Local anesthetic tox

[ghost dog]

Hi All,

I was wondering if peeps could share their stories of local anesthetic tox.

Over the past 8 years, I have had a few mild ones (i.e. transient nausea, vertigo) which have quickly resolved with Oxygen by face mask, and 1 which put the frighteners into me (he was fine in the end- but definitely brown pants time during the resuct'n).

Has anyone used Intralipid 20%? I have it in the clinic, but hope never to have to use it !!!!

Any and all stories, with management appreciated.

In particular, I note that a modification has been discussed ( recommended ? ) in regards to epi dosing / ACLS resuc and LAST - i.e. 0.1 mg versus the usual 1 mg ?

Comments?

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[IlDestriero]

I've seen QRS widening from a caudal. It went away over a few minutes, pt was stable. Intralipid was on top of the cart, waiting to be spiked. It was a nice review intralipid dosing. We have it in the code cart. There was a photo of an ECG strip showing the same thing in Anesthesiology not long ago.
Caudals aren't benign.

 

[deleted126335]

Topicalizing patients for awake fiberoptic intubations with 4% lidocaine a few got overly sedated from what I interpreted as high blood levels of lidocaine. Have switched to 3%. Tried 2%, but it just doesn't cut it. No episodes with bupivicaine.

 

[Gern Blansten]

www.lipidrescue.org has the best compilation of cases. It is run by Dr Guy Weinberg who is the one who basically figured all of the lipid emulsion therapy out in his rat and dog research.

 

[BLADEMDA]

I've seen Bupivacaine induced cardiac arrest. It ain't pretty. The case wasn't mine but the patient survived. If you see signs of an impeding arrest get the Lipids ASAP. Lipids should be close to any area where blocks are performed.

I've seen seizures a few times. That complication is easily treated. Again, I've have been fortunate and never had a seizure doing a block.

Remember, if you are doing two blocks (Lumbar Plexus plus Sciatic) the volume/concentration of local is much higher so be ready to treat a local anesthetic induced side-effect (I've seen one 30 minutes after the blocks).

 

[Gern Blansten]

Again, I've have been fortunate and never had a seizure doing a block.

Me neither, thankfully. I would imagine it would be tough to keep the needle still

 

[oldguy55]

Hi All,

I was wondering if peeps could share their stories of local anesthetic tox.

Over the past 8 years, I have had a few mild ones (i.e. transient nausea, vertigo) which have quickly resolved with Oxygen by face mask, and 1 which put the frighteners into me (he was fine in the end- but definitely brown pants time during the resuct'n).

Has anyone used Intralipid 20%? I have it in the clinic, but hope never to have to use it !!!!

Any and all stories, with management appreciated.

In particular, I note that a modification has been discussed ( recommended ? ) in regards to epi dosing / ACLS resuc and LAST - i.e. 0.1 mg versus the usual 1 mg ?

Comments?

Never had obvious toxicity from a nerve block, although I tell my assistants we have to be ready for WHEN it happens, not IF.

We did see a patient who seized shortly after arrival in PACU after a lap chole. She is the daughter of an OR nurse and the surgeon wanted to be sure she was super comfortable so he infiltrated the trochar sites with a ton of 0.5% bupivacaine.

Seizures stopped fairly quickly after IV midaolam. My partner started Intralipid anyway, while I got on-line to find the dose, interval, etc. The website mentioned elsewhere in this thread is good for such information. Maybe he jumped the gun a bit, as Intralipid is recommended for intractable cardiac toxicity, not seizures that have been controlled, but my partner was close to soiling himself about this.

Lessons: Surgeons don't use 0.5% bupivacaine for local anymore. They ask what the limits are. And no, using near toxic amounts of bupivacaine AND near toxic amounts of lidocaine isn't cool, either.

Oh, yeah, don't treat a patient differently because of who she is or who she's related to.

 

[RT2MD]

Topicalizing patients for awake fiberoptic intubations with 4% lidocaine a few got overly sedated from what I interpreted as high blood levels of lidocaine. Have switched to 3%. Tried 2%, but it just doesn't cut it. No episodes with bupivicaine.

Did you ever have any problems with methemoglobinemia from the 4% Lido? Where I worked as an RT we used to always use benzocaine spray (20%) for bronchs... but we had several cases of methemoglobinemia. We then switched over to using atomized lidocaine instead. It seemed like our cases of methemoglobinemia stopped, or at least went down dramatically.

I was wondering if this was because there was less incidence of MetHb with lidocaine or because there was more attention being drawn to the exact amount of lidocaine used - since we used a syringe instead of the spray. Any thoughts?

 

[rsgillmd]

Did you ever have any problems with methemoglobinemia from the 4% Lido? Where I worked as an RT we used to always use benzocaine spray (20%) for bronchs... but we had several cases of methemoglobinemia. We then switched over to using atomized lidocaine instead. It seemed like our cases of methemoglobinemia stopped, or at least went down dramatically.

I was wondering if this was because there was less incidence of MetHb with lidocaine or because there was more attention being drawn to the exact amount of lidocaine used - since we used a syringe instead of the spray. Any thoughts?

The only way to really tell would be if you sent blood for cooximetry or hooked up a coox type device like the Masimo monitor.

I haven't seen any evidence of clinically significant methemoglobinemia with either Benzocaine or Lidocaine. We don't have benzocaine here. We used it sparingly in residency.

 

[rsgillmd]

Hi All,

I was wondering if peeps could share their stories of local anesthetic tox.

Over the past 8 years, I have had a few mild ones (i.e. transient nausea, vertigo) which have quickly resolved with Oxygen by face mask, and 1 which put the frighteners into me (he was fine in the end- but definitely brown pants time during the resuct'n).

Has anyone used Intralipid 20%? I have it in the clinic, but hope never to have to use it !!!!

Any and all stories, with management appreciated.

In particular, I note that a modification has been discussed ( recommended ? ) in regards to epi dosing / ACLS resuc and LAST - i.e. 0.1 mg versus the usual 1 mg ?

Comments?

I've been lucky. The worst I saw was a seizure. I had put a CSE in the lady without difficulty, who went to have balloons placed in IR for possible accreta/percreta. When she got back my attending dosed the catheter and the patient seized. The catheter must have migrated intravascular. So we ended up putting her to sleep. It was a fortunate thing because it ended up as a large blood loss case anyway.

I've also seen some tinnitus and tingling around the lips when I've given a test dose, but that's rare. Usually just see an increased heart rate from the Epi.

 

[sevoflurane]

In particular, I note that a modification has been discussed ( recommended ? ) in regards to epi dosing / ACLS resuc and LAST - i.e. 0.1 mg versus the usual 1 mg ?

Comments?

I have not seen the new guidelines. A quick search seems to throw out bicarb and atropine? As for 1mg vs .1 mg of epi... I can see the rationale. Sometimes all you need is .05mg (50mcg) to get a robust return in blood pressure. Giving 1 mg (1000mcgs) can be overkill increasing oxygen supply and demand (afterload, wall tension, heart rate, etc...).

During my academic days, it killed me to see internists in the MICU push 1mg of epi in patients whose B.P. would be hovering around 50 systolics. The next thing you'd see is 210/120 and a H.R. of 150bpm. Sometimes it can do more harm than good.

10-40mcgs (in adults) is a good starting point to asses a patients need for big-gun-exogenous catecholamines. You can always give more.... but it's pretty hard to take back (1mg of epi) once it's made it's way past your angiocath and into the peripheral circulation. However, this is an anesthesia type of mentality and we are able to dilute drugs on the fly with ease.

Interested in seeing the new guidelines. Thanks for the update.

As for local toxicity. Upon questioning, I have had patients admit to ringing in the ears from 100mg of lidocaine that we typically give before induction.

I have witnessed one seizure in our block room during residency (easily treated).

I suspect that seizure rates and intravascular injections will continue to decline as USD guided RA gains further popularity and becomes the new standard.

 

[RT2MD]

The only way to really tell would be if you sent blood for cooximetry or hooked up a coox type device like the Masimo monitor.

I haven't seen any evidence of clinically significant methemoglobinemia with either Benzocaine or Lidocaine. We don't have benzocaine here. We used it sparingly in residency.

We actually had several cases of methemoglobinemia that were clinically significant. Several that ended up getting co-ox (off puncture) and a few that ended up getting methylene blue. We also had some pulm fellows that would... well... let say, go to town with the benzocaine spray. I was figuring that the decrease in metHb cases after the switch was due to the fact that they were using MUCH less of the lidocaine, since we were actually charting exact amounts given.

Thank you for your reply, I appreciate it.

 

[dhb]

As for 1mg vs .1 mg of epi... I can see the rationale.

Actually there was a paper showing resuscitation after LA cardiac arrest was less effective when epi was given. Can't look it up right know...

ok here it is : http://www.ncbi.nlm.nih.gov/pubmed/19704251

you're welcome