How deep does a needle go when injected through skin?

Question

Does the whole actual needle go in..? And how does the doctor know how much to squirt in..? What happens if an air bubble gets in? What happens if the needle goes in too much? How do you know WHERE to prick th needle through..? Do you just guess?

Answer 1

people who give injections are educated on how and where to give them, as well as the appropriate size needle to use.....there is no guessing involved, that could be dangerous

Answer 2

It kinda depends.

First of all, they know how much to put in, because they measure it in advance. The syringe is marked with measurements, just like a measuring cup. When you see them flick their finger against the syringe, that is an effort to get all of the air bubbles to the top...Then they squeeze the syringe, so that all of the air bubbles come out, and they then do a fine measurement to ensure they have exactly the right amount.

The type of injection will determine the placement of the prick...In general, they want muscle tissue...As long as they're in the muscle, there's not really much that can be done to get it "wrong". It's just a bunch of muscle, so as long as it's past the fat layer, it's fine.

For the most part, the only time the needle can go in too far, is if you're trying to draw blood, and the needle goes into the vein, and then out the other side. This doesn't usuallly cause major problems, but certainly give the patient some significant bruising.

Answer 3

There is alot of variability in the answer to this question.

Some injections are "intradermal" for example an injection in the forearm to test for tuberculosis. This injection is given just beneath the first layers of skin. More common in as intramuscular injection where the needle goes in past the skin and into the muscle. There honestly is a bit of guesswork here, especially if the patient has alot of fat between the skin and the muscle. Muscle has a good blood supply to carry the injection away. Fat does not. Injections are given usually either in the deltoid (shoulder muscle) or in the "upper-outer gluteal quadrant" ( if you drew the face of a clock on a butt cheek, the injection would be given around 1 or 2 o'clock). The areas are chosen because the muscle runs close to the skin and there are fewer nerves and bones that run through these areas (hitting a nerve or a bone can be quite painful).

An air bubble is no problem in either an intradermal or intramuscular injection as it will readily dissipate. (air bubbles are only problematic if injected into an artery).

"How much to squirt in" is determined prior to ithe injection when the injection is "drawn up" into the syringe. this is based on milligrams per milliliter. If the solution is 100milligrams per milliliter and the recommended dose is 50mg...1/2 of a milliliter is drawn up into the syringe and the entire volume is injected (no guesswork here).

Hope that this answers your questions

Answer 4

Quite simply, the needle goes in as far as it is long. Different needles are used for different applications. Each shot is specifically designed to be in a spot where it will do the best for the patient. A PPD (test for tuberculosis), is placed in your forearm and red days later. A tetanus shot is given in your arm to gradually be absorbed by the body. Only a large amount of air, (more than 1cc), will hurt you.

Answer 5

They are trained hard core to know when, where, how and how deep, the entire needle doesnt ho in- that would be VERY BAD, and it would be even worse if an air bubble got in- it would evenually go to your heart and do some damage. But if you ever feel like they dont know what they're doing- LET EM KNOW! Its your life! ♥

Answer 6

as far as you push it in. as long as the needle.

Answer 7

depends..and they get a lot of training