Heparin vs Saline Infusion to Maintain Patency of Arterial Catheters in Children: A Randomized, Double-Blind, Noninferiority Trial.

Objective: To determine whether normal saline flush solution is noninferior to heparinised saline for maintaining the patency of arterial intravascular catheters in children.

Methods: A single centre, double blind, parallel group, noninferiority, randomized control study was conducted in the Pediatric Intensive Care Unit of Kanchi Kamakoti CHILDS Trust hospital, a tertiary children's hospital, Chennai, India. 92 children requiring arterial catheters for more than 12 hours were randomized to receive either normal saline or heparinized saline (1 U/ml) flush solution. Primary outcome was a noninferiority comparison between normal saline and heparinised saline in maintaining the patency of arterial catheters using the proportion of occlusion of arterial catheters as primary endpoint. Secondary outcome was mean duration of patency of arterial catheters in each treatment group.

Results: Ninety-two children with a median (interquartile range, age of 84 (33.5-132) months and 52% males were enrolled. 15.2% of catheters in the heparin group and 17.4% of catheters in the normal saline group were occluded (P = 0.77). The 95% upper confidence interval for the difference in proportion was 0.148 (+14.8%), establishing noninferiority (< 15%). The median (IQR) duration of a patent arterial catheter was 47 (27.75 - 94.5) hours in the heparin group and 35.50 (24.50 - 62) hours in the normal saline group (P = 0.10). Comparison of duration of patency using Kaplan Meier survival analysis and log rank test showed no statistically significant difference. There were no serious adverse events noted in either group.

Conclusions: Our data suggests that normal saline is noninferior to heparinized saline infusion in maintaining the patency of arterial lines in children. This may benefit clinicians worldwide as normal saline would be a safer and cost-effective option.