Types of IV Cannulas and Their Uses

IV Cannula, types of IV cannula, intravenous cannula

A cannula is a tube inserted into the body for the removal or delivery of fluids and gathering samples. In other words, a cannula surrounds the surface of a needle, extending the effective length of the needle and making it easier to work with. Also known as intravenous cannula or IV cannula, they are available in a range of different sizes and features.


IV cannulas allow for a variety of treatments and preventive caring options. Once the cannula is inserted into the vein, it can be used by the medical staff to inject medications, fluids or blood directly. The cannula eliminates the need of using and injecting a new needle for each and every session or delivery. There are 3 main types of IV cannulas, namely: peripheral IV Cannula, central line IV cannula and mid-line IV cannula. The central line intravenous cannulas are used for long term treatments, followed by midline cannulas used in less invasive scenarios.

All these intravenous cannulas have a specific purpose and is used for separate treatments. Let’s take a look at each of the three types of IV cannula in detail:


Peripheral IV cannula: The most commonly used IV cannula, the peripheral IV cannula is usually used for emergency room and surgical patients, or for those individuals who undergo radiological imaging. Each of these IV lines is used for up to four days and not beyond that. It is attached to an IV catheter and then taped to the skin by making use of adhesive tape or a non-allergic alternative.

Central line IV cannula: This type of IV cannula is used for patients who are undergoing prolonged treatments and require medication or fluids to be administered over multiple weeks or months. They help in faster delivery of medicines for producing fast responses. They are also a good choice for transferring large amounts of blood or any other fluid into the patient’s body. This IV cannula is inserted into the jugular vein located in the neck, subclavian vein or the femoral vein.


Midline catheter: This is the perfect choice for those patients who are undergoing a treatment that lasts for more than five days but less than a month. They are considered a less invasive method and are most commonly used for drawing out blood samples or delivering contents. The IV tube is placed on a large vein in the upper part of the patients arm.

Different sizes of IV cannulas are colour coded to define the size and their usage. The IV cannula size generally varies from 14 to 24 gauge. The size is decided on the basis of the patient’s condition, purpose of the IV cannula and the urgency at which the fluid needs to be delivered.

It is important to know the different types of cannulas and their usage for effective and proper treatment of the patient. These should be used only after careful examination and a doctor’s approval.