ICU patients with central venous access devices (CVADs) saw significantly fewer complications when their line-locking fluid was switched from standard saline or citrate to 4% tetrasodium EDTA (t-EDTA), according to results from the CLiCK trial presented at the American Thoracic Society International Conference and simultaneously published in JAMA. The pragmatic, triple-blind, cluster-randomized crossover trial enrolled 1,468 adults across six Canadian hospitals — three academic, three community — making the findings broadly generalizable.

The composite complication rate dropped 32% with t-EDTA versus control (13.1 vs. 19.9 events per 1,000 catheter-days). The main driver was a 34% reduction in catheter occlusions requiring alteplase — a meaningful outcome given the nursing time and care interruptions these events cause. The benefit was especially pronounced in patients with peripherally inserted central catheters and those with seven or more days of CVAD use. No adverse events, including calcium-related concerns, were observed.

Key Takeaways:

• 32% reduction in composite CVAD complications (bloodstream infection, occlusion requiring alteplase, or catheter removal) with t-EDTA vs. control
• Catheter occlusion requiring alteplase drove the effect (11.67 vs. 17.73 per 1,000 catheter-days)
• Benefit was strongest in patients with ≥80% lock adherence and ≥7 CVAD days
• t-EDTA is approved in Canada and Europe but has not yet been reviewed by the FDA; cost-effectiveness compared to saline remains a concern

Why it matters: Central line complications are a major source of morbidity and nursing burden in the ICU. A locking fluid that meaningfully reduces occlusions could improve patient outcomes and ease clinical workflow — though broader adoption will likely hinge on further cost-effectiveness data, particularly for U.S. settings.