hi everyone this is lahiru from abcs of anesthesia and today
what i want to go through is how to put local anesthetic into the skin
now this is a really basic technique but something that's so worthwhile
especially if it's appropriately within your scope of practice it can really be amazing as
a technique to help decrease the pain of putting in a needle for your patients now what i'll do
is i'll generally put local in the skin for anywhere from an 18 gauge or larger
cannulas that means 18 gauge 16 gauge or 14 gauge especially any rick lines or central lines i've
mostly find that 20 gauge in the 22 gauges aren't that painful and so it's probably not worth doing
two needles in that circumstance that said sometimes the patient is very anxious maybe the
cannula needs an ultrasound guided technique maybe it's a difficult insertion of some sort in those
cases i have a low threshold of using local with a very tiny 30 gauge needle or 27 gauge needle
so the first thing i do is choose the right vein so this patient here has a fantastic hephalic vein
and we're going to do a demonstration later a 14 gauge large cannula insertion
so completely appropriate that i put local anesthetic in the skin for this now the things
i need for this is really quite simple i just need a syringe local anesthetic and a needle
so the syringe that i choose is just a small two or three mil syringe and it just means that
this is just really easy to hold and i have the right amount of dexterity when i'm using
it i usually choose one percent or two percent lignicane that's all you really need it's fast
onset and doesn't last too long it's a really safe local anaesthetic to use now the needle i choose
is really a fine needle it's either 25 gauge 27 gauge or 30 gauge depending on what's available
to me for example many hospitals won't have a 30 gauge in which case i'll just use a 27 or 25
and it doesn't matter which needle you use it's much smaller and less painful to
insert local handstand with this needle than to insert a large 14 gauge needle
so before i inject the local anesthetic in the skin i choose the site so here i've got
a really great cavalic vein and i'm going in a reasonably distal site so my side of entry
of my needle will be about here now i've got two options for the injection of the local anesthetic
i can either go over the vein or just to the side i think a lot of people when they're
starting out might put it to the side because you don't want any risk of puncturing that vein
what i do in my practice is i actually go over the vein i'm being really really careful not to go too
far in so i go just subcutaneously and as soon as i'm in i inject i find that if i go to the side i
need to give far more volume of local anaesthetic to make sure that it diffuses across to the
insertion area so i'm now going to start injecting the local anaesthetic i just uncap my needle
i steady all my surfaces again i'm anchoring my little finger multiple fixation points i go
really steady sometimes i'll let the syringe rest on my thumb as well to make sure that
i get that just right i'm having a really low angle of entry as soon as i get into the skin
i inject you'll notice i don't need to inject too much you'll see a blanching across the skin
that blanching means that you're going exactly in the right spot and i won't put too much right
there i've put probably 0.1 mil of one percent lignicane it's really not much at all and that
point of insertion that's exactly where i'm going to go in with my 14 gauge cannula now because i
used a very tiny 30 gauge needle and i didn't put much local anesthetic at all that means that this
injection really wasn't that painful the pain and injection of local anesthetic is usually related
to the size of the needle so it's a 30 gauge it's really small and the volume which expanded the
tissues and this was only point one of a mil of local anesthetic so really there shouldn't have
been much pain with that injection and it'll be far easier to do the 14 gauge cannula now