IV infiltration happens when fluid leaks out of a vein and into the surrounding tissue during an intravenous infusion. Treatment depends on how severe the swelling is and what type of fluid escaped, but the immediate steps are the same: stop the infusion, elevate the limb, and assess the damage. Mild cases resolve on their own within hours, while severe infiltration can threaten circulation and require surgical intervention.
Recognizing the Severity
Infiltration is graded on a 0-to-4 scale based on how much swelling is present and how the skin looks. Understanding where an infiltration falls on this scale determines everything that comes next.
At Stage 1, the skin looks pale or blanched, feels cool to the touch, and swelling is minimal, less than about an inch across. Stage 2 looks similar but with swelling up to about 6 inches. Both of these grades are common and typically resolve with basic care.
Stage 3 infiltration involves swelling beyond 6 inches, skin that appears translucent, mild to moderate pain, and possible numbness. Stage 4 is the most serious: the skin is tight, discolored, or bruised, with deep tissue swelling, impaired circulation, and moderate to severe pain. Any infiltration involving a blood product, a drug that damages veins (called a vesicant), or an irritating medication is automatically classified as Stage 4 regardless of how it looks.
Immediate Steps
The first and most important action is stopping the infusion. The IV line should not be removed right away, and the line should not be flushed, because both actions can push more fluid into the tissue. Instead, a small syringe is used to draw back and aspirate whatever fluid or medication remains in the catheter. This reduces the amount of substance sitting in the tissue.
The affected limb should be elevated above the level of the heart to encourage fluid reabsorption. No pressure should be applied to the swollen area. If there is pain, appropriate pain relief can be given. The borders of the swelling should be outlined with a skin marker so changes in size can be tracked over time, and photos should be taken to document the injury.
Warm Compresses vs. Cold Compresses
Whether to apply warmth or cold depends entirely on what was being infused. Getting this wrong can make the injury worse.
Warm compresses work by dilating blood vessels and helping the body disperse and reabsorb the leaked fluid over a larger area. They are the right choice for most situations: high-concentration sugar solutions (like dextrose), antibiotics, nutrition solutions (TPN), electrolyte infusions, fluids with very low or very high acidity, and solutions with high osmolarity (500 mOsm/L or above). Compresses should be applied repeatedly over several hours, up to 24 hours.
Cold compresses do the opposite. They constrict blood vessels and limit how far the leaked substance spreads. Cold is appropriate for IV contrast dye and a smaller number of specific medications where containment is the goal.
One critical exception: never use cold compresses for vasopressor infiltration (drugs like norepinephrine or dopamine that constrict blood vessels). These drugs are already choking off local blood flow, and adding cold on top causes even more vasoconstriction, which can lead to tissue death.
Medications Used for Severe Infiltration
Hyaluronidase
Hyaluronidase is an enzyme that breaks down connective tissue beneath the skin, allowing trapped fluid to spread out and be absorbed more quickly. It is typically used alongside warm compresses for infiltration involving concentrated or high-volume solutions. The standard dose is 150 units, and timing matters: it works best when given within 60 minutes of the infiltration event. The medication is injected into the tissue around the infiltration site at multiple points.
Phentolamine for Vasopressor Leaks
When a vasopressor drug leaks into tissue, phentolamine is the specific antidote. Vasopressors constrict blood vessels so aggressively that even a small leak can cut off blood supply and cause tissue to die. Phentolamine reverses this by blocking the receptors that vasopressors act on, relaxing the blood vessels and restoring circulation. It is mixed in saline and injected directly into the affected area. Unlike hyaluronidase, the treatment window is much longer: phentolamine can be effective up to 12 hours after the event, though sooner is always better.
Sodium Thiosulfate
Sodium thiosulfate neutralizes harmful reactive molecules that form when certain irritating drugs leak into tissue. It is considered a first-line treatment for many vesicant infiltrations. The solution is prepared by diluting a concentrated stock with sterile water, and the dose is calculated based on how much drug leaked: 2 mL of the prepared solution for every 1 mg of extravasated medication.
What to Monitor Afterward
Even after initial treatment, infiltration injuries need close watching. The tissue should be assessed every hour for the first 24 hours, checking for changes in firmness, skin color, and sensation. Monitoring should continue for at least 72 hours total.
Some complications don’t show up right away. Tissue damage from certain substances can take two to three weeks to fully manifest. Warning signs that the injury is getting worse include increasing swelling, escalating pain, blistering or ulceration, skin color changes suggesting poor blood flow, and altered sensation like tingling or numbness in the affected area.
When Infiltration Becomes a Surgical Emergency
The most dangerous complication of severe infiltration is compartment syndrome, where pressure from the leaked fluid builds up in a closed tissue space and cuts off blood supply to muscles and nerves. The classic warning signs are sometimes called “the five Ps”: pain (especially deep, poorly localized pain that seems out of proportion), pulselessness, paresthesia (tingling or numbness), paralysis, and pallor. Of these, abnormal sensation tends to appear first. By the time pulses are lost or the limb is paralyzed, permanent damage may already be underway.
Specific triggers for a surgical consultation include an estimated leaked volume of 100 mL or more, skin blistering, signs of impaired tissue perfusion, pain that keeps increasing over time, and any sensory changes near the infiltration site. In a large multicenter study, about 35% of significant infiltration cases required a hand specialist consultation, split roughly between orthopedic surgeons and plastic surgeons, with a smaller number seen by vascular surgery.
Documentation
Thorough documentation protects the patient’s ongoing care and creates a record if the injury worsens. The medical record should capture the specific drug or fluid involved, the type of IV access device, the infiltration stage, the extent and borders of the swelling, skin condition, pulse checks in the affected limb, and clinical photographs. An incident report should also note what infusion pump was in use, the level of harm, and the follow-up plan. For outpatients discharged after an infiltration event, clear instructions about warning signs that warrant an emergency visit are part of the record.