Nerve block, amide allergy

[caligas]

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Any ideas? Tetracaine?

(Just assume it’s a real allergy and they really need a block, for sake of discussion)

 

[GassYous]

I use cocaine

Not for blocks though, just thought I'd mention it

 

[Aether2000]

Is the nerve block for a brief or long surgical procedure or for post op pain? We cannot get tetracaine easily at my institutions. Of course PF Chloroprocaine may last 60 minutes- good enough for short procedure regional anesthesia but no real post op pain benefit. Tetracaine can last up to 9 hours in a nerve block but has some degree of toxicity.

 

[BLADEMDA]

Any ideas? Tetracaine?

(Just assume it’s a real allergy and they really need a block, for sake of discussion)

The vast majority of allergies are due to preservatives in the local. Most surgeons do not use preservative free local anesthetic. Second, the ester based locals are also a possibility.

The only way to know for sure are intradermal injections of small amounts of local prior to the nerve block.

 

[anbuitachi]

steroids benadryl.
have epi ready

 

[caligas]

Is the nerve block for a brief or long surgical procedure or for post op pain? We cannot get tetracaine easily at my institutions. Of course PF Chloroprocaine may last 60 minutes- good enough for short procedure regional anesthesia but no real post op pain benefit. Tetracaine can last up to 9 hours in a nerve block but has some degree of toxicity.

Post op pain

 

[deleted875186]

Either do the block with bupivacaine if the history is not reliable for true local allergy, or forgo the block all together if it’s too risky.

In the future, perhaps things like the sprint temporary peripheral nerve stimulator will be available.

 

[Hoya11]

Any ideas? Tetracaine?

(Just assume it’s a real allergy and they really need a block, for sake of discussion)

To come up with a creative solution we would have to know the specifics of the patient and case.. maybe a CPc epidural ?

 

[Planktonmd]

Always remember that surgery without regional blocks is actually possible.

 

[Iso4ane]

I know diphenhydramine has local anesthetic properties that useful for dermatological procedures. I’m curious if it works as a block. Probably, kill three birds with one stone (block, sedation, and antihistamine for the allergic reaction)

 

[Maz777]

No one needs a block.

They likely have a GA deficiency, and that needs to be corrected.

 

[patriot6]

No one needs a block.

They likely have a GA deficiency, and that needs to be corrected.

agreed.

but some people get REALLY close to needing a block. like the ICMO EF 10% for an ankle fracture I did last week, with questionable ongoing ischemia but tibia poking through the skin. surgical fem/pop + some versed and fentanyl and some oxygen. she lived.

 

[repititionition]

I know diphenhydramine has local anesthetic properties that useful for dermatological procedures. I’m curious if it works as a block. Probably, kill three birds with one stone (block, sedation, and antihistamine for the allergic reaction)

It’s a Na+ blocker, and I find it generally unknown or overlooked in this role. It is roughly unit equipotent to 1% lido. I looked and couldn’t find any case reports of using it perineurally and no chance I’d be the first. I do use it occasionally for skin infiltration in these cases of allergy, where it works great.

 

[deleted875186]

It’s a Na+ blocker, and I find it generally unknown or overlooked in this role. It is roughly unit equipotent to 1% lido. I looked and couldn’t find any case reports of using it perineurally and no chance I’d be the first. I do use it occasionally for skin infiltration in these cases of allergy, where it works great.

How on earth is Benadryl supposed to work for a block? Am I supposed to pop open 10 vials if 1 mL Benadryl and injected 500 mg? At that point just inject it subcutaneous with some versed and you’ll be at GA/coma level.

 

[Aether2000]

Of course meperidine is also a local anesthetic that I used to use as the sole agent in spinal anesthesia. But the duration is too short to be of benefit for post op pain control.

 

[nimbus]

I know diphenhydramine has local anesthetic properties that useful for dermatological procedures. I’m curious if it works as a block. Probably, kill three birds with one stone (block, sedation, and antihistamine for the allergic reaction)

I once had a mosquito bite on my hand that was driving me crazy. I injected a small wheal of IV Benadryl into the bite. That spot on my hand was numb for 3-4 months.

 

[repititionition]

How on earth is Benadryl supposed to work for a block? Am I supposed to pop open 10 vials if 1 mL Benadryl and injected 500 mg? At that point just inject it subcutaneous with some versed and you’ll be at GA/coma level.

I said specifically I wouldn’t use it as a block (?). Just mentioning its utility for infiltration.

 

[caligas]

I once had a mosquito bite on my hand that was driving me crazy. I injected a small wheal of IV Benadryl into the bite. That spot on my hand was numb for 3-4 months.

Exparel brand Benadryl?

 

[2Fast2Des]

Exparel brand Benadryl?

I call dibs on the patent right now

 

[Iso4ane]

I once had a mosquito bite on my hand that was driving me crazy. I injected a small wheal of IV Benadryl into the bite. That spot on my hand was numb for 3-4 months.

Was your intention for the antihistamine effects or the local or both? But, at least now we know it works.

 

[nimbus]

Was your intention for the antihistamine effects or the local or both? But, at least now we know it works.

Antihistamine. At the time, I didn’t even know it had local anesthetic effect 🤷‍♂️

 

[GassYous]

I once had a mosquito bite on my hand that was driving me crazy. I injected a small wheal of IV Benadryl into the bite. That spot on my hand was numb for 3-4 months.

"The stranger"?

 

[lobelsteve]

I once had a mosquito bite on my hand that was driving me crazy. I injected a small wheal of IV Benadryl into the bite. That spot on my hand was numb for 3-4 months.

Boogered the nerve that innervates the skin. Likely through compression by the wheal. I've been hit in the IA by the dentist. Lip curled up on that side for 18 mo afterwards. Sensation returned to normal.

 

[nimbus]

Boogered the nerve that innervates the skin. Likely through compression by the wheal. I've been hit in the IA by the dentist. Lip curled up on that side for 18 mo afterwards. Sensation returned to normal.

That is very possible.

 

[D P356]

Interesting prompt; I did a literature search.

I’ve not done it before, but if you had to, a peripheral nerve catheter with Chloroprocaine from an OnQ pain ball would be an option.

Probably not a good idea if Pt has pseudocholinesterase deficiency (genetic or liver disease) or if Pt is allergic to PABA.

If lower extremity procedure, place epidural, administer Chloroprocaine for intraop and duramorph for post op. Not a true post op block, but it will likely have a benefit.
Assuming…
1. you’ll have to make your own test dose with an ester and epi.
2. You’ll have to admit Pt overnight for monitoring as they received neuraxial morphine.


Or just don’t do a block at all.