Nursing care
Infiltration and Extravasation nursing care: what to assess and what to do first
Written and reviewed by Dana Whitfield, RN, MSN · 6 min read · Updated September 2026
Short answer
Infiltration is a non-vesicant IV fluid leaking into surrounding tissue, causing a cool, swollen site. Extravasation is the same leak but with a vesicant drug, and it is a tissue-damage emergency. Stop the infusion immediately, do not flush the line, and follow your facility's vesicant protocol without delay.
What it is and why it happens
Both start the same way: an IV cannula that has partly or fully dislodged from the vein, letting fluid infuse into the surrounding subcutaneous tissue instead of the bloodstream. Catheter movement, a fragile vein, a joint near the insertion site, or a line left in place too long all raise the risk. In infants and older adults, thinner vessel walls and looser tissue turgor make this more likely and harder to catch early.
What separates the two terms is the fluid, not the mechanism. If the leaking fluid is a non-vesicant, such as plain saline or a standard antibiotic, the event is infiltration: uncomfortable, but tissue damage is usually limited. If the fluid is a vesicant — a drug capable of blistering or necrosing tissue on contact, such as vancomycin at high concentration, calcium chloride, certain chemotherapy agents, or vasopressors — the same leak becomes extravasation. Same physical event, very different consequence, because the drug itself is now injuring the tissue it sits in.
Knowing which vesicants are running through a peripheral line, rather than reaching for the answer only after damage appears, is what changes the outcome.
How it presents — what you will actually see
Infiltration presents as a site that is swollen, cool to the touch, and taut, often with blanching around the cannula. The patient may report tightness or mild discomfort rather than sharp pain, and the infusion may slow or the pump may alarm on occlusion. Skin colour is usually pale, not red.
Extravasation shares the swelling but escalates fast: burning or stinging pain out of proportion to a simple infiltrate, skin that reddens then blisters, and in severe cases skin that blanches white before breaking down. Because the drug itself is caustic or vasoconstrictive, the tissue reaction continues even after the infusion stops, and damage can extend well beyond the visible margin over the following hours.
The distinction that matters at the bedside is this: cool and swollen with a non-vesicant infusing is infiltration; the same signs with a vesicant infusing is extravasation, and it is treated as an emergency from the first moment you see it, not once blistering appears.
Nursing assessment priorities
Check the site every time you assess the line, not just when the pump alarms — infiltration and extravasation can both progress silently under a dressing. Compare the affected limb to the opposite one for size, temperature, and colour, and ask the patient directly about pain, tightness, or burning rather than waiting for them to volunteer it.
Identify what is infusing before you decide how urgent the response is. A vesicant running through a peripheral line, even with an ordinary-looking site, warrants closer and more frequent checks than a maintenance fluid. Grade the site using your facility's infiltration or extravasation scale, since this drives the treatment pathway and gives the next nurse a clear baseline to compare against.
Document the scale grade, the drug, the estimated volume that infiltrated, and the time you discovered it. That timestamp matters: extravasation antidotes and thermal treatments are time-sensitive, and delayed recognition worsens outcomes.
Interventions and what to do first
Stop the infusion immediately and disconnect the tubing from the cannula, but do not remove the cannula yet if the fluid is a known vesicant — some antidotes are given through the existing line, or aspiration of residual drug is attempted first, per protocol. For a straightforward infiltration with a non-vesicant, stop the infusion, remove the cannula, and elevate the limb.
For extravasation, follow your facility's vesicant extravasation protocol precisely, since the antidote and thermal treatment depend on the specific drug: some vesicants require a cold compress to limit spread, others require warmth to promote dispersal, and applying the wrong one can worsen injury. Notify the prescriber and, where available, the vascular access or wound care team without delay.
Restart the infusion in a new site well away from the affected area, ideally a different limb, and never below the site of injury. Photograph the site per policy for the record, and escalate promptly if pain, blistering, or discolouration worsens despite initial treatment.
Complications to watch for
Infiltration left untreated can still cause compartment syndrome if volume and pressure build in a closed space, particularly in a paediatric limb or a joint area, so ongoing swelling and pain deserve escalation even without a vesicant involved.
Extravasation carries the higher-stakes complications: full-thickness skin necrosis, ulceration, and tissue loss requiring debridement or grafting. Nerve or tendon damage can follow deep extravasation near a joint, and some vesicant injuries take days to declare their full extent, so a site that looks stable on day one still needs reassessment.
Watch for compartment syndrome signs specifically — pain out of proportion to exam, pallor, paraesthesia, pulselessness, and paralysis — as this is a surgical emergency regardless of which fluid caused the initial leak.
Patient teaching before discharge
Tell the patient what to watch for at home if a site was affected during their stay: increasing redness, pain, blistering, or drainage from what looked like a resolving injury. Give a clear threshold for coming back — worsening pain, spreading discolouration, or fever — rather than a vague instruction to 'keep an eye on it'.
Explain in plain terms what happened, using infiltration or extravasation as appropriate, since patients who understand the difference are more likely to take a vesicant injury seriously rather than dismissing it as a bruise. If follow-up wound care or a specialist review has been arranged, confirm the patient has the appointment details before they leave.
For future admissions, encourage patients to mention any prior IV site problems, since a history of difficult access or a previous extravasation injury changes how cautiously the next team should site and monitor a line.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our reduction of risk potential practice questions are the closest set to what this page covers.
One question from the reduction of risk potential set
Four hours after a cardiac catheterization via the right femoral artery, the nurse notes the client's right dorsalis pedis pulse is now faint and the foot is cool and pale. What is the nurse's priority action?
Rationale
A pulse that was present and is now faint, with a cool, pale extremity distal to the puncture site, is arterial occlusion until proven otherwise — a limb-threatening complication that needs the provider now. Documenting and rechecking wastes the window, warming treats the symptom and masks the change, and asking the client to move the ankle neither restores flow nor gives you new information.
Answer: C
Common questions
How do you tell infiltration from extravasation at the bedside?
Check what is infusing. A cool, swollen, pale site from a non-vesicant fluid is infiltration. The identical presentation with a vesicant drug — one capable of blistering or damaging tissue — is extravasation, and it is treated as an emergency regardless of how mild the site looks at first.
Should you flush the cannula if you suspect extravasation?
No. Stop the infusion and disconnect the tubing, but do not flush, and do not remove the cannula until you have checked your facility's protocol, since some vesicant antidotes are given or residual drug is aspirated through the existing line first.
Is heat or cold used for extravasation?
It depends entirely on the drug. Some vesicants require cold compresses to limit local spread, while others require warmth to encourage dispersal, so the correct choice comes from the specific antidote protocol for that drug, not a default rule.
What is a common NCLEX distractor on this topic?
Questions often test whether you know that redness and blistering, not just swelling, signal a vesicant injury rather than simple infiltration, and whether you would stop the infusion immediately rather than slowing the rate and continuing to monitor.
Can infiltration still be serious?
Yes. Even without a vesicant, ongoing swelling in a closed space such as a joint or a small paediatric limb can progress to compartment syndrome, so persistent pain or tightness after stopping the infusion still needs escalation.
More on reduction of risk potential