What is the function of cannula?

Answered by Tom Adger

The function of a cannula, also known as a venflon™, is to provide a means of accessing a vein for various medical purposes. It is a small and flexible plastic tube that is inserted into a vein, typically in the arm or hand. The cannula allows healthcare professionals to administer medications, fluids, or other substances directly into the bloodstream.

One of the primary purposes of a cannula is to deliver medications that cannot be taken orally or need to have a more immediate effect. For example, if a patient is unable to swallow medication due to nausea or vomiting, or if the medication needs to bypass the digestive system for faster results, a cannula can be used to deliver the medication directly into the bloodstream.

Cannulas are also utilized for the administration of fluids when a patient is unable to drink or absorb them orally. This can occur in cases of severe dehydration, unconsciousness, or during surgical procedures where intravenous fluids are necessary to maintain hydration and electrolyte balance.

In addition to medication and fluid administration, a cannula can be used for blood sampling. By accessing a vein through the cannula, healthcare professionals can easily draw blood for laboratory tests or to monitor various health parameters.

Cannulas are typically inserted by healthcare professionals, such as nurses or doctors, who have been trained in the proper technique. The insertion process involves cleaning the area around the vein, locating a suitable vein, and gently inserting the cannula into the vein. Once inserted, the cannula is secured in place with adhesive tape or a dressing.

The small coloured cap on the outside of the cannula serves as a protective cover. It helps prevent contamination and keeps the cannula sterile until it is ready to be used. The colour of the cap may indicate the size or gauge of the cannula, which can vary depending on the patient’s needs.

It is important to monitor the cannula site for any signs of infection, such as redness, swelling, or pain. Proper care and maintenance of the cannula, including regular flushing and dressing changes, can help prevent complications.

The function of a cannula is to provide a safe and efficient method of delivering medications, fluids, or obtaining blood samples when oral administration is not possible or practical. It plays a crucial role in healthcare settings, allowing for the direct access to veins and facilitating necessary medical interventions.