What is the recommended length of time a midline (peripherally inserted central catheter) can be left in place?

Midline Catheter Dwell Time

Midline catheters should not be routinely replaced to reduce the risk of infection and can remain in place as long as clinically indicated, with no predetermined maximum dwell time specified in guidelines. 1

Guideline-Based Recommendations

The CDC explicitly states that midline catheters should not be routinely replaced to prevent infection (Category IB recommendation). 1 This is a critical distinction from short peripheral catheters, which require replacement every 72-96 hours. 1

Replace midline catheters only when there is a specific clinical indication, such as: 1

• Signs of phlebitis (warmth, tenderness, erythema, palpable venous cord) 1, 2
• Evidence of infection 1
• Catheter malfunction 1
• Infiltration or extravasation 2

Practical Dwell Time Data

While guidelines do not specify a maximum duration, real-world evidence demonstrates:

• Median dwell time: 7 days, with documented safe use up to 49 days in prospective studies 1
• Average dwell time: 16.3 days across multiple studies involving 18,972 midline catheters 3
• Midlines are routinely used for 2-6 weeks in clinical practice 4
• Some sources suggest midlines can remain in place for at least 6 weeks and potentially months with proper maintenance 4

Infection Risk Profile

The infection risk with midline catheters is remarkably low and does not increase with duration of catheterization: 1

• Bloodstream infection rate: 0.8 per 1,000 catheter-days 1
• Adjusted mean infection rate: 0.28 per 1,000 catheter-days, with 64% of studies reporting zero infections 3
• No specific risk factors, including duration of catheterization, were associated with infection in prospective studies 1

Daily Monitoring Requirements

Evaluate the catheter insertion site daily by: 1

• Palpation through the dressing to detect tenderness 1
• Visual inspection if using a transparent dressing 1
• Remove opaque dressings only if clinical signs of infection develop 1

Common Pitfalls to Avoid

• Do not apply arbitrary time limits for midline removal based solely on duration—this is not supported by evidence and differs fundamentally from short peripheral catheter management 1
• Do not routinely apply prophylactic topical antimicrobials to the insertion site 1
• Do not delay removal if signs of phlebitis or infection develop 2
• The main risk factor for catheter-associated infections is duration, so periodically reassess whether the catheter is still needed 5

Selection Criteria

Midline catheters should be considered when: 1

• IV therapy duration will likely exceed 6 days 1
• Infusates have pH between 5-9 and osmolarity less than 500 mOsm 4
• Treatment is expected to last more than 7 days with low irritant capacity fluids 4