The central venous catheter is a type of a catheter that is normally placed in a vein of large size. It is also called the central venous line or central line. Central venous catheters can be fitted in veins found in the chest, groin, arms, and neck. This type of catheter is often used in the administration of fluids or medicines that cannot be taken orally, or administered in a smaller vein. It is also used for measuring central venous blood pressure and obtaining blood samples. This catheter, is most of the time, inserted in the veins of chest or arms where it can be easily inserted into the large veins directly through the skin. Occaionally, it is even inserted in the neck, but only in the case of patients who are admitted to the hospital as an in-patient procedure for more thorough monitoring. In case of children, or if large veins are not easily identifiable, then the insertion of the Central Venous Catheter can be a very delicate job. Sometimes, it may even damage the existing veins, or the blood flow in the body. This flexible tube inserted in the body may have to be kept in the same position for a number of days, weeks or sometimes even for months till the primary treatment is successfully done.
Why is the Central Venous Catheter Used?
There are a number of reasons why the CVC insertion is important. Following are some of the reasons why doctors need to insert CVC:
• Chemotherapy/ Cancer treatments
• Long-term administration of IV fluids
• Parenteral nutrition that is long-term (mostly in people with chronic illnesses)
• Long-term administration of pain medications
• KCI (potassium chloride)
• Caustic drugs like calcium chloride
• Hypertonic saline
• Drawing blood frequently
• Collection of peripheral blood stems cells
• Administration of other medications
• Administration of blood transfusions
• The need for regular access to an IV
• Requirement of IV therapy
• Checking the CVP (central venous pressure) in patients with severe conditions
Due to the improvement in the medical science and technology, the methods of insertion of CVC are now improving as well. The new equipments and devices help aid in proper insertion with less risk of causing infections in the body. Unlike other devices that are used to access veins, central venous catheters normally stay in place for an extended amount of time, especially in long-lasting conditions such as parental nutrition. A Hickman line is typically used in such situations as it provides a lower risk of infection.
It is critical to be sterile during the insertion of a central venous catheter because the line may act as a point of entry for pathogenic organisms. If not treated with care, the catheter may also become infected by bacteria like coagulase-negative staphylococci.
Complications of Central Venous Catheters
A number of complications may be caused by central venous catheters. Their benefits do, however, usually outweigh the chances of experiencing the complications. The following are some possible complications:
This condition, which takes place in central lines located in the chest, is most commonly found in subclavian vein catheterization. The risk of pneumothorax in internal jugular vein catheterization can be decreased with the help of ultrasound. Pneumothorax occurs at around 1.5-3.1% for experienced clinicians, and is therefore fairly uncommon. It is recommended to use ultrasonography devices, therefore further decreasing the chance of experiencing this complication.
- Infections of the Bloodstream
Central venous catheters can sometimes lead to Staphylococcus epidermidis, sepsis, and Staphylococcus aureus infections, although catheters can cause a number of other bacteria to enter the bloodstream as well. Recently, the medical field has raised awareness of bloodstream infections that are associated with a central line. They can be extremely harmful, causing numerous fatalities and raising healthcare costs, as well as the length of hospital stays. Recent research has been done to minimize the occurrence of infection in patients with central venous catheters.
If infection is suspected, blood samples are taken from the catheter and other veins in the body. If the sample from the catheter grows bacteria much earlier than the sample from the other vein, infection is usually present. Although quantitative blood cultures can be more accurate in diagnosis of a central line infection, they are not normally widely available. Antibiotics are commonly given to patients who experience infection, and the catheter will sometimes be removed in serious cases. Infections that result from Staphylococcus aureus bacteria typically call for the removal the catheter, which requires antibiotics. Up to 38% of patients may develop endocarditis if the catheter is removed without administering antibiotics. The American Centre for Disease Control does not recommend repetitive culturing of the central venous catheters once they are taken out.
In central line insertion, the area where the catheter is fitted should always be thoroughly cleaned to prevent infection. The use of a povidone-iodine solution to clean central venous catheters does work, although chlorhexidine is more effective in comparison. Infection can only be prevented by cleanliness, and cannot be prevented by frequent changing of the central venous catheter.
The recovery of the Central venous Catheter becomes more complicated in case of the patients who have undergone some surgeries or treatments in the past. The CVC can be mistakenly placed at the wrong place, and may also be inserted in the artery during the placement operations. If such mistake takes place, it is easily identifiable by taking into consideration the blood pressure of the arteries. The misplacement can be easily seen in an X-ray where the CVC gets inserted in the internal jugular vein on the same side of the super vena cava.
- Other problems of CVC insertion
Improper insertion of CVC can also prevent the required amount of air to travel through the veins. In this case a very small amount of air gets sucked in the veins due to the result of negative Intra-Thoracic pressure. Using the valved pressure devices for the insertion of CVC can reduce this risk. Also the vein which is inserted may intervene with the artery with the insertion of catheter. This may stop the blood flow. However, this problem can be solved by making an ultrasonic sound test in which the blockages will be easily identified.