Peripheral venous catheter

The peripheral venous catheter, the peripheral venous catheter, the peripheral- venous access, the PVK, peripheral IV catheter, peripheral indwelling catheters ( depending on the manufacturer also Abbokath ®, Braunüle ®, Flexüle ®, Venflon ®, Viggo ®; colloquially venule ) is a special form of the catheter. It serves to fluid therapy or intravenous administration of drugs, without repeatedly burdening the patient with punctures. Also, blood transfusions are generally administered via peripheral venous catheter. Such a catheter may be used in general several days. However, for a permanent access to the bloodstream using a port catheter.

The placement of a peripheral venous catheter is usually reserved for doctors. The physician may delegate this measure also of skilled personnel such as health and nurses, midwives, paramedics or emergency medical technician or paramedic, the latter under certain conditions may also take action on their own. In Austria and Germany, this is controlled by the emergency skills.

• 2.1 Security catheter

Use

Intravenous application

The peripheral venous catheter consists of a steel tube ( steel stylet ) and a surrounding plastic catheter. First, a suitable vein is punctured and the venous catheter carefully pushed a short distance into the vessel lumen. Upon successful puncture a transparent chamber filled at the end of the puncture needle with blood. The catheter can then advance through the puncture needle into the vein.

Suitable veins are in principle all superficial veins running, usually, however, the veins of the forearm, back of the hand and the elbow ( peripheral venous access ). Punctures of veins in the hinge region are, however, be avoided if possible due to the mechanical impact of joint movements and the significantly reduced patient comfort.

Just as the steel stylet needles used are disposed of in sharps boxes.

A blood collection, particularly from already longer lying venous catheters, not always possible, though at the same time easily fluid can be injected intravenously. Blood tests may possibly be falsified by blood components or dilution effects at pre ongoing infusions. When a blood sample immediately after installation of a venous catheter, however, this problem does not exist.

Piercing

Peripheral venous catheters are not in accordance with the original purpose, also used in the piercing. Here, the venous catheter previously marked on injecting and exit points is pierced through the skin and the underlying subcutaneous fat and then removes the steel cannula. The jewelry will be inserted inserted into the end of the plastic sheath and simultaneously pulled in their pushing out through the skin.

Variations

Venous catheters are color-coded; they exist as well as the needles in several sizes. Their diameter is expressed in millimeters, often in the non-SI unit gauge. Depending on the diameter of the corresponding plastic catheter within the body has a different length ( 25-50 mm). The diameter and the length of the catheter will change the flow rate; it ranges from 22 ml / min at 0.7 mm catheters up to 330 ml / min at 2.2 mm connections ( for aqueous infusions). While the sizes of 0.7 to 1.1 mm are used in children because of the thin blood vessels, are used in an adult is usually the sizes 1.1 mm and 1.3 mm are used. In situations in which in a short time the infusion of greater amounts of blood or infusion is necessary (shock, multiple trauma ), the sizes used because of the high flow rate of 1.5 to 2.2 mm.

If an access for a short period is not required, it is generally closed by a matching plastic stylet, which fills the lumen of the catheter, thus preventing blood clotting in the catheter.

The peripheral venous catheter size 1.3 mm is available in two different versions (Green and Green / White ); the only difference is in the stitch length, so the length of the vein lying in the Teflon catheter.

A venous catheter for pediatrics in sizes 0.7 mm and 0.45 mm with and without injection valve in the materials PUR ( polyurethane) and FEP ( Teflon) is offered by some manufacturers.

Safety catheter

The use of safety catheters is mandatory since the entry into force of the TRBA 250. In these catheters, a guard over the tip of the cannula immediately after the removal of the steel stylet from the Teflon tube which is located in the vein down. This can be in the form of a small metal clip that is pushed when pulling out of the steel mandrel over selfsame, depending on the manufacturer in several other variations. Thus, the risk of needlestick injury and infection with HIV, hepatitis C, hepatitis B is reduced.

History

The inventor of the first Dauerverweilkatheters plastic was DJ Massa from the Mayo Clinic in 1950. Bernd Braun, physician and chemist, developed in 1962 a German version.