Heparin versus normal saline for patency of arterial lines.

Background: For most patients who require intensive care, the success of clinical decision making and interventions is dependent on the accuracy of different physiological variables measured or obtained from samples using an arterial catheter. Maintaining the patency of these catheters is therefore essential for obtaining accurate measures, minimizing patient discomfort and reducing expenses incurred when an occluded catheter requires replacement. Uncertainty exists amongst clinicians as to best practice surrounding the contents of the arterial catheter flush solution (heparin or saline).