How long can a midline stay in a patient?

October 2, 2025 •

3 min read

According to the Infusion Nurses Society (INS), midline catheters are designed for use over an extended period, significantly longer than a standard peripheral IV. In many cases, a midline can remain in a patient for up to 28-30 days, or as long as clinically needed without complications, to provide reliable venous access.

Quick Summary

Midline catheters can typically remain in place for up to four weeks, but their exact duration is determined by clinical assessment, patient condition, the type of infusate, and the absence of complications like infection or malfunction.

Key Points

Duration: A midline catheter can typically stay in a patient for up to 28 to 30 days, serving as an intermediate solution between short peripheral IVs and long-term PICC lines.
Factors for removal: A midline is removed sooner than its maximum potential dwell time if complications like infection, phlebitis (vein inflammation), or a blockage occur.
Placement: Unlike a standard IV, a midline is inserted into a large peripheral vein in the upper arm, with its tip terminating near the armpit, not in a central vessel.
Care and Maintenance: Consistent sterile dressing changes (weekly or more often if needed) and regular flushing are essential for maintaining the catheter and preventing complications.
Not a Central Line: It is crucial to remember that a midline is a peripheral catheter and should not be used for vesicant medications, total parenteral nutrition (TPN), or other fluids that require a central line.
Patient Benefits: Longer dwell time compared to a peripheral IV means fewer needle sticks for the patient, reducing discomfort and improving overall satisfaction with vascular access.

What Is a Midline Catheter?

A midline catheter is a longer peripheral intravenous (IV) catheter. It is inserted into a peripheral vein in the upper arm, and its tip rests in the large veins of the upper arm, at or below the level of the armpit (axilla). This positioning in a larger vein allows for longer use and better hemodilution of fluids, reducing the risk of irritation and complications like phlebitis. Midlines are used for moderate duration IV access, typically longer than a standard IV but shorter than a PICC.

Factors Determining Midline Dwell Time

Several factors influence how long a midline can stay in a patient:

Clinical Indication and Patient Condition

Midlines are typically used for treatments lasting one to four weeks, such as certain antibiotic courses. Patient health, skin condition, and venous access also play a role. Midlines can be beneficial for older adults or those with limited venous access by reducing the need for multiple venipunctures.

Catheter Material and Type

Catheter composition, such as durable and biocompatible polyurethane, can affect longevity. Some designs include antimicrobial coatings to help reduce infection risk.

Proper Care and Maintenance

Adhering to care protocols is essential for extending midline life. This includes:

Regular, aseptic dressing changes: Dressings need changing at least weekly or sooner if compromised.
Proper flushing: Regular flushing with saline prevents blockages.
Site monitoring: The insertion site should be checked regularly for signs of complications.

Absence of Complications

Complications necessitate immediate midline removal. These include:

Infection: Indicated by fever, chills, redness, or pus at the site.
Phlebitis: Inflammation causing pain, tenderness, or redness along the vein.
Occlusion: A blockage preventing fluid flow.
Catheter migration: The catheter moves from its correct position.

Midline Catheter vs. Other IV Access Devices

Comparing midlines to other devices helps clarify their use and duration:


Feature	Short Peripheral Catheter (PIV)	Midline Catheter	Peripherally Inserted Central Catheter (PICC)
Dwell Time	1-4 days (often less than 96 hours)	Up to 28-30 days	Weeks to months
Catheter Tip Location	Superficial vein, hand/forearm	Large peripheral vein, upper arm	Superior Vena Cava (near heart)
Best for...	Short-term infusions, hydration	Moderate-term IV therapy, certain antibiotics	Long-term therapy, irritant drugs, chemotherapy, TPN
Key Advantages	Quick, simple insertion	Longer use than PIV, fewer sticks	Long-term reliability, broader drug compatibility
Limitations	High failure rate, limited compatibility	Not for vesicants or TPN, cannot draw blood reliably	Higher infection risk than midline, requires more care

Midline Management: Best Practices

Healthcare providers follow guidelines for safe midline management. Best practices include using ultrasound for insertion, securing the device, and having a clear care plan. Patient education on recognizing issues and protecting the site is also vital. These practices help achieve the maximum safe dwell time.

Conclusion: How Long Can a Midline Stay in a Patient?

A midline catheter can safely remain in a patient for up to 28-30 days, serving as a reliable option for medium-term IV therapy. However, this duration depends on the absence of complications, strict care, and the patient's clinical needs. The healthcare team continuously evaluates the midline's longevity to ensure safety and effective treatment. For more on infection prevention guidelines, refer to the Centers for Disease Control and Prevention.

Frequently Asked Questions

The main difference is the catheter's length and where its tip terminates. A midline is shorter, with its tip ending in a large vein in the upper arm near the armpit. A PICC line is longer, with its tip terminating in a large central vein near the heart.

Routine blood draws are generally not recommended from a midline catheter, unlike with a PICC line or central line. This is because the midline's placement makes reliable blood return inconsistent.

Contact your healthcare provider if you experience signs of infection (fever, chills), phlebitis (redness, pain, swelling along the vein), occlusion (inability to flush the catheter), or if the catheter itself becomes damaged or migrates.

Midlines are appropriate for administering non-irritating intravenous fluids and certain medications, such as antibiotics, that are suitable for peripheral infusion. They should not be used for vesicant drugs (which can cause tissue damage), highly concentrated solutions, or Total Parenteral Nutrition (TPN).

At home, care involves keeping the dressing clean and dry, regular flushing as instructed by your nurse, and protecting the site from moisture during bathing. You must always use proper hand hygiene before touching the catheter.

You should not submerge the arm with the midline in water (no swimming or hot tubs). You can shower by protecting the site with a waterproof cover. If the dressing gets wet, it must be changed immediately.

The insertion site is numbed with a local anesthetic before the procedure, so you should only feel some pressure and minor discomfort. Afterward, most patients report little or no pain.