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Education & Training Making Midlines Mainstream
Making Midlines Mainstream
By Michael Sherman, MD, MA, and Alexandra Nordberg, MD, on behalf of the SAEM Education Committee
Difficult venous access is a daily problem encountered in the emergency department (ED), and emergency medicine (EM) has been at the forefront of this field since its inception. In the past, the expanding use of ultrasound guided IVs (US-IVs) was shown to decrease the placement of central lines needed for simple venous access; however, US-IVs continue to be plagued by a high failure rate. In recent years, midline catheters have enjoyed a renaissance, to provide reliable vascular access for patients with difficult venous access who would otherwise require multiple venipunctures or the use of central lines to obtain and maintain access.
History
Midline placement has been used clinically since the 1950s. These older midlines were usually upsized peripheral IV’s. As Seldinger technique revolutionized the placement of central lines, central line placement became commonplace. This procedure was then augmented by ultrasound guidance as a safe and reliable way to obtain venous access, and midlines fell to the wayside in clinical practice. Because of this, most of the guidelines and policy statements surrounding midlines comes from the days prior to Seldinger technique and the routine use of ultrasound for vascular access. As the placement of central lines became routine, it became common to place central lines when faced with difficult venous access; this, however, exposed patients to the mechanical and infectious risks of central access, among other risks such as patient discomfort. In fact, some hospital systems required that patients with central femoral access to be on bedrest; national focus from the Centers for Medicare & Medicaid Services (CMS) began to highlight the morbidity and mortality associated with Central LineAssociated Bloodstream Infections (CLABSIs). Given the advent of bedside ultrasound, routine use of ultrasound guided IVs was shown to decrease the
placement of central lines for venous Figure 1. Anatomic location of upper extremity veins used for midline catheter insertion. access only, and became a staple of modern ED practice. However, the limited length of ultrasound peripheral IVs has led to a high rate of failure of up to 45% and clinical frustration by ED staff.
Single Lumen vs Multi-lumen
Old and New Tech
A midline is defined as a peripheral venous line of 8-25 cm in length that is inserted in upper arm veins (brachial, cephalic, basilic) and terminates at/before axilla. With modern materials, newer midlines can be rated for power-injection for IV contrast. With advances in sterile placement, newer generation midlines can now be rated for dwell time of up to four weeks. These two advances mark a renaissance of midlines that vastly expand their clinical utility.
Clinical Utility
The clinical utility of midlines has thus become exponential along two categories: difficult venous access and long-term dwell. Given their length, midlines can reach and maintain access in the deep veins in the upper arm and provide reliable vascular access that would otherwise require central lines or multiple venipunctures. Newer midlines
are designed to provide adequate flow for power-injection for IV contrast studies such as CT angiography, often difficult to obtain in this patient population. The long-term dwell of the new midlines can thus provide sufficient, long lasting access and, in some cases, be the only access a patient needs for his or her entire hospital stay.
These factors give an immediate added benefit to the utilization of midlines; beyond this, the ability to place midlines has several additional advantages. For example, a midline program can also help expand the ED’s ability to help leverage disposition decisions. The ability to place a midline in the ED for peripheral infusions often negates the need to admit patients for PICC placement, and frequently avoids an ICU admission for a LTAC patient that would otherwise only need a PICC placement. Midlines can also facilitate discharge with reliable long-term IV access to nursing homes, hospice, and other home infusions. They also provide reliable access in patients with limited advanced directives who might otherwise decline central access. The newer generation of midlines come in multiple forms, which is often bewildering to new users. Single-lumen fixed-length midlines provide rapid and easy placement using standard Seldinger technique or accelerated Seldinger technique under ultrasound guidance. The placement of these lines is easily accomplished within the ED skillset, and accelerated Seldinger technique like commonly placed radial arterial lines. Another iteration of midlines are trim-tofit midlines that come in single or, more often, multi-lumen versions. These lines are placed using Seldinger technique and require measurement from planned insertion site to the axilla. They are then cut to length by the provider and placed through a break-away introducer sheath. In placement, these multi-lumen midlines are more similar to a PICC and require a slightly different skillset for placement; however, multi-lumen midlines provide the versatility and flexibility of multiple access points and approaches a true, central line replacement.
EDUCATION & TRAINING
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Controversy
Midline adoption is, however, often hampered by historical bias and common misconceptions. The most often cited concern is that due to the catheter length, an occult infiltration can occur and remain undetected; however, feared “occult” infiltration is not reported in any cohort examining the use of Midline catheters. (See this summative blog post for this and other references.) Unlike PIV’s, midlines rarely infiltrate, and midlines fail less often and in different ways. PIV’s infiltrate/fail because of short distance from insertion site and catheter tip due to small veins and poor vein purchase. Midlines fail much later (often due to distal occlusions), and median time to failure can be up to 6.19 days after insertion.
Another related concern is that older guidelines often site that hyperosmolar solutions or “vesicants” are not midline safe; however, the newer safety data often obviates this concern, and a common solution is to follow the hospital systems guidelines for standard peripheral medication administration. These issues highlight the importance of leveraging the EM skillset and knowledge to advise and create hospital policy and multidisciplinary teamwork.
Billing
A successful midline program also requires the need for understanding
good documentation and reimbursement. Current Procedural Terminology (CPT) govern midline reimbursement, but historically have not been immune to confusion. Previous CPT coding billed midlines as PICC lines with a modifier for reduced services, leading to the possibility of overbilling. In 2019, the American Medical Association issued new guidance for midline catheters; “Midline catheters by definition terminate in the peripheral venous system. They are not central venous access devices and may not be reported as a PICC service. Midline catheter placement may be reported with 36400, 36405, 36406, or 36410”. In the adult ED, the most used CPT code would be 36410 “venipuncture necessitating physician’s skill” and CPT 76937 “ultrasound guidance for vascular access.” Given these recent changes, we should note that CPT midline specific codes could later supplant those currently in use.
Resident/Attending Education
Instructing the department in the use of midlines is an important step to successful implementation; however, placing a midline uses already known techniques, and because of this, instruction can be done relatively easily with peripheral IV phantoms. Having someone dedicated to championing the introduction and implementation of midlines can help with on-shift education as well. For the sake of practicality, the use of fixed-length single lumen accelerated or standard Seldinger technique-based midlines is ideal for ED use and will appeal to the comfort level of most people. Nursing colleagues will also to be educated on the use of midlines. Education and implementation, therefore, involves nursing, departmental, and hospital leadership.
Conclusion
Midline programs are a novel and evolving field of knowledge. A successful midline program requires understanding of the background, current best evidence, multidisciplinary teamwork, and administrative knowledge. Given emergency medicine’s position and facility with ultrasound, EM and the ED are poised to be leaders in the local adoption and implementation of an effective midline program in the ED and across hospital systems.
ABOUT THE AUTHORS
Dr. Sherman is dual boarded in emergency medicine and critical care medicine and has extensive experience with midlines at multiple intuitions. He has successfully implemented and led a hospital-wide midline program at the University of Massachusetts Medical Center in Worcester, MA. Dr. Nordberg is an assistant professor of emergency medicine and point-of-care ultrasound. She is the assistant program director for the emergency medicine residency program at the University of Massachusetts Chan Medical School in Worcester, MA
