cancer where a tissue biopsy result is the definitive standard reference. In studies that compare HST to facility-based PSG, the investigators have used the PSG result as the standard reference, i.e. the PSG result is used to define the true disease state for the individual patient. This is less than ideal since the true sensitivity and specificity of PSG in diagnosing OSA is not well documented, and this deficiency poses a practical difficulty in diagnosing OSA. Given the absence of a true "gold standard" reference, the clinical application of terms such as sensitivity and specificity is not straightforward.

Q: So sleep deprived people have higher levels of ghrelin causing them to eat?  And those with proper sleep have higher levels of Leptin have normal appetites?

A: The levels are regulated properly in slow wave sleep, and without it (severe OSA), the levels are all over the place. They are working on leptin pills to take, but so far, have been unsuccessful other than combining them with an anti-diabetic drug, and even then, they can only help people keep weight off, not LOSE weight.

Q: Husband is having a terrible time with his somnomed... he drools so much he can't sleep so he takes it out and then I can't sleep cause he is a loud bugger.  I personally would rather him drool!  Any suggestions?

A: Ambien for a week until he gets used to it. Or, an antisialagogue. The drooling really should be better by now. How long has he been wearing it consistently? If he has a ramp, I would remove it if not needed, so he can get better lip competency.

Q: Do you still go with growth hormone lacking as a significant reason for immune depression (lack of slow wave sleep when it is released). And if so ... how come older people often have no deep (N3) sleep and yet I do not think of them as sicker (maybe they are more prone).

A: I definitely believe the lack of growth hormone and deep (slow wave) sleep in general is a major factor in older adults being unable to heal as well from injury. Not that they get sick easier, but when they do get sick or injured, it's a tougher road back.

290 E John Carpenter Fwy. Suite 2700, Irving, TX 75062 USA
B. Kent Smith, DDS Jeff Roy, DDS Ashley Bristow, DDS Irving, TX dentist providing comprehensive dentistry & sleep apnea therapy. (972) 255-3712 (972) 255-5693