Comparison of normal or heparinised saline flushing on function of arterial lines

BACKGROUND: Heparin is used as a flush solution for intravenous and intra-arterial lines, but has a number of drug interactions, as well as potentially serious side effects. METHODS: We compared the function of arterial lines for both monitoring and blood sampling when flushed with either normal saline or saline containing heparin (1 unit/mL). Sixty five patients were recruited at this mixed medical and surgical Level 2 intensive care unit. Patients were randomised to receive either normal saline (NS) or heparinised saline (HS) (3 mL/hour as a continuous flush). Each patient's nurse was asked to score the function of the line at the end of each nursing shift. RESULTS: 35 patients were recruited in the NS group and 30 in the HS group. Mean study duration was 5.8 and 6.6 days for the NS and HS groups, respectively. The scores for the intravascular line for each patient were summed, and the percentage of the total possible score was calculated. Mean percentage scores were 83% (NS group) and 82% (HS group). Comparison using the central limit theorem showed no difference between the groups at the 95% confidence interval (-6% to 10%). CONCLUSIONS: Heparin as a continuous flush at 3 units/hour does not improve the function of arterial lines compared with a continuous normal-saline flush. (author abstract)