Can an IV be infiltrated and still have blood return?

According to the National Institutes of Health, IV infiltration is a relatively common complication, often leading to discomfort and treatment delays. Despite this, a common misconception exists that a reliable blood return proves an IV is working correctly. However, the reality is that an IV can be infiltrated and still have blood return, making a full site assessment essential for patient safety.

Quick Summary

An IV can be infiltrated even when blood return is present, as the catheter's position might allow backflow while fluid leaks into the surrounding tissue. Relying solely on blood return is a diagnostic trap that can lead to delayed identification of complications and patient harm.

Key Points

• False Sense of Security: An IV can still have blood return even if infiltrated, making blood return an unreliable single indicator of proper placement.

• Look for Key Signs: Definitive signs of infiltration include swelling, pain, coolness to the touch, and blanched or taut skin, which should prompt immediate action.

• Immediate Action is Needed: If you suspect an IV is infiltrated, stop the infusion, remove the catheter, and elevate the affected limb.

• Distinguish Infiltration: Infiltration is the leakage of fluid into tissues, while phlebitis is inflammation of the vein; they have different signs and causes.

• Comprehensive Assessment: A complete assessment of the IV site, including palpation and visual inspection, is the safest way to prevent and detect complications.

• Elevate for Recovery: Elevating the affected extremity helps reduce swelling and promotes the reabsorption of leaked fluids back into circulation.

The Deceptive Presence of Blood Return

The ability to aspirate a blood return from an IV catheter is a common practice used to confirm venous access. However, this method is not infallible and can present a dangerous false sense of security for healthcare providers and patients alike. The belief that blood return rules out infiltration is a misconception that can have serious consequences, particularly with certain medications. Multiple factors can lead to a positive blood return even when the catheter has partially or fully exited the vessel, directing fluids into the surrounding tissue instead of the bloodstream. A thorough assessment that looks beyond simple blood return is always the best clinical practice.

Why a False Blood Return Occurs

The mechanisms behind a false blood return are varied and often related to the catheter's movement or the condition of the vein. Understanding these can help prevent misdiagnosis:

• Vessel Wall Perforation: During the initial cannulation, the catheter may have punctured through the back wall of the vein. While the tip remains partially in the vein, it is also leaking through the perforation. This allows for both aspiration of blood and leakage of infused fluid.
• Fibrin Sheath Formation: Over time, especially with smaller peripheral IVs, a fibrin sheath can form around the catheter tip. This can effectively seal the tip against the vessel wall, blocking blood aspiration, yet sometimes still allowing for the aspiration of blood via a small channel or by slightly moving the catheter.
• Catheter Movement: Subtle movements, such as a patient moving their arm, can shift the catheter tip just enough to allow fluid to leak out while still maintaining a connection to the vessel. The repositioning might temporarily allow for a blood return test to appear positive.

The Definitive Signs of Infiltration

Instead of relying on blood return alone, a comprehensive assessment of the IV site is paramount. While some signs may be subtle, others are a clear indication that infiltration is occurring and the IV must be removed immediately. The key is to look for a combination of these clinical indicators rather than a single sign.

• Swelling: The area around the IV site appears swollen, puffy, or tight as fluid accumulates in the interstitial space.
• Pain or Discomfort: The patient may experience localized pain, tenderness, or burning at the site that was not present before.
• Coolness to the Touch: The skin over the infiltrated area will feel cool to the touch due to the presence of extravascular fluid.
• Blanched or Pale Skin: The skin around the insertion site may appear blanched or pale due to the fluid compressing blood vessels.
• Tight or Stretched Skin: The skin will feel stretched and taut due to the volume of fluid pressing against it.
• Fluid Leakage: Visible leaking of fluid from the IV site is a clear indicator of infiltration.
• Change in Infusion Rate: The flow of the IV fluid may slow or stop completely, despite the drip chamber still having fluid, due to increased pressure in the interstitial space.

Comparison of IV Infiltration and Phlebitis

In clinical practice, it is important to distinguish between infiltration and phlebitis, as they are separate complications with different causes and treatments. While both involve IVs, their underlying mechanisms and appearances differ significantly. The Infusion Nurses Society provides clear definitions to help differentiate these conditions.

Feature	IV Infiltration	Phlebitis
Mechanism	Inadvertent leakage of non-vesicant fluid into surrounding tissues.	Inflammation of the vein, which can be mechanical, chemical, or bacterial.
Appearance	Swelling, coolness, taut or blanched skin around the IV site.	Redness, warmth, pain, and sometimes a hard or palpable cord-like vein.
Temperature	Cool to the touch.	Warm to the touch.
Pain Level	Localized pain or discomfort at the site.	Often more intense pain along the length of the vein.
Cause	Catheter dislodgement, vessel perforation.	Irritation from the catheter, medication, or infection.
Blood Return	Can have a false blood return.	Typically has a blood return unless a clot forms.

What to Do for IV Infiltration

If infiltration is suspected, immediate action is necessary to minimize patient discomfort and potential complications. The following steps should be taken:

1. Stop the Infusion Immediately: This prevents further leakage of fluid into the surrounding tissue.
2. Remove the Catheter: The IV line must be discontinued, as it is no longer in a proper position.
3. Elevate the Extremity: Position the affected limb above the level of the heart to promote drainage and reduce swelling.
4. Apply a Compress: Use a warm or cold compress as directed by a healthcare provider. A warm compress can aid in absorption, while a cold compress can help with pain and swelling.
5. Relocate the IV: A new IV must be started in a different location, typically proximal to the affected area, or in the other limb.

Conclusion: Prioritizing Comprehensive IV Assessment

In conclusion, the presence of blood return is not a foolproof method for confirming the proper placement of an IV catheter. It is a dangerous misconception to rely on this single indicator to rule out infiltration. Healthcare providers must perform a comprehensive site assessment, checking for signs such as swelling, pain, coolness, and changes in the skin's appearance and texture. By understanding the limitations of blood return and focusing on the full clinical picture, patient safety can be significantly enhanced, and complications from IV therapy can be mitigated effectively.

For more detailed information on IV complications and patient care, consider visiting a resource like the Infusion Nurses Society: https://www.ins1.org.

Frequently Asked Questions

Why is blood return not a reliable indicator for IV placement?

Blood return is not reliable because the catheter can puncture the vein wall, allowing fluids to leak out while the tip is still partially in the vessel. This can create a false positive where blood can be aspirated, but the IV is still infiltrated.

What are the most common signs of IV infiltration?

The most common signs include swelling at the IV site, skin that feels cool and firm, discoloration (blanching or redness), and localized pain or tenderness.

What should I do first if I suspect IV infiltration?

The first step is to immediately stop the infusion to prevent further fluid leakage. Next, remove the IV catheter and elevate the affected limb to encourage drainage.

How can I tell the difference between infiltration and phlebitis?

Infiltration is characterized by a cool, swollen, and blanched site, while phlebitis is marked by a warm, red, and tender area along the vein. Phlebitis is an inflammation of the vein, whereas infiltration is the leakage of fluid into tissue.

Is it possible for an IV to be blocked and not have a blood return, but not be infiltrated?

Yes. A lack of blood return can also be caused by a catheter tip being pressed against a vein wall or a fibrin sheath forming around the tip, blocking aspiration but not necessarily indicating a leak.

Can IV infiltration cause serious complications?

Yes, especially if it goes untreated. Severe infiltration can lead to skin damage, including blisters and ulcers, or even more serious conditions like compartment syndrome. If the fluid is a vesicant, it is called extravasation and can cause severe tissue damage.

Is a warm or cold compress better for treating IV infiltration?

The type of compress depends on the specific fluid that infiltrated. A healthcare provider will typically advise which to use. For many non-vesicant fluids, warm compresses may be used after the initial elevation to promote reabsorption, while cold compresses can reduce swelling and pain.