What is the issue?

Most of the people presenting end-stage kidney disease use haemodialysis (HD) to replace kidney function. Frequently, a central venous catheter (CVC) is needed to begin HD. In between HD sessions, the CVC needs a sealing solution to avoid catheter thrombosis (an obstruction due to clots), and this is frequently heparin.

In addition to catheter thrombosis, another frequent complication is catheter-related infection (CRI). CRI originates in the catheter and then spreads to the blood or other organs.

Heparin prevents clot formation but does not prevent infections. Therefore, instead of heparin, the use of sealing solutions that can reduce CRIs has been proposed. These antimicrobial lock solutions could be divided into antibiotic (e.g. vancomycin) and non-antibiotic (e.g. citrate) solutions. Antimicrobial lock solutions should fill the catheter lumen and then be locked in the catheter during in-between HD sessions with or without heparin.

What did we do?

We did a systematic review to assess the question whether antimicrobial (antibiotic or non-antibiotic) lock solutions were better than heparin to prevent CRIs in patients undergoing HD through a CVC and thrombosis compared to heparin. We searched the literature up until 18 December 2017 and identified 39 studies enrolling 4216 patients that met our inclusion criteria.

What did we find?

We included 39 studies, including 3,945 participants undergoing HD through a CVC. The studies compared CVC sealing solutions with heparin to antimicrobial lock solutions. Fifteen studies used only antibiotic lock solutions, 21 used non-antibiotic lock solutions, and 4 used both (antibiotic and non-antibiotic) lock solutions. Studies measured the incidence of CRIs and catheter thrombosis, or both. Overall quality of the studies was low for CRIs and very low for thrombosis. There was no information on funding sources for most of the studies.

In general antimicrobial lock solutions are likely superior to standard solutions in preventing CRIs among patients undergoing HD through a CVC, but non-antibiotic solutions did not prove to reduce CRI. They are no worse than heparin at preventing thrombosis. Other adverse effects were not reported in most studies. Our confidence in these results is low due to the quality of the studies.

Conclusion

Some antimicrobial (antibiotic and the combination of antibiotic-non antibiotic) lock solutions decrease the incidence of CRIs compared to heparin. Their effect on CVC permeability remains unclear. The quality of the studies is low and very low, respectively; therefore, more studies are needed to confirm the benefits and harms of antimicrobial lock solutions.