The Difference Between IV Cannula and Catheter

When it comes to medical procedures that involve the administration of fluids or medications, two terms that often come up are “IV cannula” and “catheter.” While they may seem similar at first glance, there are key differences between these two devices. In this blog post, we will explore these differences and delve into the uses and benefits of each.

IV Cannula

An IV cannula, also known as an intravenous cannula or IV catheter, is a thin, flexible tube inserted into a patient’s vein. It is primarily used for administering fluids, medications, or blood products directly into the bloodstream. IV cannulas come in various sizes, typically measured by their gauge, which refers to the diameter of the needle. The smaller the gauge number, the larger the diameter of the needle.

The main purpose of an IV cannula is to provide a reliable access point to a patient’s vein. This allows healthcare professionals to deliver necessary treatments efficiently and effectively. It also enables continuous monitoring of a patient’s condition, such as blood pressure and oxygen levels. IV cannulas are commonly used in hospitals, clinics, and other healthcare settings.


A catheter, on the other hand, is a flexible tube used to drain fluids or deliver fluids directly into various body cavities or vessels. While IV cannulas can be considered a type of catheter, the term “catheter” is more commonly used to refer to devices that stay in place for an extended period.

Catheters are widely used in medical procedures that involve drainage or prolonged administration of fluids. They come in different types and sizes, depending on their specific application. Some common types of catheters include urinary catheters, central venous catheters, and nasogastric tubes. Each type is designed for a specific purpose and requires careful insertion and maintenance to prevent complications such as infection or blockage.

Differences Between IV Cannula and Catheter

While both IV cannulas and catheters serve similar purposes, there are several notable differences between the two:

  • Duration of Use: IV cannulas are typically used for short-term treatment, such as intravenous medication administration, blood transfusions, or fluid resuscitation. In contrast, catheters are designed for long-term or continuous use, such as draining urine from the bladder or providing nutrition directly into the gastrointestinal tract.
  • Insertion Technique: IV cannulas are often inserted using a needle or an angiocath into the patient’s vein. Once the cannula is in place, the needle is removed, leaving only the plastic catheter inside the vein. Catheters, on the other hand, require specialized techniques for proper placement, as they are intended to stay in the body for an extended period.
  • Flexibility: IV cannulas are relatively flexible and easy to move within the vein if necessary. They allow for adjustments and repositioning without removing the device fully. Catheters, however, are usually anchored in place to prevent unintentional movement or dislodgment.
  • Size Range: IV cannulas come in various sizes, with gauge numbers ranging from 14 to 24, depending on the patient’s condition and the required flow rate. Catheters, on the other hand, have larger sizes due to their intended purpose of draining fluids and require careful size selection for proper drainage or administration.

These differences highlight the varying applications and functions of IV cannulas and catheters, emphasizing the importance of understanding which device is appropriate for specific medical procedures.


IV cannulas and catheters are both essential medical devices used to administer or drain fluids from the body. While IV cannulas are primarily used for short-term treatment and intravenous access, catheters are designed for long-term or continuous use. Understanding the differences between these devices is crucial for healthcare professionals to choose the appropriate device for each patient’s specific needs.

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