Central venous catheter

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Double-lumen ZVK
Sketch-like anatomical relationships of a non-tunneled central venous catheter in the right subclavian vein . The proximity to the pleura is not shown

The central venous catheter or central venous catheters ( CVC ; synonyms: Cavakatheter, Kavakatheter , central venous catheter , central venous catheter ) is a thin plastic tube via a vein is inserted (blood vessel) of the upper half of the body into the venous system and its end in the upper or inferior vena cava before the right atrium of the heart .

In contrast to peripheral venous catheters , a CVC allows the supply of highly concentrated electrolyte and nutrient solutions and the measurement of the central venous pressure ( CVP ) as a guide for the intravascular volume (= blood volume). The installation of a central venous catheter (after puncture or - as a venae sectio - exposure of the vein) is more complex and more complicated than that of a peripheral indwelling venous catheter, so that this procedure requires a strict indication, taking into account the contraindications given below.

If the CVC is placed completely under the skin and ends in a small reservoir that can be pierced through the skin, it is more likely to be referred to as a port catheter . If the CVC is advanced through a central vein into the right atrium, then further through the right ventricle into the pulmonary artery, it is a Swan-Ganz catheter , which is located behind the right atrium and the right ventricle in the trunk of the pulmonary artery comes to rest.

Indications and contraindications

There are several indications for the placement of a central venous catheter:

  • Infusion of solutions and drugs that have a strong vein irritant effect (higher doses of sodium bicarbonate, potassium chloride and high-energy glucose or amino acid infusions, especially in the context of parenteral nutrition )
  • continuous infusion of circulatory and cardiac medication (e.g. catecholamines )
  • Inability to create a peripheral infusion line, for example in shock (especially volume deficiency shock and septic shock), in extensive burns, in hypothermia or in long-term infusion therapies with recurrent punctures of peripheral veins
  • Measurement of the central venous pressure
  • Massive transfusions
  • Surgery with the risk of air embolism (air accumulations in the right heart can, in favorable cases, be suctioned through a CVC that is advanced into the right atrium)

Relative contraindications are anatomical malformations due to the risk of incorrect punctures, disorders of blood coagulation due to the risk of extensive bruising, severe chronic and acute lung diseases with a risk of pneumothorax and allergy of the patient to the CVC materials.

Since the creation of a CVC should only be carried out if there is a clear indication, it can also be done after weighing up the risks and benefits if these relative contraindications are present.

ZVKs are available with up to seven lumens. Most often, two- and three-lumen variants are chosen. It can then via individual lumina z. B. parenteral nutrition , catecholamines and other drugs run in parallel without the risk of chemical incompatibilities between the individual substances. However, the risk of infection increases with the number of lumens, so that the indication for several lumens should be made strict.

Access routes for the ZVK

Catheter located in the internal jugular vein

For many doctors, the preferred approach is the internal jugular vein on the side of the neck. Here, the vein is usually easy to find on the basis of anatomical landmarks and can be easily visualized sonographically. It is also a large vein fixed behind muscles and almost always open when lying down. The right-sided puncture is often preferred because the vein is easier to hit because of its course and the thoracic duct that opens on the opposite side cannot be injured.

There is a risk of puncturing the common carotid artery in the event of a defective puncture (but this can be minimized under sonographic perspective). This can lead to thrombus formation in the carotid artery with subsequent thromboembolism in the vessels supplying the brain and thus to an apoplectic insult ( stroke ). Acute occlusion of the carotid artery due to thrombus formation can also lead to apoplexy.

The subclavian vein under the collarbone is an alternative . Advantages in the hands of the experienced are a clear anatomical orientation and an often quick attachment. This access route is particularly advantageous in the case of a lack of volume, because this vein is stretched between the clavicle and the 1st rib and is therefore always unfolded (the internal jugular vein can collapse and cannot be punctured). The distance from passage through the skin to entry into the vein is relatively long, which constitutes an infection barrier. Subclavian catheters can therefore often be left in place longer before a catheter-associated infection occurs. Most patients also find the subclavian catheter less disruptive than the internal jugular catheter emerging from the neck. Serious disadvantages are the risk of pneumothorax in the event of accidental puncture of the tip of the lung and bleeding into the skin and chest that is difficult to control, since the subclavian vein is not accessible to compression from outside. Incorrect punctures of the subclavian artery are common, but usually have no adverse consequences for the patient. Because of the risk of pneumothorax, the healthy side should not be punctured in unilateral lung diseases. For the same reason, a new puncture on the opposite side should be avoided if possible if the puncture is incorrect.

Under certain circumstances, access via the external jugular vein - if it is clearly visible from the outside - can be a technically simple alternative, but it is often associated with incorrect positions (e.g. kinking of the catheter in other veins or cranially).

Puncturing the arm veins is not always possible, even if there are few complications. The catheter can not always be advanced sufficiently, particularly when the cephalic vein is punctured . Because of the long catheter, complications such as phlebitis or thrombosis of the arm veins are more common, so that an arm vein catheter can usually only be left for a few days.

The vena femoralis in the groin represents a vascular access that is technically rather easy to puncture. A catheter placed here is associated with a risk of thrombosis in the leg vein. Lesions of the femoral nerve are also possible. From a hygienic point of view (colonization of the groin area with aerobic and anaerobic bacteria), a puncture of the femoral vein should be viewed critically. Mainly because of possible infectious complications, this access route is less suitable for leaving the catheter for longer. If possible, the femoral vein should only be selected for puncture if other puncture sites are not an option or, if possible, for temporary placement, until a catheter can be inserted into the jugular vein or subclavian vein under possibly improved initial conditions.

3Sites study

In the French multicentre randomized clinical study "3Sites", the working group of Jean-Jacques Parienti compared the complication rates of the CVC system via the subclavian, jugular and femoral veins. 3471 CVCs were placed in 3027 patients, which remained on average for five days. Catheter-associated infection or thrombosis were considered the primary endpoint. This was calculated over 1000 days of catheter exposure in 1.5 patients of the subclavian group, 3.6 of those with jugular CVC and 4.6 with femoral catheter, so the hazard ratio for a jugular catheter was 2.1 and for a femoral catheter 3.5 . However, the risk of mechanical complications in the femoral group was significantly lower (0.7%, odds ratio 0.3 for the subclavian group) compared with 1.4% in the jugular group and 2.1% in the subclavian group. When considering the overall complication rate of 3.1% in the subclavia group versus 3.3% in the femoral group and 3.7% in the jugular group, no significant differences were found, so that the access route can be selected individually. However, it was not investigated to what extent an ultrasound-supported CVC system influences the risk of complications, especially for a pneumothorax.

execution

ZVK with puncture material

First, the puncture region is inspected, possibly using ultrasound . With the jugular vein and subclavian vein puncture, if possible, the patient should be positioned head-down or the leg elevated to better fill the vein (especially the internal jugular vein) and to protect against air aspiration (jugular vein and subclavian vein). If the veins are inadequately filled, volume supply via peripheral veins and letting the patient squeeze can be helpful. Then disinfection and subsequent local anesthesia is carried out.

The sterile puncture is performed either on the basis of certain anatomical structures and their “landmarks” or with ultrasound imaging. The catheter is often inserted using the Seldinger technique . But there are also direct puncture sets on the market. The advantage of this is the faster application without a guide wire, the disadvantage in the venipuncture with a large-lumen cannula through which the catheter is inserted directly.

If necessary, a position check can now be carried out with the aid of the endo-ECG . A monitor ECG is derived from the Seldinger wire, which is pulled back to the tip of the CVC with the help of a marking. In the vicinity of the right atrium there is a sharp elevation of the P wave, which normalizes again when the catheter is withdrawn, so that the correct position in the superior vena cava can be set.

This is followed by an aspiration check (sucking in blood with the attached syringe) and rinsing the catheter. The CVC can be attached to the surrounding skin with a clip and seam, or with adhesive plasters. Finally, a sterile plaster bandage is applied. A chest x-ray can be used for final documentation of the position and to rule out a pneumothorax in the event of a difficult puncture.

Complications

When placing central venous catheters, there is a risk of various complications. These include the formation of hematomas after a malpuncture or perforation of the vein, more rarely an artery (especially the internal carotid artery ) or damage to neighboring nerves, an incorrect position of the CVC (with cardiac arrhythmia in intracardiac position or incorrectly high venous pressure in contact with the vascular wall) and a pneumothorax , also known as an acutely life-threatening tension pneumothorax, if the pleura is injured, and in extreme cases a pericardial tamponade if the puncture is incorrect.

A colonization by bacteria or fungi leads to so-called central venous catheter -associated bacteremia or fungemia and often to a catheter-related blood stream infection (CRBSI) called catheter-related blood stream infection (CRBSI) in the Anglo-Saxon area , which occurred in 1994 15-25 % of patients died. The incidence of catheter sepsis in the European Union was given as 1.55 per 1,000 CVC days.

If air penetrates the venous system, there is a risk of air embolism . Thrombus formation and thrombophlebitis are other complications. For this reason, when using the catheter, for. B. for regular blood sampling , special precautions must be taken to protect against air being drawn in, as well as adequate disinfection of the hose connections. Before attaching an adapter or an injection syringe , clamping devices and valve locking devices must be used so that no air can enter.

When taking blood, ensure that a small amount of blood is taken and discarded before real blood samples are taken for the laboratory in order to ensure correct preanalytics . Rinsing with physiological saline solution or any non-aggressive infusion solution with a briefly increased flow rate or number of drops is also part of the dutiful and proper handling of this catheter close to the heart and therefore not harmless.

See also

literature

  • Amitava Majumder, Anne Paschen: Medical working techniques. In: Jörg Braun, Roland Preuss (Ed.): Clinic Guide Intensive Care Medicine. 9th edition. Elsevier, Munich 2016, ISBN 978-3-437-23763-8 , pp. 29–93, here: pp. 32–38 ( central venous catheter ).

Individual evidence

  1. ^ Rainer Fritz Lick , Heinrich Schläfer: Accident rescue. Medicine and technology . Schattauer, Stuttgart / New York 1973, ISBN 978-3-7945-0326-1 ; 2nd, revised and expanded edition, ibid 1985, ISBN 3-7945-0626-X , p. 184 (on infraclavicular and supraclavicular subclavian function).
  2. ^ Jean-Jacques Parienti et al .: Intravascular complications of central venous catherization by insertion site . New England Journal of Medicine 2015; Volume 373, Issue 13 of September 24, 2015, pages 1220-1229; doi: 10.1056 / NEJMoa1500964
  3. ↑ Nadine Eckert: Choose the access route individually . Deutsches Ärzteblatt 2016, Volume 113, Issue 5 of February 5, 2016, Page A-186
  4. ↑ Amitava Majumder, Anne Paschen: Medical working techniques. 2016, p. 38.
  5. ↑ P. Muñoz et al. a .: Clinical-epidemiological characteristics and outcome of patients with catheter-related bloodstream infections in Europe (ESGNI-006 Study) . In: Clinical Microbiology and Infection . tape 10 , no. 9 , 2004, p. 843–845 , doi : 10.1111 / j.1469-0691.2004.00955.x ( researchgate.net (PDF) [accessed October 27, 2013]).