Flushing the central venous catheter: is heparin necessary?

Purpose: The aim of this systematic review was to assess the efficacy of heparin flushing in the lock of central venous catheters. Methods: We searched MEDLINE and CINAHL databases. Eligible studies were randomized controlled trials evaluating the use of heparin versus normal saline or other solution in the flushing of central catheter among adult patients. No language restrictions were applied. Two reviewers independently screened titles and abstracts in order to identify relevant publications. The same two reviewers retrieved and evaluated full texts. Parameter estimates regarding catheter occlusion were pooled using network meta-analysis with Bayesian hierarchical modeling. Results: We identified 462 references. Eight studies were included. There was no evidence that heparin was more effective than normal saline in reducing occlusions. It was unclear whether urokinase and lepirudin were more effective than heparin in reducing occlusions. Vitamin C solution does not appear to prolong catheter patency. Conclusions: There is no evidence of a different effectiveness between heparin flushing and normal saline or other solutions in reducing catheter occlusions. Due to the little and inconclusive evidence available in this field, further studies might be necessary.