An angiocatheter is a specialized medical device designed to provide temporary access to a patient’s vascular system, typically a peripheral vein. This small, hollow, flexible tube allows healthcare providers to introduce fluids, medications, or draw blood samples directly from the bloodstream without requiring repeated needle sticks. It is a device commonly encountered in hospital and clinical settings, often simply referred to by patients as an “IV.” The core function of the angiocatheter is to establish a secure, continuous pathway into a blood vessel for diagnostic or therapeutic purposes.
Understanding the Device Components
The physical structure of an angiocatheter is composed of two primary parts that work together to achieve vascular access. The first is the sharp, stainless steel needle, known as the stylet or introducer needle, used for the initial puncture of the skin and the vein wall. This needle is hollow and extends slightly beyond the tip of the surrounding tube to ensure clean entry into the vessel.
The second part is the flexible plastic tube, called the cannula or catheter, which remains in the vein after the needle is removed. This cannula is often made from a polymer material that makes it radiopaque, allowing it to be detected on an X-ray. The device includes a hub, where syringes or IV lines connect, and a flash chamber. Blood flowing back into this clear flash chamber confirms proper placement before the stylet is withdrawn. Angiocatheters are sized by a gauge system; a smaller gauge number indicates a larger internal diameter.
Insertion Procedure and Clinical Applications
The process of inserting an angiocatheter begins with identifying a suitable vein, often in the arm or hand, and preparing the site with an antiseptic solution. The healthcare provider inserts the entire assembly—the needle encased within the cannula—through the skin and into the vein. As the needle tip enters the vessel lumen, blood “flashes” back into the clear chamber, signaling successful cannulation.
Once the flash of blood is confirmed, the provider carefully advances the flexible cannula further into the vein while simultaneously withdrawing the stylet. The flexible catheter remains inside the patient. The cannula is then secured to the skin with tape or a specialized dressing to prevent dislodgement or movement.
The primary clinical application for the angiocatheter is to facilitate the administration of intravenous (IV) fluids to correct dehydration or maintain hydration during medical procedures. It is also the standard method for delivering medications directly into the bloodstream for rapid effect or continuous infusion. The established venous access allows for repeated blood sampling for laboratory tests without subjecting the patient to multiple venipunctures. Furthermore, these catheters can be used as an access point for more complex procedures, such as threading a guidewire for the placement of a central venous line.
Monitoring and Potential Complications
After an angiocatheter is placed, continuous monitoring of the insertion site is necessary to ensure the device remains functional and to detect adverse reactions. Monitoring involves checking for signs of swelling, pain, redness, or leakage around the catheter. The device is designed for short-term use and requires regular changing to mitigate risks.
One of the most common complications is infiltration, which occurs when the administered fluid or medication leaks out of the vein and into the surrounding subcutaneous tissue. This can cause discomfort, swelling, and sometimes tissue damage. Another frequent issue is phlebitis, an inflammation of the vein wall that presents as redness and tenderness along the path of the vessel.
Other potential complications include the formation of a hematoma, or bruising, at the insertion site due to blood leaking from the vessel during or after the procedure. Infection at the site is a serious risk, requiring sterile technique during placement and keeping the dressing clean and dry. When the catheter is no longer needed or if a complication develops, the device is removed, and pressure is applied to the site to prevent further bleeding.