Overview of Femoral Vein Central Venous Access
Doctors can put a tube, or a ‘cannula’, into different veins in your body to give you medicines or fluids. They can do this in two ways. The first is by putting the cannula into a small vein close to the surface of the skin, like those in the bend of your arm or your leg (these are called ‘peripheral veins’). The second is by putting the cannula into a larger vein deep inside your body (these are called ‘central veins’).
Using central veins can sometimes be a lifesaver. This is because in emergencies, doctors can give large amounts of fluids or medicines through these veins quickly. They can also give strong medicines that might harm smaller veins. This discussion will focus more on placing the cannula into the large vein in the groin area (the ‘femoral vein’). However, a lot of this information applies to other large vein access points too.
Anatomy and Physiology of Femoral Vein Central Venous Access
The veins in your leg allow blood to flow back to your heart. This is known as venous drainage. This starts from a vein called the popliteal vein in your lower leg, moving up to a vein called the superficial femoral vein in your upper leg. This vein is joined by another vein named the deep femoral vein, creating what is known as the common femoral vein.
The great saphenous vein, another large vein in your leg, connects with the common femoral vein near a band of connective tissue in your lower abdomen called the inguinal ligament. Above this ligament, the common femoral vein changes its name to the external iliac vein. The internal iliac vein, another vein in the pelvic region, drains into the external iliac vein. Together, they form a vein called the common iliac vein. Finally, two common iliac veins join to form the inferior vena cava, a large vein that carries blood from the lower half of your body back to your heart.
When doctors need to access a large vein in the body, they often choose the common femoral vein in the leg. This vein is located in a region known as the “femoral triangle” in your groin area. This area is framed by the inguinal ligament at the top, a muscle named the adductor longus on the inside, and another muscle known as the sartorius on the outside.
It’s important for doctors to understand the layout of this area. A helpful way to remember this layout is by using the acronym “NAVEL”. Moving from the outside to the inside, there’s the (N) femoral nerve, (A) femoral artery, (V) femoral vein, (E) empty space, and (L) lymph vessels. In the rest of this explanation, when we talk about the femoral vein, we’re referring to the common femoral vein.
When a doctor needs to insert a tube into the femoral vein for medical procedures, they need to find specific landmarks in the groin area. These include the inguinal ligament and the pulse of the femoral artery. While most doctors use ultrasound images to guide them, it’s also important to know and use these landmarks. This can make the procedure more successful.
Why do People Need Femoral Vein Central Venous Access
A central venous access is a procedure where a small tube is inserted into a large vein in your neck, chest or groin. This access is required for a variety of reasons. These could include some of the following:
- If it is not possible to get access through the smaller veins in your arms or hands, often referred to as “peripheral access”.
- If the medicine to be given might cause irritation and inflammation in the smaller veins, a condition known as peripheral phlebitis.
- If you need a high amount of fluids or nutrition given intravenously (directly into your bloodstream).
- If you need emergency resuscitation, which means you need help with breathing or to restart your heart.
- If your healthcare team needs to monitor the oxygen levels or pressure inside your big veins (this is known as central venous oxygen saturation and central venous pressure).
- If your healthcare team needs to frequently take blood samples from you.
- If you need certain medical procedures like dialysis, a treatment for kidney problems, or apheresis, a procedure to remove certain parts of your blood.
It’s important to note that these situations don’t always absolutely require central venous access. Your healthcare team will consider the potential benefits and risks involved for you specifically before deciding to proceed with the procedure.
Other considerations include whether short-term or long-term access is more beneficial for you. In some cases, devices like a PICC (Peripherally Inserted Central Catheter), Port-a-cath or Broviac catheter may be needed for long-term access. Your medical team will also consider where exactly in your vein the tube should be positioned. For instance, during an emergency, the tube may need to be placed in a lower position. But if they need to measure the oxygen levels or pressure in your veins, a higher position may provide more accurate data.
When a Person Should Avoid Femoral Vein Central Venous Access
There are certain conditions that might prevent a doctor from being able to insert a central venous line through the femoral vein (a vein in your thigh), which is a tube used to deliver medication or nutrients directly into your bloodstream. These conditions can include:
- Blood clotting,
- An infection on your skin where the needle would go
- Trauma or injury
- Unusual body structures
- A condition that interferes with normal blood clotting
However, the central venous line can be crucial in some life-saving procedures. So, even if these problems exist, they might not completely stop the procedure from happening. If these problems exist at the place in your thigh where the tube is usually inserted, your doctor might consider another place to insert it, like the internal jugular vein in your neck or the subclavian vein near your collarbone.
Equipment used for Femoral Vein Central Venous Access
The following standard equipment is typically needed to establish a central vein access point in your body. This is where a small, flexible tube (referred to as a catheter) is inserted into one of your central veins. This procedure allows doctors to administer medications, insert diagnostic devices, or take blood samples. Some suppliers offer pre-packaged kits with many of the necessary tools:
- A central venous catheter: This is a small, flexible tube that’s inserted into a large vein, typically in your neck, chest, or groin.
- An introducing needle and a slip-tip syringe: These help to guide and insert the catheter.
- A guidewire: This works as a pathway that helps to guide the catheter into the vein.
- A dilator: This tool is used to enlarge the opening in your skin and vein so that the catheter can be inserted.
- A scalpel: A small surgical knife for making an incision or cut in the skin.
- 4×4 gauze: This absorbent material is used to clean the wound and absorb any excess body fluids.
- Hubs: These are attached to the catheter’s ports (or openings) to maintain sterility when not in use.
- Normal saline: A sterile saltwater solution used to clean the catheter before use.
- Topical disinfectant (like Chlorhexidine gluconate or Povidone-iodine): These are used for cleaning the skin around the insertion site to prevent infection.
- Topical anesthesia (like 1% lidocaine): This is a local anesthetic applied to numb the site of the procedure.
If ultrasound guidance is used, it will include extra equipment like an ultrasound machine, a sterile cover for the ultrasound probe, and both sterile and non-sterile ultrasound gel.
For properly covering the catheter after insertion, standard equipment includes a facemask, sterile gloves, anti-microbial disc, occlusive dressing (a waterproof adhesive dressing), and a solution for additional cleaning if necessary. The dressing used is clear, to allow for easy visibility of the insertion site to monitor for any signs of infection.
Who is needed to perform Femoral Vein Central Venous Access?
During a medical procedure, it is usually beneficial to have a properly cleaned person whose job is to open packages and pass on sterile equipment in a way that keeps the operation area free of germs or bacteria. This role is crucial as infection prevention is of high importance. Another helper is needed to give medicine that causes relaxation or reduces pain and closely watch its effects on the patient. This person makes sure the medicine works correctly and everyone is safe. Finally, depending on how comfortable or experienced the medical specialist is, a third clean person might be needed to help with the use of an Ultrasound machine, an equipment that creates pictures of the inside of your body. Each role in the medical team is important and contributes to your safety during a medical procedure.
Preparing for Femoral Vein Central Venous Access
Before starting any medical procedure, like inserting a central venous catheter (a tube placed in a large vein in the body to administer medication or fluids), the doctor will talk to the patient about what they should expect. They will explain the reasons for the procedure, its benefits, any risks involved, and any other options the patient might have. This is known as informed consent, and patients are encouraged to ask any questions they may have.
The doctor will then decide on the right size of tube or catheter to use for the patient, taking into account their body size and the size of the vein where it will be placed. Key factors include the diameter of the catheter (measured in a unit called French, or F), its length, and the number of openings (lumens) needed.
A “procedural timeout” is then conducted. This is a safety procedure that ensures everyone, including the patient, knows what procedure is being done, on which patient, and on what side of the body.
The patient is then positioned in a way that makes the procedure as easy and safe as possible. For example, the patient may be placed in a slightly inclined position lying face-up to fill the leg vein with blood and make it larger. They might also position the patient’s leg in a certain way, like with the knee bent and the foot placed outwards.
Next, the doctor washes their hands and puts on sterile protective clothing, including a hat, mask, gown, and gloves. They then clean the skin where the catheter will go with a special disinfecting liquid, and cover the patient with a sterile sheet.
If they’re using an ultrasound to help see where the vein is, the doctor will put a special sterile jelly inside a clean cover for the ultrasound probe, which helps get a clear picture. They’ll use more sterile jelly during the procedure.
Next, they’ll use a local anesthetic to numb the area where the catheter will be inserted to keep the patient as comfortable as possible.
The catheter lumens will be flushed with normal saline (sterile salt water) before being inserted into the vein. This ensures that the catheter is clean and ready for use.
How is Femoral Vein Central Venous Access performed
To locate the correct spot where the femoral vein lies, doctors may use something called the “landmark technique”. Here’s a simple explanation of how they do it:
1. First, they use their index finger to find the pulse along the groin line that runs between the front edge of your hip bone and your pubic bone. From there, they move about 1-2 cm (or roughly half an inch) down. This spot needs to be below the groin line. Then they move another 1-2 cm inward because the vein is located on the inside of the artery.
2. Alternatively, they may use both their index and middle fingers to find the two ends of the pulse in the femoral artery. Just inside of your fingertips should be the general course of the femoral vein. So when they insert the needle, they aim to go inside from the index finger towards the middle finger.
At just the right location and at an angle of 30 to 45 degrees to your skin, they insert the needle using an instrument called a slip-tip syringe.
Using an ultrasound can also help as it shows where the vessels are relative to each other and to other structures. It also allows doctors to see the depth of the vessels, the size and whether they’re open or blocked. This information works hand-in-hand with the landmark technique to help decide the best place and angle to insert the needle.
While smoothly guiding the needle deeper, they’ll gently pull back the syringe’s plunger. If blood flows back into the syringe, this means the needle is in a blood vessel. Withdraw the syringe if there is any resistance, this is because the needle might have gone through the blood vessel. If there is no blood flowing back, the needle and syringe are pulled back a little but not entirely out of the skin, and the direction or angle of the needle may have to be rethought.
Once blood can be easily drawn into the syringe, they would hold the needle in place, take off the syringe, and look for a steady drip of blood from the needle. If the blood is pulsating, this could signal that the needle has accidentally gone into an artery rather than a vein. Then, they’d add a guidewire through the needle hub and move it forward slowly. They never let go of the guidewire to prevent any accidents. The needle is gradually removed while they still hold on to the guidewire.
They make a small cut in the skin at the puncture site using the scalpel, being careful not to cut the guidewire. The guidewire is then used to guide in a dilator to widen the opening on your skin and the slight cut made on the vessel. The dilator is slowly removed, keeping the guidewire in place before the central venous catheter is advanced over the guidewire. Through each access port of the catheter, they’ll typically try to draw out some blood to make sure the catheter is working properly, they then put hubs on each access port. Using silk sutures and a needle holder, they then stitch the catheter in place. An antimicrobial disc is placed over where the catheter went in, and a dressing applied to cover up the site.
After the procedure, your doctor will make sure the catheter is in the right place by doing some tests: checking the blood gas, taking an x-ray and measuring the pressure in the catheter. Finally, they’ll document the procedure in your medical record.
Possible Complications of Femoral Vein Central Venous Access
Problems connected with inserting a central venous catheter – a tube put into a large vein in your neck, chest, or groin to give fluids or medication – can be categorized as early and late complications. Some of these issues are not specific to the groin (femoral) site and can happen with insertion at any site where a central vein is accessed.
Early complications might include:
* Accidental poking of an artery which could cause a lump of collected blood, or hematoma.
* Hematoma could also happen just after placing the catheter.
* Accidental poking of the bladder. Before placing a central line in the groin at our hospital, we often use one or other form of catheter to empty the bladder first.
* Heavy bleeding.
* A piece of the catheter could break off leading to a blockage in a blood vessel by a broken piece of guidewire – a long thin wire used to guide something into place.
* Irregular heartbeats, particularly from central lines placed too high.
Late complications might involve:
* An infection in your bloodstream related to the central line, known as a Central Line-Associated Bloodstream Infection (CLABSI).
* Inflammation of a vein, or phlebitis.
* A blood clot forming in the vein, or thrombosis.
* Wearing away of the skin or wall of the vein, resulting in a hole or perforation.
Furthermore, issues, not precisely complications but potentially causing them, could be a patient not cooperating or lack of experience or oversight from the health care team.
In summary, looking at early and later stages after placement, problems that could occur are varied and range from accidental injuries during placement (artery or bladder puncture or hematoma), potential complications connected to the guidewire (guidewire embolism), heart problems (cardiac dysrhythmias), or infection and vein related issues (infection, phlebitis, thrombosis, erosion or perforation). Besides, patient cooperation and adequate supervision also play a big part in successful catheter placement and management.
What Else Should I Know About Femoral Vein Central Venous Access?
CLABSIs, short for Central Line-Associated Bloodstream Infections, are the most frequent problems that occur when a central venous catheter, a tube placed into a large vein to give medication or fluids, is used. Unfortunately, these infections can lead to serious health risks, longer hospital stays, and higher healthcare costs.
Several measures, including the right equipment, preparation, and specific techniques, are put into practice to reduce these infection rates. They’re often combined into standard procedures and checklists that have been proven to help lessen the chance of getting a CLABSI.
In adults, the vein in the thigh area – the femoral site – is generally not preferred for inserting these catheters because it has shown a higher chance of infection compared to other body sites. However, this isn’t the case with children. For kids, the femoral site is preferred because it’s easier to access.
Additionally, the use of PICCs (Peripherally Inserted Central Catheters), a type of long-term central venous catheter usually inserted in the arm, is linked with a lower risk of bloodstream infections.