when you go to sleep if I pinched you
you'd be up if I shook you you'd be up
right but under anesthesia I'm gonna
pinch you and do a full operation and
you're not up so it's really further on
the spectrum of unconsciousness ten nine
eight when you wake up after being put
under with general anesthesia you barely
feel like any time has passed you could
have been out for an hour or a day and
you wouldn't know the difference when
you go to a natural sleep people call
your name your alarm goes off you wake
up right this is not what's going to
happen during general anesthesia you're
gonna be unconscious you're closer to
being in a coma than being asleep
anesthesia was first used during surgery
in 1846 the drug provided at that time
was ether now anesthesiologists more
commonly use a combination of drugs like
propofol and fentanyl which interrupt
neural pathways so you don't feel pain
and you don't remember the surgery three
things that you need for general
anaesthetic are you need amnesia so that
they don't remember analgesia so they
have pain relief and then operating
conditions for the surgeon some
surgeries you need the patients to be
very relaxed so you would use a muscle
relaxant other surgeries the patient
just needs to be asleep and anesthetized
but they don't need relaxation so how
they do that varies upon the different
medications that you're using some will
depress excitatory neurons and some will
enhance inhibitory neurons excitatory
neurons for example get excited and send
signals to other neurons to fire
depressing them means less signals
telling your brain you're in pain
inhibitory neurons do the opposite they
make it harder for neurons to generate
these electrical signals in either case
this means fewer active neurons overall
which is important because when your
body is being poked and prodded neurons
would typically fire to tell your brain
you're in pain
if those neurons aren't firing your
brain doesn't know that your body is
well being cut open basically it
interrupts the pathways and the
communication between your neural
networks we're aiming for them to be not
in pain while looking at their vital
signs their heart rate their blood
pressure then we want to make sure that
they're unconscious without anesthesia
many important surgeries wouldn't be
possible because they'd be way too
traumatic surgery didn't move forward
really until anesthesia moved forward
you know you watch those old movies they
give you a swig of alcohol they put a
tourniquet and they hack your leg off
and people don't do well with that right
if you had a bad heart that would be the
end of that after the procedure is
complete
the doctors stopped administering the
meds and the most powerful effects of
the drugs wear off but even though
you're conscious again you might
continue to experience some of the drugs
side effects like a trampoline