Making a lecture top ten myths of anesthesia

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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.

I go at or lower than the crest. I usually still palpate

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You still have patients where the iliac crests are palpable? Must be nice.

I generally aim for one of the creases in the lower 1/3rd of the back, and I'm just happy when I don't need some sort of retraction to get to the skin level in a sterile fashion.
 
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You still have patients where the iliac crests are palpable? Must be nice.

I generally aim for one of the creases in the lower 1/3rd of the back, and I'm just happy when I don't need some sort of retraction to get to the skin level in a sterile fashion.

you shove your arm in there and feel for a difference in texture, that's prob the crest. much harder palpating the spine though
 
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Level isn't that important. Even a low thoracic epidural is fine for labor and c-section ... and may even be technically easier in morbidly obese patients.
 
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You still have patients where the iliac crests are palpable? Must be nice.

I generally aim for one of the creases in the lower 1/3rd of the back, and I'm just happy when I don't need some sort of retraction to get to the skin level in a sterile fashion.
Well, I palpate the iliac crest out of habit and I can appreciate it in most patients. However, the ob anesthesia attending insists that I don't do that because she says it's useless. That's what prompted me to look up medical literature. She insists I count but I think it's really cumbersome to arrive at an appropriate spot counting from, say the inferior angle of the scapula. I don't like her, so I just want to prove her wrong.
 
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Tell her you'd rather count the number of days til you never have to see her again.

I palpate for the crest to get a rough idea where I'm at though exact space isn't too important. Depending on how big the pt's hip or butt are, sometimes L3-L5 are higher than I would have visually guessed compared to a more normal location in a more normal non-pregnant or pregnant body weight.
 
Well, I palpate the iliac crest out of habit and I can appreciate it in most patients. However, the ob anesthesia attending insists that I don't do that because she says it's useless. That's what prompted me to look up medical literature. She insists I count but I think it's really cumbersome to arrive at an appropriate spot counting from, say the inferior angle of the scapula. I don't like her, so I just want to prove her wrong.


Your attending sounds stupid, counting is useless. Who the f*** does that? I wouldn't like her either.
 
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You still have patients where the iliac crests are palpable? Must be nice.
At term gestation, I'd estimate 60% are <160lb, 20% are 161-200lb, 15% 200-250lb, whereas in residency it was 75% >200lb. Basically reflects income level and not being a popular place for walk-ins with no prenatal care.
 
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you shove your arm in there and feel for a difference in texture, that's prob the crest. much harder palpating the spine though

True, but one attending showed me that if you go paraspinally and try to ballotte for the transverse process (index and middle finger in a 'V'), you can sometimes feel a difference in texture/give inbetween spaces better than trying to palpate the spinous process themselves.
 
At term gestation, I'd estimate 60% are <160lb, 20% are 161-200lb, 15% 200-250lb, whereas in residency it was 75% >200lb. Basically reflects income level and not being a popular place for walk-ins with no prenatal care.

Yup. Salty's Law: Quality of payer mix is inversely proportional to average LOR depth.
 
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Iliac Crest is likely not a reliable anatomical guideline specifically for L4-L5 for pregnant patients with the reasoning that they have exaggerated lumbar lordosis. That being said for most patients it seems likely that is a marker for being below the conus with the exception being tall males. This actually does seem like a good myth to include as it was part of my institution's academic dogma.

Ultrasound assessment of the vertebral level of the intercristal line in pregnancy.
Ultrasound assessment of the vertebral level of the intercristal line in pregnancy. - PubMed - NCBI
CONCLUSION:
The anatomical position of the intercristal line was at L3 or higher in at least 6% of term pregnant patients using ultrasound. Clinical estimates were found to be ≥1 vertebral level higher than the anatomical position determined by ultrasound at least 40% of the time. This disparity may contribute to misidentification of lumbar interspaces and increased risk of neurologic injury during neuraxial anesthesia.

The intercristal line determined by palpation is not a reliable anatomical landmark for neuraxial anesthesia.
The intercristal line determined by palpation is not a reliable anatomical landmark for neuraxial anesthesia. - PubMed - NCBI
RESULTS:
Forty-five women were studied. The palpated intercristal line was located above the L4-L5 interspace in all of the women. The median level of intersection was immediately below the L2-L3 interspace, with a range from immediately above L1-L2 to immediately above L4-L5. There was a low positive correlation between the level of intersection and the body mass index (r = 0.32; P = 0.03).

CONCLUSIONS:
In pregnant women at term, the intercristal line determined by palpation does not correspond to the Tuffier's line determined radiologically, and it may intersect the spine at up to three interspaces higher.
 
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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.
It is stupid.

I do stupid things all the time and I'll keep doing them because it doesn't matter that much as many has pointed out. You will titrate to effect and it is easy to do. I'm not sure how people have forced an either-or on the issue (like those that weight based don't estimate or titrate but those brilliant physicians that use the superior non-weight based dosing use their special gift of intuitness to work their magic).

The reasons scientists use weight based dosing has great scientific background and reasons. Go pick a battle with them and read a textbook if you have no idea where the concept of weight based dosing came from or why it is useful.

But in the end - what is most important is that YOU (all those who argue for non weight based dosing) aren't hypocritical.

If you think standardization and consistency is important and it breeds safe practice in medicine - then make sure you are consistent with everything you use. Make sure when you speak to others you explain a non-weight based dosing with every drug. Make sure you document a non-weigh based dosing on everything.
 
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Another potential myth: is it bad to put IVs and BP cuffs on hemiplegic limbs? I know there is concern about increased DVTs and the BP measurements aren't as accurate but is there any data supporting this?
 
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Another potential myth: is it bad to put IVs and BP cuffs on hemiplegic limbs? I know there is concern about increased DVTs and the BP measurements aren't as accurate but is there any data supporting this?

And BP measurement on patients who had ALND.
 
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I never bought it, that's why I just extubate without deflating the cuff. Hard to cough or laryngospasm with dislocated VC's.

I'm hoping, for your sake, this is a joke. Regardless if pt is/was deep or awake, cartilage tears are documented. Case reports/litigations/etc. exist because of practice like this...in my opinion.


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That's how I've had it explained to me. Said you had to inject with a tourniquet up and let it sit for a good minute before letting the tourniquet down and pushing propofol. I've never actually seen anyone do that though.

I'll do it once in a while for a sedation or a sensitive IV. Not with a BP cuff, I just go rogue and hold the vein with my fingers for 10-20 seconds. It doesn't require much lido and the patients stop complaining.
 
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.
Do you tell this to all your women?
 
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Tattoo artists are inherently better at finding the midline than anesthesiologists (JAMA June 2014). If you're lucky your patient has a nice tattoo on her lower back to guide your spinal needle to the sweet spot.
 
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