Anesthesiology Myths

[Intubate]

---

Members don't see this ad.

It looks like these guidelines basically say patients should avoid IVs, blood draws, and BP monitoring, but there's no evidence to support this.
Unfortunately, as with many guidelines, not very helpful. It is at least nice to see that there is no data.

 

[hokie]

Lymphedema Workshop IV from the National Cancer Institute has guidelines and references

Thanks... Here is an excerpt for those interested:

To avoid arm swelling and/or infection, the patient should be instructed to:

1. Avoid vaccinations, injections, blood-pressure monitoring, blood drawing, and intravenous administration in the affected arm.
2. Avoid puncturing or injuring the skin in any way. Use meticulous skin and nail/cuticle care. Pay immediate attention to and use standard first-aid care on all small or large injuries. Utilize antibiotics liberally.
3. Avoid constricting sleeves or jewelry and wear a padded bra strap to avoid constriction and pressure.
4. Avoid heat, including sunburns or tanning, hot baths, and saunas.
5. Avoid violent exercise and strenuous exertion. Consider vigorous aerobic arm exercise only when the arm is supported by compression garments.

There are no data to govern any of these recommendations. The finding that no increase in risk of lymphedema was noted in women who had had bilateral axillary dissection compared with those who had had unilateral axillary dissection16,35 calls into question the implication that blood drawing, intravenous administration, blood-pressure monitoring, and injections hasten the development of lymphedema. Data for any of the other arm and hand precautions are even more speculative. On the other hand, breaking the skin barrier, even during medical procedures, could predispose to infection, and blood-pressure monitoring could cause injury

Also:

Such research is desperately needed. All patients are currently instructed in the same arm and hand care precautions; however, these precautions may be too severe for those at low risk, while not aggressive enough for those at the greatest risk. Furthermore, as lymphedema may occur even several decades36 after axillary treatment, patients are admonished to follow these demanding precautions for the remainder of their lives.

As suspected little or no data... at least I don't feel as bad violating these precautions from time to time as needed.

 

[epidural man]

thanks to VenTY's FAQ sticky posts, I found this cool thread.

Anyway, I have another myth I wanted to ask about. What about the data that shows that lidocaine actually does anything to blunt laryngoscopy reflexes (HR, BP increase)?

I don't think there is any good data. To my knowledge, the only good thing to really blunt the response is opioids, and you have to give a lot.

Some myths that I always heard about that turn out to be false...

1. Saline for blood patch doesn't work. (it seems to do something in some papers)
2. Prophylactic blood patch doesn't work.
3. Peripheral nerve block adjunctive medicines don't work. (there is good data that clonidine and buprinorphine prolong a block)
4. preloading for a spinal works to prevent hypotension. (colloid seems to work, but who is doing this?)
5. Regional is no more safer than general and have similar outcomes
6. Bupivicaine is more cardiotoxic than ropivicaine.
7. Opioid at induction causes chest wall rigidity. (It appears that the rigidity is from vocal chord closure, not chest wall rigidity).
8. Cereberal autoregulation is from 50mmHg to 150mmHg.
9. Married life is better than single life
10. Single life is better than married life.
11. BIS doesn't work.
12. BIS works.

 

[jetproppilot]

thanks to VenTY's FAQ sticky posts, I found this cool thread.

Anyway, I have another myth I wanted to ask about. What about the data that shows that lidocaine actually does anything to blunt laryngoscopy reflexes (HR, BP increase)?

I don't think there is any good data. To my knowledge, the only good thing to really blunt the response is opioids, and you have to give a lot.

Some myths that I always heard about that turn out to be false...

1. Saline for blood patch doesn't work. (it seems to do something in some papers)
2. Prophylactic blood patch doesn't work.
3. Peripheral nerve block adjunctive medicines don't work. (there is good data that clonidine and buprinorphine prolong a block)
4. preloading for a spinal works to prevent hypotension. (colloid seems to work, but who is doing this?)
5. Regional is no more safer than general and have similar outcomes
6. Bupivicaine is more cardiotoxic than ropivicaine.
7. Opioid at induction causes chest wall rigidity. (It appears that the rigidity is from vocal chord closure, not chest wall rigidity).
8. Cereberal autoregulation is from 50mmHg to 150mmHg.
9. Married life is better than single life
10. Single life is better than married life.
11. BIS doesn't work.
12. BIS works.

1)Why would someone do a saline patch?

2)I'll bet they work.

3) Don't have enough experience to comment, but very interesting subject.

4)What works better is IV ephedrine immediately after spinal placement regardless of starting BP.

5)I dont think its safer, but its better for certain surgeries.

6) Huh? Take another hit off that blunt, Dude. 😆

7)Givva dude a big shlog of sufentanil before induction to disprove your stance. Ask Jeff Pisto MD who did this during our residency just to see what would happen....and, uhhh, it happened.

8) Gotta go with the textbooks since I'm not smart enough to argue on this subject.

9) not sure.

10) not sure.

11) Yes they do. Not for preventing recall, though.

12) I agree. Disclaimer: I bought ASPM after the NEJM article killed the stock. 😀

Thanks for your post. 👍

 

[epidural man]

1)Why would someone do a saline patch?

uhhhh.....don't know really. I've just read they help cut down on the symptoms. I would never do it. Maybe it works prophylactically and I can't remember what I read exactly. I guess for prophylaxis after a wet tap one might put a bunch of saline.

1)Why would someone do a saline patch?

6) Huh? Take another hit off that blunt, Dude. 😆

The problem is that most when considering toxicity consider that they are equipotent, which is not true. Ropivicaine is ~%40 less potent (at the usually considered equipotent doses) and so of course it is less toxic because you are giving less drug in effect. When considered at REAL equipotent doses, they have the same toxic profile.

7)Givva dude a big shlog of sufentanil before induction to disprove your stance. Ask Jeff Pisto MD who did this during our residency just to see what would happen....and, uhhh, it happened.

A cool and nifty article on the subject. There are also references that say the same thing. I just think it is an interesting idea.

Bennett JA, Abrams JT, Van Riper DF, Horrow JC.Difficult or impossible ventilation after sufentanil-induced anesthesia is caused primarily by vocal cord closure.
Anesthesiology. 1997 Nov;87(5):1070-4.

 

[epidural man]

8) Gotta go with the textbooks since I'm not smart enough to argue on this subject.

9) not sure.

10) not sure.

As far as the autoregulation thing, Dr Drummond at UCSD who wrote all the chapters and did the studies and was the one who came out with the numbers originaly recently wrote (and I have heard him say) that he regrets those numbers because the lower number of 50 is so variable and often times it is 60 or 70, and he fears that people cling to the 50 and think that a MAP of 50 will most always be safe and sometimes running an anesthestic of 50 (in an otherwise healthy individual) can be dangerous.

The marriage/single thing, I have done both, and both are true, although I have not seen this in any of our peer reviewed journals. I tried to submit the case report to Internet Journal of Anesthesia, but alas it got rejected. The internet school of medicine, where I got my medical degree, said they would put it in their school paper.

 

[jetproppilot]

The problem is that most when considering toxicity consider that they are equipotent, which is not true. Ropivicaine is ~%40 less potent (at the usually considered equipotent doses) and so of course it is less toxic because you are giving less drug in effect. When considered at REAL equipotent doses, they have the same toxic profile.

.

Interesting.

You're saying ropiv is 40% less potent?

I've dosed epidurals/done interscalenes...axillaries....femorals....sciatics with .5% ropiv and haffta say the block quality seemed equipotent to the thousands I've done with .5% bupiv.

Seems like I'd have had a problem by now achieving surgical analgesia when using regional-alone if what you say is true about ropiv. Seems equipotent to me. 20 mL .5% ropiv acts like 20 mL .5% bupiv in my book. But hey, I'm just a private practice jockey.

All I can say is I remember the link Mil posted concerning lipid rescue for a bupiv-toxic heart.....dude was dead and the lipid sh i t brought him back to planet earth. Since they've got a proprietary lipid emulsion for bupivicaine toxicity, I'd say its a real issue.

I've yet to see any literature on adverse cardiovascular sequelae from ropivicaine, nor a successful rescue emulsion.

 

[epidural man]

Interesting.

You're saying ropiv is 40% less potent?

I've dosed epidurals/done interscalenes...axillaries....femorals....sciatics with .5% ropiv and haffta say the block quality seemed equipotent to the thousands I've done with .5% bupiv.

Seems like I'd have had a problem by now achieving surgical analgesia when using regional-alone if what you say is true about ropiv. Seems equipotent to me. 20 mL .5% ropiv acts like 20 mL .5% bupiv in my book. But hey, I'm just a private practice jockey.

All I can say is I remember the link Mil posted concerning lipid rescue for a bupiv-toxic heart.....dude was dead and the lipid sh i t brought him back to planet earth. Since they've got a proprietary lipid emulsion for bupivicaine toxicity, I'd say its a real issue.

I've yet to see any literature on adverse cardiovascular sequelae from ropivicaine, nor a successful rescue emulsion.

I wonder what others that use ropiv regularly think about this equipotent issue. Mil? Noyac? BladeMD? (What happened to Blade?)

As far as ropivicaine cardiac arrest, it does happen, but it seems like at a much less rate.

Khoo LP, Corbett AR.Successful resuscitation of an ASA 3 patient following ropivacaine-induced cardiac arrest.Anaesth Intensive Care. 2006 Dec;34(6):804-7.


Litz RJ, Popp M, Stehr SN, Koch T.
Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion.Anaesthesia. 2006 Aug;61(8):800-1.

Successful defibrillation immediately after the intravascular injection of ropivacaine.
Can J Anaesth. 2005 May;52(5):490-2.

Klein SM, Pierce T, Rubin Y, Nielsen KC, Steele SM.
Successful resuscitation after ropivacaine-induced ventricular fibrillation.Anesth Analg. 2003 Sep;97(3):901-3. Erratum in: Anesth Analg. 2004 Jan;98(1):200.

 

[jetproppilot]

I wonder what others that use ropiv regularly think about this equipotent issue. Mil? Noyac? BladeMD? (What happened to Blade?)

As far as ropivicaine cardiac arrest, it does happen, but it seems like at a much less rate.

Khoo LP, Corbett AR.Successful resuscitation of an ASA 3 patient following ropivacaine-induced cardiac arrest.Anaesth Intensive Care. 2006 Dec;34(6):804-7.


Litz RJ, Popp M, Stehr SN, Koch T.
Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion.Anaesthesia. 2006 Aug;61(8):800-1.

Successful defibrillation immediately after the intravascular injection of ropivacaine.
Can J Anaesth. 2005 May;52(5):490-2.

Klein SM, Pierce T, Rubin Y, Nielsen KC, Steele SM.
Successful resuscitation after ropivacaine-induced ventricular fibrillation.Anesth Analg. 2003 Sep;97(3):901-3. Erratum in: Anesth Analg. 2004 Jan;98(1):200.

WOW!

Thanks for the links.

Wasnt aware of these.

Looks like I've been operating under a smaller mostly-interscalene-security-blanket than I thought.

Thank you.

 

[starsop93]

Sorry that I don't have the data either, but I was told repeatedly throughout residency that ropivicaine is just as toxic as bupivicaine.

In the doses that it is marketed, it is slightly less toxic than bupiv, but it is marketed at a less potent concentration. However, when equalized to equal potency (and therefore, equal effect) there is no difference. Ironically, levo-bupivicaine is supposedly less toxic than racemic bupiv, but is not marketed anymore because ropiv cornered the market.

 

[Jeff05]

for the boards ropiv is LESS cardiotoxic than bupiv.

 

[militarymd]

I wonder what others that use ropiv regularly think about this equipotent issue. Mil? Noyac? BladeMD? (What happened to Blade?)

As far as ropivicaine cardiac arrest, it does happen, but it seems like at a much less rate.

Khoo LP, Corbett AR.Successful resuscitation of an ASA 3 patient following ropivacaine-induced cardiac arrest.Anaesth Intensive Care. 2006 Dec;34(6):804-7.


Litz RJ, Popp M, Stehr SN, Koch T.
Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion.Anaesthesia. 2006 Aug;61(8):800-1.

Successful defibrillation immediately after the intravascular injection of ropivacaine.
Can J Anaesth. 2005 May;52(5):490-2.

Klein SM, Pierce T, Rubin Y, Nielsen KC, Steele SM.
Successful resuscitation after ropivacaine-induced ventricular fibrillation.Anesth Analg. 2003 Sep;97(3):901-3. Erratum in: Anesth Analg. 2004 Jan;98(1):200.

I don't know...we only use bupivicaine and lidocaine....

wow...I can't believe these guys wrote some of these reports....like "we mistakenly injected the WRONG drug...and caused someone to arrest"....if you listen to Plank....No one would ever report something like that.

 

[Planktonmd]

I don't know...we only use bupivicaine and lidocaine....

wow...I can't believe these guys wrote some of these reports....like "we mistakenly injected the WRONG drug...and caused someone to arrest"....if you listen to Plank....No one would ever report something like that.

I said: no one would report something like that unless they are crazy, how do you know these guys are not crazy?
The other difference is that these guys did not willingly inject the wrong drug, now this is not the same as WILLINGLY and INTENTIONALLY injecting Sux in a hyperkalemic patient, is it?
It's like the difference between manslaughter and first degree murder.

 

[rsgillmd]

What about allergy to eggs and givin' propofol? I do it and never had a problem. What about allergy to sulfates(SO4) and givin' the sulfite based propofol(SO3)? I give it and never had a problem. How about everybody and their mother with allergies to latex? If they don't have a history of resp. symptoms and/or anaphylaxis with exposure to latex, I treat them as any other pt. Regards, ----Zip

I haven't heard of anyone saying they have a "sulfate" allergy. They usually say "sulfa" as in sulfonamides (like the trimethoprim and sulfamethoxazole combo). But either way, I agree with you -- no problems.

 

[2win]

Ehhh.. what profession if you don't mind? MD consultant anesthesia? well - open for discussion ( with md-s of course, no ofense..).