This is a topic I tend to get very interested in when I have Advanced EMT (current EMT-IV here in TN) or Paramedic students riding with me. Naturally people are very timid when they have to purposely inflict pain on someone in order to help them. My first day of paramedic school at Grant one of the instructors, Jamie, told us that “we are going to teach you to hurt someone very badly in order to help them.” I take it very seriously because it is one of the few things that separate advanced providers from their basic counterparts. I’m going to discuss the basic procedure first, then talk about things to make it easier and faster.
First, your assessment should indicate that it is a necessary procedure to perform. These patients are usually in some sort of distress and require medication (yes I consider IV fluids to be a medication, on a rudimentary level) to treat their condition. I often transport patients without IV access because my assessment indicates they are neither unstable nor potentially unstable.
Once you determine that it is necessary to perform, you must select a site. Most of the IV starts that I see are either at the posterior hand (metacarpal vein) or antecubital fossa (cephalic and median cubital vein) sites because the veins present close to the surface of the skin at those locations. I do a “site survey,” which is also part of my physical assessment, looking for places where the veins come close to the skin and I can get a quick start. I also usually follow up with the question “where do they usually put IV’s (or “needles” depending on where I am working it). The patient is often the best source of information about these things. Sometimes you have to palpate where you think the vein is, particularly if the patient is large or has a darker skin tone.
You should be cautious about placing IV’s in a few popular places. The antecubital fossa poses the danger of infiltration because the joint behind it moves frequently. Two other sites, the anterior wrist and the posterior forearm, pose a danger to nerves that run close to the veins in those locations. Also, patients that have had a mastectomy are open to the possibility of lymphedema (swelling of the lymph nodes) because the fluid pathways that remove excess fluids are reduced. In an emergency, these considerations are irrelevant, but are something to think about when you consider starting an IV that may not be necessary. Remember, every procedure and treatment we do poses a risk of permanent damage to something in the way.
You may even have to select a site based on your patient’s type of complaint. Tributaries in the forearm are popular sites for OB/GYN emergencies, particularly patients that are in labor. This may or may not be a truth but I know that almost every OB patient that I have seen has either had an IV in the hand or in the forearm. External jugular (EJ) veins at the lateral neck are popular in trauma, although I tend to use them as a last ditch effort for access before I use the interosseous route. You should rely on your state/local protocols and scope of practice for guidance before you attempt this, as in some states and regions the EJ route is reserved for paramedics only due to the high risk for embolism.
So now you have a site, so what about the IV catheter itself? What size to use? Well, that depends on a few factors. You should consider what you are starting it for. Using a 14 gauge catheter for routine access is excessive, and in Tennessee could be considered abuse (people have had their licenses suspended or revoked for that sort of thing). If you desire to infuse fluids, you should consider how fast you want them to infuse. An 18 or 20 gauge catheter is generally appropriate for most instances where you would be giving a medication or a modest IV infusion. It is recommended that larger sizes be used if more fluid is needed. I will post a link to a good reference site if you feel the need to review anatomy or equipment.
Now that you have selected your site, gathered your equipment (tourniquet, tape, IV catheter, and a saline or heparin lock with a fluid flush), you are prepared to start the IV. This is the tricky part. I like to place my tourniquets high and tight, then let the patient’s arm hang for a few seconds. This will engorge the veins sufficiently if there is enough blood volume and pressure. You can use a blood pressure cuff if you are in a pinch, but it takes time to inflate the cuff.
Something to remember is that this is a sterile technique. You should swap the site with some sort of cleaning pad, whether it be alcohol or a cholorhexidine/alcohol pad. The book recommends using a circular technique starting inside the circle and expanding outward, and it’s a good technique to use. Remember DO NOT TOUCH the site once you have prepped it as this will contaminate the site and leave the patient open to infection.
Something I try and teach students that come through me, when they say 45 degree angle and insert till you feel a “pop,” forget it. Most of the IV starts I perform I feel no pop. I believe this to be a hold over in the technique from more simplified explanations. You should watch the flash chamber for a flash of blood, then push the catheter forward. It may come to a stop before the hub is all the way in, depending on how much catheter you have in and how bad you need it, this is ok. So long as it is not infiltrated it will be ok.
Some people have trouble with the angle of insertion. The book will say insert at a 45 degree angle, any street-wise advanced EMT or paramedic will tell you that typically the flatter the better. Pull traction on the skin, insert needle bevel up, around a 10 degree angle, and I like to start 1-2 mm behind the vein I selected, then watch for flash.
Something I also see new students and even veterans who are out of practice do is they take their time. Talking this over with some other paramedics, we came to one conclusion: it is a procedure that, although simple, needs to be done with purpose. It is one of the few things that we do that patients fear the most. It should be done quickly and with confidence, I often limit my students to one or two IV attempts for this reason.
Now that you know the technique in words, I will demonstrate it in pictures, but that is for another day.