Indwelling Cannulas and Catheters

Indwelling Venous Cannulas

An indwelling cannula is a thin, flexible tube that allows fluids and medications to be administered directly into the bloodstream via a vein. The tube is inserted into the veins, typically in the elbow crease, forearm, or the back of the hand. Depending on the manufacturer, it may also be called a Braunüle, Flexüle, Abbokath, Venflon, or Vygonüle. Common informal names include Vigio, Venule, needle, or venous access. In southern Germany and Austria, it is often referred to as a ""line."" It is used to deliver intravenous fluids, medications, or blood transfusions when a patient has difficulty swallowing. An indwelling cannula spares patients from multiple punctures and is commonly used for transfusions.

Who Needs an Indwelling Venous Cannula?

These cannulas are used for patients who cannot drink due to swallowing difficulties, such as those who have had a stroke or head injury. They are also used for post-surgical patients to support faster recovery. Additionally, they are beneficial for individuals with gastric tubes due to bowel obstruction and are frequently used in chemotherapy infusions for cancer patients. Indwelling venous cannulas can also be placed during endoscopic procedures to enhance internal visualization.

Benefits of Using a Flexüle

Indwelling venous cannulas offer several medical advantages over other administration methods such as intravenous drips, catheter-based systems, and oral capsules. They also provide pain relief and support breathing difficulties in patients with epilepsy or neurological conditions. A Braunüle can help facilitate eating and drinking, reducing risks like pneumonia or dehydration. Additionally, doctors can monitor patient responses and adjust treatments accordingly.

Who Can Insert an Indwelling Venous Cannula?

Generally, placing a peripheral venous catheter should be done by a doctor or medical students under supervision. However, in many hospitals, this task is delegated to trained medical staff, such as nurses, midwives, or other healthcare professionals. For safe application, high-quality disposable cannulas are used to minimize risks of infection and needle-stick injuries.

How Is a Flexüle Inserted?

Typically, the cannula is inserted into the skin at an angle of about 30 degrees. To prevent puncturing the vein, the insertion angle is gradually reduced. If the puncture is successful, the hub of the cannula fills with blood. The indwelling venous cannula should then be advanced another 1 to 2 mm into the vein using a suitable venipuncture cannula system.

Where Should an Indwelling Venous Cannula Be Placed?

The forearms and the backs of the hands are the preferred sites for placing a Braunüle, as veins in these areas are more visible. Patient comfort is a priority, so sites near joints or the dominant hand should be avoided. Special caution is needed when inserting a cannula in the elbow crease due to the proximity of arteries and nerves. If a patient experiences severe, unusual pain after insertion, it may indicate a nerve has been punctured, requiring immediate removal. Arterial mispunctures can be identified by pulsatile blood flow.