Overview of Peripheral Line Placement
A peripheral line placement, or peripheral intravenous (IV) cannulation, is a procedure where a small plastic tube is inserted through the skin into a vein in the arm or hand. This tube is usually called a peripheral IV line, cannula, or catheter, depending on where you live.
This tube allows for direct delivery of fluids, medicines, or even blood products into your body’s blood circulation system. This direct path allows these treatments to bypass barriers in the body and reach the target organs much quicker. Once it’s in place, this line can stay there for several days if needed. This means you won’t have to get a new needle every time you need treatment.
Peripheral lines are very common in healthcare settings; about 80% of hospital inpatients may need one at some point during their stay. In fact, globally, over 1 billion of these lines are used every year.
This piece is focused on techniques for peripheral line placement that are guided by physical markers on the body. There are other methods too; for example, real-time ultrasound guidance. This can be especially helpful if you have hard-to-access veins or if previous attempts to place the line haven’t worked.
Anatomy and Physiology of Peripheral Line Placement
A peripheral venous line is a medical device that doctors use to give you medication or fluids through your veins. It can be placed in different parts of your body. The upper arm is often chosen, especially on the side you use less often. This is because it’s more comfortable, less likely to be knocked out of place, and there is a lower chance of complications like blood clot formation or inflammation of the veins.
In the arm, possible placement spots start at the back of your hand with veins that carry blood towards your body, passing through an arc of veins on the back of your hand, eventually reaching the cephalic and basilic veins in your forearm. Near the elbow, these veins are joined by other veins before they continue up your arm.
In your lower leg, the line may be placed starting with a network of veins on the top of your foot, which later forms the large and small veins of your leg.
In babies or small children, if using the arm or leg veins is unsuccessful, the scalp may be a suitable place for the line. This could be in frontal, occipital, superficial temporal, or veins behind the ear.
Doctors usually look for veins that are straight, closer to the skin surface, and not branched upstream, as these are the easiest to use. When the line is positioned on a leg or arm, a band may be tied further up from the site to swell the vein and make it easier to access. The vein should feel soft and not pulse; pulsing suggests it’s an artery instead of a vein.
Finding a suitable vein can be challenging in some individuals, like in kids, overweight individuals, pregnant women, individuals with darker skin tones, patients in shock, or those whose veins may have been damaged by previous drug treatments or intravenous drug misuse.
Why do People Need Peripheral Line Placement
The primary reason for inserting these kinds of tubes is to let the doctor give you medicines and fluids into your veins. These tubes are often used to draw blood when they are first put in. This is done before giving any drugs or fluids that could make the blood samples less accurate by diluting them or introducing other substances.
When a Person Should Avoid Peripheral Line Placement
While there are no absolute reasons to avoid placing an intravenous (IV) line, there are some circumstances that might make it more complicated. These include:
- Coagulopathy, which is a condition that affects the blood’s ability to clot
- Existing infections, burns, or damaged skin where the line would normally be placed
- Past procedures that could complicate line placement, like the removal of lymph nodes (lymphatic nodal clearance), creation of an abnormal connection between an artery and vein (arteriovenous fistula), or a deep vein blood clot (deep venous thrombosis) in the same limb.
In such situations, doctors have to consider the pros and cons before deciding to place the line at that site.
If long-term IV therapy is needed, a different type of vascular access device might be a better choice. For example, a peripherally inserted central catheter, also known as a “PICC” line, might be considered. This is a bit more complicated and needs a specialist to place it but lasts longer without failure. If the standard IV lines are used in these cases, they may need to be replaced frequently.
Patients who are known to have difficult veins to access or who have already had a couple of unsuccessful attempts at placing a line might need an ultrasound to guide the placement of the IV. Or, in these cases, doctors might have to consider different ways to give medicine – like orally (by mouth), via a muscle (intramuscular), through the bone marrow (intraosseous), or directly into a larger vein (central venous access).
Equipment used for Peripheral Line Placement
An IV line is a small plastic tube that is inserted into your body. It has a larger attachment or ‘hub’ that stays on the outside of your skin. Most IV lines today are made from a material called polyurethane. This is because it is thought to be a safer choice compared to older materials, such as polyvinylchloride, which were more likely to cause blood clots. The IV line is placed on a needle, which is specially designed with a clear chamber, helping the doctor or nurse know when blood starts to flow into the needle during the insertion process.
The ‘hub’ the IV line is attached to is color-coded. This allows healthcare professionals to easily identify the size of the needle – which can range from 14G to 24G, depending on the patient’s age and other health features. The bigger the gauge number, the thinner the actual needle is. The IV line can be different lengths, depending on what the manufacturer makes. The needle can be removed from the ‘hub’, revealing a standard connection point for different equipment – like a needle-free cap (called a ‘bung’) that can be used for drawing blood or giving medication, or a device to administer IV fluids.
Some IV lines, known as “safety lines”, have been designed with safety features to reduce accidental injury during use. These designs cover the sharp end of the needle after it’s withdrawn from the ‘hub’. There are two types of safety features – active ones, where the user presses a button to shield the needle with a plastic sheath, and passive ones, where the shield is automatically positioned over the needle tip as it’s taken out from the ‘hub’.
In order to fit the IV line, the healthcare worker will need some additional items, like antiseptic wipes, gauze, sterile saltwater for flushing the line, and a sterile, see-through dressing that lets moisture through. In cases where a larger IV line is needed, or if the patient is a child, they might use a local anesthetic to numb the skin. This could come in a couple of forms. One option is a small injection under the skin immediately before the IV line is fitted. Another option is a cream containing anesthetic, put on the skin beforehand and covered with a dressing.
Who is needed to perform Peripheral Line Placement?
Usually, one healthcare worker is enough to insert a peripheral line, which is a small, flexible tube inserted into a vein in your arm or hand to deliver medication. However, having an extra person around can be helpful if the patient is nervous, if the patient is a child, or if it’s difficult to find a good vein. This assistant can help comfort the patient or get them in the best position for the line to be inserted.
Preparing for Peripheral Line Placement
When a medical staff needs to put in a peripheral line, or a small tube into a vein, for a procedure or treatment, they should ideally do it as close to the time of the procedure as possible. This helps to prevent the tube from coming loose. Before starting, the staff washes their hands and puts on gloves for single use. Any local pain-numbing cream that was applied before should be wiped away, and a special box for throwing away sharp objects should be within an easy reach.
To get ready for inserting the tube, a tourniquet (a tight band) is wrapped around your arm about two to four inches above the insertion point. This band has to be tight enough to fill up the veins with blood, but not too tight to cut off the blood flow completely. This way, the veins get bigger and easier for the doctor to see and succeed in getting the catheter in. Then, the doctor checks your arm and feels for a good vein to use, before cleaning that area with antiseptic (a germ-killing solution).
If the medical staff decides to use a local anesthetic (a medication that numbs a small area), they will inject the anesthetic near the vein with a thin needle, causing a small bump in the skin where the tube will go in. The place for the injection will be a little further down the vein from where they plan to insert the tube itself.
How is Peripheral Line Placement performed
When having a cannula placed or a vein accessed for a procedure, the healthcare provider will hold the cannula firmly between his or her forefinger and thumb. Sometimes, they might use a side port, which means that the forefinger will be curled around the cap of the side port, and the thumb over the end of the chamber where the blood will ‘flashback’. The other hand is used to pull the skin taut around the vein and keep it stable. The needle is then inserted at an angle of less than 45 degrees into the skin towards the vein and is slowly pushed in until a ‘flash’ of blood can be seen in the chamber.
If only a drop of blood is seen, the needle might still be outside the vein, and will be lowered slightly and inserted a little further (1-2mm) until blood flows normally. The cannula is then pushed over the needle until it is flush with the skin. When the cannula enters the vein, a second ‘flash’ of blood should appear. The band or tourniquet around your arm to make the veins more visible is then loosened or taken off. In order to prevent blood from flowing out, pressure is applied over the vein and cannula. The needle is then taken out and disposed of safely.
If blood tests are needed, samples are taken now. They may put the band back on to get a good flow of blood. The healthcare provider will then attach a cap or an IV tube to the cannula and secure it on your skin with a dressing. To make sure that the cannula is working correctly and with a good flow they will flush it with saline (a mixture of water and salt) or a bag of IV fluid. They will also check to make sure there is no swelling or fluid build-up around the puncture site.
In cases where the placement of the cannula is difficult, there are some techniques that can help. These include lightly tapping the skin over the vein, cleaning the area with an antiseptic swab, using a warm compress or soaking the arm in warm water before trying to place the cannula, and making sure the procedures are comfortable for the healthcare provider, like adjusting the lighting and making sure the patient is in a comfortable position. Some providers might also apply a topical gel to help with placement.
If these methods don’t work and emergency access to a vein is needed, a method called peripheral venous cut-down might be used. In this process, a small cut is made over a vein in the arm or leg. The healthcare provider will carefully dissect the tissues until reaching the vein and can then directly insert the cannula into the vein. Although this method was used frequently in the past, it’s now less common due to the availability of other techniques like using ultrasound guidance, central venous access, and intraosseous access. Plus, it isn’t used as much in countries with well-developed healthcare systems.
Possible Complications of Peripheral Line Placement
There can be complications when placing an intravenous (IV) line, a tube inserted into your vein to deliver medicine or fluids. Some problems that can occur include failure to place the line correctly, injury to arteries or nerves, and bleeding or bruising where the IV was inserted. Sometimes, even if an IV line is successfully inserted, it could stop working correctly before it’s no longer needed. This can happen in about half of the cases.
In some instances, particularly in children, the IV can accidentally be inserted into an artery instead of a vein. This may cause serious issues if substances that are not compatible with arteries are injected. If this happens, the IV line will be removed immediately and pressure will be applied to stop any bleeding.
If the IV line slips out of the vein or wasn’t fully inserted into the vein to begin with, there’s a possibility that the fluids or medicine meant to go into your bloodstream could instead leak into the tissue around the IV. This can also happen if the IV goes completely through the vein. Inflammation of the vein is another potential problem that can occur from subpar hygiene practices or if the IV stays in for a long time. This can potentially lead to a local infection or skin inflammation.
If the IV line is not flowing correctly, it can become blocked. This might occur due to damage from the insertion, if it’s near a vein valve, or if a clot forms inside the IV. If the fluid bag of the IV line is empty and is still connected to the needle in your vein, and particularly if your arm is in a tight position, blood might flow back into the IV line. This can cause clots and blockages. For young children and babies, IV lines in the scalp have a higher risk of being knocked out of place and leaking.
Serious body-wide reactions, like severe allergic reactions, due to the process of placing the IV line itself are rare. It’s more likely that these types of reactions would be caused by the medicine or fluids being given through the IV line. Some people might faint during the process of having an IV line placed, particularly if they’re sitting up, have a history of fainting, or are significantly distressed by the sight of blood or needles. There’s also a very tiny chance that a piece of the IV could break off inside the patient and travel through the veins, but this would require a surgeon to remove.
What Else Should I Know About Peripheral Line Placement?
In hospitals, the most common way to deliver fluids or medication directly into a person’s bloodstream is through a peripheral IV line. It’s like a tiny plastic tube that’s inserted into a vein, usually in your arm or hand. Many healthcare workers, and sometimes even trained assistants, know how to insert these IV lines.
You can imagine the flow of fluid in an IV line a bit like water in a garden hose. If you increase the water pressure or use a shorter hose, the water flows faster. But the biggest factor affecting flow is the width of the hose. Just like in a hose, the wider the IV line, the faster the fluid can flow!
The size of an IV line is measured using two different systems— gauges or French. In the gauge system, a lower number means a wider IV line. IV lines usually range from 14 to 26 gauge. A 14 gauge line, being the widest, can deliver fluid the fastest. But be careful, because keeping such high flow rates for a long time can cause damage to the vein, which could make the IV line fail.
On the other hand, the French system measures the size based on the outside diameter of the catheter in millimeters. Despite being another measurement system, it’s usually not used for regular IV lines, but for larger medical devices and catheters.
