00:01
All right.
00:01
So we're gonna talk a little bit about acetaminophen overdose
which is actually a common
and disturbing problem in the United States.
00:10
Acetaminophen is also known as paracetamol in other settings
and it's a readily available over the counter drug
that has highly lethality potential
and produces very minimal symptoms at least in the initial phase.
00:23
So the way acetaminophen works
or the way that toxicity works, I should say,
is that the liver metabolizes the acetaminophen
into a compound called NAPQI which is highly toxic.
00:36
Now in normal dozes of acetaminophen,
your NAPQI is combined in the body with thiols
that produces a non-toxic metabolite
which is then eliminated.
00:46
However, in overdoses,
your thiols stores are depleted
and the toxic metabolite accumulates.
00:53
Now, the main effect of acetaminophen is liver injuries.
00:57
So in high dozes,
acetaminophen can actually cause permanent liver failure
and it’s one of the leading causes
of liver transplantation in young people.
01:07
The antidote for this is called NAC or N-acetyl-cysteine
and basically what it does,
is it detoxifies NAPQI
and decreases the production of it.
01:16
It’s a very, very effective antidote
but it has to be given early.
01:20
It should be initiated within eight hours of the ingestion.
01:23
So this is very important.
01:24
You can't wait around to see
if the patient is gonna have manifestations of liver failure.
01:29
You need to initiate treatment
based on your clinical suspicion.
01:33
So there's a nomogram that helps guide our decision
about whether to give NAC to patients
with acetaminophen overdoses.
01:41
Note that the nomogram doesn't start
until four hours after the ingestion.
01:45
So it takes four hours for GI absorption to be complete.
01:50
Meaning, we don't check a level
until four hours after the ingestion.
01:54
After that point,
depending on what level we get,
we can differentiate between high risk of toxicity
and low risk of toxicity,
and if the patient is above that threshold for toxicity,
we wanna go ahead and treat them.
02:09
All right.
02:10
So obviously,
I couldn't cover every possible poisoning.
02:13
So I tried to give you some essential principles.
02:16
It's really important to know your toxidromes,
so that you can recognize
what drug class your patient might have been exposed to
and narrow your differential diagnosis.
02:25
Otherwise, you're gonna be left trying to figure out
the individual properties of lots of different drugs
which is not really realistic.
02:32
You wanna make sure you externally decontaminate your patient
in order protect both yourself and them.
02:38
You wanna provide aggressive support of care
with the real focus on the ABCs.
02:43
You wanna recognize any potential high toxicity
or high lethality ingestions and get help.
02:49
You wanna consider GI decontamination,
especially in patients with the high risk of morbidity
or mortality from their toxic ingestion.
02:56
But remember to always protect their airway when you do that.
03:00
And then you wanna be aware of antidotes
and use them when they're available and indicated.