What about midline catheters (peripherally inserted central catheters) for patients with difficult vascular access?

Midline Catheters for Difficult Vascular Access

For patients with difficult vascular access requiring peripherally compatible infusates for ≤14 days, midline catheters are preferred over PICCs and should be your first-line choice after failed standard peripheral IV attempts. 1

Key Indications for Midline Catheters

Midline catheters are appropriate for:

• Patients with difficult venous access (≤2 palpable veins) requiring therapy for 1-4 weeks 1
• Anticipated duration of IV therapy ≥5-6 days with peripherally compatible infusates 1
• Patients requiring frequent peripheral access where standard PIVs repeatedly fail 2

The Michigan Appropriateness Guide (MAGIC) specifically recommends midline catheters over PICCs when expected duration is ≤14 days for difficult venous access. 1

Technical Specifications

Midline catheters are:

• 10-20 cm in length 1
• Inserted into upper arm veins (basilic, brachial) using ultrasound guidance 1
• Tip positioned in peripheral veins, NOT in central circulation 1
• Suitable for short to medium-term access (typically 1-4 weeks) 1

Critical Contraindications

Midline catheters are INAPPROPRIATE for:

• Vesicants or irritants (chemotherapy, parenteral nutrition, high-osmolality solutions >500 mOsm/L) - these require central access 1
• Patients with CKD stage 3b or greater (eGFR <45 mL/min) - arm vein preservation is essential for future dialysis access 1
• Solutions with pH <5 or >9 1
• IV therapy expected to last >2 weeks 1

Clinical Performance Data

Recent evidence demonstrates superior outcomes compared to standard peripheral IVs:

• 99% insertion success rate with median 1 attempt 3
• Median dwell time of 5-9 days 3, 4
• Lower post-insertion failure rates than peripheral IVs 2
• Longer functional dwell time in difficult access patients 2
• Fewer patient-reported complications than PICCs 5

Complication rates are acceptably low:

• Overall dwell-time complications: 12% 3
• Severe complications: 0.7% 3
• Catheter-related bloodstream infections: 0.48 per 1,000 catheter-days 6

Practical Implementation Algorithm

Step 1: Patient has difficult venous access (failed ≥2 peripheral IV attempts or ≤2 palpable veins) 1, 2

Step 2: Determine expected duration and infusate type:

• If ≤14 days + peripherally compatible infusate → Midline catheter preferred 1
• If 6-14 days + difficult access → Midline catheter over PICC 1
• If >14 days OR vesicants/irritants needed → PICC or central line required 1

Step 3: Check for CKD:

• If eGFR <45 mL/min → AVOID midline; use hand dorsum PIVs or tunneled central catheter 1
• If eGFR ≥45 mL/min → Midline appropriate 1

Step 4: Insert using ultrasound guidance into basilic or brachial vein 1

Prevention of Thrombophlebitis

Critical preventive measures include:

• Aseptic technique during insertion and care 1, 7
• Smallest gauge catheter possible (ideally catheter diameter ≤1/3 vein diameter on ultrasound) 1, 7
• Polyurethane or silicone catheters preferred over Teflon 1, 7
• Adequate fixation with transparent adhesive membranes 1, 7
• Monitoring infusion osmolarity and pH 1, 7

If thrombophlebitis develops:

• Remove catheter immediately 7
• Consider anticoagulation with fondaparinux 2.5 mg daily for 45 days if at risk for progression 7
• Ultrasound to rule out deep vein extension 7

Common Pitfalls to Avoid

• Using midline catheters for vesicants/irritants - this causes severe complications and is never appropriate 1
• Placing midlines in advanced CKD patients - this jeopardizes future dialysis access 1
• Choosing PICC over midline for short-term therapy - midlines have fewer complications when duration ≤14 days 1, 2, 5
• Failing to use ultrasound guidance - blind insertion has lower success rates 1
• Not monitoring for thrombophlebitis - requires daily assessment of catheter site 1, 7