Intravenous (IV) therapy delivers fluids, medications, and nutrients directly into the bloodstream. While highly effective, a common local complication at the insertion site is venous infiltration. This occurs when the fluid’s intended pathway is disrupted, causing it to leak into the surrounding tissue instead of the vein.
Defining Venous Infiltration
Venous infiltration describes the accidental leakage of a non-vesicant IV solution from the vein into the perivascular tissue, the soft tissue surrounding the blood vessel. This happens when the intravenous catheter, a small flexible tube, either slips entirely out of the vein or punctures through the vein wall. The fluid then flows into the subcutaneous space instead of circulating through the venous system.
Infiltration must be distinguished from two similar complications: extravasation and phlebitis. Extravasation is a more serious event where a vesicant (caustic) fluid or medication leaks out, potentially causing blistering, severe tissue injury, and necrosis. Phlebitis is an inflammation of the vein wall itself, often caused by mechanical trauma from the catheter or chemical irritation from the solution. Infiltration involves non-irritating fluid leaking into the tissue, which is generally less harmful than extravasation but still requires immediate action.
Recognizing Signs and Symptoms
Identifying venous infiltration early prevents discomfort and potential complications. The most observable physical change is localized swelling or puffiness around the insertion site as fluid collects under the skin. This area often feels tight or firm to the touch due to the sudden increase in fluid volume.
The skin overlying the infiltration may appear blanched, or pale, and feel noticeably cooler than the surrounding skin. This temperature change results from the introduction of room-temperature IV solution directly into the subcutaneous space. Patients may report discomfort, tingling, or a general tightness in the limb.
A significant decrease in the flow rate of the IV, or an alarm on an electronic pump indicating a pressure change, is another strong indicator. This suggests the fluid is meeting resistance and not entering the vein correctly.
Common Causes and Risk Factors
Infiltration occurs due to a mechanical failure of the catheter’s position within the vein. Patient movement is a primary cause, especially when the IV is placed near a joint, where flexion can push the catheter tip through the vein wall. Inadequate securement of the catheter to the skin is another common procedural factor that allows slight shifts, leading to dislodgement.
Certain patient populations are inherently more vulnerable to this complication. Individuals with fragile veins, such as the elderly, those receiving long-term IV therapy, or those with chronic illnesses, are at greater risk of the vein wall being punctured or easily damaged. Additionally, repeated venipuncture attempts in the same area or the use of a catheter size that is too large for the chosen vein can weaken the vessel wall, increasing the likelihood of fluid leakage.
Necessary Steps for Management
When infiltration is suspected, the immediate action is to stop the infusion of the fluid to prevent further leakage into the tissue. After the flow is halted, the intravenous catheter must be carefully removed from the site. Following catheter removal, the affected extremity should be elevated above the level of the heart, if possible, to encourage the reabsorption of the leaked fluid and reduce swelling. Medical staff will then often apply thermal compresses to the site.
A warm compress is typically used for non-vesicant infiltrations, as the heat helps to increase local blood circulation and speed up the body’s natural reabsorption of the fluid. A new IV line will need to be established in an unaffected limb to resume necessary therapy. Most venous infiltrations resolve completely within a few days without any long-term consequences.