Introduced in the 1950s, midline catheters have become a popular option for intravenous (IV) access.1,2 Ranging from 8 to 25 cm in length, they are inserted in the veins of the upper arm. Unlike peripherally inserted central catheters (PICCs), the tip of midline catheters terminates proximal to the axillary vein; thus, midlines are peripheral, not central venous access devices.1-3 One popular variation of a midline catheter, though nebulously defined, is the long peripheral catheter (LPC), a device ranging from 6 to 15 cm in length.4,5
Concerns regarding inappropriate use and complications such as thrombosis and central line-associated bloodstream infection (CLABSI) have spurred growth in the use of LPCs.6 However, data regarding complication rates with these devices are limited. Whether LPCs are a safe and viable option for IV access is unclear. We conducted a retrospective study to examine indications, patterns of use, and complications following LPC insertion in hospitalized patients.
Our institution is a 470-bed tertiary care, safety-net hospital in Chicago, Illinois. Our vascular access team (VAT) performs a patient assessment and selects IV devices based upon published standards for device appropriateness. 7 We retrospectively collated electronic requests for LPC insertion on adult inpatients between October 2015 and June 2017. Cases where (1) duplicate orders, (2) patient refusal, (3) peripheral intravenous catheter of any length, or (4) PICCs were placed were excluded from this analysis.
VAT and Device Characteristics
We used Bard PowerGlide® (Bard Access Systems, Inc., Salt Lake City, Utah), an 18-gauge, 8-10 cm long, power-injectable, polyurethane LPC. Bundled kits (ie, device, gown, dressing, etc.) were utilized, and VAT providers underwent two weeks of training prior to the study period. All LPCs were inserted in the upper extremities under sterile technique using ultrasound guidance (accelerated Seldinger technique). Placement confirmation was verified by aspiration, flush, and ultrasound visualization of the catheter tip within the vein. An antimicrobial dressing was applied to the catheter insertion site, and daily saline flushes and weekly dressing changes by bedside nurses were used for device maintenance. LPC placement was available on all nonholiday weekdays from 8 am to 5 pm.
For each LPC recipient, demographic and comorbidity data were collected to calculate the Charlson Comorbidity Index (Table 1). Every LPC recipient’s history of deep vein thrombosis (DVT) and catheter-related infection (CRI) was recorded. Procedural information (eg, inserter, vein, and number of attempts) was obtained from insertion notes. All data were extracted from the electronic medical record via chart review. Two reviewers verified outcomes to ensure concordance with stated definitions (ie, DVT, CRI). Device parameters, including dwell time, indication, and time to complication(s) were also collected.
The primary outcome was the incidence of DVT and CRI (Table 2). DVT was defined as radiographically confirmed (eg, ultrasound, computed tomography) thrombosis in the presence of patient signs or symptoms. CRI was defined in accordance with Timsit et al.8 as follows: catheter-related clinical sepsis without bloodstream infection defined as (1) combination of fever (body temperature >38.5°C) or hypothermia (body temperature <36.5°C), (2) catheter-tip culture yielding ≥103 CFUs/mL, (3) pus at the insertion site or resolution of clinical sepsis after catheter removal, and (4) absence of any other infectious focus or catheter-related bloodstream infection (CRBSI). CRBSI was defined as a combination of (1) one or more positive peripheral blood cultures sampled immediately before or within 48 hours after catheter removal, (2) a quantitative catheter-tip culture testing positive for the same microorganisms (same species and susceptibility pattern) or a differential time to positivity of blood cultures ≥2 hours, and (3) no other infectious focus explaining the positive blood culture result.
Secondary outcomes, defined as minor complications, included infiltration, thrombophlebitis, and catheter occlusion. Infiltration was defined as localized swelling due to infusate or site leakage. Thrombophlebitis was defined as one or more of the following: localized erythema, palpable cord, tenderness, or streaking. Occlusion was defined as nonpatency of the catheter due to the inability to flush or aspirate. Definitions for secondary outcomes are consistent with those used in prior studies.9
Patient and LPC characteristics were analyzed using descriptive statistics. Results were reported as percentages, means, medians (interquartile range [IQR]), and rates per 1,000 catheter days. All analyses were conducted in Stata v.15 (StataCorp, College Station, Texas).
Within the 20-month study period, a total of 539 LPCs representing 5,543 catheter days were available for analysis. The mean patient age was 53 years. A total of 90 patients (16.7%) had a history of DVT, while 6 (1.1%) had a history of CRI. We calculated a median Charlson index of 4 (interquartile range [IQR], 2-7), suggesting an estimated one-year postdischarge survival of 53% (Table 1).
The majority of LPCs (99.6% [537/539]) were single lumen catheters. No patient had more than one concurrent LPC. The cannulation success rate on the first attempt was 93.9% (507/539). The brachial or basilic veins were primarily targeted (98.7%, [532/539]). Difficult intravenous access represented 48.8% (263/539) of indications, and postdischarge parenteral antibiotics constituted 47.9% (258/539). The median catheter dwell time was eight days (IQR, 4-14 days).
Nine DVTs (1.7% [9/539]) occurred in patients with LPCs. The incidence of DVT was higher in patients with a history of DVT (5.7%, 5/90). The median time from insertion to DVT was 11 (IQR, 5-14) days. DVTs were managed with LPC removal and systemic anticoagulation in accordance with catheter-related DVT guidelines. The rate of CRI was 0.6% (3/539), or 0.54 per 1,000 catheter days. Two CRIs had positive blood cultures, while one had negative cultures. Infections occurred after a median of 12 (IQR, 8-15) days of catheter dwell. Each was treated with LPC removal and IV antibiotics, with two patients receiving two weeks and one receiving six weeks of antibiotic therapy (Table 2).
With respect to secondary outcomes, the incidence of infiltration was 0.4% (2/539), thrombophlebitis 0.7% (4/539), and catheter occlusion 0.9% (5/539). The time to event was 8.5, 3.75, and 5.4 days, respectively. Collectively, 2.0% of devices experienced a minor complication.
In our single-center study, LPCs were primarily inserted for difficult venous access or parenteral antibiotics. Despite a clinically complex population with a high number of comorbidities, rates of major and minor complications associated with LPCs were low. These data suggest that LPCs are a safe alternative to PICCs and other central access devices for short-term use.
Our incidence of CRI of 0.6% (0.54 per 1,000 catheter days) is similar to or lower than other studies.2,10,11 An incidence of 0%-1.5% was observed in two recent publications about midline catheters, with rates across individual studies and hospital sites varying widely.12,13 A systematic review of intravascular devices reported CRI rates of 0.4% (0.2 per 1,000 catheter days) for midlines and 0.1% (0.5 per 1,000 catheter days for peripheral IVs), in contrast to PICCs at 3.1% (1.1 per 1,000 catheter days).14 However, catheters of varying lengths and diameters were used in studies within the review, potentially leading to heterogeneous outcomes. In accordance with existing data, CRI incidence in our study increased with catheter dwell time.10
The 1.7% rate of DVT observed in our study is on the lower end of existing data (1.4%-5.9%).12-15 Compared with PICCs (2%-15%), the incidence of venous thrombosis appears to be lower with midlines/LPCs—justifying their use as an alternative device for IV access.7,9,12,14 There was an overall low rate of minor complications, similar to recently published results.10 As rates were greater in patients with a history of DVT (5.7%), caution is warranted when using these devices in this population.
Our experience with LPCs suggests financial and patient benefits. The cost of LPCs is lower than central access devices.4 As rates of CRI were low, costs related to CLABSIs from PICC use may be reduced by appropriate LPC use. LPCs may allow the ability to draw blood routinely, which could improve the patient experience—albeit with its own risks. Current recommendations support the use of PICCs or LPCs, somewhat interchangeably, for patients with appropriate indications needing IV therapy for more than five to six days.2,7 However, LPCs now account for 57% of vascular access procedures in our center and have led to a decrease in reliance on PICCs and attendant complications.
Our study has several limitations. First, LPCs and midlines are often used interchangeably in the literature.4,5 Therefore, reported complication rates may not reflect those of LPCs alone and may limit comparisons. Second, ours was a single-center study with experts assessing device appropriateness and performing ultrasound-guided insertions; our findings may not be generalizable to dissimilar settings. Third, we did not track LPC complications such as nonpatency and leakage. As prior studies reported high rates of complications such as these events, caution is advised when interpreting our findings.15 Finally, we retrospectively extracted data from our medical records; limitations in documentation may influence our findings.
In patients requiring short-term IV therapy, these data suggest LPCs have low complication rates and may be safely used as an alternative option for venous access.
The authors thank Drs. Laura Hernandez, Andres Mendez Hernandez, and Victor Prado for their assistance in data collection. The authors also thank Mr. Onofre Donceras and Dr. Sharon Welbel from the John H. Stroger, Jr. Hospital of Cook County Department of Infection Control & Epidemiology for their assistance in reviewing local line infection data.
Drs. Patel and Chopra developed the study design. Drs. Patel, Araujo, Parra Rodriguez, Ramirez Sanchez, and Chopra contributed to manuscript writing. Ms. Snyder provided statistical analysis. All authors have seen and approved the final manuscript for submission.
The authors have nothing to disclose.