Heparin flushing and other interventions to maintain patency of central venous catheters: a systematic review

Title. Heparin flushing and other interventions to maintain patency of central venous catheters: a systematic review. Aim. This paper is a report of a review to assess clinical studies comparing the effectiveness of different means of maintaining central venous catheter patency. Background. Flushing with heparin is a routine part of central venous catheter maintenance, but it presents risks, including heparin‐induced thrombocytopenia. Other techniques used to prevent occlusion of catheters include saline flushes, heparin‐bonded catheters and pressure caps. Data sources. A search was conducted using the MEDLINE, CINAHL, EMBASE, Cochrane, National Guideline Clearinghouse and University Healthsystem Consortium databases. Methods. A systematic review of effectiveness was conducted, using GRADE criteria to assess the strength of evidence for each intervention. The review period covered 1982 or earlier to January 2008. Results. There is weak evidence that heparin flushing reduces occlusion of catheters, but no evidence that it reduces bloodstream infections. Results from clinical trials of pressure caps are inconsistent regarding their ability to maintain catheter patency, but provide moderate evidence that at least some varieties of caps are associated with increased bloodstream infections. Conclusion. The evidence base on heparin flushing and other interventions to prevent catheter occlusion is small, and published studies are of low quality. There is insufficient evidence on which to conclude that flushing catheters with heparin is more effective than flushing with saline solution.