Greater antimicrobial efficacy of citrate 47% over herapin     Study Aim: To determine the incidence of symptomatic bacteraemia with different locking solutions, including heparin (5,000 - 10,000 units, Soldium Citrate (10-67.7%) plus Gentamicin). Study Design: - 2 year observational study, single centre, 40 tunnelled catheters, locking solution changed every 3-4 months. Conclusion:   The greatest significant decrease in incidence of symptomatic bacteraemia appears to occur with the use of 47% citrate _ The use of urokinase reduced significantly from 41 vials/month to 0 vials/month citrate 47% _ It prevents formation of biofilm in the catheter lumen, by eliminating the growth of bacteria, yeast and fungi which would normally form the biofilm