lets discuss extubation

Specialties CRNA

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i have been working on smoother wakeups. the technique i have been employing is using either morphine or fentanyl and titrating in 2mg per cc of mso4 or 10 mcg of fent to keep respirations about 12- 18 per minute. (obviously in patients that are spont vent.) while doing this i cut back on the gas in increments. when it comes time to extubate they usually will open their eyes to command, wont buck as much and seem more comfortable. i try this in patients that i am not worried about resp depress and airway issues. adn the morphine keeps em more comfortable into postop for obvious reasons.

the question is, do many of you do this? i have worked with some ppl that almost refuse to use narcs near the end of the case on anyone. i dont know if they have been burned in the past or what. this also is adults, not peds where i currently am.

d

georgia ... agreed... i like adding vioxx 25mg po prior to induction... in my practice, i feel it has made a nice improvement on limiting narcotic use...

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I have read that low does of ketamine (5-20mg iv) provide profound analgesia and may act to decrease narcotic requirements. Does anyone out there do this?

C-thor,

Hey, i just was catching up with missed threads... I know this is a couple of days late, but I saw no one responded to your question, so I thought I would add my 2 cents. Ketamine is indeed a potent multimodal analgesic; it acts to inhibit both NMDA receptors(R's) and also non-NMDA glutamate R's. These actions alone decrease neuronal windup/central sensitization/peripheral sensitization. CNS NMDA R activation is known to stimulate nitric oxide production, which in this case enhances nociception. NMDA R activation is also known to participate in the establishment of acute opioid tolerance. Blocking this theoretically (and in randomized trials) decreases narcotic need. , and thus narcotic side effects. Ketamine also inhibits substance P R's which are a known nociceptive pathway. In addition, ketamine can activate opioid R's, and enhance GABA's Cl- current, but neither of these is thought to be analgesically significant, though activation of Kappa R's may partially explain dysphoric reactions. Incidentally, ketamine as supplied is a racemic mixture;the S+ isomer has a 2-4 times greater attraction to the Mu opioid R's, and has been shown in European trials to exhibit approx twice the analgesic potency of racemic ketamine with nearly zero dysphoric reactions. Nicotinic and muscarinic R's are weakly inhibited by ketamine; the decreased cholinergic transmission may also be a reason for dysphoric reactions. Ketamine also acts to stimulate the monaminergic descending pain pathway, which is inhibitory to nociception. Ketamine has been shown to actually stimulate endogenous beta-endorphin release as well, a possible explanation for why ketamine action often outlasts its pharmacokinetics. In addition, the central stimulatory actions of ketamine combat respiratory depression and hemodynamic instability.

Ketamine's affinity for NMDA R's far exceeds its affinity for any other sites, which is why low dose ketamine is specifically analgesic and not anesthetic. If you review the literature, you will find that the consensus on "low dose" ketamine is less than 1 mg/kg IV or epidurally or if continually infusing , less than 20 ucg/kg/min. You will find most investigators used much less and still established efficacy.

With the caveat that my experience is limited, as I am a SRNA, allow me to say I am a fan. I have used small doses pre-incision, repeated every 30-60 minutes for long procedures until about 30 minutes or so before closure, making sure to keep my total below 1mg/kg. I have used it in a mixture with propofol for MAC/IVS cases, as an infusion, where the decrease in resp. depression is an incredible plus. The CRNA that gave me her recipe for this infusion called it the "milk of human kindness" :-)) I have never used it without establishing a benzo base first, and I avoid it in patients with psych histories, esp. vets with post traumatic stress syndrome. Of course, not good with hypertensives/ICP issues, etc....I have used small boluses in peds sedation cases, esp. burns, to ease the patient through especially painful portions... most burn staff will tell you there is nothing like it. My experience with it is purely anecdotal, but I have the references for the controlled trials if you would ever like them. I am sure my first dysphoric patient will dampen my enthusiasm, but I just try to be cautious with my total dose, my benzo prep, and patient selection.

later....sorry for the length..........lalaith

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Lalaith,

Thanks for taking the time to compose a wonderful post. I sent you a pm.

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No one likes diprivan? Short life span, fast-acting. I was able to perform conscious sedation on a pt going through dt's using diprivan and ativan so that the urologist could insert a coudet (?) catheter. That was pretty sweet. Had the guy asleep all throughout my shift then dropped him onto the next shift. Haha!

Fentanyl is good for the longer procedures, especially because it's cheap, but IMHO nothing beats diprivan just before extubation after CPAP trial. Would love to be able perform some titration of paralytic trials on some pts while on CPAP, but unable to at this point in time.

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no flame intended and i'm no expert, but i think this would get you into trouble

Would love to be able perform some titration of paralytic trials on some pts while on CPAP, but unable to at this point in time.
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Fentanyl is good for the longer procedures, especially because it's cheap, but IMHO nothing beats diprivan just before extubation after CPAP trial.

Am I missing something? Diprivan prior to extubation? Makes little sense to me. Someone enlighten me.

Would love to be able perform some titration of paralytic trials on some pts while on CPAP, but unable to at this point in time.

I think this was discussed on another thread with an overall negative opinion.

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dip vent, although we did discuss this in an earlier thread there are some questions i would like to ask.

1. why do you want to titrate a paralytic on a patient you want to extubate.

2. as far as muscle paralysis. what muscles are you looking to paralyze specifically.

3. what is to be gained from partial paralysis that cannot be gained through sedation.

now as i remember muscles are paralyzed in this order:

1. eyes

2. extremeties

3. chest (intercostals from the strap muscles downward)

4. abd muscles

5. the diaphram

they recover in the reverse order.

i'm just not following your rationale.

d

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Let me just preface this with the fact that this is all theory. I wouldn't ever do this nor do I have it within my scope of practice to do this. Also, I think I am using the word "paralytic" more liberally than you guys are. In my view, a paralytic is anything that would stop a pt from reponding to a nauseous stimuli. So in my view, a sedative at the right dosage could be a paralytic, but then you have to worry about impaired respirations. The only thing I've noticed with sedatives and analgesics is that they affect the conscious part of the brain and depress the respiratory system while still leaving reflexes in tact. So you could have a pt breathing in the low teens, O2 sat in the mid 90's, and still able to respond to simple nauseous stimuli, such tickling his nose and him still able to wiggle his head away. You can't really perform any complex procedure with these reflexes still intact. If you guys know of any meds that would nullify these reflexes while still keeping intact the respiratory drive, I'd love to hear it. Then we wouldn't need to discuss extubation because we wouldn't need to intubate in the first place. I know gaspassah mentioned ketamine. I don't have any experience with ketamine.

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Let me just preface this with the fact that this is all theory. I wouldn't ever do this nor do I have it within my scope of practice to do this. Also, I think I am using the word "paralytic" more liberally than you guys are. In my view, a paralytic is anything that would stop a pt from reponding to a nauseous stimuli. So in my view, a sedative at the right dosage could be a paralytic, but then you have to worry about impaired respirations. The only thing I've noticed with sedatives and analgesics is that they affect the conscious part of the brain and depress the respiratory system while still leaving reflexes in tact. So you could have a pt breathing in the low teens, O2 sat in the mid 90's, and still able to respond to simple nauseous stimuli, such tickling his nose and him still able to wiggle his head away. You can't really perform any complex procedure with these reflexes still intact. If you guys know of any meds that would nullify these reflexes while still keeping intact the respiratory drive, I'd love to hear it. Then we wouldn't need to discuss extubation because we wouldn't need to intubate in the first place. I know gaspassah mentioned ketamine. I don't have any experience with ketamine.

What you're describing is called ANESTHESIA.

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simple nauseous stimuli, such tickling his nose and him still able to wiggle his head away

Noxious stimuli?

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