Central Venous Catheter
Central venous catheterization is a method used to ensure venous access in patients in severe condition, usually hospitalized in intensive care units. The catheterization is not always easy and its presence is in addition to indisputable advantages also associated with a number of potential complications.
Central venous catheter is a tube that is inserted into one of large veins in the organism. These include the subclavian vein (running below the collarbone), internal jugular vein (carrying blood from the head) and femoral vein (located in the inguinal region). Other large veins are used less commonly. The tube may have one or more openings that serve for administration of medications and infusions.
The procedure should be performed in a sterile environment. The local skin is disinfected and the surroundings are covered with sterile covering. Local anesthetic is applied subcutaneously and into deeper tissues. The catheter is introduced by the so-called Seldinger technique, which is widely used to ensure entry into blood vessels and body cavities. First, the vein is punctured with a hollow needle, which is used for inserting a guide wire. The wire serves as carrier for the catheter. Once the catheter is in place, the wire is pulled out. The catheter is sewn to the skin.
Catheter in subclavian, or jugular vein should be replaced every three weeks, catheter in femoral vein should be changed every week.
Direct approach into large central veins has many benefits comparing to small superficial veins of the limbs. We can administer larger volume of fluids and special intravenous nutrition. A central venous catheter is therefore suitable for patients in severe conditions, particularly when they need a large number of intravenous drugs applied at the same time. The catheter may be used for measuring the central venous pressure, i.e. the blood pressure in large veins of the body. This allows us to evaluate the venous return to the heart and overall hydration. Special types of dialysis central catheters may serve to conduct dialysis. Furthermore, the central venous access is suitable for any patient who needs any intravenously administered drugs and has not suitable veins in the extremities.
The patients should not use anticoagulants due to increased risk of bleeding and we should test their basic coagulation parameters (from a sample of venous blood). Acute and required procedure can be done even in a patient taking anticoagulants, but the risk of bleeding is significant.
Disadvantages and complications
There are numerous risks of both catheter insertion and its prolonged use. Local puncture may cause bleeding and accidental puncture of an artery, which runs closely to the targeted vein. Arterial puncture is usually not life-threatening, but the puncture site must be quickly and firmly compressed for a short period of time. Typical complication of a catheter insertion into the subclavian vein is entry of air into the pleural cavity, which is called pneumothorax. Longer presence of a catheter increases the risk of infectious complications and local venous thrombosis.