Hypoxic drive?

Years ago, when I was in Nursing school first time around, I was told that you do not administer O2 therapy of more than 2L/min to people with COPD. Second time around in Nursing school 3 years ago, We were told the hypoxic drive theory was all a misconception and has research to prove it.

Asked an MD, and he reckoned that when you take the O2 mask off a COPD patient, they miraculously wake up from their "sleep" - hypoxic drive theory at play???

What is your experience of this?

After you have seen a patient with COPD gasping for breath 24/7, doesn't it seem a little more humane to give them enough oxygen that they don't have to work quite so hard to breathe?

With COPD patients in respiratory distress (uh, when aren't they...), supplement enough 02 to maintain their "usual saturation". I've knocked out (or think I did) exactly one hypoxic drive in the last 8 years- I was recovering a fresh CABG who was obviously still tubed. I reversed him and waited to see if he'd start spontaneous resps (it was getting to be about 8 hours post op) and still nothing. RT started to fiddle around with the vent settings and decreased the FiO2 an after a few minues, YAHTZEE! He starts overbreathing the vent. Knocked out his hypoxic drive? Dunno. And to tell the truth, I don't get real uppity about giving more than 2LPM to ANYONE in respiratory distress, COPD or not.

COPD patient was hospitalized for incredibly high CO2 levels and, once she was somewhat stable and off the BiPAP machine, the more O2 you gave her, the more her sats eventually dropped to the low '80s because, presumably, there wasn't enough hypoxic drive to get her breathing more on her own.

RT would put a sign on the O2 saying don't touch it, then some other nurse would come in on a different shift and turn up the O2 because they wanted to get the sats in the '90s. Sats would increase temporarily and then drop even lower. It was a viscious cycle.

Based on this particular case, I believe the hypoxic drive was needed because within just within an hour or two of increasing the O2, her stats were dropping even lower. So ... I think RT was right on this one.

P.S. This wasn't a situation where the patient was gasping for breath and, the patient was actually ambulating.

:typing

Found one patient unresponsive. Charge nurse took one look and took the O2 off. It had been on about 5L NC. Patient came around. Charge had had this patient before and apparently Patient was a big CO2 retainer.

So yeah, I'm careful with messing with O2 above 2L.

Yes on cO2 retainers i do believe in the hypoxic drive. However, i never base this on how much O2 you'r giving the patient, but rather on how high you get his sats (and therefore his pO2). If your patients pO2 is only 40, you are not going to knock out his hypoxic drive by delivering 100% FIO2(even if he is a cO2 retainer). Many of our pulmonologist will write orders to tirate to O2 to keep sats 87-90% type thing.

Many of our pulmonologist will write orders to tirate to O2 to keep sats 87-90% type thing.

Yeah, that was the problem with this COPD patient. The sats were hovering at about 88 percent, which is normal for a COPD patient but, there was an order (not from a pulmonologist) to keep them at 92. Consequently, when you upped the O2 and got to 90 or 91, the patient would then drop to 85 and below a couple of hours later.

The other problem, of course, is that RT comes in and they have different equipment than we do ... which reads the O2 sats at completely different levels than what we've been getting. Kinda hard to figure out where the O2 sats really are at that point.

Hypoxic drive is very real, and something that is rare except in certain pulmonary cases when you need to be aware! But let me give you some things to think about that may help the fear of hypoxic drive.

First, a pulse ox machine is a great tool...but in no way totally accurate or something you can depend on alone to save a life or keep it going! If I was to go out right now and have a ciggie, I will have a pulse ox of 100% instead of my typical98-99! WHY? The pulse ox uses a red laser light to go into capillary blood, it sends back a reading according to a spectrum of red. When hemoglobin is holding something like oxygen or even CO2 or CO...the color changes and according to the spectrum of color gives a result. So it isn't a tool to just see oxygen levels...it will if hemoglobin is holding molecules! And considering it is in the capilary area, one of the last places to get a molecule...you can get false readings as well...not necessarily what is going on that moment...but once blood gets to those beds! Another thing to consider. A ABG is the only way to get a real accurate result if it comes to needing a critial reading! Also, remember that temp effects the binding and release of molecules from hemoglobin...so if you have a pt with warm or cold hands..that makes a difference to if you put it on a finger!!!

Now with that said...always watch the patient when you change levels of oxygen! I will monitor closely for 15 minutes to see if there is a change in condition, and typically if you have a hypoxic pt...you will easily spend that much time tending to them! Watch their cognition, skin, nailbeds, lips, movements, talking...etc. Using your eyes and clinical knowledge beats a machine every time! Use that tool instead of a machine to make your choises.

And lastly, although not as fun...if you put someone into hypoxic drive in the hospital or field setting...you have the technology (hopefully) and skills to reverse it! It may take someone tubing them...but it can be reversed so keep your eye on your patient and be aware of having to call in help.

If I have someone that is needing oxygen, I give it! If they are in a very sorry state, I call in respiratory therapy or the MD to come in to help! I also check out my charts to see if this is a common thing, what they have done and so on. Also I speak to my patients...they can typically tell me what they do if they are SOB (I do this before during my initial assessment so I save time wondering).

Talking to a Respiratory Therapist when they are attending a patient or after is also a very wonderful thing to do so you are discussing things as a team! I always talk with the RT's about our patients so we are on the same page :)! And typically I get them to order a bag valve mask PRN to keep in that room for them if needed (I have had so many times when that thing was missing when I needed it! GRRRRR!).

Just be aware, just like any other medication of side effects, watch your patient, be prepaired for intervention, and speak with the other healthcare teams to make sure you have all the info you need to safely care for these patients! It is not really any different from giving an antibiotic or blood in my opinion...things can happen, best be prepared :).

While we're on this subject... I'm an EMT and have seen increased attention to the use of portable units in EMS that can measure CO2 levels. The service I work for has used capnometry on intubated patients for several years now, but these new units are used to non-invasively monitor the CO2 levels. While none of our local EMS providers have them, I've read a couple of case studies on situations where they would be a great asset making appropriate treatment desicions... It seems to me that COPD patients would also benefit from this technology, yet I haven't seen or read anything about them being used in the hospital setting (I'm also a nursing student). Is anyone familiar with them being used in this setting?

My hubby is a paramedic and they are starting the use of them, but so far I haven't heard of them in the hospital setting except for a few trials in the ER of some major trauma hospitals in Portland, Oregon (near where I live).

I am totally for those also as another tool for my clinical assessment and judgement...but I hope they don't turn into a pulse ox deal where people are treating only according to a reading and not watching the pt carefully!

You may want to check OHSU for clinical studies of these...I think they are heading up a study in hospital settings with these...

TriageRN 34- thanks for the info. And do you mean to say that it's not just in Indiana that people treat the machine instead of treating the patient?

Okay, getting back on topic, hypoxic drive theory. When I worked at a LTC facility, on several occasions I saw non-rebreathers applied to patients at 2L and 4L. In fact, the facility protocols did not allow the nurses to apply non-breathers over 6L. To me, it always seemed logical that this would increase the hypoxia. Is there something I'm not considering?

WOW, we didn't even allow NRB masks at our facility...if a pt needed one, they had to move on to a more skilled facility! In fact, I had to teach RN's and CNA's about the liters of Oxygen per NC or NRB because they were constantly getting it wrong!!!!!! I mean...someone bumped up a pt to 7 L/Min with NC...poor lady had her hair blow back like she was on a motorcycle without a helmet! It was doing NOTHING but giving her a bad hair day!

Me, I like the NC for 2-4, but if it is going to be above...I am talking with RT and MD! If I have a mouth breather..then again...I talk with RT and MD and get specific orders INCLUDING PRN titration orders and what to do if a hypoxic drive happens! And I communicate with RT so that if I need them stat..they know why!

Funny story actually...I was working at a concert with some new EMT's and they were complaining about not finding a pulse ox on a hypoxic pt! They were running around looking for it instead of treating the pt!!! I was stunned and got on it fast, put them with their head up (they had him supine) and started vs. They finally found it, but untill they did they didn't even look at the dudes nailbeds or the fact he was speaking in gibberish! I got 9-11 on the way, kept him stable..and barely looked at the machine which really stunned them!

I talked to them afterwards when they complained at me for not getting the pulse ox before tx (I about killed them then and there..LOL!). I told them "well maybe I am a 5 year old medical dino then...I do remember days before pulse ox, and you know what...people DID survive!". Then I went into a long lecture on pulse ox! They got it finally with the help of another Paramedic and my hubby (who is paramedic) who agreed full heartedly with me! And they reminded the boys that I may be an RN, but trained by paramedics and still go to CME with paramedics!

It was disturbing, but at the same time kinda funny that these newbies relied on a machine. But believe me..they know better now!

BTW the patient was having an asthma attack due to smoke (legal and not), didn't need to be tubed, and was A-Okay with a couple nebs and a ride home.

Nonrebreathers at 2 -4 lpm? I dont' think that would even work.

About CO2 narcosis, I believe in it but I would like to see the research that the OP mentioned saying it was an old wives tale.

I do, however, think that people overestimate this reactiong with COPDers thinking that everyone is gonna crash if they get to much oxygen. And there's no hard and fast rule about not increasing the 02 above 2L for a c02 retainer. It is so patient specific. That's why ABGs are so important in this case. If he have a severely low PaO2 like an poster mentioned, why not use the non-rebreather...cuz like, he NEEDS 02 bad!!