Efficacy of normal saline in the maintenance of the arterial lines in comparison to heparin flush: a comprehensive review of the literature.

PURPOSE: The aim of this study is to examine the efficacy of normal saline (0.9% sodium chloride) as a flush solution on patency of arterial lines in comparison to heparin flush. Data have been examined in various categories of specialty (medical, surgical, cardiac, burns, gynecology), frequency of flushes, strength and volume of flushes, continuous versus bolus, duration of each flush and patency incidence (range, ≤ 24 to ≥ 96 hours). The secondary aim focused on the incidences of reported heparin-induced thrombocytopenia (HIT type I and II). METHODS: A comprehensive review of the literature from 1951 to 2012. An electronic search of OVID, Medline, Embase, Cochrane, Scopus and CINAHL database in English language was conducted. The search was limited to adult subjects only. The following keywords were used: heparin flush, saline flush, 0.9% sodium chloride flush, arterial line and indwelling vascular line. A total of ten papers (n=10) were found eligible. RESULTS: The evidence suggests patency is feasible with both solutions but if longer duration of use (arterial line) is advocated, heparin is superior in the long term. Furthermore, heparin flush effects are dose dependent and require fewer numbers of flushes. In addition, no adverse effects were found with heparin flush solution. CONCLUSION: There is level 1 evidence to support heparin as a flush solution once the time frame exceeds 48 hours. In addition, there is level 1 evidence to suggest that heparin at higher doses and in continuous infusion has better patency incidence with no reports of HIT type II or I.