Question on Lidocaine Toxicity via Local

jwk · Apr 4, 2006

Thank you for taking the time to read this.
I work in a procedure lab that does a lot of local anaesthesia with Lidocaine 2% and though not often, some patients are having very similar rx's to something in the procedure. At first I thought it was related to part of my moderate sedation meds but now I'm looking out farther and eyeballing Lidocaine 2% as a possible suspect.
What I would like is your personal experiences ie. signs, symptoms and treatment when you suspected a lidocain OD.
PLease refrain from too much quoting from a book. I am looking for personal accounts please.
Thanks
Joshua

How much lidocaine are you giving? The generally accepted max dosage is 5-7mg/kg, but there's a lot of wiggle room in that depending on route of administration. If you need a lot of volume of local for big areas, then 2% may be too high a concentration to use safely.

Numb lips and a funny metallic taste in the mouth are often cited as signs the patient can tell you about. If you're using lido with epi, tachycardia shortly after injection is a good tipoff you're giving an intravascular injection. What kinds of reactions are you seeing? What meds are you giving for sedation?

Local anesthesia toxicity should be a pretty rare event. If you're starting to see it with any regularity at all, whoever is doing your procedures needs to be re-educated. I've seen one local anesthetic seizure in 25 years - it's a very impressive event and not easily forgotten.

gaslinq · Apr 4, 2006

I have seen one episode of Lidocaine toxicity and ,believe me, it was catastrophic, to say the least. It is not advisable to give more than 7 mg/kg of Lidocaine at one time. Epinephrine can be added at 1:200,000 concentration to delay the systemic absorption of the drug and at the same time, to be able to easily detect intravascular absorption (there will be immediate tachycardia). As jyk said, peri-oral numbness as well as a metallic taste are usually signs of impending toxicity. CNS toxicity is manifested by restlessness, tinnitus (ringing in the ears) and more often than not, is mistaken as inadequate anesthesia, leading the person performing the procedure to ADD more anesthetic, aggravating the situation.

One must never perform procedures under local anesthesia without preparing for the possibility of such a reaction. It is unfortunate that more and more procedures are being performed in settings where there are no equipment available for airway management and cardiac resuscitation as well as trained personnel.

yoga crna · Apr 4, 2006

You leave out a lot of information. Is the lidocaine with or without epinephrine? Does the patient have hepatic disease? The maximum doses are higher if it is with epi (slower absorption). I find that 2% lidocaine is a very high concentration and is not needed. My surgeons use 0.5% lidocaine with 1:200,000 epinephrine for long facial plastic cases.

Understand that when there is an overdose, you will get CNS excitability, leading to seizures. There is no easy reversing agents.

While you ask for personal experiences and not book information, I think it is critical that you review the pharmacology of local anesthesia. Hopefully, you are not a CRNA or SRNA. If you are, I would really be upset that you didn't know this information or, at least where to get it. It is unacceptable to be part of any procedure not having sufficient knowledge to take care of the patient. If anything would happen to the patient, it would be hard to defend yourself in a negligence action.

I know you came to us for information, but evidence-based practice is quickly becoming the standard of care. Research the literature and get the evidence you need.

Yoga crna

Joshua21 · Apr 5, 2006

Thank you all for your responses so far, even your's yoga despite the unwarranted crisp hostility. I am pursuing many avenues in researching this problem and my suspicions related to Lido Tox.

I am being specifically vague as I do not want to contribute to your experiences and biased them.

Being as your all so helpful so quickly I would be happy to share some of the background.

Recently I've been exposed to 4 cases of an odd phenomenon that appears like acute seizures, with gross global tonic/clonic movement, eye deviation, aniscoria and incomprehensible sounds. The patients appear ill but gradually over an hour seem to improve, usually by the time we get them to the unit, tubed, otherwise unsupported. This is usually preceded by a bout of hypotension. One moment I'm speaking with the person, next they're seizing.

By morning at the latest they're back on the floor.

The procedure is implanting of Pacers and ICD's.

The people are of variying health backgrounds but usually compromised cardiovascularly. Two were very emaciated.

All were female.

Meds used by myself are usually

Diphenhydramine 50 mg iv once

Fentanyl 25-50 mg bumps

Midazolam 0.5-2mg bumps

Docs use Lidocaine 2%, anywhere from 60-100ml's volume, instilling the tissue involved with the generator pocket and obtaining venous access.

Sedations scores are different at every location so suffice it to say we want to keep VS within 10% of baseline, patient will awake to voice, not evidence pain or little discomfort and maintain own airway.

Take from this what you will but again I am looking for witness accounts to see if these match up.

If you feel you have knowledge that will contribute or direct me please feel free to offer a hand.

Thank you

URgettingsleepy · Apr 5, 2006

Well lets see.........

Toxic dose of lido 5mg/kg without epi

7mg/kg with epi

Your docs give 60-100cc of 2%!!!!!

2%= 20mg/ml

Best case 60x20=1200mg

Unless your patients are over 200kg you have problems.

Please verify the concentration of Local your Docs use: verify the percent and any dilution they may be using.

Scary.....

deepz · Apr 5, 2006

.........Recently I've been exposed to 4 cases of an odd phenomenon that appears like acute seizures........
The procedure is implanting of Pacers and ICD's.
..........
Meds used by myself are usually
Diphenhydramine 50 mg iv once
Fentanyl 25-50 mg bumps
Midazolam 0.5-2mg bumps
.......
As this is a CRNA forum, please do not take offense when I suggest that these patients sound as if they would be best served by having an anesthesia provider giving them their MAC.
deepz

jwk · Apr 5, 2006

This is classic local anesthetic toxicity. It's really scary that your docs don't recognize this issue, especially since they keep having the same problems.

rn29306 · Apr 5, 2006

Sorry to the OP, but this kind of stuff really burns me. I hate it when staff RNs start playing mini-CRNA and get outside of fentanyl / versed for CS.

Why on earth do some staff RNs that I know start throwing benadryl and phenergan into the mix. The OP even said these people were emaciated. Let's see - that means the patients were OLD and FRAIL. 50 of Benadryl IV would wrech havoc on my system and I'm a 6 foot 2 guy in early thirties. While the OP didn't say he used phenergan, I know some that do and this stuff put me out of my mind for 4 hours in an ER in Georgia. Old people, much less anyone else, don't need this type of continual sedation. Heck, while you are at it, why don't you give scop to these people just to add to your 'recipie'.

My brother just had esophageal dilation under CS by staff RNs. I begged him to find another MD that used anesthesia for this, but he didn't listen to me. He has had this done before and he had a very extended period of sedation. Yep, after the procedure they almost couldn't get him to move into a wheelchair and went home and slept for 18 hours. This is a family man with two young children. I asked him to obtain his records just for him to know not what to be given again, for his sake. I am absolutely positive that they strayed outside of fentanyl and versed and got into the phenergan / benadryl BS game.

Yeah, staff RNs, your people stay sedated and on the table, but what about how you affect their lives afterwards. I can tell you that 50 mgs of Benadryl will def play with old people's minds and urine output. Phenergan will scramble anyone's brain.

Why on earth (actually I do and its all about the benjamin's) do people still continue to do this when anesthesia can have you back on the golf course in 2-3 hours or at least go home in a functional state with propofol and minimal narcotics. Just because it happens doesn't mean its right.

Unless you anticipate a histamine release, there is no need to give benadryl for CS. It is a disservice to your patients, if anyone gives a crap anymore.

jwk · Apr 5, 2006

Unless you anticipate a histamine release, there is no need to give benadryl for CS. It is a disservice to your patients, if anyone gives a crap anymore.

I'll OCCASIONALLY use benadryl for sedation, but never 50mg. More like 12.5 or so. We also have a lot of plastic surgeons wanting it for it's anti-emetic properties, but again, just 12.5mg.

Although I agree, the CS recipe stated is a problem, their main issue is a repeated gross overdosage of local anesthesic. Ya gotta assume this is their norm with EVERY patient, and they've only gotten lucky that a few of them have seized.

The most impressive local anesthetic seizure I've seen was with a surgeon who does his carotids under local. Great concept, until he injected lido with epi directly in the carotid. Huge seizure, even bigger BP, but amazingly, they didn't stroke out, and had their procedure done the next day without further incident.

rn29306 · Apr 5, 2006

I'll OCCASIONALLY use benadryl for sedation, but never 50mg. More like 12.5 or so. We also have a lot of plastic surgeons wanting it for it's anti-emetic properties, but again, just 12.5mg.

Yoga said her facial plastics guys had documented proof that benadryl reduces local inflammation at the surgical site and most often her patients had minimal facial swelling after condiderable tissue manipulation.

I know the OP was talking about LA and seizures, but I had to throw my 2 cents in concering how some staff RNs give absolutely retarded recipies that reduce a person to essentially a non-functioning state sometimes.

rn29306 · Apr 5, 2006

The most impressive local anesthetic seizure I've seen was with a surgeon who does his carotids under local. Great concept, until he injected lido with epi directly in the carotid. Huge seizure, even bigger BP, but amazingly, they didn't stroke out, and had their procedure done the next day without further incident.

Wonder who said 'oh shiz' first - you or surgeon?

How did you break the seizure and control the BP?