Intravenous (IV) therapy is one of the most common procedures performed in healthcare. Approximately two billion IVs are administered globally every year. Yet despite how routine IV therapy has become, up to 50% of peripheral IVs fail before treatment is complete, often due to infiltration or extravasation.
Unfortunately, many misconceptions about IV infiltration and extravasation continue to influence clinical practice. These myths can create a false sense of security, delaying recognition of injuries that may result in tissue damage, nerve injury, compartment syndrome, treatment delays, medication errors, and in severe cases, permanent disability or amputation.
Let’s examine five of the most common myths—and the evidence that disproves them.
Myth #1: "The IV flushes fine, so it's working properly."
This is one of the most common assumptions in IV therapy.
While resistance during flushing may indicate a problem, a successful flush does not guarantee that fluid is staying inside the vein.
Many clinicians picture an infiltration as a catheter that has completely dislodged from the vein. In those situations, flushing is often difficult or impossible. However, infiltration and extravasation can occur through several other mechanisms, including:
- Leakage through the opposing vein wall
- Increased vein permeability due to inflammation
- Leakage around the insertion site
- Small defects in the vessel wall from difficult cannulations
In these cases, the catheter may still sit partially inside the vein and allow fluid to flow normally while some portion of the infusion leaks into surrounding tissue.
The result? The IV flushes without difficulty, yet an infiltration is already in process.
Clinical Takeaway: A good flush confirms flow—it does not confirm containment.
Myth #2: "Blood return means the IV is okay."
For decades, blood return has been considered a gold standard indicator of IV integrity.
The problem is that blood return only confirms that the catheter remains in contact with the vessel lumen. It does not prove that all infused fluids remain within the vessel.
Several infiltration mechanisms may continue to produce normal blood return while leakage is occurring.
This is particularly important when administering:
- Vesicant chemotherapy
- IV iron
- Contrast media
- Vasopressors
- Hyperosmolar solutions
- High-volume fluid infusions
A catheter can still draw blood while allowing infused medication or fluid to escape into surrounding tissue.
Clinical Takeaway: Blood return is an important assessment finding—but it is not definitive proof that infiltration or extravasation is absent.
Myth #3: "Only chemotherapy causes serious damage."
When clinicians hear the word extravasation, many immediately think of vesicant chemotherapy—and for good reason. Vesicant anticancer agents can cause severe tissue destruction, ulceration, necrosis, and long-term functional impairment when they leak into surrounding tissue.
However, one of the most dangerous misconceptions in IV therapy is the belief that only chemotherapy medications can cause serious injury.
The reality is that the risk of harm depends on the medication, solution, volume infused, patient factors, and how quickly the infiltration is detected—not simply whether a drug is chemotherapy.
Many hospitals use a Red/Yellow/Green (RYG) or Red/Amber/Green (RAG) classification system to help clinicians understand the potential severity of injury if a medication infiltrates.
Red Category: Severe Injury Risk
These medications are considered vesicants or highly irritant solutions and may cause:
- Tissue necrosis
- Chemical burns
- Neurovascular injury
- Compartment syndrome
- Permanent functional impairment
Examples include:
- Vesicant chemotherapy agents
- Vasopressors
- Hyperosmolar solutions (>600 mOsm/L)
- Medications with extreme pH (<5 or >9)
Yellow (Amber) Category: Intermediate Risk
These medications are considered irritants rather than vesicants but can still produce significant inflammation, pain, swelling, and tissue injury—particularly in vulnerable populations such as pediatric, oncology, or elderly patients.
Green Category: Lower Risk—But Not Harmless
A common misconception is that “green” medications are safe if infiltration occurs.
They are not.
Take normal saline, for example. It is the most administered IV fluid in healthcare and is often perceived as harmless because it is a non-vesicant. Yet large-volume saline infiltrations have been associated with:
- Tissue ischemia
- Nerve compression injuries
- Skin necrosis
- Compartment syndrome
- Surgical intervention
- Permanent loss of function
In fact, severe infiltrations of normal saline can produce injury patterns similar to those seen with some vesicant extravasations.
Read our complete guide: “Red/Yellow/Green (RYG) and Red/Amber/Green (RAG) Risk Categories Explained” to learn more.
Clinical Takeaway: No intravenous infusate is completely safe once it leaves the vein. Even lower-risk medications can cause significant harm when large volumes infiltrate tissue or when recognition is delayed.
Myth #4: "You can always see an infiltration."
Perhaps the most dangerous misconception is the belief that an infiltration becomes obvious as soon as it occurs.
In reality, the earliest stages of infiltration happen beneath the skin, before visible signs develop.
Fluid can accumulate within the tissue for a period of time before clinicians observe:
- Swelling
- Redness
- Skin blanching
- Tightness
- Leakage
- Temperature changes
This challenge becomes even greater in patients who:
- Are sedated
- Are mechanically ventilated
- Are under surgical drapes
- Have edema
- Are neonates or young children
- Cannot effectively communicate discomfort
By the time visible symptoms appear, tissue injury may already be progressing into a potentially severe injury.
Clinical Takeaway: The absence of visible symptoms does not mean the absence of infiltration.
Myth #5: "Hourly checks are enough."
Routine IV assessments remain an essential part of patient care.
However, infiltration does not operate on an hourly schedule.
An IV site may appear normal during one assessment and begin leaking minutes later. Between assessments, fluid can continue accumulating while tissue injury progresses quietly and goes unrecognized.
This creates a critical surveillance gap.
Traditional monitoring relies on:
- Intermittent visual inspection
- Palpation
- Pump alarms
- Patient-reported symptoms
Each of these methods has dangerous limitations.
Research has increasingly demonstrated that delayed detection—not poor insertion technique—is often the primary contributor to severe infiltration injuries.
Clinical Takeaway: While routine assessments are a critical component of IV care, they cannot continuously detect changes that may occur between observations.
The Reality: IV Injuries Often Begin Before Anyone Can See Them
The common thread behind these myths is the belief that infiltration and extravasation are obvious events.
They are not.
Many injuries begin with small, subclinical leaks that are:
- Invisible
- Asymptomatic
- Undetectable through flushing
- Undetectable through blood return assessment
Small leaks can quickly progress to serious injuries when they go undetected. As a result, healthcare organizations are moving beyond traditional “wait and see” monitoring and exploring technologies that provide continuous visibility into the IV site status.
Because infiltration and extravasation remain among the most common, yet often underrecognized, complications in healthcare, clinicians are increasingly reexamining long-held assumptions about IV surveillance.
The goal is simple: identify problems before visible injury occurs. When it comes to IV therapy, earlier awareness enables earlier intervention, helping prevent avoidable IV harm. Technologies such as ivWatch are designed to support this proactive approach by providing continuous IV site monitoring that helps clinicians identify potential issues sooner. Learn more about the technology here: https://www.ivwatch.com/tech-overview/