A central venous catheter is an external access to the venous system via a large vein. The plastic tubing used for this purpose is placed centrally in front of the right atrium of the heart. The advantage of this technique is that highly irritating as well as multiple drugs can be administered in parallel.
What is a central venous catheter?
A central venous catheter is an external access to the venous system through a large vein. A central venous catheter, also known as a CVC, is central access through an inserted plastic tube (catheter) into a large vein. Veins in the neck or collarbone are often used for this purpose. The end of the plastic tube is just before the right atrium of the heart and is therefore ‘central’ in the individual. The central venous catheter allows intravenous drug administration and diagnostic procedures, such as measuring central venous pressure. This form of access to the venous system is used in intensive care and emergency care. Within Germany, an average of 4110 central venous catheters are placed per day. It is one of the most commonly used products in the field of medicine.
Forms, types, and styles
A distinction is made between the size of a central venous catheter. The decisive factor is the subsequent purpose of use. Three- to five-lumen venous catheters are most commonly placed. Later purposes of use may be parenteral high caloric nutrition or chemotherapy. Through the individual lumens, it is possible to deliver several drugs or even liquid nutrition to the patient in parallel without incompatibility of the individual substances. It should be noted that the risk of infection increases with the number of lumens. Therefore, the actual use of lumens should be analyzed beforehand and the duration of use should be kept as short as possible. The placement of a CVC should be performed by an experienced physician. The patient’s general condition and any injuries present should be considered. Sterile conditions for placing a catheter should also be present. If a central venous catheter must be performed as an emergency measure, careful care should be followed thereafter. Regular CVC dressing changes should be performed and the insertion site should be checked for redness and swelling without gaps. There are many options for access routes. However, the internal jugular vein at the neck or the subclavian vein below the clavicle (collarbone) are preferred. Alternatively, access via the basilic vein in the arm or the brachiocephalic vein in the neck is possible. Rarely, accesses are made in elbow veins or in the groin area.
Structure and mode of operation
To place a venous catheter, the following materials are needed:
Sterile gloves, a gown and mouth guard, sterile drapes, local anesthetic, a scalpel, scissors, forceps, a needle holder, suture material, sterile dressing material, and a puncture kit flushed with saline. If a central venous catheter needs to be placed, the puncture area is inspected by the attending physician; this can also be done with a sterile ultrasound machine. The area around the puncture site is then locally anesthetized with an anesthetic. The venous catheter is inserted blindly under sterile conditions. If the access is in front of the right atrium, it is flushed with a saline solution and fixed with a CVC dressing. Positional control can be performed by ultrasound or X-ray, thus excluding pneumothorax if necessary. The patient should be connected to an ECG device during the procedure, because myocardial irritation can cause tachycardia or fibrillation. If the catheter is incorrectly positioned or there is intravascular turnover of the CVC, the plastic tubing will not be in front of the right atrium of the heart. This can result in the formation of hematomas or perforation of the vein. Rarely, arteries or nerves may be injured as a result. In the event of malposition, cardiac arrhythmias or acute tension pneumothorax may also occur. This can potentially cause life-threatening injuries. Other undesirable side effects, such as catheter sepsis, may occur. This can be triggered by bacteremia (bacteria) or fungemia (fungal infection).In addition, if air enters the central venous catheter, complications may occur in the form of pulmonary embolism, thrombus formation, or thrombophlebitis. General symptoms such as fever, pain, swelling, and aspiration may indicate possible complications.
Medical and health benefits
A central venous catheter is used to administer infusion solutions or medications that are highly irritating to the vein walls. These may include potassium chloride, sodium bicarbonate (sodium bicarbonate), and glucose or amino acids. These substances irritate the veins too much to be administered through a peripheral venous catheter. They may also be cytostatics, antibiotics, drugs with short half-lives, or long-term infusion therapies lasting more than 10 days. Not only irritating substances, but also infusion solutions for cardiovascular stability often have to be administered via a CVC. If a peripheral venous catheter is to be placed, a central venous catheter is often placed as an alternative in poor venous conditions to prevent possible perforation. Indications for a central venous catheter include all forms of shock, such as volume deficiency shock (hypovolemic shock), cardiogenic shock or septic shock, hypothermia (hypothermia) or extensive burns. Furthermore, a CVC can be used to measure central venous pressure and assess intravascular volume status and right ventricular function.
