1. peachalulu
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    peachalulu Contributing Member Reviewer Contributor

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    Amateur drawing blood with needle

    Discussion in 'Research' started by peachalulu, Nov 13, 2013.

    In the story I'm working on for nanowrite I have a scene in which
    a character needs to draw blood from his arm with a needle and has
    never used needles. A doctor talks him through it. I'm not quite
    sure what he'd say, and would it be a worry for a character to
    wonder how deep do you shove in the needle? And also if it would
    be dangerous to draw back the plunger if he hasn't hit the vein?
     
  2. GingerCoffee
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    GingerCoffee Web Surfer Girl Contributor

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    It's only hard if you can't see the vein or if you use the wrong needle. People with a lot of body fat are sometimes hard to find veins on. Most men have easier to find veins than women.

    A butterfly needle works best for self draw but junkies use straight needle on a syringe on themselves all the time.

    Put on a tourniquet, a belt works but anything will do. Sometimes you have to use your teeth to pull or hold it tight if you don't have the rubber kind that you tuck into themselves.

    Aim the needle up the arm, not down it, about a 45 degree angle.

    For a young healthy person with good veins, you just stick the needle in slowly and stop when you see a little blood to show up in the needle. Older people can have stiffer vein walls that you need a little jab motion to get through or the needle pushes the vein out of the way instead of going through it.

    It's really not hard on most people.

    It's not dangerous to pull back on the plunger if you are not in a vein. Normally you would put a little air in the syringe to start with and that allows the blood to flash back into the syringe without needing to draw back. You see you are in the vein. And when filling the syringe, pulling back too hard will cause the blood vessel wall to suck up against the needle bevel and stop the flow, so you pull back gently.

    With vacutainer blood draws you have to feel when you enter the vein, that would be hard for someone with no experience and especially hard to use on oneself. So stay away from that in your story.
     
    Last edited: Nov 13, 2013
  3. jazzabel
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    jazzabel Contributing Member Contributor

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    When you draw the blood using hollow needle and syringe, you can miss the vein completely. Nothing happens, it just hurts and can block the needle (not likely). They can then stab in different directions, trying to find it, sometimes that works.

    If I had to talk someone over the phone how to do it I'd get them to practice first, withdrawing the plunger with one hand, whilst keeping the syringe very still. I imagine that would be really difficult and I'd be tempted to get them to use a syringe without the plunger, and let the blood trickle into a container of some kind instead. Obviously, use dominant hand to work the needle and syringe.

    Then, tell them to find something that can act as a tourniquet (a strip of cloth, a piece of stretchy rubber tubing, whatever) and tie it around their biceps, tightly. Look at the veins pop up. If you need to, pump the fist, warm up the limb tap where the vein is, all this will make it pop more. You want the vein to be engorged with blood, so it doesn't move around and it gives nice pressure.

    The thickest vein will be in the cubital fossa (inside part of the elbow, where blood is usually drawn from) but lower down is also ok. Place the needle at 30 degrees with the surface of the arm. Point the needle towards the body, not away. If the vein is very pumped, you can come from the side, or from the top. Advance the needle very gently, a couple of millimetres at a time, until you get a flush back which is blood filling up the plastic bit on top of the needle. That tells you you're in position. If you shove it too hard, or keep going, you'll go through the vein, it'll bleed into the tissues giving you a haematoma and a big bruise, plus the vein will be useless for a while. So you really want to avoid that. If by some miracle he can operate the syringe plunger with one hand, he needs to do it slowly, and blood will fill the syringe as he withdraws. More simply, let the gravity do the work, and let the blood drip into a container. The result of the blood test might be a bit messed up (blood cells might haemolyse, obviously it'd be useless for a bacterial culture, but it depends what he needs the blood for).

    When finished, release the tourniquet, withdraw the needle and press on the puncture until it stops bleeding. Done! ;) However, if I had to take blood from myself, I'd take it from the top of my foot, so I have both hands free, which is infinitely easier to do.
     
    Last edited: Nov 13, 2013
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  4. GingerCoffee
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    GingerCoffee Web Surfer Girl Contributor

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    If you poke around too many times with the needle trying to find a vein, the damage to the cells releases chemicals and you can end up with hemolyzed blood (the red cells fracture), which in some cases can't be used, or, clotting factors result in the blood clotting in the needle and you have to start over.

    Gravity won't push a syringe plunger back. Blood banks, though, do use gravity to fill a blood donation bag.

    Veins in the top of most people's feet are going to be harder to find. Junkies don't get to the veins in their feet until they use their arm veins up. You don't need two hands to draw blood with a syringe.
     
  5. Steerpike
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    Steerpike Felis amatus Supporter Contributor

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    We had to draw each other's blood in a hematology class in school. My lab partner was a trained phlebotomist, so that was great for me. I, on the other hand, missed his vein a few times (he was a big guy) and ended having him guide me verbally with the needle already in until I found it. He had a big bruise under the skin the next day and I was like "OK, well, clearly not my calling."
     
  6. jazzabel
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    jazzabel Contributing Member Contributor

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    @GingerCoffee: Please read my post more carefully next time, to avoid misunderstandings.

    I quite clearly indicated that if the plunger is REMOVED, the gravity will allow blood to trickle through the hollow syringe and into a container of some kind. This would be much simpler than trying to work the plunger and syringe with one hand. This is my opinion based on years of taking bloods with a needle and a syringe.

    I won't be discussing any medical issues with you so I will ask you once again to stop tagging me repeatedly. However, I will set you straight when you misquote me. That is all.
     
    Last edited: Nov 13, 2013
  7. GingerCoffee
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    GingerCoffee Web Surfer Girl Contributor

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    I've drawn my own blood a few times. Sometimes it's easier to order my own lab work than it is to go into the clinic. I have one of those metal lock boxes at the door the lab picks specimens up from. I draw blood on patients all the time.

    @jazzabel: I did read your post, did you read mine? "Blood banks, though, do use gravity to fill a blood donation bag."

    I know you don't like it when I post anything that dares differ from what you've said, but in this case I was adding a few things to your comments, I don't believe other than wondering why someone would draw from a foot, that I said anything that contradicted what you posted.
     
  8. Aurin
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    Aurin Member

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    To just the OP, from someone who has had the above happen to me, it would be interesting in a story. Hurt like all hell at the time (from a qualified nurse who soon as she shoved it in I knew something was wrong) and took weeks and weeks to heal completely - bruise went from halfway up my upper arm and almost to the wrist; elbow was easily the most disgusting thing myself and my co-workers had ever seen.

    I've heard several times (from friends and my boss who is a surgeon) about taking the blood from the feet, or the wrists (though the wrists wouldn't help in this situation). From having the veins in my own feet injected, I can imagine it would hurt considerably worse than in the elbow?
     
  9. Daniel
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    Daniel I'm sure you've heard the rumors. Founder Staff Contributor

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    In regards to pulling the plunger back, there's no risk doing so if you haven't hit the vein; I believe it's actually recommended during intermuscular injections to pull back slightly to make sure you haven't hit a vein. The real danger is when you push the plunger in and risk putting air into your bloodstream.
     
  10. GingerCoffee
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    GingerCoffee Web Surfer Girl Contributor

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    The air in the vein thing is a bit fact but mostly myth. You need about 10 ccs of air pumped into a vein to get an injury from an air embolism. Think air lock in a fuel pump, a few small bubbles are just absorbed.

    The way patients get killed by air emboli is with IV pumps that don't have alarms when the bag runs dry and also have some means of air leaking into the lines. Typically this was a pediatric hazard. Now in modern countries you almost never see an IV pump that doesn't have an empty bag alarm.

    The only other way it can happen not counting willful murder is with a sucking chest wound.

    As for drawing back with an IM injection, a lot of nurses have stopped the practice. They're wrong to do so. I've been in a vein 3-4 times over the years, so it's extremely rare, but for the minor effort of pulling back, there's no reason not to.

    The thing about pulling back on a syringe that missed the vein or even if you pull too hard when in a vein is, nothing gives. So if you are not in the vein you damage cells and get those annoying clotting factors and histamines into to the needle. If you are in a vein you suck up the vein wall and plug your needle. I can't imagine trying to remove the plunger of a syringe while in a vein in order to let the blood drain out on it's own accord. If you could pull that hard you'd likely suck the cells from the vein wall right into the needle. You'd have to unscrew the syringe from the needle, it makes no sense. Pulling the plunger out ahead of time and just using the syringe barrel and gravity really limits the control you have. While it would work with a very large needle and some people, with other people the blood would likely clot the needle before you had the blood you needed. Then there's that whole contamination problem if you are looking for something only in the blood. And I would think (as in opinion) some readers might find the method unusual and perhaps less credible.

    You don't need to pull back to see the flashback, you need to pull the plunger back a 1/4 inch (or 1/2 cm) first before inserting the needle, leaving enough airspace so that when you hit the vein the blood enters the needle from the venous pressure alone. If you don't see blood, you aren't likely in a vein.

    If one really wants the minutiae, when you see the blood you advance the needle another millimeter to be sure you are in the vein (unless you know you are in a very tiny vessel). Yes, you can go all the way through if you don't know how short a millimeter is, but you can also lose the vein if you are only barely in the wall when you try to collect the blood.

    Going through the vein rarely causes a huge hematoma by itself (but you don't get the blood you are trying to get). Rather it's when the vein wall splits or tears that you get problems. And that can happen for a number of reasons.
     
    Last edited: Nov 14, 2013
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  11. peachalulu
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    peachalulu Contributing Member Reviewer Contributor

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    Thanks, for the great advice everyone! BTW - My mc is out in a yard being penned up. The scientists don't want to approach him as they
    assume he is sick, hence they want to check his blood to see if he is infected. They toss him a kit. It's a small but major scene
    and I wanted some accuracy. Nice to have people in the know when you're doing research - :)
     
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  12. Daniel
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    Daniel I'm sure you've heard the rumors. Founder Staff Contributor

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    Wow @GingerCoffee thanks for schooling me (in a good way) and dropping some mad knowledge!
     
  13. mammamaia
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    mammamaia nit-picker-in-chief Contributor

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    peachy...
    since there are scientists on the scene, why wouldn't someone who's trained to take blood just suit up in biohazard gear and do the drawing?
     
  14. thewordsmith
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    thewordsmith Contributing Member Contributor

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    That was my first thought as well.
     

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