Peripheral intravenous (IV) cannulation is one of the most common clinical procedures across hospital and prehospital settings. While it's routine, complications can occur — and early recognition is key to preventing patient harm.

In this post, we break down the most common peripheral IV complications, their signs and symptoms, causes, and what to watch for on your next shift.

Infiltration

What is it?

Infiltration occurs when non-vesicant IV fluid leaks into the surrounding tissue instead of the vein.

Signs & Symptoms:

• Swelling around the IV site
• Coolness to touch
• Blanched or pale skin
• Discomfort or tightness
• Sluggish or stopped infusion

Causes:

• Cannula dislodgement
• Puncture through the vein wall
• Excessive pressure during flushing or infusion

Extravasation

What is it?

Extravasation is the leakage of vesicant (tissue-damaging) medication into the tissue. This is more serious than infiltration and requires immediate attention.

Signs & Symptoms:

• Pain, burning, or stinging
• Swelling and redness
• Skin blistering or ulceration
• Tissue necrosis (in severe cases)

Causes:

• Vesicant drugs administered via a peripheral line
• Poor cannula placement
• Lack of site monitoring during high-risk infusions

Note: This is a medical emergency — stop the infusion immediately and follow your institution’s protocol.

Phlebitis

What is it?

Phlebitis is inflammation of the vein wall, which can be mechanical, chemical, or bacterial in origin.

Signs & Symptoms:

• Redness and warmth along the vein
• Pain or tenderness
• Palpable cord-like vein
• Swelling at or near the IV site

Causes:

• Poor aseptic technique or repeated cannulation
• Large-gauge cannula in a small vein
• Irritating solutions or medications
• Long dwell time of the IV

Infection

What is it?

Infection at the IV site can be local or progress to a more serious bloodstream infection if not addressed.

Signs & Symptoms:

• Redness, swelling, or warmth at site
• Pus or discharge
• Pain or tenderness
• Fever or chills (systemic involvement)

Causes:

• Poor aseptic technique during insertion or care
• Contaminated IV equipment
• Prolonged cannula use

Haematoma

What is it?

A haematoma is a localised collection of blood outside the vein, usually caused by vein trauma during insertion or removal.

Signs & Symptoms:

• Bruising or discolouration
• Swelling or a hard lump at site
• Tenderness
• Resistance during flushing (if still cannulated)

Causes:

• Vein perforation
• Inadequate pressure post-removal
• Multiple failed cannulation attempts
• Fragile or anti coagulated patients

Peripheral IV complications are common, but preventable with careful technique, proper assessment, and regular monitoring. If you're a nurse, student, or paramedic, staying alert to the early signs can make a significant difference in patient outcomes.