Relation between narcolepsy like sleep incidents and varying pulse ox.

Hi -
I have obstructive sleep apnea.  I sleep with a BiPap at 17/12 and with a 2 liter oxygen bleed.  I take Provigil, 200 mg x2 daily.  I still fall asleep while working at my desk or watching TV.  

My pulmonologist/sleep specialist has confirmed the problem with an MSLT of 9.0 minutes.  I feel like I have a narcolepsy like issue, without any associated falling.  My doc cannot put me on any stimulants because of my high blood pressure.

I recently noticed that when I’m working at my computer and starting to feel very tired, my pulse ox is about 93.  If I then put on my Bipap mask and continue working, my pulse ox climbs to 97 – 98 and the tiredness goes away.

Would this be indicative of (1) some other system in my body that is not functioning properly, and/or (2) is this is worth exploring further – or not unusual?

I have CKD and had a rear wall myocardial infarct in 1986.

Let me know what you think and/or whom I should follow up with this, i.e., what specialty, sub-specialty.  I of course do not expect a diagnosis, but some thoughts about direction to go in so I can stop falling asleep in the daytime would be appreciated.

[J.M. Keyes, MD]

Hi there,

Because of your other medical history, my main concern would be to make sure that there is no cardiac cause for your decreases in oxygen saturation and related fatigue during the day.  If you have a history of hypertension, as well as MI, you are at risk for heart failure.  There is also an association between heart failure and central sleep apnea.  I would follow up with your family doctor and discuss your symptoms further to determine whether you need a work up/referral to check on your cardiac function, if it hasn't been checked recently.

Ruling that out, another thought may be to look at trying to treat the cause for your obstructive sleep apnea- if you are overweight, that needs to be addressed (especially with your cardiac history), or if you have abnormally large tonsils or something like that causing the obstruction, I'd see an ENT for consideration of surgery.

Good luck.   I hope you find some answers.
JMK MD