Appropriate COPD Pulse Ox numbers

[coffeestainedscrubs]

Hi, I am a nursing student. Yesterday, in my clinical a patient with a number of issues (we were focused on his CHF but has COPD) was on 3L of oxygen. His pulse ox was recovering from his exacerbation and he was reaching 96-98%. The nurse mentioned for COPD patients it needs to be between 88-93% and she took off the oxygen for a while. She was out the door before I could ask why. Can someone explain this to me? Is this because if their hemoglobin is highly saturated (98-100%) they'll have a hard time getting more oxygen because of like movement of molecules from high to low and since they have breathing problems they take in less molecules of air and the pressure change won't occur well and then they're saturation will suddenly drop or something?

[VANurse2010]

In normal people, the respiratory drive is governed by blood carbon dioxide levels, not oxygen. COPD patients become accustomed to elevated CO2 and switch to oxygen sensing to drive their respirations. Over-oxygenating patients like this can depress their respirations and drive up their CO2. However, not all COPD patients retain carbon dioxide, and the evidence of over-oxygenating retainers isn't as clear cut as is often portrayed.

[Ccipencil]

VANurse2010 said:

In normal people, the respiratory drive is governed by blood carbon dioxide levels, not oxygen. COPD patients become accustomed to elevated CO2 and switch to oxygen sensing to drive their respirations. Over-oxygenating patients like this can depress their respirations and drive up their CO2. However, not all COPD patients retain carbon dioxide, and the evidence of over-oxygenating retainers isn't as clear cut as is often portrayed.

Not true, old research. Giving too much o2 doesn't depress the respiratory drive of COPD pts. COPD pts typically have a lower SpO2 because they have a harder time ventilating out the CO2 due to air trapping in the lung. Steroids and inhalers can help this. I would refer to the MD orders, if they are OK with a SpO2 of 88, which is uncommon, then I would follow their orders.

[coffeestainedscrubs]

Ccipencil said:

Not true, old research. Giving too much o2 doesn't depress the respiratory drive of COPD pts. COPD pts typically have a lower SpO2 because they have a harder time ventilating out the CO2 due to air trapping in the lung. Steroids and inhalers can help this. I would refer to the MD orders, if they are OK with a SpO2 of 88, which is uncommon, then I would follow their orders.

I understand why they have low saturation generally, but why (when they are on oxygen through a nasal cannula) would we desire the COPD patient's saturation between 88-93% and not 100%.

[Ccipencil]

They are not going to be 100% except on a ventilator or NRB. COPD pts are generally used to lower SpO2. As long as they are asymptotic then it is OK. COPD treatment includes much more than SpO2. Treatment goal isn't to maintain 100% SpO2 but to treat the symptoms of COPD I.e. SOB, wheezing, elevated PA pressures , elevated CO2 etc. They may end up needing home O2 or BiPap at night.

If u have a COPD pt wheezy, SOB, clammy etc. and a SpO2 in the 88-90 range then I would up their O2 and give some inhalers and Neb treatments but if they at their baseline and not wheezy, SOB, etc. then I would follow the MD orders.

The other item to keep in mind is COPD isn't curable so trying to maintain them at 100% isn't going to benefit them in the long run.

I would focus on the symptoms

[Ccipencil]

My guess would if this pt still is in the upper 80's on room air at time of discharge then they will need home O2 to maintain in the low 90's

[ArtClassRN, ADN, RN]

"Treat patients, not numbers."

[Kitiger, RN]

Ccipencil said:

Not true, old research. Giving too much o2 doesn't depress the respiratory drive of COPD pts.

Would you point me to this research? All I'm finding so far is dated in the 80s.

Thanks

[Kitiger, RN]

The info I'm finding relates to the how and why of oxygen therapy, but not to the question of whether too much is harmful.