Supplemental oxygen with CPAP?

[CPAPforever]

I have been on CPAP for 20 years, the last 5 on BiPAP. My last sleep study 6 years ago showed AHI at 75 and desats as low as 77%. My sleep apnea was totally obstructive until past year. Half of events are now central. My AHI on BiPAP 20/16 is less than 2 each night. I am beginning to think that although AHI is low with BiPAP, I am having s
low level oxygen due to hypoventilation. I am having low number of apneas but because of decreased tidal volume, I am not getting enough oxygen.

Has anyone used supplememtal oxygen with CPAP or BiPAP? I see new sleep specialist in a month. I think I will buy a cheap pulse oximeter to wear at night to monitor oxygenation status. If I have low oxygenation throughout the night with AHI below 2, might this indicate the need for supplemental oxygen?

[palerider]

I am beginning to think that although AHI is low with BiPAP, I am having low level oxygen due to hypoventilation. I am having low number of apneas but because of decreased tidal volume, I am not getting enough oxygen.

Why do you think that?

[CPAPforever]

I have low PO2 (92%) during the day watching TV. Spontaneously taking occasional deep breaths. Hypoventilation while awake could also be happening during sleep on BiPAP. So although I am not having sleep arousals due to apnea events, I am probably not getting enough oxygen most nights.

[palerider]

I have low PO2 (92%) during the day watching TV. Spontaneously taking occasional deep breaths. Hypoventilation while awake could also be happening during sleep on BiPAP. So although I am not having sleep arousals due to apnea events, I am probably not getting enough oxygen most nights.

Low SpO2 during the day really has nothing to do with sleep, unless you've just got general decreased lung function.

Increase your PS if you want more ventilation. You said you're on bilevel, yes?

[CPAPforever]

Increase in EPAP/IPAP caused many CA events.

Hypoventilation is common in disordered breathing due to obesity. I am not morbidly obese. Unable to fully expand lungs due to external body fat. Increasing PS will not help hypoventilation. And it increases breathing effort on exhale stressing the heart. Low P02 during day at rest while sitting is indicative of hypoventilation. If hypoventilation present during day in upright position, more of a problem while supine position during sleep.

[CPAPforever]

You need to research OHS (Obesity Hypoventilation Syndrome) to understand. This is in addition to OSA.

[palerider]

Increase in EPAP/IPAP caused many CA events.

Since you mention it though, increasing EPAP increases oxygenation.

Increasing PS will not help hypoventilation.

On the contrary, it does. Increased PS is what is used for OHS,

And it increases breathing effort on exhale stressing the heart.

Increased PS *decreases* breathing effort.

Resmed titration guide:
Obesity Hypoventilation Syndrome (OHS)
Obesity hypoventilation patients often have reduced tidal volumes caused by the additional weight pressing down on the chest and abdomen. Additionally, these patients may also have obstructive sleep apnea (OSA) caused by excess tissue in the upper airway and a high body mass index (BMI).
The recommended settings use a higher EPAP pressure to keep the airway open and a higher IPAP to provide additional pressure support and ventilatory assistance.

Suggested starting values are 15/7, for a PS of 8

[palerider]

You need to research OHS (Obesity Hypoventilation Syndrome) to understand. This is in addition to OSA.

I do understand, and what I suggested is the standard response.

Alternatively, you could get an iVAPS system, which uses.... PS... to overcome OHS.

But, to answer your initial question, yes, lots of people use supplemental oxygen with cpap, apap, bilevel, asv, etc.

[CPAPforever]

Mayo Clinic website says how to treat OHS with OSA. First try CPAP. If insufficient, try BiPAP. These will keep airway open preventing obstruction. But these do not totally compensate for hypoventilation. So add O2 to CPAP/BiPAP if needed. Increasing pressure beyond what is needed to keep airway open increases respiratory effort on exhale and causes high CA events for me. I don't need fancy ventilator. Just asking about adding oxygen to BiPAP to decrease buildup of CO2 and increase oxygenation.

[greatunclebill]

many people use supplemental o2. If you get it will ultimately depend on what your doctor prescribes based on your medical condition and what your insurance will pay for, not what you, forum members or medical websites say. good luck.

[palerider]

Mayo Clinic website says how to treat OHS with OSA.

The "mayo clinic website" is dumbed down for the rank and file.

First try CPAP. If insufficient, try BiPAP. These will keep airway open preventing obstruction. But these do not totally compensate for hypoventilation.

cpap doesn't compensate for it at all. The *entire* point of bipap (bilevel), is that it has PRESSURE SUPPORT, pressure support is what compensates for hypoventilation. PS increases ventilation, HYPOventilation means too little ventilation. Facts are facts, whether or not you want to believe them.

Increasing pressure beyond what is needed to keep airway open increases respiratory effort on exhale

You seem to not understand the difference between "increasing pressure" and increasing "pressure support".

Increased EPAP does result in increased respiratory effort on exhale. Increased pressure support *REDUCES* respiratory exhale effort.

and causes high CA events for me. I don't need fancy ventilator.

No, you just need extra pressure support

Just asking about adding oxygen to BiPAP to decrease buildup of CO2 and increase oxygenation.

Adding oxygen does not decrease paco2.

[raisedfist]

If you add oxygen your tidal volume will not change one bit. O2 easily fixes the hypoxemia portion of the equation, but it does nothing to address hypoventilation in terms of the removal of CO2. Increasing pressure support increases your tidal volume, which increases your minute ventilation, which increases the removal of CO2. PS lessens work of breathing. Easy measures of this are invrease in Vt and reduction in Respiratory Rate.

[palerider]

If you add oxygen your tidal volume will not change one bit. O2 easily fixes the hypoxemia portion of the equation, but it does nothing to address hypoventilation in terms of the removal of CO2. Increasing pressure support increases your tidal volume, which increases your minute ventilation, which increases the removal of CO2. PS lessens work of breathing. Easy measures of this are invrease in Vt and reduction in Respiratory Rate.

Good luck... Not seeing much light getting in so far.

[raisedfist]

If you add oxygen your tidal volume will not change one bit. O2 easily fixes the hypoxemia portion of the equation, but it does nothing to address hypoventilation in terms of the removal of CO2. Increasing pressure support increases your tidal volume, which increases your minute ventilation, which increases the removal of CO2. PS lessens work of breathing. Easy measures of this are invrease in Vt and reduction in Respiratory Rate.

Good luck... Not seeing much light getting in so far.

It is amusing to see someone refute the basic *facts* that you shared. Maybe they will believe ResMed regarding what IPAP and EPAP, and Pressure Support, are for. I think they may know something about ventilation and oxygenation.

As a side note, a lot of OHS is treatable with CPAP alone, as often times with an unobstructed airway, you are not having events that cause oxygen desats and increases in CO2. If you aren’t ventilating adequately, supplemental O2 can be dangerous because you are given the false impresssion that everything is fine and dandy. You can have an O2 sat of 100% and still have a CO2 level that is dangerously high.

[SewTired]

Just as an FYI - at 92% chances are that your doc will not give you supplemental oxygen at all because insurance won't pay for it unless you are below 89%. Sometimes they won't issue the script because they already know you won't be approved by insurance/Medicare. In that case, consider having a discussion about buying out-of-pocket and finding out if the recommendation would change. Please note that I am ONLY talking about actually getting the oxygen - I don't know anything about the actual medical issue you are talking about.