Phlebitis: Recognition, Grading, and Management in Vascular Access

Phlebitis — inflammation of the vein at or near a vascular access device — is the most common complication of peripheral intravenous therapy and a significant complication in midline and PICC patients. While it ranges in severity from mild redness requiring monitoring to severe suppurative thrombophlebitis requiring surgical intervention, phlebitis at any grade represents a patient safety event and a signal that the infusion system may need to be changed.

Parent guide: Catheter Complications: Complete Clinical Reference

Types of Phlebitis

Mechanical Phlebitis

Cause: Catheter movement within the vein causes friction against the endothelium, triggering an inflammatory response. More common with:

• Larger gauge catheters relative to vein diameter
• Catheter tip at a valvular junction or bifurcation
• Inadequate catheter securement (movement at insertion site)
• Catheters in flexion areas (antecubital fossa, wrist) — joint movement creates catheter movement within the vein

Onset: Typically 24–48 hours post-insertion.

Prevention: Use smallest gauge that meets clinical need; secure catheter to prevent movement; avoid flexion area insertion sites when possible.

Chemical Phlebitis

Cause: Infusate properties (osmolarity, pH, vesicant potential, particle contamination) cause endothelial injury. More common with:

• High-osmolarity infusates (potassium chloride concentrations >40 mEq/L, hyperosmolar antibiotics)
• Extreme pH infusates (phenytoin pH ~12; erythromycin pH ~4)
• Long-term infusion of irritant medications (vancomycin, amiodarone)
• Inadequately diluted medications

Onset: Variable; may appear during infusion or within hours of medication administration.

Prevention: Dilute medications to recommended concentration; use large-bore veins when infusing osmolar agents; consider midline or central access for medications approaching peripheral osmolarity limits.

Bacterial (Infectious) Phlebitis

Cause: Microbial colonization of the catheter or infusion system — represents a subset of catheter-related infection. Presents with purulent discharge, warmth, marked tenderness.

Onset: Usually after >3–4 days of catheter dwell.

Significance: Bacterial phlebitis may indicate catheter-related infection with potential for bacteremia. Requires catheter removal, culture of catheter tip (optional, per institutional policy), and provider notification.

Post-Infusion Phlebitis

Cause: Develops 24–48 hours after catheter removal. The inflammatory process initiated during catheter dwell manifests clinically after removal. May represent chemical or mechanical injury that became clinically apparent after the acute stimulus (catheter) was removed.

Management: Symptomatic treatment (warm compress, elevation, NSAIDs if appropriate). Monitor for progression; should resolve within 5–7 days.

The INS Visual Infusion Phlebitis (VIP) Scale

The VIP Scale (Jackson 1998) is the most widely used validated phlebitis grading tool in clinical practice, endorsed by INS 2021 as the standard assessment scale.

Assessment frequency: VIP score should be documented at every catheter assessment (minimum every 8 hours for PIVs; minimum every 12 hours for midlines and CVADs with peripheral venous course).

Assessment and Scoring

What to Assess

At every catheter assessment, evaluate:

1. Pain: Ask patient to rate pain at insertion site (0–10 scale); document presence of pain on touch, during infusion, and at rest
2. Erythema: Area of redness at or extending from insertion site; document diameter (in cm) and direction of spread
3. Edema/swelling: Palpate for firmness or swelling; compare to contralateral site
4. Streak formation: Linear erythema tracking along the vein path above the insertion site — indicates venous wall inflammation extending proximally
5. Palpable cord: Firm, rope-like structure palpable under the skin along the vein path (fibrin/thrombosis in the vein)
6. Purulent discharge: Visible pus at insertion site

Documentation

Document the VIP grade at every assessment with the specific findings that led to the grade. “VIP Grade 2: erythema 2 cm circumferential at insertion site, patient reports pain 4/10 at site, mild swelling.” Do not document grade without supporting clinical findings.

Management by Grade

Grade 0: Continue monitoring

No action required; continue scheduled assessment.

Grade 1: Observe

• Assess more frequently (every 4 hours)
• Ask patient about pain progression
• Consider re-siting if pain persists or progresses

Grade 2: Re-site catheter

• Remove catheter from current site
• Apply warm moist compress for 20 minutes 3–4 times daily
• Re-site in new location if IV access still required
• Document and report (most institutions require incident reporting for grade ≥2 phlebitis)

Grade 3: Re-site and treat

• Remove catheter
• Apply warm moist compress
• Elevate extremity
• NSAIDs (if not contraindicated) may reduce inflammation
• Monitor healing site; follow up in 24 hours

Grade 4: Re-site, treat, and document

• All grade 3 actions
• Notify provider
• Monitor for signs of progression to grade 5
• Consider topical NSAID (diclofenac gel) or topical heparin gel (limited evidence but used in some institutions)

Grade 5: Infectious/suppurative thrombophlebitis

• Remove catheter immediately
• Culture catheter tip and wound drainage
• Draw blood cultures
• Notify provider immediately
• Consider surgical consultation (suppurative thrombophlebitis may require surgical excision of the involved vein)
• Antibiotics per provider order and culture results

CVAD-Associated Phlebitis

PICC-Associated Phlebitis

PICC phlebitis — occurring along the upper arm cannulated vein — is evaluated with the same VIP scale principles. Important distinctions:

Post-insertion phlebitis: Common within 48–72 hours of PICC insertion; often mechanical (catheter insertion trauma). Warm compresses; monitor for resolution. PICC does not necessarily require removal for Grade 1–2 post-insertion phlebitis if symptoms are mild and trending toward resolution.

Delayed phlebitis (>1 week post-insertion): More concerning for infectious phlebitis or chemical injury from high-osmolarity infusates. Evaluate infusate compatibility; assess for infection. Grade ≥3 in a PICC patient typically warrants provider notification and assessment for catheter removal.

Preventing PICC Phlebitis

• Confirm catheter-to-vein ratio ≤45% at insertion
• Use basilic vein (largest diameter) when possible
• Correct tip position reduces osmolarity injury at the insertion site
• Ensure all infusates via PICC are compatible with central access guidelines

Documentation and Reporting

Minimum documentation at each assessment: VIP grade, specific findings, action taken, time of reassessment planned.

When to report: Most institutions require incident report or quality event documentation for phlebitis grade ≥2. This data feeds complication rate tracking for quality improvement.

Phlebitis rate calculation: Phlebitis rate = (Number of phlebitis events / Number of peripheral IVs × 100%). INS recommends tracking phlebitis rates as a quality indicator; INS benchmark is <5% phlebitis rate for PIV therapy.

Related Resources

Related guides:

• Infiltration and Extravasation Guide
• Catheter Occlusion Management

Related policies:

• Phlebitis — Vascular Access Management

References

1. Gorski LA, et al. (2021). INS Infusion Therapy Standards of Practice (Standards 46–47). J Infus Nurs, 44(Suppl 1).
2. Jackson A. (1998). Infection control: a battle in vein — infusion phlebitis. Nursing Times, 94(4):68–71.
3. Wallis MC, et al. (2014). Risk factors for peripheral intravenous device failure. J Clin Nurs, 23(9–10):1373–1381.
4. Nassaji-Zavareh M & Ghorbani R. (2007). Peripheral IV catheter-related phlebitis and related risk factors. Singapore Med J, 48(8):733–736.