Effect of heparin in arterial line flushing solutions on platelet count: a randomised double-blind study
ABSTRACT
Introduction: Arterial catheters are widely used inintensive care units for continuous blood pressuremonitoring and blood sampling. Studies have examined theeffect of heparin on patency of arterial catheters but not onplatelet counts. Heparin is a naturally occurringanticoagulant that helps prevent clotting and is given toprevent and treat thrombosis. It has many other effects,including reducing platelet counts.
Methods: A prospective, randomised, double-blind studycompared the effects of heparinised and normal saline(both administered via a continuous flush device to anarterial catheter) on patients’ platelet counts. All patientsadmitted to a mixed medical-surgical ICU between Apriland December 2003 were eligible for entry. Exclusioncriteria were age under 16 years, known sensitivity toheparin, pre-existing coagulopathy that precluded heparin,or requirement for therapeutic heparin. Lines were insertedinto radial, brachial or femoral arteries. A 500 mL bag ofsaline for the flush was injected with numbered syringes,containing either normal saline (NS, 35 patients) or 500 IUheparin (HS, 30 patients), and pressurised. Platelet countwas assessed daily.
Results: Mean platelet counts were 234.6 x 109/L (NS)versus 256.6 x 109/L (HS). Comparison using the centrallimit theorem showed means were not different at the 95%confidence interval (- 77.6 to 37 x 109/L).
Conclusion: Use of heparin in normal saline as acontinuous flush for an arterial catheter does not reduceplatelet counts in critically ill patients.
Crit Care Resusc 2006; 8: 294-296
