Source
r/medicine•
Snoww

Have you ever witnessed the failure of respiratory drive in a patient with type 2 respiratory failure who was given high conc. O2 ?

Just curious to find out if withholding high conc oxygen is a theoretical precaution .

Most of the professors I've talked to in the pulmonary department do not seem to practise this or believe in it yet they do teach it to us but with the disclaimer rhat it may only be a theoretical phenomenon.

Has anyone seen this is their practise ?

Posted Apr 28, 2014, 12:06 PM UTC

2024
bayesianqueerMD - Emergency Medicine•

Yes. Most of them don't but a few do.

There is one frequent flier who comes to my ER who is a CO2 retaining baaaad COPDer but she is also a flaming bitch. Totally A&Ox4, but she is mean as a snake. I've seen her throw a vomit basin at a 4 year old that was admittedly not being well managed by her parents. I had to pull the dad off of her.

So it is to mine and everyone else's advantage in the ER to have her CO2 be about 70-80. I put the CO2 detector on her, and give her just enough O2 to get her in that sweet spot. Then when I am ready for dispo I wake her up if she's either going home or the hospitalist who is admitting her is on my shit list.

12
HuhDude•

That isn't true... you're going to kill someone.

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bayesianqueerMD - Emergency Medicine•

For something I've done over a dozen times, it's amazing how something that works so well for this lady "isn't true".

And much as I will breathe a sigh of relief when she and her full code status finally shuffle off this mortal coil, my aim to kill as few people as possible is what's brought me to use this technique. In addition to her other endearing qualities she is an opioid and benzo addict. (Not that I blame her. If I was in that fucked up of a body, I'd want to be stoned all the time too). Unfortunately for her, she has developed some nasty habits around obtaining the quantity of both drugs that she wants; namely using her super-bitch powers to annoy every provider enough to acquiesce to her demands. To quote her: "If you don't give me another fucking 2 mg of dilaudid now, you won't have any other patients to worry about".

I made that mistake once and did almost kill her (and ended up intubating her). There is no medicine that can safely calm this woman down. She will be insane up to a dose that is 98% of what will guarantee her a respiratory rate of 2. So given the choice between titrating her CO2 to level of sedation, and have her smoke the plastic cigar, I'll take the former.

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drchekmateEM Attending•

Ever tried Haldol or Droperidol? Wonderful drugs with low side effect profiles, even at relatively high doses. We call Haldol the Fuck You Thank You drug: The patient's go from saying "fuck you doctor!" to "thank you doctor!"

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[deleted]•

[deleted]

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bayesianqueerMD - Emergency Medicine•

Droperidol... That's nice. Maybe even an older school DPT. So when did you leave practice? If you are in the US good luck finding dropreridol today.

1
A_nice_fucking_Fish•

Sorry to burst your bubble but just because your physiology book says something does not mean it's true. Everyone's body reacts differently. Have you thought that this patient is a long term smoker and that is why this treatment is effective?

2
HuhDude•

So you're allowed to sedate your patients as long as they're mean? It seems paternalistic, not just dangerous.

2
nigraplz•

Actually in many US jurisdictions, if the behavior has a psychiatric cause and is dangerous (throwing a plate of vomit at a 4 year old qualifies), you most certainly can, although permissive hypercapnea is not the recommended intervention. And in an emergency, how do you know if the cause is psychiatric or not?

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bayesianqueerMD - Emergency Medicine•

Did you actually read my comment...? Where I said she was a COPDer? She only stopped smoking when she moved into the SNF. As to knowing the physiology, you did note the OPs question to which I directed my answer.

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A_nice_fucking_Fish•

Yea. I was referring to the guy that thinks you are going to kill someone. I believe you are right in what you said. In no way do I think you are wrong. I apologize for the misdirection

1
Anime419•

They teach this concept in my Reapiratory Therapy program too. The instructors say that it's not necessarily an uncommon thing to see.

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bayesianqueerMD - Emergency Medicine•

The RTs I work with are epic... And while I can't actually write the order to titrate O2 to an ETCO2 of 70, they are experts at it.

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DocSpachemmenBrainologist•

I've seen it a few times, in people referred for decreased GCS. Not seen it in anyone except the end-stage COPD though. CO2s in the order of >100mmHg.

Took the O2 down to nasal prongs (from 15L) and BAM, woke up.

One might argue though that I was merely witnessing a severe hypoactive delirium or other pathology, and the CO2 and O2 were innocent bystanders. I defer to Pulmonologists in this regard.

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SnowwOPMS4 - Non US•

I'm assuming you switched them from a face mask to nasal prongs and they woke up ?

-1
DaZedMan•

Many times. There's a lot of COPD in my patients. It seems no matter how many time I put in an order to provide supplemental O2 but do not titrate above says of 92%, somebody walks by, sees a sat of 88% and cranks up the oxygen. They get really narced up--looks like an opiate overdose when they retain CO2. I have had to intubate at least 2 patients because of this, and put many many more in Bi-PaP

5
E1520•

Yep, seen it. Total failure of ventilation. Bagged the patient for some time, without added O2, got back to spontanious breathing like nothing had happened.

Obviously, COPD patient.

4
schlingfoFNP-BC•

I've never seen it in practice, that I'm aware of.

As I understand it, the Haldane effect and V/Q mismatch contribute to the hypercapnic state along with the respiratory drive. Even in a COPDer who's in Type 2 failure, the respiratory drive is still a spectrum of oxygen and CO2 receptors contributing to the drive.

High concentration O2 (usually greater than .6) could theoretically have an effect on the respiratory drive, but the extent of the effect would likely vary from person to person. And, the depression of the respiratory drive would be only one of three factors contributing to the hypercapnea.

I only understand the basics, however. The more nuanced aspects are over my head.

Edit: To go off DocSpachemmen's point regarding other pathologies, I generally only see them when they're brought in for an exacerbation and they're already in distress and needing respiratory support. For the ones who end up requiring intubation, it's hard to determine exactly which factor involved contributed to the need for intubation.

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docbauiesAnesthesiologist•

only once, i cannot think of any other explanation. he was hypercapneic to begin with, received some O2. I believe this depressed his respiration slightly, which led to CO2 narcosis, which then exacerbated the problem.
however the vast majority of patients who i give O2 to do not have any problems.

2
McFeenyMD - Internal Med/Pulmonary/Critical Care/Sleep•

I've told this story here before, but here goes.

I was on night float at the VA, intern year, got called about a COPDer who had mental status changes. Got an ABG, acute respiratory acidosis.

I quickly call an ICU consult. Resident covering (who was set to be chief) wordlessly walks in and goes straight to the O2 flowmeter on the wall. Turns it to zero.

We wait about 90 seconds and the guy wakes up. He asks something like, "what's everyone doing in here?"

Soon-to-be-chief walks out without a word.

On a less anecdotal note, high concentrations of oxygen can inhibit the drive of those with obesity-hypoventilation too (one article was in Chest about 3 years ago, another was in some obscure journal a year ago but senior author was Piper AJ).

I think many pracitioners say, "I've never seen it." That's incorrect. The proper way to state it is "I've never recognized it."

You only see it if you look for it. If you don't expect to see it, you won't look for it.

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nigraplz•

I bet if you put together a book of stories like this "Intern Consults" you would have MS3's functioning at the level of interns.

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SnowwOPMS4 - Non US•

Thanks for sharing. Bet the resident looked like a bad ass walking out without saying anything haha

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