COPD and O2 use, am I wrong?

[tsm007]

Going to give you background information and then want some feedback.

I am new to med surg, been here about 2 months, been a nurse about a year. My preceptor has been a nurse a few months more than me, but all med surg experience. I go with the flow and don't really argue with my preceptor, but she's been wrong on another occasion. She's really nice and for the most part does a good job. She's just not always as knowledgable as the more experienced nurses on the floor.

My patient was admitted for a fall, been stuck on the floor for a couple days before anyone found him. He's a heavy smoker with a history of sleep apnea. My preceptor kept saying he had COPD, but now in hindsite I don't recall seeing that in his chart or on in report. (However, can't look that up now so let's just say hypothetically that he does have COPD for this question.) First 2 days I took care of him he didn't sleep well and his O2 sats were 94-95ish. On the second day he got a little wheezy around 5am and his O2 sats dropped to 90-92%, but all during the dayshift and mostly through the night lung sounds were perfectly clear and O2 sats were good.

Last night pt took xanax for anxiety which was a new med for him. I had a sneaking suspicion that his O2 sats would drop once he was all relaxed and sleeping. I know xanax doesn't have a side effect of low O2, but with a history of sleep anea and he was so sedated from it I wanted to check his O2 and vitals.

Check O2 and vitals around 1am and Pulse Ox is 88%. I ask preceptor if I can put him on O2 and what the protocol is for starting O2. So we start him on 2L NC. This is the part that I have the question on. My preceptor then states that if his O2 gets above 92% I need to turn his O2 down because his baseline is probably this low all the time and he has COPD.

Now how does that make any sense??? 1) If his baseline is that low all the time why am I putting him on O2? 2) His baseline hasn't been that low in the past 2 days I've been taking care of him.

I know you don't want to give COPD people too much O2, but 2L should not be a problem and I thought the goal was to keep *above* 92% for most people (unless doctors make target goal lower). I just wouldn't see any reason to bump O2 down if it was above 92%. I mean if he's running 98% or something I can see bumping it back down because he might no need it any more, but I wouldn't think it would be harmful to him either.

I eventually wound up calling RT and he wound up on a venti mask until morning. because his O2 sats dropped to 77-82% on RA (the nasal canula migrated from his nostrils) and the 2L wasn't budging him above the 88%.

I know I'm being a brat and I appreciate anyone who read this book long post, but wanted thoughts on COPD and adjusting O2. Is there any reason you need to bump O2 down if their sats go above 92% on 2L? I know I wouldn't put them above 2L without getting doctor or RT involved.

[amoLucia]

Am remembering that chronic COPD pts usually compensate and function decently with lower O2 sats while on room air. So to minimally 'enrich' his inspiratory effort makes sense to me.

[Anna Flaxis, BSN, RN]

Did you have orders for oxygen? What did the orders say?

In someone with a history of sleep apnea and mild lung disease, I would expect that he probably drops down below 88% in his sleep on a regular basis at home. It sounds like during the day, when he's awake, 94-95% is his normal. I agree with your preceptor, except that I would accept anything above 90% in this fellow.

Remember also, to assess the whole patient, not the monitor, and that the SpO2 should not be used in isolation, or regardless of other assessment data. Of interest would be his respiratory rate and effort, heart rate, skin signs, mentation, and airway status.

Your instincts were correct that the Xanax could relax him enough to diminish his respiratory effort as well as relax his airway protective mechanisms. In addition to considering supplemental oxygen to keep him above 90%, I'd suggest stimulation (i.e. waking him up) and positioning (i.e. turning him on his side) to prevent airway obstruction.

But I think your preceptor is correct - he probably lives with lower than normal SpO2 levels, and you should titrate down once he's above 92%. Also, this is information that should be passed along to the physician. This patient would benefit from a sleep study and a pulmonology consult.

[tsm007]

Anna Flaxis said:

Did you have orders for oxygen? What did the orders say?

In someone with a history of sleep apnea and mild lung disease, I would expect that he probably drops down below 88% in his sleep on a regular basis at home. It sounds like during the day, when he's awake, 94-95% is his normal. I agree with your preceptor, except that I would accept anything above 90% in this fellow.

Remember also, to assess the whole patient, not the monitor, and that the SpO2 should not be used in isolation, or regardless of other assessment data. Of interest would be his respiratory rate and effort, heart rate, skin signs, mentation, and airway status.

Your instincts were correct that the Xanax could relax him enough to diminish his respiratory effort as well as relax his airway protective mechanisms. In addition to considering supplemental oxygen to keep him above 90%, I'd suggest stimulation (I.e. waking him up) and positioning (I.e. turning him on his side) to prevent airway obstruction.

But I think your preceptor is correct - he probably lives with lower than normal SpO2 levels, and you should titrate down once he's above 92%. Also, this is information that should be passed along to the physician. This patient would benefit from a sleep study and a pulmonology consult.

Hmm, that makes sense, but honestly don't think the O2 was doing any good anyway. Once I slept on this a minute. RT put him on a venti mask because he was mouth breathing. He had been ordered a CPAP at home, but won't use it. You can lead a horse to water. Thanks for the input.

I did realize that he could be running that low during his sleep on a regular basis. I just didn't know that would be considered his baseline since most of the day he runs normal. I thought baseline would be what you run majority of the time. I put in the order, but I think it said titrate to keep O2 sats above 90%. So I knew I *could* turn it down. I just didn't realize I had to turn it down. Good info.

[Anna Flaxis, BSN, RN]

tsm007 said:

I did realize that he could be running that low during his sleep on a regular basis. I just didn't know that would be considered his baseline since most of the day he runs normal. I thought baseline would be what you run majority of the time.

Ah, I see where the disconnect is. "Baseline", to me, refers to the overall big picture of what is happening on a regular basis - not necessarily what is happening most of the time. For instance, from my cardiology days, I remember having patients that, most of the time ran with a heart rate in the 50s or 60s. But, at night time, in their sleep, they dropped below 40 on a regular basis. It didn't freak us out because we knew this was probably how they lived.

In the ER or on Med-Surg, this would have been cause for concern and most likely would have bought them pacer pads. But on the cardiology floor, we took into consideration that the person had a long history of cardiac disease, had been on beta blockers for years, had an old LBBB at baseline, and so most likely dropped into the 40s at home all the time. If in doubt, we would wake them up and see how they were feeling, because whether or not the patient is symptomatic is pertinent information.

It's not so different with your patient. The fact that he had already been prescribed CPAP which he chooses not to use tells me he probably has hypoxic episodes in his sleep all the time. To me, this is his "baseline".

Does this mean you shouldn't intervene? Not at all. If you suspect your patient is hypoxic, you should wake them and assess them and inform the provider.

[amoLucia]

Normal daytime 'awake' respiratory effort will most likely differ from 'sleeping' or 'resting' respiratory effort. The pt is awake, more active, talking and usually in an upright position (allowing better chest expansion). So again it makes sense that his sats would reflect better oxygenation levels than when asleep or resting with a slower resp rate and more shallow breathing.

Without getting into depth about normal O2 and CO2 drives, there's differences here too which concerns what stimulates you & me to breathe and what stimulates a COPDer to breathe. To flood a COPDer with supplemental O2 risks affecting his stimulatory drive. Not what you want to do. So so very much can impact respiratory status (respiratory pts disease processes are fascinating to me).

[MaxAttack, BSN, RN]

COPD is a great disease to get to know in detail - you'll see it a lot. The simple explanation for lower saturation goals with COPD patients is that higher saturations encourage CO2 retention, so you really do want to keep his FiO2 as low as possible. Goals of 88-92% aren't uncommon for a COPD patient. With a hx of apnea and COPD and no symptoms, I would've been ok with 88%.

The most common explanation for titrating down FiO2 is the hypoxic drive theory. This is for practical purposes a myth. Look into V/Q mismatching and the effects of oxygen on pulmonary tissue if you want to explore it further.

[MHunterRRT]

I'm usually ok with sats as low as 88% for the copd patient, if they don't have home O2(I don't titrate below what's ordered for home use). If they have consistent nocturnal desaturations below 88%, I would consider putting them on 1L or 2L while they sleep and see if it makes any difference.

[Fancypants09]

For the rare times when we have a COPD pt on our surgical floor, there are physician orders to titrate oxygen sats. to between 88%-92%

[Lev, MSN, RN, NP]

I would do the same as you for a COPDer with normal sats during the day that drop at night from sleep apnea. Just like any sleep apnea patient who is noncompliant with CPAP. I will give my COPDers who come in with an exacerbation oxygen if they drop below 90%. It usually brings them up to 92-95% and I don't titrate them up beyond that. If this guy was wheezing, maybe a neb treatment is what he needed initially.

[pmath_RRT]

Hypoxic drive THEORY. Notice I put theory in all caps because it is just a theory and actually more of a myth. Look into the Haldane effect and V/Q mismatch. Also if this pt has never had a PFT done then you can't assume he has COPD just because he was a smoker. Sounds like the guy has sleep apnea and should be wearing his CPAP.