Research Note: Heparinized Saline for Catheter Patency

Heparinized saline flushes are a common means of maintaining peripheral IV catheter patency in human and veterinary medicine. The assumed benefit is that heparin acts as an antithrombotic agent and its use would result in fewer blood clots, and therefore fewer occluded IV catheters; however, potential risks from IV heparin include allergic reactions, drug interactions, and inadvertent bleeding complications. This study examined whether heparinized saline (10 IU/mL) would be more effective at maintaining peripheral IV catheter patency than 0.9% sodium chloride. 

Each of 30 healthy dogs had an 18-gauge, polyurethane IV catheter placed in either the right or left cephalic vein. Dogs were randomly assigned into 1 of 3 groups: a group receiving heparinized saline flushes (HS), a group receiving 0.9% sodium chloride flushes (S), and a control group receiving no catheter flushes during the study. No significant difference was found between the HS and S groups pertaining to maintenance of catheter patency; however, more S group dog catheters, from which aspiration of blood could not be performed compared to HS group dogs, suggested that heparinized saline flushes may be preferred for peripheral catheters used for serial blood collection. Catheter size and indwelling period may play a role in phlebitis and subsequent IV catheter occlusion; thus, limitations of this study included the use of only one catheter size (18-Ga) and a study period of only 42 hours.

SourceComparison of heparinized saline and 0.9% sodium chloride for maintaining peripheral intravenous catheter patency in dogs. Ueda Y, Odunayo A, Mann FA. JVECC 23:517-522, 2013.