Papaverine vs Heparin for Peripheral Arterial Catheter Patency in Pediatric Patients

The purpose of this study is to compare intraoperative papaverine plus heparin to heparin alone for prevention of arterial spasm and maintenance of patency of peripheral arterial catheters during surgery in pediatric patients. The hypothesis is that periodic, intraoperative small-volume boluses of diluted papaverine plus heparin in peripheral arterial catheters of pediatric patients will prevent arterial spasm and help maintain patency of arterial catheters during general anesthesia.