Making a lecture top ten myths of anesthesia

[vector2]

And why is that stupid? Every pump we have is programmed to have phenylephrine, norepinephrine, and epinephrine infusions in mcg/min...and literally every professor I had in residency dosed it that way as well (in adults). So why is it wrong to do this again? Sounds similar to insisting on a certain type of tape for the tube or something...where multiple methods can accomplish the same goal but one is clearly "more better" and the other methods are idiotic.

It is stupid, but mostly because of the nursing issues it creates if mcg/min is implemented hospital-wide. ICU nurses won't think twice about cranking up the neo drip to 200 mcg/min if some 80yo 45kg lady in rapid fib has some asymptomatic but persistent hypotension. If the guideline is set to max 1.2 mcg/kg/min or something like that it gives me some peace of mind because I know the nurse will escalate the situation to me before the patient is on elephant doses.

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[psychbender]

It is stupid, but mostly because of the nursing issues it creates if mcg/min is implemented hospital-wide. ICU nurses won't think twice about cranking up the neo drip to 200 mcg/min if some 80yo 45kg lady in rapid fib has some asymptomatic but persistent hypotension. If the guideline is set to max 1.2 mcg/kg/min or something like that it gives me some peace of mind because I know the nurse will escalate the situation to me before the patient is on elephant doses.

Well, that's why you alter your titration order to whatever max you feel most comfortable handling. I trained at a place where we only did mcg/min for most vasoactive agents, and got used to thinking that way. Then, for four years, I was at a place where we weight-based everything, and got used to thinking in those terms. Both work just fine for adult patients, as long as everyone is on the same page, and has in mind dose ranges in which they are comfortable.

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[epidural man]

And why is that stupid? Every pump we have is programmed to have phenylephrine, norepinephrine, and epinephrine infusions in mcg/min...and literally every professor I had in residency dosed it that way as well (in adults). So why is it wrong to do this again? Sounds similar to insisting on a certain type of tape for the tube or something...where multiple methods can accomplish the same goal but one is clearly "more better" and the other methods are idiotic.

How is propofol dosed? How is Neostimine/Robinol dosed? How is Precedex dosed? How is sufenta infusion dosed? How is EVERY OTHER infusion in anesthesia dosed?

Yet we don't dose these very potent drugs the same way? Why? It is because nurses have gave a huge tissy-fit in the ICU when pattients come back from the OR with a properly programmed pump....so I guess we let them tell us what to do.

To me...that is stupid.

It is stupid, but mostly because of the nursing issues it creates if mcg/min is implemented hospital-wide. ICU nurses won't think twice about cranking up the neo drip to 200 mcg/min if some 80yo 45kg lady in rapid fib has some asymptomatic but persistent hypotension. If the guideline is set to max 1.2 mcg/kg/min or something like that it gives me some peace of mind because I know the nurse will escalate the situation to me before the patient is on elephant doses.

THis. There is a reason we dose EVERY OTHER DRUG in anesthesia based on weight - and if an infusion, weight based with a time.

 

[epidural man]

It makes more sense done properly: give a big VC breath, wait, then pull the tube during expiration. No idea if it works but at least it's easy.

If you want to make sure they exhale with extubation, then put the pop-off at 20-30, wait until pressure builds to 25 or so, then pull the tube. Exhale will automatically happen. But there is no reason to try and time pulling with an exhale, or do some complicated cordination of giving a breath while pulling (which is just pushing stuff down).

 

[pgg]

What? your pumps are mcg/min? ours are all ng/kg/min, it just feels a lot easier using weight based. it feels more error prone if you dont use weight. what is your go to starting norepi infusion dose for a 1kg patient vs a 150kg patient?

I'll never touch another 1 kg patient again as long as I live. With luck, I'll never even see someone else touching one.

Honestly, this doesn't matter. By now most every civilized institution in the world has pumps with drug libraries and different modes for adult, pediatric, and neonatal patients. It's totally reasonable to have an adult library with mcg/min and a peds library with mcg/kg/min.

My last institution had pumps with mcg/kg/min adult libraries. My current institution has mcg/min adult libraries. You're going to pick a reasonable starting number and titrate to effect anyway. It doesn't matter.

Well, it does matter a little. You should use whatever the ICU nurses are accustomed to and comfortable with.

 

[pgg]

How is Neostimine/Robinol dosed?

neostigmine is dosed in milligrams per reciprocal of twitches
glycopyrrolate is dosed in milligrams per reciprocal of heart rate


Edit 'cause I'm a '****

 

[Urzuz]

What? your pumps are mcg/min? ours are all ng/kg/min, it just feels a lot easier using weight based. it feels more error prone if you dont use weight. what is your go to starting norepi infusion dose for a 1kg patient vs a 150kg patient?

If I had a 1 kg patient I would use a weight-based dose. But the reality is that for adults you can start the infusion at what you think would be appropriate and do what you do for anything else -- you titrate it. Do you always calculate a weight-based propofol dose before induction? Or do you have a sense for how much propofol it will take to induce someone?

 

[GravelRider]

How is propofol dosed? How is Neostimine/Robinol dosed? How is Precedex dosed? How is sufenta infusion dosed? How is EVERY OTHER infusion in anesthesia dosed?

Yet we don't dose these very potent drugs the same way? Why? It is because nurses have gave a huge tissy-fit in the ICU when pattients come back from the OR with a properly programmed pump....so I guess we let them tell us what to do.

To me...that is stupid.



THis. There is a reason we dose EVERY OTHER DRUG in anesthesia based on weight - and if an infusion, weight based with a time.

Then why give titration parameters at all? You are titrating to an effect, not to a weight. Set your parameters accordingly based on what you feel is appropriate for your patient. Use whatever the nurses at your institution are comfortable with. Don't sweat the small stuff. The attendings in residency who were nitpicky over whether I programmed phenylephrine in mcg/min vs mcg/kg/min were the same ones who liked to show me their favorite way to tape a tube.

 

[Urzuz]

It is stupid, but mostly because of the nursing issues it creates if mcg/min is implemented hospital-wide. ICU nurses won't think twice about cranking up the neo drip to 200 mcg/min if some 80yo 45kg lady in rapid fib has some asymptomatic but persistent hypotension. If the guideline is set to max 1.2 mcg/kg/min or something like that it gives me some peace of mind because I know the nurse will escalate the situation to me before the patient is on elephant doses.

That is a rather silly example of why weight-based dosing is superior. Whose fault is it that the max titration dose is set to 200 mcg/min in a 45 kg lady? You are the doctor, you set the titration parameters and max doses, not the nurse. The nurse was probably also the one who told you to order phenylephrine for hypotension in a patient with rapid atrial fibrillation.

 

[anbuitachi]

If I had a 1 kg patient I would use a weight-based dose. But the reality is that for adults you can start the infusion at what you think would be appropriate and do what you do for anything else -- you titrate it. Do you always calculate a weight-based propofol dose before induction? Or do you have a sense for how much propofol it will take to induce someone?

Not saying non weight based dosing is wrong or anything, but i dont see the point of using two different systems. It's just as simple to use weight based on a pump (well unless your pump doesn't come with it then can't do anything about that), so might as well use it for both adult and kids.. why bother switching? It's like let me use Kg for adults and lb for kids. why? I mean in the end you do what is most comfortable for you, if you were trained like that then it makes sense i guess

 

[Urzuz]

How is propofol dosed? How is Neostimine/Robinol dosed? How is Precedex dosed? How is sufenta infusion dosed? How is EVERY OTHER infusion in anesthesia dosed?

Yet we don't dose these very potent drugs the same way? Why? It is because nurses have gave a huge tissy-fit in the ICU when pattients come back from the OR with a properly programmed pump....so I guess we let them tell us what to do.

To me...that is stupid.



THis. There is a reason we dose EVERY OTHER DRUG in anesthesia based on weight - and if an infusion, weight based with a time.

It has nothing to do with nursing. The bottom line is that, like any other medication, you should have an idea of what effect you will achieve with a certain dose in a particular patient. You start the medication, and then titrate it based on the effects you see. You are doing the exact same thing with weight-based dosing. You choose a starting point based on what effect you are trying to elicit, and then titrate it based on response. It still baffles me how people can become so pedantic and dogmatic that they fail to grasp the simple concept that there are other ways of practicing that achieve similar results.

And in regards to "EVERY OTHER" infusion being weight-based, you are just wrong.

 

[anbuitachi]

I agree. Why am i doing whatever teh nurses prefer? Am i working for the nurses? Not really. To me i think weight based dosing is more precise. As far as I know, i dont know of any studies showing difference between weight based, and non weight based, and since everything else in anesthesia is dosed based on weight, why not pressors, to me it makes more sense. And regarding the propofol. I always look at the weight in the chart before giving propofol. Besides, propofol isn't exactly the same as norepi.

 

[pgg]

I agree. Why am i doing whatever teh nurses prefer? Am i working for the nurses? Not really.

Because they're not as smart or as well educated as you are, and when things slip outside their comfort zone, they make mistakes and they hurt your patient.

 

[anbuitachi]

Because they're not as smart or as well educated as you are, and when things slip outside their comfort zone, they make mistakes and they hurt your patient.

i dont know about other places but here nurses switch to their mcg/min and titrate per their protocol . and ICU isn't nurse run, there are doctors there to hopefully keep the patients safe. also the nurses titration protocol has upper limit parameters so they dont do 200mcg/min of NE

 

[deleted162650]

This is ridiculous.


Real men use mini-drippers.

 

[Ignatius J]

You should also consider adding - stupid things people do in the OR.

Like using phenylephrine or norepinephrine in a non-weight based dosing....

Or when extubating, giving a positive pressure breath on the bag while pulling the tube (it baffles me that anyone would want to blow that snot and spit and all the SH$T into the lungs while pulling the tube...but I see it all the time)

I do non-weight based dosing every time. Not going to be weight-dosing a titration.

 

[nimbus]

Why are we arguing about this? I've done it both ways. IT DOESN'T MATTER. Do want you want.

 

[okayplayer]

Okay I have one that I don't know to be a myth but I highly suspect is: after trying to advance a catheter through a tuohy (and meeting resistance) don't pull the catheter back out and leave the tuohy because it could shear off the end of the catheter.

Feels like BS dogma and I find it very annoying when I have to pull the needle and catheter out in this scenario but I'm not ballsy enough to do it.

 

[teeva]

We use the soft flexible epidural catheters. If I can't push the catheter in, it's because the tip of the needle is just barely in the epidural space to cause LOR but not enough to feed the cath. I pull the cath out alone and advance the needle 0.5mm more, which then allows the cath to slide in smoothly 99% of the time and never has this caused a wet tap (or even dural knick and PDPH).

The stiff Braun caths are nothing but trouble when I had to use them in the past. Attendings I trained under never had any troubleshooting tips with them other than pull everything out and try again.

 

[anbuitachi]

I do non-weight based dosing every time. Not going to be weight-dosing a titration.

what doses do you use for your precedex infusions?

 

[deleted171991]

Not what I said/meant. There's a propagated myth that in an intubated patient with bronchospasm you need to switch from Des to Sevo/Iso. Deepening with any agent will result in bronchodilation, a characteristic of all volatile anesthetics.


There's no denying that an inhaled induction with desflurane can precipitate bronchospasm. But when are you using an inhaled induction to treat bronchospasm?

In my logic, if a substance irritates the airways when the subject is awake, it will irritate them even when asleep.

 

[deleted171991]

Another HUGE myth and legend: nitrous increases the incidence of PONV at usual concentrations (50% or less). Best inhalational agent since sliced bread.

 

[Urzuz]

I agree. Why am i doing whatever teh nurses prefer? Am i working for the nurses? Not really. To me i think weight based dosing is more precise. As far as I know, i dont know of any studies showing difference between weight based, and non weight based, and since everything else in anesthesia is dosed based on weight, why not pressors, to me it makes more sense. And regarding the propofol. I always look at the weight in the chart before giving propofol. Besides, propofol isn't exactly the same as norepi.

If you only feel comfortable giving propofol to a patient after knowing their exact weight, and you feel unable to look at a patient's body habitus and estimate how much you need (also taking into account age, comorbidities, etc) you should do more cases and stop relying on the weight as a crutch. How do you dose drugs if you get a trauma in the middle of the night? Do you stop the resuscitation until you weigh the patient? Or, do you use your clinical judgment and dose appropriately, and then titrate the dose based on the effect you see?

You are correct, norepinephrine and propofol are different, yet the exact same concept applies.

 

[Robotic Wis-Hipple]

Another HUGE myth and legend: nitrous increases the incidence of PONV at usual concentrations (50% or less). Best inhalational agent since sliced bread.

That itself is a myth, Nitrous predates sliced bread (1912) so clearly the best inhalational agent since sliced bread is Sevo.

 

[twoliter]

If you only feel comfortable giving propofol to a patient after knowing their exact weight, and you feel unable to look at a patient's body habitus and estimate how much you need (also taking into account age, comorbidities, etc) you should do more cases and stop relying on the weight as a crutch. How do you dose drugs if you get a trauma in the middle of the night? Do you stop the resuscitation until you weigh the patient? Or, do you use your clinical judgment and dose appropriately, and then titrate the dose based on the effect you see?

You are correct, norepinephrine and propofol are different, yet the exact same concept applies.

I think in a way you agreed with him. I don't think he's necessarily saying Patient A should only get 157 mg of propofol based on their exact weight instead of 160 mg. But even you implied you "look at a patient's body habitus and estimate how much you need." That's much closer to "weight based dosing" which he supports than "blindly giving 'adult dosing' to every adult," which he is against.

 

[Urzuz]

I think in a way you agreed with him. I don't think he's necessarily saying Patient A should only get 157 mg of propofol based on their exact weight instead of 160 mg. But even you implied you "look at a patient's body habitus and estimate how much you need." That's much closer to "weight based dosing" which he supports than "blindly giving 'adult dosing' to every adult," which he is against.

Of course you look at a patient and dose it appropriately, that is why this whole thing is so idiotic (see the above discussion about the 40kg lady). What him and epidural man were saying is that it is "stupid" to do non-weight based dosing, where we are saying that the SAME AMOUNT OF DRUG is delivered with non-weight based dosing, but instead of displaying mcg/kg/min, your pump displays mcg/min.

 

[twoliter]

Of course you look at a patient and dose it appropriately, that is why this whole thing is so idiotic (see the above discussion about the 40kg lady). What him and epidural man were saying is that it is "stupid" to do non-weight based dosing, where we are saying that the SAME AMOUNT OF DRUG is delivered with non-weight based dosing, but instead of displaying mcg/kg/min, your pump displays mcg/min.

I don't disagree with that. I do think (somewhat unrelated) it is much easier to program/titrate/dose/whatever a pump using mcg/kg/min instead of mcg/min. That takes the weight based/estimated calculations out of it (or at least out of my brain and into the pump).

 

[anbuitachi]

If you only feel comfortable giving propofol to a patient after knowing their exact weight, and you feel unable to look at a patient's body habitus and estimate how much you need (also taking into account age, comorbidities, etc) you should do more cases and stop relying on the weight as a crutch. How do you dose drugs if you get a trauma in the middle of the night? Do you stop the resuscitation until you weigh the patient? Or, do you use your clinical judgment and dose appropriately, and then titrate the dose based on the effect you see?

You are correct, norepinephrine and propofol are different, yet the exact same concept applies.

You put estimated weight on the pump and titrate from there. Obviously its situation specific. If you tell me your pump has no weight based infusion obviously ill use whatever is available.

 

[epidural man]

Is desflurance a bronchodilator?

 

[zizzer]

As for the mcg/min phenylephrine thing, I'm just going to point out that you can the mcg/min makes the math one step easier to the point where it's very quick to do in your head almost instantly. If I've had to give two 100 mcg boluses over the past 10 minutes with good effect, then I can reasonably start at 200/10 --> 20 mcg/min. Also, people are acting like it's impossible to estimate weight adjustments without using a per weight infusion unit. If a patient is 25 percent lighter than usual, it's extremely easy to pick a mcg/min starting point that is about 25 percent lower than what you would use for an average patient.

 

[epidural man]

I have a top ten - but probably not a myth...more like a controversial topic.

I have read a ton on this years ago and now the data escapes me.

But I don't think that if a patient has a PCN allergy, it makes any sense to not give a cephalosporin. I don't remember exactly why it doesn't make sense, but I seem to recall that maybe one of the reasons was that if you are allergic to PCN, you are much more likely to be allergic to clinda then you are to a cephalosporin.

Anyway, that would be a great topic to look into and talk about. There is some great articles and review things written on the topic - a lot in the peds literature.

 

[fakin' the funk]

The stiff Braun caths are nothing but trouble when I had to use them in the past. Attendings I trained under never had any troubleshooting tips with them other than pull everything out and try again.

I've used both catheters, semi-extensively.

The saying I remember about the Arrows is that it just won't thread into any plane other than the epidural space. Of course, I know that's not 100% failsafe, but it certainly is tough to put it subdural, intravascular, etc, bc it's so floppy. Hell, you can barely thread the thing into a giant pocket of local you've made with an ultrasound PNB.

The Brauns aren't "nothing but trouble," they're just different. They will readily thread intravascular or into mystery tissue planes. It's a lame reason for telling a mom in pain that you have to redo their epidural because it aspirated frank blood. I've had a stone-cold epidural Braun catheter migrate intravascular after several hours of good labor analgesia. On the plus side, you never have the issue with the catheter not wanting to thread bc the Tuohy tip is only partly in the epidural space (the "advance another 0.5-1.0mm" thing).

 

[deleted171991]

I have a top ten - but probably not a myth...more like a controversial topic.

I have read a ton on this years ago and now the data escapes me.

But I don't think that if a patient has a PCN allergy, it makes any sense to not give a cephalosporin. I don't remember exactly why it doesn't make sense, but I seem to recall that maybe one of the reasons was that if you are allergic to PCN, you are much more likely to be allergic to clinda then you are to a cephalosporin.

Anyway, that would be a great topic to look into and talk about. There is some great articles and review things written on the topic - a lot in the peds literature.

There is an awesome thread somewhere on the forum exactly about this. I remember somebody posting an article about the importance of side-chains; I think it was @periopdoc.

P.S. Found it: pcn allergy and keflex.

 

[dchz]

Since someone else bumped the other thread here about Abx infusion rate, i think its worth bringing up here.

What happens if you push clinda or gent? or infuse at rates < 2 mins?

Some say cardiac death, i'm seriously doubting this but i still infuse both slowly.

 

[dchz]

Okay I have one that I don't know to be a myth but I highly suspect is: after trying to advance a catheter through a tuohy (and meeting resistance) don't pull the catheter back out and leave the tuohy because it could shear off the end of the catheter.

Feels like BS dogma and I find it very annoying when I have to pull the needle and catheter out in this scenario but I'm not ballsy enough to do it.

I just started OB and in all my ignorance i've pulled the catheter back several times through the touhy and the tip is intact, several diff attendings with many years of exp has watched me do this and not said anything. so i assume it's safe with the braun kit we use.

 

[anbuitachi]

I just started OB and in all my ignorance i've pulled the catheter back several times through the touhy and the tip is intact, several diff attendings with many years of exp has watched me do this and not said anything. so i assume it's safe with the braun kit we use.

i tried to pull back thru the touy and it wouldnt!! i figured its stuck on the sharp part so i stopped.

 

[deleted171991]

i tried to pull back thru the touy and it wouldnt!! i figured its stuck on the sharp part so i stopped.

Never ever do that. You don't want to leave a foreign body 6 cm from the skin surface and only 1-2 from the CSF, even if the body can take it.

 

[anbuitachi]

Never ever do that. You don't want to leave a foreign body 6 cm from the skin surface and only 1-2 from the CSF.

yea i know. i forgot, it was like 3am haha

 

[deleted171991]

yea i know. i forgot, it was like 3am haha

Happened to me, too, recently, around the same hours. It got caught in the Tuohy for a second, and that was the wake-up call.

 

[cognitus]

Is the Iliac crest a useful landmark for epidurals/spinals in pregnant patients?

 

[Arch Guillotti]

Is the Iliac crest a useful landmark for epidurals/spinals in pregnant patients?

Are you an anesthesia resident?

 

[IlDestriero]

Normal saline in renal failure/hyperkalemia... One of my biggest pet peeves. Love this idea btw, please let us know what your final list entails!

Myth-busting: Lactated Ringers is safe in hyperkalemia, and is superior to NS.

This was an issue that came up not that long ago, a CQI discussion, etc. It was hard to sit through without yelling GTFOWTS. It was enlightening.
I'm still waiting to find out how a reasonable amount of LR in a short procedure lead to the hyperkalemia, need for dialysis and delayed discharge. I have other theories but I keep them to myself to protect the stupid.
I suspect I'll wait forever.


--
Il Destriero

 

[IlDestriero]

I just started OB and in all my ignorance i've pulled the catheter back several times through the touhy and the tip is intact, several diff attendings with many years of exp has watched me do this and not said anything. so i assume it's safe with the braun kit we use.

Not safe.
Not for blocks either, but I've seen the block experts do it.
I've also seen them shear off the end of the catheter as well.


--
Il Destriero

 

[cognitus]

Are you an anesthesia resident?

Seems like a loaded question...Yes I am

 

[MirrorTodd]

Are you an anesthesia resident?

lol

 

[MoMoGesiologist]

Not safe.
Not for blocks either, but I've seen the block experts do it.
I've also seen them shear off the end of the catheter as well.

Wait so when you guys are threading epidural catheters and sometimes they won't go beyond the touhy (often just the tip of the touhy is barely through the ligamentum flavin so you have LOR but can't thread the catheter), are you saying it's unsafe for me to pull out the epidural catheter from the touhy so I can advance the touhy a couple mm more because the catheter may shear? I feel like people do this all the time. Do people pull out the catheter and touhy needle together and restart the whole procedure?

 

[deleted171991]

Wait so when you guys are threading epidural catheters and sometimes they won't go beyond the touhy (often just the tip of the touhy is barely through the ligamentum flavin so you have LOR but can't thread the catheter), are you saying it's unsafe for me to pull out the epidural catheter from the touhy so I can advance the touhy a couple mm more because the catheter may shear? I feel like people do this all the time. Do people pull out the catheter and touhy needle together and restart the whole procedure?

No. Only if you are beyond the tip. As long as the catheter is still inside the needle or at the tip, it's still safe to pull.

I had one case where I just couldn't advance more than 2 cm beyond the tip. I pulled out everything together. (The best solution would have been to inject some saline through the catheter and try advancing it again.)

 

[Arch Guillotti]

Seems like a loaded question...Yes I am

 

[cognitus]

I asked an honest question. Enlighten me. I used iliac crest as a landmark for the l4-5 space but I read studies that say that the level you palpate with this method is variable and usually at a higher spot in pregnant women. This is a myth thread, so it seems like an appropriate question to me.

 

[deleted162650]

I asked an honest question. Enlighten me. I used iliac crest as a landmark for the l4-5 space but I read studies that say that the palates iliac crest is actually at a higher spot in pregnant women. This is a myth thread, so it seems like an appropriate question to me.

I honestly couldn't tell you the last time I felt for someone's iliac crest. I really don't care what level I'm at as long as I'm below L2 and above S1.