The Middle Ground: Midline Catheter use and Trainee Involvement in US Critical Care Fellowships

Background Midline catheters (MC) are 10-20 cm intravenous (IV) lines inserted in the peripheral veins of the upper arm and utilized for patients who require longer term IV access, making them advantageous in the intensive care unit (ICU). Guidelines on medication infusion through MC are limited and clinical practice varies. It is unclear how MC practice variation affects critical care fellowship experience. Objectives We sought to investigate the relationship between institutional practices surrounding MC and the role of trainees. Methods A survey was sent to all Critical Care Fellowship program directors investigating their use of MC. Program type, number of hospital beds and trainees were collected. The use of vasopressors (VP), hypertonic saline (HS), and parenteral nutrition (PN) through MC was assessed, as well as which providers were placing MC (interventional radiology (IR), fellows, residents, or advanced practice providers). Statistical analysis was performed using IBM SPSS statistics. Associations between clinical variables were assessed using Fisher's exact test. Results Seventy programs responded to the survey (30.4% response rate). Of these 70 programs, 53 (75.7%) reported MC use. IR placed MC at 79.2% of programs. Larger hospitals (≥500 beds) were significantly more likely to use IR (88.9% vs 58.8%, P = .025), while smaller hospitals more often utilized residents (17.6% vs 2.8%, P = .032). Among programs using MC, 66% administered vasopressors (VP), 62.3% used hypertonic saline (HS), and 20.8% gave parenteral nutrition (PN). Critically, programs with fellow-placed MC were significantly more likely to use VPs (93.3% vs 55.3%, P = .03) and PN (33.3% vs 15.8%, P = .030) compared to programs without fellow involvement. No differences in MC use were found across institution types, bed capacities, or trainee numbers. Conclusions Though MC use in critical care ICUs in the US is prevalent, hospital factors appear to influence who is placing the MC and how MC are utilized.