Title: The Utility of Midline Intravenous Catheters in Critically Ill Emergency Department Patients. Ann Emerg Med. 2019 Dec 24. pii: S0196-0644(19)31236-3. doi: 10.1016/j.annemergmed.2019.09.018.

1. What is already known about this topic?
   1. Previous studies have shown midline catheters inserted in upper arm veins have lower complication rates compared to central lines, and high rates of successful placement in critically ill ED patients.
   2. Standard IV catheters placed in deeper veins under ultrasound guidance don’t tend to last long, maybe a day.
2. What is the PICO question?
   1. Population: prospective observational case series of 403 critically ill patients who had midline catheters placed over 2 years.
      1. Indications for placement of a midline catheter included difficult access, need for reliable access during an active resuscitation, or need for vasopressor or inotropic agents.
   2. Intervention: Midline catheter placement  
   3. Comparison: N/A
   4. Outcome: 
      1. Midline placement success was 99%, with 64% first time success. Of these, 96% used ultrasound; others were over a wire. 
      2. They remained in for a median duration of 5 days. 
      3. 14 patients (3.5%) had 15 insertion complications, mostly failure to aspirate, but there was 1 arterial puncture, 4 hematomas, 1 DVT, 1 infiltration, and 3 that failed. 
      4. 98% of were inserted without complications. 10 patients (2.5%; 95% CI 1.2% to 4.5%) experienced 10 insertion-related complications.
      5. 49 patients (12%) had 60 complications related to ongoing use, such as leaking, dislodgment, or redness. 
      6. What the authors determined to be severe complications occurred in 3 patients (0.7%), 1 arterial cannulation and 2 vesicant extravasations, but without clinical consequences.
      7. There were no known bloodstream infections. 
      8. No difference in attempts or dwell time based on anatomic location. 
3. What are the main findings?
   1. Midline intravenous catheter insertion was successful in 99%.
   2. Insertion and use complications occurred in 3.5% and 12% of patients, respectively.
4. What are its limitations?
   1. Data collection was performed by the physicians and nurses via electronic procedure note embedded in the workflow. Independent data collectors and systems would improve accuracy and precision. 
   2. In same vein, this study was susceptible to response bias in terms of attempts and insertion-related-complications which were prone to under-reporting. 
   3. Due to observational nature, in hospital morbidity and mortality possibly caused by infections related to midline catheters may have been missed and thus under-reported. 
5. How will this article change practice?
   1. Midline intravenous catheters present a feasible vascular access option in select critically ill ED patients with high success rate and low complication rate.
   2. Ultrasound use is preferred similar to central venous cannulation. 
   3. Upper arm is the preferred site using basilic, cephalic, deep brachial vein. 
   4. Further study related to speed of access compared to central line placement may be useful. 

Written by: Taylor Brittan, MD