Peripherally inserted central catheters (PICCs) are considered valuable instruments in healthcare as a safe means of delivering treatment, especially to stable patients. However, during the past ten years, complications including infections, thrombosis, and mechanical issues have surfaced, introducing risks to their use.
Manufacturers have developed a set of new products, activities, and technologies that can help to address these threats. For instance, hydrophobic and antimicrobial coatings of catheters are said to alleviate complications. Bioengineered hydrophobic materials used in the BioFlo PICC do not allow platelet adhesion and formation of thrombus while chlorhexidine-coated PICCs have an efficiency in reducing bloodstream infections. Peripherally inserted central catheter innovation to reduce infections and clots (PICNIC) trial explores these possibilities hypothesizing that they minimize the risk of device failure compared to conventional polyurethane PICCs.
The PICNIC trial was a pragmatic, multicenter, randomized, controlled trial intended to evaluate the efficacy of innovative PICCs (hydrophobic and chlorhexidine-coated) against standard polyurethane PICCs. Carried out in three hospitals in Brisbane Australia, the study enrolled both adults and children who needed PICC placement. Ethical approval for the study was obtained from Queensland Health, Griffith University, and the University of Queensland. The participants for this study were selected from three tertiary hospitals in Brisbane. Candidates for PICC among the study participants comprised the adult population and children whose veins were suitable for a 4.0 French size or larger. Participants could be part of the trial only once and the selection of the participants was standardized with the trial having inclusion and exclusion criteria.
The experiment employed centralized randomization with a 1:1:1 ratio, adjusted by hospital location and thrombosis risk. Randomization was assigned and stratified according to the hospital site and thrombosis risk level.
Research nurses administered the assigned PICC to practitioners who had knowledge of the insertion of the non-standard PICC for patients. Standard protocols in the care and management of patients were practiced. The subjects were followed weekly for up to 8 weeks or until the removal of the PICC with data being captured using a secure online database.
The main outcome was device failure, compromising events that led to PICC removal or the cessation of its function. Secondary endpoints included complications, PICC placement, participant satisfaction, and quality-adjusted life days.
The trial was designed with 85% power to detect differences in device failure rate between the innovative PICCs and the standard PICC. Logistic regression was used for primary outcome analysis and Cox and Poisson regression for time-to-event and count-based outcomes respectively. All analyses were conducted using an intention-to-treat approach with missing values handled by complete case analysis.
Between September 2019 and December 2022, 2,325 patients underwent screening, with 1,227 excluded for various reasons. A total of 1,098 participants were randomized into three groups: hydrophobic (365), chlorhexidine (365), and standard polyurethane (368). Due to clinical contraindications, 14 patients did not get the allocated PICC, and four patients missed out on follow-up. The study recruited 178 children (mean age, 12 years) with multiple comorbidities and 920 adults (mean age, 57 years).
Device failure rates were 5.9% in the hydrophobic group, 9.9% in the chlorhexidine group, and 6.1% in the standard polyurethane group. There was no statistically significant difference between the hydrophobic group and the standard-polyurethane group (P = 0.89), or between the chlorhexidine and standard-polyurethane groups (P = 0.06).
The hydrophobic group had 2.2 devices failed by 1000 catheter days while the chlorhexidine group had 3.6 and the standard-polyurethane group had 2.1. A complication from any cause was identified in 21.5% of the hydrophobic group, 38.6% of the chlorhexidine group, and 21.7% of the standard polyurethane group.
Catheter occlusion rates were 17.0% in the hydrophobic group, while the chlorhexidine group came with 33.6% and standard polyurethane 14.2%. Venous thrombosis was present in 3.1% of patients in the hydrophobic group, 3.3% of patients in the chlorhexidine group, and 6.4% of patients in the standard polyurethane group. Overall, PICC-associated bloodstream infection rates were 1.4% in the hydrophobic group, 1.7% in the chlorhexidine group, and 1.9% in the standard-polyurethane group.
The overall rate of adverse events of any type in the study was 3.4% in the hydrophobic group, 1.1% in the chlorhexidine-coated group, and 1.9% in the standard polyurethane group. These were not considered to be associated with the PICC by the medical monitor, except for one case of systemic allergic reaction in the standard polyurethane group.
In this trial, no differences were observed in the risk of device failure when hydrophobic or chlorhexidine-coated PICCs were compared to polyurethane PICCs. The most prevalent reason for failure was catheter occlusion, and there was a significantly higher rate of catheter occlusion in the chlorhexidine-coated PICCs group. No advantage in infection prevention was observed with chlorhexidine-coated PICCs, although complications were higher in the chlorhexidine group based on prior studies. These results raise the concern that further studies on the risk of occlusion particularly with chlorhexidine coatings.
The findings contradict previous guidelines that were derived from observational research and indicate that existing standards governing the usage of medical devices appear to be ineffective at promoting the best outcome. While hydrophobic PICCs showed a tendency toward a reduced incidence of venous thrombosis, the study did not show any superiority of either hydrophobic or chlorhexidine-coated PICCs in reducing failure or infection rates. Further research is needed to refine the use of PICCs and improve patient outcomes.
References: Ullman AJ, August D, Kleidon TM, et al. A comparison of peripherally inserted central catheter materials. N Engl J Med. 2025;392:161-172. doi:10.1056/NEJMoa2406815
