The Effects of Heparin Versus Normal Saline for Maintenance of Peripheral Intravenous Locks in Pregnant Women

Abstract

To compare the efficacy of two available preparations (heparin, 10 U/mL, 1 mL, vs. normal saline, 1 mL) used for maintaining patency in peripheral intravenous (IV) locks during pregnancy. Prospective, randomized, and double-blind. Eligible patients who were to receive a peripheral intermittent IV lock were randomly assigned to receive either heparin flushes or normal saline flushes for IV lock maintenance. IV locks were flushed after each medication administration, or at least every 24 hours, with the assigned blinded flush solution. Intermittent IV lock sites were also evaluated every 12 hours for the development of phlebitis. A large academic medical center in the Midwest that has both community-based and regional-referral obstetric practices with more than 2,000 deliveries per year. A convenience sample included 73 hospitalized pregnant women who were between 24 and 42 weeks gestation. Exclusions from the study were women with significant abnormalities in the fetal heart tracing on admission, cervical dilation > 4 cm, presence of hypersensitivity to heparin, presence of clotting abnormalities, and anticoagulation therapy (including low-dose aspirin). Data indicate there were no statistically significant differences in IV lock patency nor in phlebitis between heparin or normal saline flushes. This study provides support that both normal saline and heparin in the doses studied may be equally effective in the maintenance of peripheral IV locks. Due to small sample size, additional studies are needed to determine optimal therapy over time.