Making a lecture top ten myths of anesthesia

[somedumbDO]

Advertisement - Members don't see this ad

fellow sdn anesthesia people,

I have a monthly lecture series I do for the group and need your assistance. I want to do a top 10 myths of anesthesia backed w research of why some things we do are inherently dumb. I have a partial list and would love to hear your input.

Red haired people have higher mac requirements
Sellick maneuver for rsi
Gravid women needs a lower does of local for sab due to smaller epidural space
Test ventilation before giving paralytics
Miller blade as your back up for dl
Colloid vs crystaloid for volume recessitation
Oj with pulp 6 hrs npo

Granted this is an abbreviated list but for an 1 hr lecture I can get thru a top ten. What else do you guys have ?

Thanks for ideas

Sdd

 

[Onefellswoop87]

Myth - recall is common

 

[Ronin786]

Difficult airways in OB population

 

[facted]

What do you mean about Miller blade?

Also, per NYSORA, intra abdominal volume (ie: obesity and pregnancy) does influence block height, so it's not a myth. Not a big factor, but it is a factor:
Spinal Anesthesia - NYSORA The New York School of Regional Anesthesia

 

[Robotic Wis-Hipple]

I love the testing ventilation before paralytics one. That academic dogma drives me nuts.

But..... Miller blade ftw.

 

[STLINI]

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.

 

[Robotic Wis-Hipple]

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 is s good one.

 

[Urzuz]

Red haired people have higher mac requirements

This is a myth?

 

[ZzzPlz]

Use trendelenberg when patient is hypotensive

 

[Temeraire]

That you can't transfuse pRBCs with LR (there's a 1998 paper showing it's ok, but I think the myth persists in some places).

 

[anbuitachi]

fellow sdn anesthesia people,

I have a monthly lecture series I do for the group and need your assistance. I want to do a top 10 myths of anesthesia backed w research of why some things we do are inherently dumb. I have a partial list and would love to hear your input.

Red haired people have higher mac requirements
Sellick maneuver for rsi
Gravid women needs a lower does of local for sab due to smaller epidural space
Test ventilation before giving paralytics
Miller blade as your back up for dl
Colloid vs crystaloid for volume recessitation
Oj with pulp 6 hrs npo

Granted this is an abbreviated list but for an 1 hr lecture I can get thru a top ten. What else do you guys have ?

Thanks for ideas

Sdd

Red haired people with higher mac sounds like something you find with p hacking. but i didn't read the paper. maybe they have some genetic difference?
Gravid women does have smaller space and height does change. probably not significant in clinical practice..
Whats wrong with miller blade? I use it as a backup
colloid vs crystaloid? what is the myth?

why is trendelenburg for hypotension a myth? I use it all the time, works great til i can fix the hypotension more permanently


But yea I hate the NS myth in ESRD patients in kidney transplants. Our hospital protocol is normal saline. For all other cases we use plasmalyte. Studies have shown that normal saline actually often cause higher K intraop due to pH of 5.5

 

[deleted59964]

Preoxygenation

 

[deleted643396]

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.

Yes. This is a big pet peeve of mine. Another myth on a similar line of thinking is that LR is incompatible with PRBC transfusions.

Normal Saline really isn't "normal."

The history of 0.9% saline. - PubMed - NCBI

 

[somedumbDO]

As far as blades are concerned which ever blade you are comfortable should be the first blade you use for dl if that doesn't work using a blade your NOT comfortable with rarely works...

↑
I was referring to sab dosage for gravid females for c/s

Increased intrabdominal presure compressing intrathecal space causing high spinals in pregnant women is dogmatic myth. Parturients tend to get higher (hyperbaric) spinal levels because the larger hindquarters they usually carry effectively put them in Trendelenburg, even when the table is flat. I think Datta's complicated OB book discusses this but my copy is in a box somewhere.

i like the NS and renal failure as well as blood with LR keep the ideas flowing...

 

[fittipaldi1of1]

- Cricoid pressure
- npo time
- left uterine displacement

 

[Arch Guillotti]

Preoxygenation
Ultrasound for nerve blocks

😉

 

[FiremedicMike]

What is the myth of preoxygenation?

 

[deleted643396]

You can't use positive pressure ventilation with an LMA.

 

[deleted171991]

Difficult airways in OB population

They are not really "difficult", just congested, and thus more difficult than what would be expected for the BMI.

 

[deleted171991]

You can't use positive pressure ventilation with an LMA.

Another one: you can't use muscle relaxants with an LMA.

 

[Robotic Wis-Hipple]

Another one: you can't use muscle relaxants with an LMA.

You're so European 😉

 

[deleted162650]

Preoxygenation
Ultrasound for nerve blocks

😉

And U/S for central lines

 

[MirrorTodd]

You can't use positive pressure ventilation with an LMA.

That's new to me.

 

[periopdoc]

Can't do prone LMA or LMA for laparoscopy

 

[periopdoc]

The supposed difficulty of the gravid airway and the no LR for renal failure or with PRBCs are particularly galling.

 

[OB1🤙]

That cricoid pressure is a myth is itself a recently-propagated myth. There's quite a bit of quite good modern evidence that it works, when done correctly.

Now, whether CP is actually indicated in most situations in which it is commonly used, now there's probably some myth there.

Other myths:
You should extubate on 100% oxygen.

You need to prove you can mask before you paralyze.

Decreased ejection fraction is an indication for inotropes in cardiac anesthesia.

 

[OB1🤙]

Sevo needs to be run at 2L/min (though I don't care about this one much because I rarely use sevo).

Corollary: very low fresh gas flows are dangerous.

 

[MirrorTodd]

Something about maintenance fluids and deficits etc etc

 

[hankbb02]

Hydrocortisone should be used when one wishes to use stress dose steroids for its mineralocorticoid effects.

 

[MoMoGesiologist]

Hydrocortisone should be used when one wishes to use stress dose steroids for its mineralocorticoid effects.

We always give 4mg dexamethasone for antiemetic to most patients and I always wonder if that's good enough for a stress dose if needed. Usually end up giving 100mg hydrocortisone as well anyways if need a stress dose.

 

[deleted643396]

We always give 4mg dexamethasone for antiemetic to most patients and I always wonder if that's good enough for a stress dose if needed. Usually end up giving 100mg hydrocortisone as well anyways if need a stress dose.

4mg dexamethasone is adequate and the need for stress dose steroids is often overblown anyway.

 

[anbuitachi]

4mg dexamethasone is adequate and the need for stress dose steroids is often overblown anyway.

i always do 8mg dex for antiemetic. the more the better.

 

[deleted171991]

Can't do prone LMA or LMA for laparoscopy

Here's another "European", @Robotic Wis-Hipple, so I am proud to join the club. 🙂

 

[deleted171991]

4mg dexamethasone is adequate and the need for stress dose steroids is often overblown anyway.

Except in people with true adrenal insufficiency. 🙂

 

[deleted171991]

i always do 8mg dex for antiemetic. the more the better.

How about 12? 😀

 

[deleted643396]

i always do 8mg dex for antiemetic. the more the better.

Why the more the better? I like to give the lowest effective dose possible of any medication I give.

Dexamethasone to prevent postoperative nausea and vomiting: an updated meta-analysis of randomized controlled trials. - PubMed - NCBI

 

[anbuitachi]

How about 12? 😀

I do 10-12 for orthopedic/neurosurgeries

 

[Urzuz]

i always do 8mg dex for antiemetic. the more the better.

4 mg has been shown to have equal antiemetic effect to anything more. Doesn't make much sense to give more if you're strictly giving it for antiemetic purposes...

 

[anbuitachi]

Why the more the better? I like to give the lowest effective dose possible of any medication I give.

Dexamethasone to prevent postoperative nausea and vomiting: an updated meta-analysis of randomized controlled trials. - PubMed - NCBI

Some studies show the effect is greater in 8mg+.
Also with 8mg you get pain reducing effects. So I just give 8

 

[MoMoGesiologist]

Except in people with true adrenal insufficiency. 🙂

Do you think 4mg dexamethasone isn't enough or are you saying it has to be hydrocortisone? 4mg dex = ~100mg hydrocortisone in terms of glucocorticoid efficacy from what I read.

 

[MoMoGesiologist]

Some studies show the effect is greater in 8mg+.
Also with 8mg you get pain reducing effects. So I just give 8

Any dose adjustments for diabetics?

 

[deleted643396]

Except in people with true adrenal insufficiency. 🙂

My emphasis should have been on the overblown need for prophylactic stress dose steroids in patients taking chronic corticosteroids. Treating true adrenal insufficiency is different. Steroids have enough unwanted side effects that I don't think we should just be pulsing high doses without thinking about it.

 

[anbuitachi]

Do you think 4mg dexamethasone isn't enough or are you saying it has to be hydrocortisone? 4mg dex = ~100mg hydrocortisone in terms of glucocorticoid efficacy from what I read.

Dex has no mineralocorticoid effects. in true adrenal inefienfucecy, you should replace both

 

[deleted171991]

4 mg has been shown to have equal antiemetic effect to anything more. Doesn't make much sense to give more if you're strictly giving it for antiemetic purposes...

Oh, wait! The next thing you'll say is that 10 mg of Toradol are about as analgesic as 30, but with more side effects. OMG! 😀

 

[anbuitachi]

Any dose adjustments for diabetics?

I kind of individualize for these. Normally I give them 8mg anyway if their diabetes is well controlled on oral meds or low dose insulin. But i just skip it all together when their glucose prior to surgery is already 300+. they can deal with the slightly higher risk of nausea. Or i just give them some other anti nauseas

 

[deleted171991]

Any dose adjustments for diabetics?

They need 16 because of their increased body weight (and insulin resistance). 😀

 

[pgg]

Dex has no mineralocorticoid effects. in true adrenal inefienfucecy, you should replace both

Nothing wrong with using hydrocortisone, but hypotension isn't caused by mineralocorticoid deficiency.

 

[MJ978]

fellow sdn anesthesia people,

I have a monthly lecture series I do for the group and need your assistance. I want to do a top 10 myths of anesthesia backed w research of why some things we do are inherently dumb. I have a partial list and would love to hear your input.

Red haired people have higher mac requirements
Sellick maneuver for rsi
Gravid women needs a lower does of local for sab due to smaller epidural space
Test ventilation before giving paralytics
Miller blade as your back up for dl
Colloid vs crystaloid for volume recessitation
Oj with pulp 6 hrs npo

Granted this is an abbreviated list but for an 1 hr lecture I can get thru a top ten. What else do you guys have ?

Thanks for ideas

Sdd

Thank you to everyone responding to this thread, I'm a resident and find it very helpful!
If you are able, could you please link an article with your comment, so that I could have it available when my attending (no doubt) chastises me for using LR with pRBC, etc.

I'd also like to know more about the usefulness of testing ventilation before paralytics are given.

 

[migm]

Preoxygenation

huh?

 

[AdmiralChz]

I thought we had some ridiculous academic dogma in our program, but glad I haven't been exposed to some of these!