In our ED, we prefer to use the antecubitals with 18g to allow for high volume resuscitation if needed. I especially like the AC area for those patients who are on the heavier side or check the hand veins or the wrist area.
Usually I use an 18g or 20g (I don't work with children). Sometimes a 22g if the veins are really tiny. Very rarely a 24g if it is an extremely tiny vein and the patient is an extremely tough stick.
If the patient seems tough, always ask the patient where their best veins are!! They will usually know if they have been tough in the past.
On men whom I don't see a vein right away, I always check the back of the arm as those veins pop up nicely in men.
For those difficult sticks, I do a few things. If the vein is small or not particularly palpable, I will get a washcloth as warm as possible (without being hot) and wrap it around the preferred vein, then wrap a chux or dry towel around the wet washcloth to keep the warmth in. It only needs to stay on about 5 minutes and in the meantime you can be doing other things, like checking the other arm for possible veins, etc. (Plus taking this 5 minutes and being able to hit a vein is alot easier than not doing it and taking 30 minutes of 5 sticks to find a vein!) The heat really helps to dilate the vein to make it easier to dilate, palpate, see and stick. You would not believe how much this helps. I will then use either a BP cuff OR 2 tourniquets. For some reason, the 2 tourniquets helps the veins to pop up better-I only use the BP cuff OR 2 tourniquet method in difficult sticks- otherwise one tourniquet will suffice. Place one tourniquet about 5 inches above the preferred vein and the other one another 3 inches above the first tourniquet.
For any stick:
I stick at a 15 degree angle and to the right side of the vein with my right hand while anchoring the vein with my left hand. I prefer to gently anchor the vein from above the stick site but don't press too hard or as someone said, the blood won't flow and the vein will flatten out. (Some people prefer to anchor the vein from below the site). Once you see a GOOD flashback, advance the whole catheter a little bit more. If your flashback is slow, don't get nervous and feel rushed- wait a few seconds to see if it will flow in, then if not, advance the catheter towards the direction of the vein and see what happens. Once in the vein with a good flashback, hold the apparatus with your insertion hand and use your OTHER hand to advance the actual catheter with your thumb and forefinger. I was never able to use that same-hand finger advancing method myself either.
Always make sure the arm you are using is in a downward direction to improve blood flow.
In those older folks, sometimes it is actually easier not to go for the huge rope veins because they tend to roll. Go for smaller diameter vein.
Just remember that starting IV's is like learning to ride a bike. Once you get it down, it is like second nature, and you'll hardly ever think about it!!
Good luck, you'll do fine! Jeanne