What Is a Central Venous Catheter?

Central venous catheter (central venous catheter; CV cath .; CVC) is a type of intravascular tube that is placed in the large vein.

Chinese name: Central venous catheter
Foreign name: central venous catheter; CV cath.; CVC

Type: Single / Double / Triple / Quad
Conduit shape: Straight, elbow and elbow extension
Material: Silicone and PU materials

Central venous catheter use

1. Measure the central venous pressure (central venous pressure, central venous pressure) to evaluate the circulation physiology

Central venous catheter Parameters, and estimated body fluids. Because of the purpose of measuring central venous pressure, in hospitals in Taiwan, central venous pressure is often used as the nickname for CVC.

2. Large and rapid intravenous infusions often occur in surgery where blood loss may be large, or to maintain blood pressure during first aid.

3. Long-term parenteral nutrition, long-term antibiotic injection, and long-term painkiller injection.

4. For peripheral veins (small veins) more irritating drugs, inject from the central venous catheter. For example: amiodarone.

5. Hemodialysis channels such as plasma exchange or dialysis

6. Chemotherapy of tumors to prevent the occurrence of chemical phlebitis and prevent extravasation of medicinal solution,

7. Establish a good infusion channel for patients with repeated infusions to avoid the pain of repeated punctures.

8. Establish an infusion channel in critically ill patients.

Specifications

Model: single cavity / double cavity / three cavity / four cavity

Specifications: single 14G / 16G / 18G / 20G double 4Fr / 5Fr / 7Fr / 8Fr three-chamber 5.5Fr / 7Fr / 8.5Fr four-chamber 8.5Fr

Among them, different types of catheters have different lengths.

Conduit shape

Straight, elbow and elbow extension

Central Venous Catheter Material

Silicone and PU materials

Central venous catheter applicable department

Department of Anesthesiology, Emergency Department, ICU Ward, Surgery, Internal Medicine, Thoracic Surgery, Vascular Surgery

Central venous catheter

Internal jugular vein (internal jugular vein)

Subclavian vein (subclavian vein)

Femoral vein (femoral vein)

Puncture care

Central venous catheter puncture method

The choice of puncture route depends on the doctor's personal habits, proficiency, and puncture equipment. The internal jugular vein and subclavian vein are usually punctured with the head 15 ° supine, with a thin pillow under the shoulder, and the head turned to the opposite side. Taking the right side is more profitable than the left side.

Internal jugular vein

Using the sternocleidomastoid muscle as a marker, it can be divided into three methods: anterior, middle, and posterior approach. The way forward: the surgeon uses his left index finger and middle finger to open 3cm beside the midline, at the midpoint of the anterior edge of the sternocleidomastoid muscle, which is equivalent to the level of the upper edge of the thyroid cartilage, and touches the common carotid artery to beat and push inward, away from the common carotid artery The needle was inserted at the outer edge of the pulsatile 0.5cm, the needle body and the leather surface were at an angle of 30 ° ~ 40 °, the needle point pointed to the triangle of the sternocleidomastoid muscle, and the needle was withdrawn while seeing the dark red blood. Middle approach: take the apex of the sternocleidomastoid muscle triangle as the point of entry, this point is 3 to 5 cm from the upper edge of the clavicle (about 1 to 2 horizontal fingers), the angle between the needle body and the skin is 30 °, pointing parallel to the midline Lateral nipples are usually inserted into the internal jugular vein 2 to 3 cm. Posterior approach: The needle is inserted at the middle and lower 1/3 intersections of the outer edge of the sternocleidomastoid muscle.

Subclavian vein

With the clavicle as the sign, it is divided into two approaches. Upper clavicle: The needle is inserted at the lateral edge of the clavicle head of the sternocleidomastoid muscle approximately 1.0 cm above the clavicle. The needle body and the sagittal plane and the clavicle are each at a 45 ° angle, and the coronal plane is horizontal or slightly forward 15 ° angle, the needle point to the sternoclavicular joint, generally 1.5 ~ 2cm into the needle can enter the subclavian vein. Subclavian approach: The traditional approach is to enter the needle from the junction of the middle and inner 1/3 of the clavicle, and the lower edge of the clavicle is 1 to 1.5cm. The improved new approach is the best puncture point at the intersection of the right vertical line of the clavicle and the horizontal line of the sternoclavicular joint. The needle point points to the lower edge of the thyroid cartilage.

Femoral vein

At the two transverse fingers below the inguinal ligament, touch the femoral artery with the index finger of the left hand and the middle finger, insert the needle 0.5cm inside, point the needle point to the side of the head, and the needle body and skin are at an angle of 30 °. In clinical practice, the author prefers to use the "three designation method" to determine the femoral vein puncture site, and the positioning method is simple and accurate.

4. Methods and materials

The puncture site is routinely sterilized. After 2% procaine local anesthesia, first try the blood back with a disposable syringe, and then introduce the central venous catheter puncture needle in the original direction. Keep the needle under pressure and draw blood slowly Later, the needle was fixed in the left hand, the guide wire was introduced to the right length in the right hand, and the needle was retracted while the guide wire was being advanced. Catheter semicircular suture to secure three needles.

Central venous catheter care points

Topical skin care

In addition to closely observing the local skin for inflammatory reactions such as redness, swelling, and heat pain, the puncture site is disinfected daily with iodine and alcohol. After the volatilization and drying, add iodophors, because iodophors have the property of gradually releasing iodine, which can play Continuous sterilization. In addition, the local skin to which iodophor is applied is formed with a layer of dark brown thin palate that can cover the entrance of the skin of the catheter and has a positive effect on preventing bacteria from entering the blood along the parasinus of the catheter. Cover the puncture point and the catheter with a 3M transparent film, because it has good breathability and sterility, it is not easy to cause the skin excrement at the cap site to be unable to volatilize and cause infection. These may be the main causes of infection in this group. It is also necessary to closely observe changes in body temperature. Body temperature is an important indicator for monitoring the occurrence of infection during the indwelling of a central venous catheter. When a patient suddenly has a cold and fever, the body temperature suddenly rises, and when other causes are not found clinically, it should be considered as a catheter. Related infections.

2. Anti-embolic care

The end of the indwelling catheter is connected to a heparin lock, because heparin lock can prevent blood in the catheter from clotting, reducing the possibility of bacterial intervention. The scalp needle is inserted into the heparin lock infusion. At the end of the daily infusion, 3ml (125U / ml) of heparin solution is injected through the scalp needle. The speed should be slow. Pay attention to retract the scalp needle to only the tip of the needle to ensure that the heparin solution fills the entire lumen. In order to avoid the relative decrease in the concentration of heparin solution, blockage can be avoided. When you connect the scalp needle daily, pay attention to draw back the blood to determine whether the catheter is unobstructed. If you don't see blood back, you should judge whether the tube is detached or the blood in the tube is coagulated. Air embolism often occurs in deep venous catheters. If no rapid measures are taken, the patient will die of air embolism within minutes. All patients in this group are provided with an infusion pump device before puncturing, and set alarm items according to the function of the infusion pump, such as blockage, air, and completion of the infusion to ensure that the liquid enters the body smoothly and avoids accidents.

From "Chinese Journal of Modern Clinical Medicine" and "Chinese Journal of Nursing"