Hit That Vein - Tips and Techniques for Inserting an IV Cannula


Published: 12 September 2016

If you are the type who is just scared out of your mind when asked to insert an IV cannula, you are not alone.

IV cannulations are amongst the most challenging skills a nurse has to learn, yet they are so common it is a wonder that nurses aren’t more comfortable with them. As one nurse pointed out, inserting an IV cannula is a numbers game. You have to insert dozens of them before you get to feel confident that you can hit the mark. No one likes to hurt patients, either, and that can make some nurses reluctant to try. If you have trouble inserting IVs, do not fear. Many nurses have gone before you and have tips and tricks for how to start them with the least amount of fuss. However, the best way to learn to insert IVs is to insert a great deal of IVs. Nothing can substitute for pure practice.

Tourniquet Trouble

Applying the tourniquet can actually start the trouble with IV insertion. You should always check for veins with the equipment in place. If you try to palpate veins without the tourniquet, you won’t see as many veins as are available to you. Putting the tourniquet on makes them pop out. If it is too tight, though, you simply cut off circulation and there is no blood in the veins to make them puffy. Too loose and the blood continues to flow and won’t pool for the puncture.

Another tourniquet tip is to use a blood pressure cuff. Cuffs can actually provide better obstruction of venous flow, show more veins, and is usually more comfortable for the patient. Put the cuff on and turn it upside down so the tubes are facing away from you. Pump up the cuff to just below the patient’s diastolic pressure to get the best results and keep it comfortable for your patient. Pumping it up any higher will likely cause the patient a great deal of pain in their fingers and obstructs the blood flow too much.

inserting an iv or how to place an IV

Learning how to place an IV cannulation is one of the more challenging skills a nurse has to learn.

Bringing the Warmth

If your patient’s arms are cold, you aren’t going to see any veins. Even if your patient’s arms are merely room temperature, your chances of seeing and feeling veins diminishes drastically. You need to warm them up, and some old school nurses have the best tips for how to do this. Take some chux or other water-proof covering, such as a thick bed pad, and place it under the patient’s arm. Warm up washcloths with hot water – make sure it isn’t so hot that it will scald the patient – and layer the warm, damp cloths along the patient’s arm to the elbow. Wrap the arm with the bed pad, and allow the patient to sit for ten minutes. In this time, it should warm the arm enough to bring the veins to the surface. If you are lucky, your hospital will supply hot packs for this trick, but warming with washcloths is just as effective.

Position, Location, and Other Tips

You need to think of your patient’s anatomical positioning when you try to insert an IV. Put your patient’s hand below the level of their heart and ask them to make a strong fist. However, when you make your insertion, have them relax their hand and arm to prevent rolling. It is also important that you focus on the location you are inserting the IV. Try to avoid inserting the IV at the bend points of the elbow and especially the wrist. Wrist sites are highly prone to infiltration, pain, and positional flowing of the IV solution. Select something mid-arm or in the hand for the best results, and always start distal and work your way proximal unless there is a clinical reason for a larger vein.

Another tip when inserting IVs focuses on the mechanics of the cannula you are using. Most cannulas are a combination of a needle with the plastic catheter over it. The plastic catheter does not go all the way to the end of the needle, though. In fact, it stops about 1/8th of an inch short. When you cannulate a vein and get your flash, that only means that the needle has made it into the vein. The catheter has not yet penetrated the lumen. To solve this problem, wait until you get flash, decrease the angle of the insertion to zero degrees, and advance the needle no more than 1/8th of an inch. This should allow you to slip the cannula off into the vein and establish your line.

Further Reading: Central Line-Associated Bloodstream Infections (CLABSI)