Heparinised saline or normal saline?

Using heparinised saline as a flush to maintain the patency of arterial and central venous lines is a well-known practice. A literature search was undertaken but found no evidence to support the use of heparinised saline over normal saline. In addition, the use of heparinised saline may be associated with adverse effects. The literature search strategy utilised Ovid CINAHL and Medline databases, as well as hand-searching bibliographies of clinical and research articles from the University of Cambridge Medical Library. Keywords and phrases included 'heparin', 'normal saline', 'arterial', 'haemodynamic lines' and 'catheters'. All types of evidence from each of these resources were examined to identify major themes, areas of agreement and disagreement across clinical practice, changesin the concept over time and emerging trends.