Comparison of normal saline and heparin solutions for maintenance of arterial catheter patency

A double-blind, randomized study was conducted in 30 adult medical intensive care unit patients to determine if the presence of heparin in continuous-flush solutions prolongs the functional life span of radial arterial catheters compared with catheters flushed with solutions not containing heparin. Patients were consecutively entered into the study and randomly assigned to receive arterial line flush solutions containing 0.9% sodium chloride (NSS) or heparin 4 U/ml in 0.9% sodium chloride. The flow rate of each flush solution was approximately 3 ml/hr. Use of the heparin-containing flush solution resulted in a catheter survival rate of 86% at 96 hours compared with a rate of only 52% after 40 hours with NSS (p less than 0.05). In addition, the heparin-flushed catheters required significantly less manipulation to prevent catheter occlusion and arterial pressure-wave dampening (p less than 0.01). The use of NSS as a continuous flush for radial artery catheters is associated with an increased frequency of catheter occlusion and malfunctions compared with solution containing heparin, and thus is not recommended in patients with normal coagulation status and platelet count.