IV therapy delivers fluids, medications, and nutrients directly into the bloodstream. A “blown IV” describes a common complication where fluid leaks out of the vein into the surrounding tissue. Medically, this is known as infiltration, or extravasation if caustic medications are involved. This failure interrupts treatment, causes discomfort, and can lead to tissue injury. Infiltration is frequent, with many peripheral IVs failing before therapy is complete.
The Physical Mechanism of IV Failure
A vein is composed of three layers: the tunica intima, the tunica media, and the tunica externa. An IV catheter must sit entirely within the vein’s lumen to allow fluid to enter the bloodstream. Failure occurs when the catheter tip slips out or punctures through the vein wall, often the posterior wall, creating a tear.
Once the vein wall is breached, continuous pressure from the infusing fluid forces the solution into the interstitial space beneath the skin. This leakage is called infiltration if the fluid is non-irritating, such as saline or common antibiotics. Extravasation is a more serious event involving vesicant or irritating medications, like certain chemotherapy drugs or concentrated electrolytes, which can cause blistering and tissue damage. In both scenarios, the mechanism is a break in the vein’s integrity, allowing fluid to flow outside the circulatory system.
Patient and Vein-Related Causes
Several biological factors can make veins fragile and prone to failure. Chronic dehydration reduces blood volume, resulting in smaller, flatter veins that are more likely to collapse when punctured. These veins are difficult to access and easily damaged by the catheter.
Frequent IV treatments can lead to internal vein scarring, known as phlebosclerosis, making the vein hard and non-elastic. This scar tissue results from repeated phlebitis, or inflammation of the vein wall, increasing the chance of rupture during insertion or movement. Chronic use of corticosteroids, such as prednisone, also contributes to vascular fragility by thinning the skin and reducing supportive connective tissue.
Vein preservation is a primary concern for individuals with chronic kidney disease who may require an arteriovenous fistula for future dialysis access. This often restricts access to larger veins, forcing providers to use smaller, less robust veins in the hands or feet. Veins in older adults are less elastic and have reduced supportive tissue, causing them to roll away from the needle and increasing the risk of the catheter puncturing the wall.
Technical and Procedural Factors
The insertion technique and equipment choice significantly influence IV failure. A common procedural cause is the “through-and-through” puncture, which occurs if the insertion angle is too steep. If the clinician does not flatten the needle quickly after entering the vein, it punctures both the front and back walls, creating a leak point.
Selecting an inappropriately large catheter size for a small vein is another frequent cause of trauma. A high catheter-to-vein ratio causes mechanical irritation of the vein lining, leading to inflammation and rupture. Poor stabilization after placement can cause “catheter pistoning,” where the device repeatedly rubs against the inner vein wall during patient movement. Insertion sites over a joint, such as the wrist, are vulnerable to this mechanical failure.
High-pressure administration of fluids, such as rapid infusion via an electronic pump, is also a factor. If the catheter tip is dislodged or resting against the vein wall, the high pressure can force fluid out into the surrounding tissue. A minor puncture that might not leak under gravity flow can fail catastrophically when a pump applies significant force.
Recognizing and Responding to Infiltration
Recognizing the signs of a blown IV minimizes harm. Common signs of infiltration include:
- Swelling, tightness, or pain at the site.
- Skin that is cool to the touch, pale, or blanched compared to surrounding skin.
- A pump alarming due to occlusion, or a gravity infusion slowing or stopping completely.
Immediate action is necessary to prevent further damage. The infusion must be stopped immediately, and the catheter removed to prevent further leakage. The affected limb should then be elevated above the heart, which reduces swelling and promotes the reabsorption of leaked fluid.
Post-removal care involves applying a compress, with the type depending on the fluid. For standard non-irritating infiltrations, a cold compress is applied initially to reduce swelling, followed by a warm compress after 24 hours to help disperse the fluid. If extravasation involved an irritating medication, a cold compress is generally used to limit the drug’s spread, but a warm compress may be needed for specific solutions like concentrated dextrose.