To better understand midlines, it helps to define peripheral intravenous catheters, as midlines fall under this category of vascular access catheters. In the following blog post, we define the types of PIVCs and highlight when midlines should be ordered for a patient.
Types of PIVC
A peripheral intravenous catheter (PIVC) is inserted into and resides in the veins of the periphery that includes all extremities, the external jugular vein, and scalp vein in neonates. PIVCs are inserted into superficial veins located just under the skin in the superficial tissue, as well as deep veins located under muscle tissue. The Infusion Nurses Society categorizes PIVCs into 3 types: short peripheral intravenous catheters (short PIVC), long peripheral intravenous catheters (long PIVC), and midline catheters.
- A short peripheral intravenous catheter (SPIVC) is an over-the-needle catheter with a hollow metal stylet (needle) positioned inside the catheter, generally inserted in superficial veins.
- A long peripheral intravenous catheter (LPIVC) is inserted in either superficial or deep peripheral veins and offers an option when a short PIVC is not long enough to adequately cannulate the available vein. A long PIVC can be inserted via traditional over-the-needle technique or with more advanced procedures, such as Seldinger and accelerated Seldinger.
- A midline catheter is inserted into a peripheral vein of the upper arm via 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.
Midlines are placed using Max Barrier Precautions and with the Modified Seldinger Technique MST
When to Choose a Midline
When choosing an appropriate type of vascular access device, it needs to be selected to accommodate a patient’s vascular access needs based on the prescribed therapy or treatment regimen, including anticipated duration of therapy vascular characteristics, patients age, comorbidities, history of infusion therapy, preference for VAD type and location, and ability and resources available to care for the device. For selection of the most appropriate vascular access device occurs at the earliest opportunity and is a collaborative process among the health care team, the patient, and the patient’s caregivers.
The Infusion Nurses Society states to choose a midline catheter as follows:
- Assess infusate characteristics and planned duration of infusion therapy for tolerability by peripheral veins.
- Variation in the category and number of therapies infused through midline catheters exists. More studies are needed to guide clinical decision-making on appropriate type and number of therapies. One small retrospective cohort study and 1 ovine randomized controlled trial (RCT) report increased failure when multiple therapies, infused through dual lumen catheters and infusions of extreme pH and osmolarity, respectively, were used.
- Use a midline catheter for medications and solutions such as antimicrobials, fluid replacement, and analgesics with characteristics that are well-tolerated by peripheral veins.
- Assess the clinical benefit of using a midline catheter that inhibits bacterial attachment and biofilm formation.
- Do not use midline catheters for continuous vesicant therapy, PN, of infusates with extremes with extremes of pH or osmolarity.
- Increase catheter site surveillance when administering intermittent infusions of known irritants and vesicants due to increased risk of phlebitis or extravasation.
- Evaluate the risk and benefit of intermittently infusing vesicant medication for more than 6 days.
- Further research is needed to establish the safety of using midline catheters for intermittent vesicant therapy and as strategy for reducing catheter-associated bloodstream infection (CABSI). Some midline catheters have been associated with bloodstream infection (BSI) rates similar to those of central venous catheters.
- Avoid the use of a midline catheter when the patient has a history of thrombosis, hypercoagulability, decreased venous flow to the extremities, or end stage renal disease requiring vein preservation.
Midlines provide a reliable vascular access option for those patients with difficult venous access who would otherwise require multiple venipunctures or the use of central lines to maintain access. They are inserted in a secure, stable location in the mid-upper arm with the terminal located at or distal to the level of the axilla in children and adults. It aids in the prevention of thrombosis for midlines.
The Health Line CT Midline Catheter is intended for short-term peripheral access to the venous system for the purpose of intravenous therapy, medicines, and blood products. A single midline IV access can meet infusion therapy requirements for patients needing many, eliminating multiple needle sticks, and enhancing patient comfort. Additionally, our midline peripheral catheter can reduce vein inflammation better than a short peripheral catheter and does not require an X-ray after placement. The Health Line CT Midline Catheter is available in single and dual lumen configurations and is the ideal choice for clinicians and patients looking for reliable, short-term access.
Health Line International Corp. is not responsible for any errors, omissions, injury, loss, or damage arising from or relating to the use (or misuse) of any information, statements, or conclusions contained in or implied by the contents of this document or any of the source materials. This content is not intended to replace professional medical advice.
Gorski LA, Hadaway L, Hagle ME, et al. Infusion therapy standards of practice. J Infus Nurs. 2021;44(suppl 1):S1S2-S224. Doi:10.1097/NAN.0000000000000396