My roommate just got a novocaine injection used for a cavity filling for the first time. While I’m not sure where I heard it, I warned him that it is possible for the dentist to accidentally kill you if s/he injects the novocaine directly into a nerve in your jaw. He couldn’t believe me so we turned to google, but I can’t find any references for or against this. Could this be an urban legend? Thanks,
Kevin
(P.S. This never stopped me from having them use novocaine… drug me up doc! 
)
Novocaine (generic drug name procaine) can cause major problems if directly injected into the blood stream in large amounts and too rapidly (that is, injected directly into a blood vessel). Direct injection into the blood stream can cause a seizure, which in some circumstances could result in death. Direct injection into a nerve would not be deadly – the drug only works when it is injected in close proximity to a nerve, thereby inactivating the ability of the nerve to send pain signals. So, unless the dentist mistakenly injected the anesthetic into a vessel, no worries - unless of course the patient has an previously unknown allergy to the drug and has a severe hypersensitivity reaction (but that’s a whole different story).
Use of the “caine” anesthetics (lidocaine, cocaine, novocaine, etc) does have some risks, as the medications can cause heart arrhythmias when injected directly into the vein. One may also get (mostly) minor arrhythmias from injecting high concentrations into soft tissues when trying to get them to numb up. But I’m unaware of any direct fatal toxicity mechanism when injected into a nerve. Frankly, that’s where the medication is supposed to go, to numb the nerve. It does so by blocking sodium channels in the nerve.
It is actually used to counter arrhythmias in many folks who are having rhythm disturbances, like after heart attacks.
Of course, any drug, given in excess, can be fatal. The LD 50 dose (the dose at which 50% of the test specimens die) is 250 mg/kg when given IV to a rabbit. That’s a pretty big dose. I doubt I’ve given more than 50 mg for any local procedure.
Two doctors who agree on the same issue - imagine that!!! Hey QtM - we haven’t crossed the same thread since andrewdt85…
Should we engage in some “fee splitting”? 
Ah, good thought - hey I didn’t know it was possible to bill for services rendered on the SDMB…
Sadly, battling ignorance remains poorly remunerative. It’s a non-covered benefit for most insurers, ya know!
Well said
While the good doctors have chimed in with book smarts, I can tell you from first hand experience, that having novocaine injected directly into a nerve, while rather (rather = really really) painful, is hardly deadly…at least not for me.
While preping me for a root canal, the dentist noticed that I jumped a little while he was injecting the novacaine. He asked “Did you just feel an electric shock sensation”? I nodded “yes”. He said “Cool! I hit the nerve dead on. That means good news and bad news. The good news is that you won’t feel anything at all during the procedure. The bad news is you won’t feel anything for a long time after the procedure”. He was right. It took more than 24 hours for the effects to wear off completely.
I am now at the age when some of my doctors are younger than me, but it would still give me pause if my dentist, in the middle of a procedure, started a sentence with “cool.” Or even worse, “Awesome.”
Just to confirm something - even if injected into a vein, the normal dental dose of novocaine wouldn’t prove fatal in a normal patient (that is, someone without an allergy or pre-existing heart condition)? The figures quoted seems to suggest that you’d need something like 400 times the normal dose (injected incorrectly) to get to the LD50 - am I interpreting them correctly?
Yes, you are interpreting them correctly.
We would still like to avoid directly injecting into a vein, as it can cause nausea and some rather interesting (if you’re watching the patient) heart rhythm disturbances, but it would rarely be fatal.
There are techniques for avoiding a deposit of anesthetic into a vein. Aspirating (pulling back on the ring) and checking for blood in the carpule is one of them also a double check by turning the needle and aspirating again. But if for some reason the good hygienist or dentist injects anesthetic into a vein, and the anesthetic contains epinephrine, you will experience an extremely fast heart rate and can be fatal if you have heart problems.
Also, people with liver problems or kidney problems, also others with thyroid conditions and diabetes. All of these conditions deserve special attention by the dentist and hygienist, all play a part in which type of anesthesia is used in comparing amides and ester type anesthetics. All can have fatal results of the precautions and protocol are not followed.
Novacaine is also known as procaine which is in the ester family. The ester family is not used anymore for one thing, and one reason being is that too many people had an allergic reaction, of which can be fatal for some. Especially people today with their plethora of allergies and asthmatics. Just a tid-bit of info. Cocaine is an ester also, and is the original anesthetic and was also the original pain medication also before they knew their addictive properties.
Years ago I was getting a shot waaay back in the crock of my jaw, each time the dentist moved the needle it felt like water was spraying on my face, (and it was rather painful to boot). I asked about it afterwords and she said that means she hit a nerve. It was numb before she was done injecting and stayed numb for a looong time after.
I seem to remember a news story from long ago about a man who basically went nuts, ran out of the dentist office, and committed some sort of crime after the dentist accidentally injected the novocaine into a vessel rather than IM.
Is that a reasonable possibility?
Hm…time to Snopes, I guess.
Interesting things also happen if you use a local anaesthetic containing adrenaline for a ring block.
That’s if you count you patient’s anaesthetised digit (or, in one memorable malpractice case, penis) falling off as being interesting.
Do you have actual cites for that, irishgirl? I’m not asking to be snotty, but I’ve been told the same thing about adrenaline for over 25 years, and recently heard from a semi-reliable source that it was all based on theoretical risk, there were no documented cases of digits, noses, ear bits or other members being lost due to the vasoconstrictive properties of adrenaline.
I have not started using it in my digital blocks yet, however.
…Is it safe?