HEPARINIZED SALINE VERSUS NORMAL SALINE IN MAINTAINING PATENCY OF THERADIAL ARTERY CATHETER

Objective: To compare the ability of normal versus heparinized saline infusion to maintain patency of the radial artery catheter used for mo nitoring or multiple blood sampling. Design: Randomized double-blind t rial. Setting. A university-affiliated hospital. Patients: All 108 pat ients admitted to the surgical intensive care unit who required radial arterial line catheters. Excluded were patients who required emergenc y admission, those who refused to give consent, those who needed antic oagulants, thrombolytic or platelet therapy, those whose cannulation s ite was other than the radial artery, inadvertent discontinuation of t he arterial line or incomplete data collection. This resulted in a sam ple of 78 adults, randomized according to date of admission. Intervent ions: Forty patients admitted on odd-numbered dates received hepariniz ed normal saline (2 units/mL), and 38 patients admitted on even dates received normal saline, both as continuous flush solutions. Main Outco me Measures: Measurement of radial artery flow and pressure before and after cannulation, and catheter patency during cannulation. Results. The type of flush solution did not adversely affect the radial artery or the hand in any measurable way. Catheter blockage occurred in three patients receiving heparinized saline and seven patients receiving no rmal saline as the flush solution (p = 0.06). At 96 hours of cannulati on, 92% of the catheters in the heparinized saline group were patent c ompared with 74% in the normal saline group. Intra-arterial blood pres sure was inaccurate compared with the brachial cuff pressure in 6 pati ents in the heparinized saline group compared with 14 patients in the normal saline group (p < 0.03). Conclusions. There is no significant d ifference between flushing with normal saline and heparinized saline i n the maintenance of radial arterial line patency. However, the use of a continuous heparinized flush solution in pressurized arterial lines is beneficial in that it results in greater accuracy of blood pressur e monitoring than normal saline infusion.