How Do Seldinger, MST, and AST Compare in Midline Insertion Procedures?
In medical procedures, precision and technique are crucial. Among the various tools and methods used in patient care, midline catheters play a vital role in providing intravenous access for patients who require extended IV therapy. There are three primary types of midline catheters: Seldinger Technique, AST (Accelerated Seldinger Technique) and MST (Modified Seldinger Technique). Understanding the differences between these three can help healthcare professionals make informed decisions about patient care.
What Are Midline Catheters?
According to the 2024 Infusion Therapy Standards of Practice, a midline catheter is a vascular access device that is inserted into a vein in the upper arm, usually the basilic, cephalic, or brachial vein, with the terminal tip located at the level of the axilla in children and adults. For neonates, in addition to arm veins, midline catheters may be inserted via a scalp vein with the distal tip located in the jugular vein above the clavicle or in the lower extremity with the distal tip located below the inguinal crease. Midline catheters are often used for short-term intravenous therapies and infusions. They can remain in place for up to 28 days or longer if there are no complications.
Seldinger Technique: A Foundational Method in Vascular Access
The Seldinger technique was invented by Dr. Sven Ivar Seldinger, a Swedish radiologist, in 1953. It is a medical procedure to obtain safe access to blood vessels. The technique involves inserting a needle into a vessel, followed by the placement of a guide wire through the needle. The needle is then removed, and a catheter is threaded over the guide wire into the vessel, allowing for various diagnostic and therapeutic procedures. Dr. Seldinger’s innovation has greatly improved the safety and efficacy of numerous medical interventions.
The Seldinger Technique provides key benefits that enhance patient care:
Reduced Risk of Complications: By utilizing a guidewire, the Seldinger technique decreases the likelihood of damaging the vessel, thus lowering the risk of complications such as hematoma or vessel perforation.
Increased Success Rates: This technique has been associated with higher success rates in difficult vascular access cases, particularly in patients with small or challenging veins.
Flexibility: The Seldinger technique allows for a variety of catheter sizes and types to be used, making it adaptable to the specific needs of the patient.
AST Midline Insertion Technique: Accelerated Seldinger Technique
AST midlines are designed for simplicity and efficiency. This is a single-step process where the entire procedure, from needle insertion to catheter placement, is completed in one continuous action. This all-in-one technique is user-friendly, reducing the complexity of the procedure and potentially minimizing the risk of complications. Additionally, because the procedure is streamlined, it can be performed more quickly than the two-step MST method, making it beneficial in busy clinical settings.
The AST technique offers these key benefits:
Reduced Procedure Time: The single-step process can save valuable time, which is critical in emergency situations or when dealing with multiple patients.
Simplified Training: The straightforward nature of the AST technique can make it easier to train new healthcare professionals.
MST Midline Insertion Technique: Modified Seldinger Technique
MST midlines involve a more traditional, two-step process. This method includes an initial needle insertion followed by the placement of a guidewire. Once the guidewire is in place, the catheter is threaded over the wire and into the vein. The use of a guidewire allows for greater precision in catheter placement, which can be particularly important in patients with difficult venous access.
Key Advantages of the MST Technique:
Enhanced Control: The two-step process provides greater control over the catheter placement, which can be beneficial in complex cases.
Versatility: The MST technique can be used in a wider range of patients, including those with challenging anatomy or compromised veins.
Reduced Risk of Misplacement: The guidewire helps ensure that the catheter is placed accurately, reducing the risk of complications associated with improper placement.
Choosing the Right Midline Insertion Technique
When choosing the right midline insertion technique, it’s essential to consider the patient’s vein accessibility and the clinician’s expertise. The Standard Technique (ST) is simple and quick, suitable for patients with easily accessible veins, but it carries a higher risk of complications. The Modified Seldinger Technique (MST), often performed with ultrasound guidance, offers greater precision and reduces complication risks, making it ideal for patients with difficult venous access. However, it requires more equipment and advanced clinician skills. The Accelerated Seldinger Technique (AST) streamlines the MST process, maintaining safety and efficacy while reducing insertion time, making it perfect for experienced clinicians needing a quicker procedure. By carefully assessing the patient’s needs and the clinician’s proficiency, the most appropriate technique can be selected to ensure optimal outcomes.
- Use ST for straightforward cases with easily accessible veins and when resources are limited.
- Use MST for patients with challenging venous access and when precision is crucial.
- Use AST for proficient clinicians who want a faster procedure while maintaining the benefits of MST.
Seldinger Inserted Midlines: Our ProV Midline ST Catheter is designed to meet your specific needs with multiple configurations. It offers the benefits of extended dwell peripheral intravenous catheters, which is why healthcare professionals are choosing our product. The ‘V’ tipped catheter design enables a smooth transition from the wire to the vessels, ensuring consistent aspiration and flow rates, ultimately enhancing procedural outcomes.
MST Inserted Midlines: The Health Line CT Midline Catheter is designed for short-term peripheral access to the venous system to facilitate intravenous therapy, medication administration, and blood product infusion. Utilizing a single midline IV access can fulfill infusion therapy needs for patients, minimizing the need for multiple needle sticks and improving patient comfort. Additionally, our midline peripheral catheter offers superior reduction in vein inflammation compared to a short peripheral catheter and does not require X-ray confirmation post-placement.
Explore our Health Line CT Midline and ProV Midline ST, customized to meet your unique requirements with a variety of configurations. Designed to satisfy the needs of both medical professionals and patients, our vascular access devices stand out as the best option. Please contact us today for more information about our products and for a custom quotation.
References:
Nickel, B. et al., (2024, January/ February) Infusion Therapy Standards of Practice 9th edition. Journal of Infusion Nursing. https://www.ins1.org/publications/infusion-therapy-standards-of-practice/
Hafiani, H. et al., (2024, May 16) Sven Ivar Seldinger (1921-1998): The Founding Father of Interventional Radiology. Cureus. https://www.cureus.com/articles/254481#!/
Bunch J. (2022, September/ October) A retrospective assessment of peripheral midline failures focusing on catheter composition. Journal of Infusion Nursing. https://journals.lww.com/journalofinfusionnursing/fulltext/2022/09000/a_retrospective_assessment_of_midline_catheter.6.aspx
Carr, A. et al.,(2021, April 22) Midline venous catheters as an alternative to central line catheter placement: a product evaluation. British Journal of Nursing. https://www.britishjournalofnursing.com/content/product-focus/midline-venous-catheters-as-an-alternative-to-central-line-catheter-placement-a-product-evaluation/
What are the Differences between PICC Line and Midline Catheter?. Infusion Therapy Institute https://infusioninstitute.com/what-are-the-differences-between-picc-line-and-midline-catheter/