By Betty Tran, MD, MSc
Associate Professor of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago
SYNOPSIS: Whenever possible, use of midline catheters over peripherally inserted central catheters could be safer for patients.
SOURCE: Swaminathan L, Flanders S, Horowitz J, et al. Safety and outcomes of midline catheters vs peripherally inserted central catheters for patients with short-term indications. A multicenter study. JAMA Intern Med 2022;182:50-58.
This multicenter observational cohort study sought to compare safety outcomes in patients receiving midline catheters vs. peripherally inserted central catheters (PICCs), specifically for the indications of either difficult vascular access or antibiotic therapy for 30 days or fewer. These inclusion criteria were used because they usually are the primary considerations when choosing between midline or PICC placement for a patient. Data came from 48 Michigan hospitals participating in the Hospital Medicine Safety Consortium. The main outcome was a composite of upper extremity deep venous thrombosis (DVT) or pulmonary embolism (PE), central-line associated bloodstream infection (CLABSI) or catheter-related bloodstream infection (CRBSI) in the case of a midline, and catheter occlusion. The definition of a CLABSI was based on the Centers for Disease Control and Prevention’s criteria of a positive blood culture with a PICC in place for at least 48 hours without other source of infection, a positive PICC tip culture if CLABSI was suspected, or documentation of CLABSI in the medical record. Similarly, a CRBSI was present if there was documentation of such in the medical record, the midline was removed specifically for suspected bloodstream infection, or if there were positive blood cultures with an organism known to cause CRBSI with no other source of infection. Statistical models were adjusted for patient characteristics, such as age, sex, comorbidities, cancer, history of DVT, PE, CLABSI, or CRBSI, and previous central venous line placement, in addition to device factors including number of catheter lumens, device dwell time, and number of insertion attempts.
Between December 2017 and January 2020, data from 5,758 PICCs and 5,105 midlines were available to be analyzed. Most of the PICCs (63.2%) and midlines (84.9%) were single-lumen. Median (interquartile range) dwell times for PICCs were 14 (seven to 27) days vs. six (three to 12) days for midlines. After adjustment for patient characteristics and device factors, patients who received a PICC were nearly twice as likely to develop a complication compared to patients who received a midline catheter (odds ratio [OR], 1.99; 95% confidence interval [CI], 1.61-2.47); results were similar regardless of the indication for catheter placement. Specifically, compared to midlines, PICCs were associated with more than two-fold odds of occlusion (OR, 2.24; 95% CI, 1.70-2.96) and more than four-fold risk of bloodstream infection (OR, 4.44; 95% CI, 2.52-7.82). There was no significant difference in risk of symptomatic DVT or PE. When the device dwell time was taken into account, higher hazards of bloodstream infection and catheter occlusion were observed with PICCs vs. midlines. There was a lower hazard of DVT in PICCs; this may be a reflection of the higher number of DVT events occurring in fewer total catheter days in midlines. In sensitivity analyses limited to complications occurring in the first 10 days after catheter placement, the risks of PICC over midlines were again observed with regard to major complications overall (OR, 1.45; 95% CI, 1.12-1.88), bloodstream infections (OR, 2.83; 95% CI, 1.37-5.84), and catheter occlusion (OR, 1.66; 95% CI, 1.19-2.32).
COMMENTARY
Given the frequency with which vascular access devices currently are placed as part of medical treatment, there is obvious interest in determining the optimal device based on patient needs that minimizes risks of complications.
This is the largest study comparing the complications of PICC vs. midline catheters to date. Its results support previously published guidelines1 favoring midline catheters over PICCs for use in patients who need vascular access for peripherally compatible infusions, who have difficult venous access, and who require frequent phlebotomy if the duration is anticipated to be less than or equal to 14 days. Overall, midlines were associated with a lower risk of infection compared to PICCs. Although some would argue that this may be the result of confounding variables, such as less robust surveillance of CRBSI compared to CLABSI and longer duration of PICC use, the study did specifically adjust for line duration and clearly adjudicated infections for both catheters in addition to performing a sensitivity analysis focused on complications within the first 10 days.
Midlines also outperformed PICCs with regard to lower risk of catheter occlusion, which may have important cascade effects on timing of intravenous medication administration, need for declotting agents, and need for premature device removal. There was no significant difference in terms of DVT risk between midlines vs. PICCs in logistic models, although according to time-to-event models, midlines may be associated with an increased daily hazard of DVT, possibly related to a similar number of events factored within a shorter catheter dwell time. This observation is in keeping with a prior study showing a higher risk of catheter-associated thrombosis associated with midline use, although this was a retrospective study in which it may have been difficult to account for all confounding variables (e.g., illness severity, medical history, medication history) that could influence thrombosis risk.2 However, it is biologically plausible that midline catheters may pose a higher risk of DVT given their placement in smaller veins with lower flow rates compared to central veins.3
Overall, it appears that midlines may be the preferable vascular option over PICCs depending on the clinical indication. However, firm conclusions will depend on head-to-head prospective randomized clinical trials.
REFERENCES
- Chopra V, Flanders SA, Saint S, et al. The Michigan Appropriateness Guide for Intravenous Catheters (MAGIC): Results from a multispecialty panel using the RAND/UCLA appropriateness method. Ann Intern Med 2015;163(6 Suppl):S1-S39.
- Bahl A, Karabon P, Chu D. Comparison of venous thrombosis complications in midlines versus peripherally inserted central catheters: Are midlines the safer option? Clin Appl Thromb Hemost 2019;25:1076029619839150.
- Tripathi S, Kumar S, Kaushik S. The practice and complications of midline catheters: A systematic review. Crit Care Med 2021;49:e140-e150.
Whenever possible, use of midline catheters over peripherally inserted central catheters could be safer for patients.
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