Corpus: Central venous catheter

A central venous catheter, or CVC for short, is a catheter inserted into a large vein near the heart. It is used for administering intravenous medications and infusions or for measuring central venous pressure.

A CVC may be required for various reasons, including:

• Administration of multiple medications
• Use of infusion pumps (perfusors)
• Continuous infusions
• Delivery of medications with a short half-life and cardiovascular effects (e.g., catecholamines)
• Administration of hyperosmolar or vasoactive solutions (e.g., potassium, chemotherapy drugs, parenteral nutrition)
• Poor peripheral venous access
• Critically ill patients in intensive care
• Extended diagnostic options, such as CVP measurement or central venous blood sampling to determine central venous oxygen saturation

A CVP measurement alone is not a sufficient reason to place a CVC.

Central venous catheters can be inserted into different veins, each with specific advantages and disadvantages. Common insertion sites include:

• Internal jugular vein: jugular catheter (iCath)
• Subclavian vein: subclavian catheter (sCath)

Other possible access routes are:

• Basilic vein
• External jugular vein (eCath)
• Brachiocephalic vein (vena anonyma)
• Femoral vein (fCath)

Only rarely used:

• Cephalic vein
• Brachial vein

Depending on the insertion site, the catheter tip is placed in either the superior or inferior vena cava. If a peripheral vein (e.g., basilic vein) is used, the catheter is called a peripherally inserted central venous catheter (PICC) or a midline catheter (if the tip does not reach the central veins).

CVCs may have between one and five lumens, depending on the indication. A three-lumen catheter is most commonly used. In some cases, large-lumen catheters, such as a Shaldon catheter, may be necessary.

The choice of insertion site depends on several factors, including:

• Intended use (e.g., volume replacement, chemotherapy, parenteral nutrition)
• Patient condition (e.g., age, general health, injuries)
• Insertion conditions (e.g., emergency setting vs. sterile hospital environment)
• Experience of the physician
• Venous pressure dynamics

CVCs may be mispositioned or migrate within the veins. Instead of being correctly placed near the right atrium, they may end up in an unintended vessel. For example, a subclavian catheter may accidentally advance into the jugular vein. A catheter positioned too deeply, such as in the right atrium or ventricle, is also undesirable.

To ensure proper placement, continuous monitoring is performed during insertion. An ECG-guided technique can be used, recording electrical activity between the catheter tip and a surface electrode. As the catheter approaches the heart, characteristic ECG changes occur. If the tip is too close to or inside the right atrium, an exaggerated, pointed P wave appears (similar to a pacemaker spike). The catheter should then be pulled back until the P wave normalizes.

After insertion, a chest X-ray is typically performed to confirm correct placement and to rule out complications such as pneumothorax.

Additionally, blood can be drawn from one of the catheter lumens for blood gas analysis. By evaluating pO₂, it is possible to distinguish between arterial and venous blood. A high pO₂ suggests an unintended arterial placement.

• Bleeding and hematoma
• Arterial puncture
• Infection (especially in femoral vein placement, due to contamination risk in incontinent patients)
• Air embolism
• Nerve injury
• Pneumothorax, hemothorax, hydrothorax, chylothorax
• Thrombosis
• Cardiac arrhythmia