An intravenous (IV) line is a small catheter inserted into a vein, typically in the arm or hand, allowing fluids, medications, or blood products to be delivered directly into the bloodstream. This method is common in healthcare settings for its speed and efficiency. Localized swelling, known as edema, is a common complication associated with peripheral IV use. It occurs when fluid collects in the surrounding tissue near the insertion site.
Why Swelling Occurs During or After an IV
Swelling is often caused by the inadvertent leakage of fluid or blood outside the vessel wall. The most frequent cause is infiltration, which occurs when the IV catheter punctures through the opposite wall of the vein or becomes dislodged. The infused fluid (non-vesicant) leaks into the soft subcutaneous space instead of the circulatory system. The volume of this escaped fluid causes the localized swelling.
A more serious form of leakage is called extravasation, which involves a vesicant medication. A vesicant is a substance that can cause blistering, severe pain, and tissue damage if it escapes the vein. The resulting swelling carries a higher risk of injury due to the substance’s irritating nature. Both infiltration and extravasation can happen if the catheter is poorly secured, the patient moves excessively, or the vein wall is fragile.
Another cause of swelling is phlebitis, which involves inflammation of the vein wall. This inflammation may be triggered by mechanical irritation from the catheter, chemical irritation from the infused medication’s pH or osmolarity, or an infection. The body’s inflammatory response causes the vein and surrounding tissue to swell and become tender.
Swelling can also result from a hematoma, which is essentially a bruise forming at the IV site. A hematoma occurs when blood leaks out of the vein and pools in the surrounding tissue. This usually happens immediately after insertion if the needle passes through both walls of the vein, or if insufficient pressure is applied after the catheter is removed. Although the blood collection causes a lump and discoloration, it resolves over time as the body reabsorbs the pooled blood.
How to Identify Different Types of Swelling
Recognizing the specific type of swelling is important because it dictates the appropriate response. Swelling due to infiltration typically presents with distinct characteristics. The skin around the IV site will feel cool to the touch and appear pale or blanched due to the presence of fluid under the skin. The area will feel tight or puffy, and a visible pitting edema, where a finger press leaves a temporary indentation, may be present.
In contrast, swelling associated with phlebitis involves signs of inflammation. The area will feel warm and tender, and the skin will appear red or inflamed. Sometimes a red streak is visible along the path of the affected vein. When touched, the vein may feel hard or cord-like beneath the skin due to the inflammation. The presence of redness and warmth helps distinguish phlebitis from the coolness and pallor of infiltration.
A hematoma is visually distinct from both infiltration and phlebitis because its swelling is accompanied by noticeable bruising. The area will show a purple or blue discoloration and may present as a firm, localized lump near the puncture site. While a hematoma can cause mild discomfort, the swelling is localized and does not spread as extensively as fluid infiltration.
Immediate Steps and Warning Signs
If swelling is noticed, immediately stop the infusion to prevent further leakage into the tissue. The IV catheter should be removed by a healthcare professional. The affected limb should then be elevated above the level of the heart, using gravity to help drain the trapped fluid and reduce the edema.
For minor swelling, such as mild infiltration or hematoma, applying a cold compress for the first 24 hours can help limit fluid spread and reduce discomfort by constricting blood vessels. After the initial 24-hour period, or for phlebitis, a warm compress is recommended to promote circulation and aid in fluid reabsorption or decrease inflammation. Always follow the specific compress instructions provided by a healthcare professional, as they vary depending on the type of medication infused.
Certain symptoms require immediate medical evaluation as they may signal a more serious complication. Seek immediate care if you develop a fever or notice pus draining from the site, as these are signs of a potential infection. Severe or rapidly increasing pain, blistering, numbness, or tingling in the fingers or arm are serious warning signs. These symptoms could indicate nerve damage or a rare but dangerous condition called compartment syndrome, which results from excessive pressure on the tissues.