Some of these other posters have already mentioned some of these things, but these are all things that I mention to people starting out or looking to improve. For the cases that you mention specifically (frail, tiny, delicate veins), these tips should help a lot. Those veins require patience and POSITIONING.
- Ask your patients about their veins. I've seen how easily forgotten this step can be. Is there one side that's better? Do they usually get the hand or the AC? Is it just where ever they can find one? Heed their warning if they say that their veins roll, blow, hide, etc. and be prepared for that.
- Make it easier on yourself by utilizing gravity/positioning and a warm pack. I always get a kick out of people who leave the patient lying in bed and they lift up their arm to look for access. Raise the bed and have them drop their arm off of it. It can be a HUGE difference just with positioning. In regards to warm packs, I will take a large sized glove and fill it with warm water to create a makeshift warm pack. Very effective.
- I'm a firm believer that if someone misses a rolling vein, it is the IV starters fault, NOT the vein itself. I hate hearing the excuse "the vein rolled away so I couldn't get it". It rolled away because it was not anchored properly. The phrase shouldn't be "the vein rolled", it should be "I didn't anchor the vein well". To combat that, if someone tells you their veins roll or if you can tell just by evaluating the veins yourself, take the extra time to position the vein exactly where it needs to be so that it doesn't roll. I will tell my patients to expect to feel me pull their skin multiple directions before I stick them because I am trying to make sure I am able to hit the vein without it rolling away. Get that vein in a steady position before you start.
- This sorta goes along with my last tip, but when you're anchoring the vein, if it does move away or if you are having trouble entering it, do NOT release the traction you are holding with your opposite hand. Do that as a last resort. If you have a vein get away from you and you release the traction you were holding, you will have a much tougher time trying to line everything up again. This is especially important with the elderly who have loose skin. My tip is try to move slow and don't fish around. Pull traction tighter, find which direction the vein went, reposition your sharp, and try to enter the vein from the side if needed. Don't be afraid to get a second set of hands if the patient has very loose skin, but be careful to not pull traction so tightly that it collapses.
- With IVDU, if they still have veins but you are having a difficult time (or anticipate having a difficult time) cannulating the vein, go for a larger IV. Sometimes you may miss with a 20g or 22g trying to sneak around the scar tissue when really what you need is an 18g to be able to push through the scar tissue. (This is not true for every IVDU, but something to consider).
- Another trick for IVDU or people with difficult to find veins is using the basilic vein in the forearm (that wraps around the underside of the arm that is difficult to access). This vein is more difficult to IVDU to access themselves, and if the patient has veins that are used/damaged from multiple IVs and medical procedures, this vein probably hasn't been used much because of it's awkward position. To position this patient, have them rest the arm across their stomach, then stand on the opposite side of them.
- Flicking is your friend. Everyone has their own methods for getting veins to appear. For me, my tried and true is flicking. I never every slap veins. By flicking, I mean the motion you make with your thumb and index finger where you flick your index finger forward so that you would hit the vein with the flat part of the nail of your index finger. It doesn't have to be super aggressive, and be careful with very thin skin or those who are prone to bruising. This works best in hands and wrists, and can work ok in forearms. I almost never flick ACs.
- If you're feeling for a vein you can't see, especially deep ACs, don't look! Seriously, look away from the site. If it's an AC you're not seeing anyway, don't distract yourself by trying to look for something that isn't there. Go entirely be feel. Once you think you feel something, THEN look.
- If you're feeling for a deep AC and you can't tell if it's a vein next to a tendon, if it is actually a tendon, or if it is just the skin (like a stretcher mark), have the patient bend their arm slightly while you feel where you think you feel a vein. If it's a tendon, you'll know immediately, if it's next to a tendon, you might be able to tell exactly where it is, and if it's a stretcher mark, this may help you determine that it is just that.
- If you see an indentation up the medial part of the AC where the basilic vein would be, there very well may be a vein in there. It's happened to me a few times on (usually) obese patients that have difficult to feel veins where I have found this indentation even without being able to feel a vein there, and sure enough it was there.
- If you're dealing with a superficial vein, always try to position yourself so that the needle doesn't have to pass over your fingers. So for example, don't pull traction straight down with your thumb and then have to come directly over your thumb so you can't be as parallel to the skin.
- Veins that genuinely blow are, for me, the trickiest. Sometimes it is extremely unexpected that a very elastic and fairly decent sized vein cannot handle IV placement. I'm not talking about the ones that I accidentally manage to blow through either with the needle or aggressive cannulation, but those ones that you hit (seemingly) perfectly and smoothly and they just straight up pop. If that happens and you're going to attempt again, I suggest going with a smaller catheter size, really try to get the next vein to puff up as best you can, and go slow!
The biggest takeaway from my post and my recommendations is positioning is (almost) everything!! Be aware of what you are doing to the vein and have your plan laid out. Get your vein exactly how and where you want it before you break the skin. Good luck!!