Central Venous Access - Indications, Types, and Complications

Introduction :

Central venous access (CVA) is when a long, thin, hollow plastic tube called a 'catheter' or 'line' is placed in a vein. It gives a way of putting regular intravenous (IV) medication. The advantage is that there is no need for further IV access sites.

The long catheter is put into a vein in the chest's arm, neck, or front. The catheter extends into a 'central vein' next to the heart. The larger central vein can endure the catheter line better than a small vein. As a result, the catheter can stay in place safely for weeks or months, even more than a year.

What Is a Central Venous Catheter?

It helps take out blood and provides intravenous fluids, drugs, or blood transfusions. In a vein below the collarbone, a small, extensible tube is placed. It is inserted into the superior vena cava, a large vein located above the right side of the heart. A needle is placed into a port outside the body for blood collection or fluid administration.

What Are the Main Sites for Central Venous Catheters?

The three primary access for the placement of central venous catheters are :

• The internal jugular vein.

• Common femoral vein.

• Subclavian veins.

These are the preferred sites for temporary central venous catheter placement. In addition, the basilic and brachial veins are utilized for mid-term and long-term central venous access. Finally, the internal jugular vein (IJ) is picked chiefly because of its definitive anatomy, accessibility, low complication rates, and the ability to employ ultrasound while performing the procedure.

What Are the Indications for Central Venous Catheters?

• There is a need for multiple infusions that might conflict with peripheral intravenous access, such as vasopressors, total parenteral nutrition, chemotherapy, and other medications.

• Inability to earn venous access in emergencies.

• Extracorporeal therapies, like hemodialysis (a process that purifies blood when kidneys do not function properly), plasmapheresis (removal, treatment, and exchange of blood plasma or other components from and into the blood circulation.), and continuous renal replacement therapy (restores kidney’s blood filtering function).

• Hemodynamic monitoring.

• Venous interventions include thrombolytic therapy, transvenous cardiac pacing, and intra-venous stenting.

What Medications Are Given Through CVA?

There are different types of IV medications that are given repeatedly over a long period:

• Intravenous antibiotic treatment.

• Chemotherapy (drugs that kill cancer cells).

• Haemodialysis.

What Are the Different Types of CVA?

Various central venous access devices are available, with their own risks and benefits. Central venous access devices are usually classified based on the following:

• Duration of Use of a Catheter - Dwell time; short-term, mid-term, long-term.

• Type of Insertion - Central, peripheral.

• Location of Insertion - Jugular, brachial.

• The Number of Lumens -Single, double, or triple.

• Whether the catheter is implanted or not, and to what extent, like tunneled, totally invested.

1. Nontunneled Catheters: Nontunneled centrally inserted central catheters (CICCs) are placed percutaneously with the catheter leaving the skin in the region of the venous cannulation site. It may be single, double, triple, or quadruple lumen.

2. Implanted Catheters: These are semi-permanent and can be removed if complications occur, or the device is no longer needed (completion of chemotherapy), or for patient comfort. Two types of implanted central venous devices are available: tunneled catheters and implantable venous access devices.

3. Tunneled Catheters: Traverse a subcutaneous tunnel between the cathected vein and the skin exit site. The tunnel refers to the passage of a short length of the catheter from the site of skin entry to venous puncture, either with or without a cuff to anchor it in place and limit bacterial access.

4. Implantable (Ports): These catheters pass from the cannulated vein under the skin and attach to a subcutaneous infusion port or reservoir placed into a subcutaneous pocket. Most often placed in the upper chest of adult patients, but in the upper extremity, abdominal wall, and lower extremity is also possible. They are typically used for shorter durations compared to other implanted ports.

5. Coated and Impregnated Catheters: Antibiotic or antiseptic-impregnated CICCs and PICCs also Heparin-bonded catheters decrease complication rates like bacterial colonization and catheter-related infection.

6. Antimicrobial-Impregnated Catheters: Coated catheters like Chlorhexidine-silver Sulfadiazine (CHSS) and Minocycline-Rifampin (MR) have an apparent benefit of antimicrobial. However, the efficacy and role in clinical care remain uncertain.

What Are the Complications of CVA?

Central line insertion can cause several complications, but the benefits should outweigh the risk of complications. Some of the difficulties are as follows:

1. Pneumothorax: Pneumothorax is a condition that occurs when there is an air leakage in the spaces present between the chest wall and the chest lungs. Its incidence rate is the highest. A chest X-ray will be recommended if pneumothorax is doubted. The risk of pneumothorax is minimized using ultrasound guidance.

2. Vascular Perforation: Perforation of vasculature by a catheter is a scary and potentially life-threatening complication. The incidence is extremely rare, particularly when lines are positioned guided by an ultrasound.

3. Catheter-Related Bloodstream Infections: All catheters can result in bacterial invasion in the bloodstream, which results in severe conditions that can be life-threatening in around 25% of cases.

4. Occlusion: Venous catheters can become occluded by kinks in the catheter, and the backwash of blood into the catheter leads to thrombosis.

5. Misplacement: Misplacement is expected when the person's anatomy is different or challenging due to injury or past surgery.

6. Venous Air Embolism: Entry of air into venous circulation may cause a venous air embolism. It is a rare complication. However, it can be fatal (causing death).

How to Prevent Complications?

The recommendations regarding the risk reduction for infection of CVCs include:

• The preferred site of insertion: To avoid the femoral vein if possible.

• The selection of catheters: Includes those with minimal ports.

• Use sterile gloves.

• Use sterile drapes, caps, and masks.

• Monitoring of catheter sites visually and with palpation regularly.

• Use clean, non-sterile gloves while changing the dressing of intravascular catheters.

• Both Chlorhexidine and Povidone-iodine are good skin cleansers and are safe to use.

Conclusion:

Central venous access is a frequently performed procedure, with approximately eight percent of hospitalized patients needing the same. Since they are commonly used, careful and regular surveillance is required to avoid infections. Keeping in mind the cons and pros of CVA, it has been proven life-saving for several people.