Heparin for prolonging peripheral intravenous catheter use in neonates

Peripheral intravenous (PIV) catheters are widely used in modern medical practice. However, mechanical or infectious complications often necessitate their removal and/or replacement. Heparin has been shown to be effective in prolonging the patency of peripheral arterial catheters and central venous catheters, but may result in life threatening complications, especially in preterm neonates.

The primary objective was to determine the effectiveness of heparin versus placebo or no treatment on duration of PIV catheter patency, defined as number of hours of catheter use. The secondary objectives were to assess the effects of heparin on catheter blockage, phlebitis or thrombophlebitis, catheter related sepsis, and complications including abnormality of coagulation profile, allergic reactions to heparin, heparin induced thrombocytopenia, intraventricular/intracranial hemorrhage and mortality.

A literature search was performed using the following databases: MEDLINE (1966-December 2001), EMBASE (1980-December 2001), CINAHL (1982-December 2001), Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001), and abstracts from the annual meetings of the Society for Pediatric Research, American Pediatric Society and Pediatric Academic Societies published in Pediatric Research (1991-2001). No language restrictions were applied.

Randomized or quasi-randomized trials of heparin administered as flush or infusion versus placebo or no treatment were included. Studies which included a neonatal population and reported on at least one of the outcomes were included.

The methodological quality of the studies was assessed using criteria for blinding of randomization, blinding of intervention, completeness of follow-up and blinding of outcome assessment. Data on relevant outcomes were extracted and the effect size was estimated by calculating WMD (weighted mean difference, 95%CI), RR (relative risk, 95% CI) and RD (risk difference, 95% CI).

Eight eligible studies were identified. Heparin was administered either as a flush solution or as an additive to the total parenteral nutrition solution. Five studies reported data on the duration of use of the first catheter. Two of these studies found no statistically significant effect of heparin; two studies showed a statistically significant increase and one study showed a statistically significant decrease in the duration of PIV catheter use in the heparin group. The results were not combined for meta-analysis due to significant heterogeneity of the treatment effect (p<0.01). In addition, there were marked differences between the studies in terms of the methodological quality, the dose, the timing, the route of administration of heparin and the outcomes reported. From a limited number of studies, there were no significant differences between the heparin and the placebo/no treatment groups in the risks of infiltration, phlebitis and intracranial hemorrhage.

The effect of heparin on the duration of peripheral intravenous catheter use varied across the studies. Because of clinical heterogeneity and heterogeneity in treatment effect, recommendations for heparin use in neonates with PIV catheters cannot be made.

There are insufficient data concerning the effect of heparin for prolonging PIV catheter use in neonates. Further research on the effectiveness, the optimal dose, and the safety of heparin is required.