I decided that I should take the effort to learn something new everyday.
It can be anything - related to work or just a general thing.
A new thing a day, or at least a new thing every blog entry.
Since it is a little late right now, and I am kind of sleepy, I am not going to think very hard about what to write for today.
I was given a 'homework' by one of my specialists that I have to present during passover tomorrow. That will be my 'new thing for the day'.
Today, I found out why local anaesthetic(LA) doesn't work if the area of interest is inflamed/infected.
LA is a base. Inflamed tissues are acidic.
So, as the LA is neutralized, there won't be sufficient amount of LA to penetrate the tissue and produce it's effect. (something like that la)
Hopefully it will go well during passover tomorrow..
It can be anything - related to work or just a general thing.
A new thing a day, or at least a new thing every blog entry.
Since it is a little late right now, and I am kind of sleepy, I am not going to think very hard about what to write for today.
I was given a 'homework' by one of my specialists that I have to present during passover tomorrow. That will be my 'new thing for the day'.
Today, I found out why local anaesthetic(LA) doesn't work if the area of interest is inflamed/infected.
LA is a base. Inflamed tissues are acidic.
So, as the LA is neutralized, there won't be sufficient amount of LA to penetrate the tissue and produce it's effect. (something like that la)
Hopefully it will go well during passover tomorrow..
3 comments:
Now i learnt smt new today.. thanks! (=
Me too! Now I know more about it. LOL :D all the best with your passover!
There is a decreased response of local anesthetics in an acidic (inflammed/ischemia) area because local anesthetics are considered weak bases so the acidic environment ionizes the local anesthetic..in order for the local anesthetic to penetrate lipid bilayer (of the neuron) it needs to be nonionized.
Usually once the local anesthetic is intraneural it becomes ionized and is able to block the Na+ channel therefore signal is blocked in the afferent nerve...therefore no pain is sensed.
Key points for local anesthetics...pKa and pH provides how much of the local anesthetic is nonionized vs ionized therefore governs its ONSET.
Often diabetic patients are brought to the OR for a toe amputation and an ankle block with local anesthetics are performed. If the area is acidic/ ischemic/ inflammed the local anesthetics are less efficient.Often these patients have neuropathy in which they have poor sensation to begin with...thats why diabetic ulcers tend to worsen.
They can be supplemented with intravenous medications ex. opiod narcotic: fentanyl,ketamine also provides analgesia and amnesia.
Generally with an ankle block...you are blocking nerves more proximal to the actual acidic environment (ex. gangrenous toe). No sticking needles in infected tissue.
The whole concept of ionization vs nonionized form of local anesthetics is why some people add HCO3- to local anesthetics to speed the onset.
Thank you.
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