DDX of umbilical arterial catheter malfunction

Approach to the DDX of umbilical arterial catheter malfunction:

  • Normal umbilical artery catheter (UAC) course is umbilical artery to internal iliac artery to common illiac artery to aorta (in and caudad and then cephalad on an AP image) while coursing anterior to the spine on the lateral image
  • The correct position for the umbilical arterial catheter tip should be at T6-T9 vertebral body (high UAC) or L3-L5 vertebral body (low UAC)
  • High malposition is an umbilical arterial catheter tip positioned above T6 which is near the origin of great vessels from aortic arch
  • Low malposition is an umbilical arterial catheter tip positioned between T9-L2 which is near the origins of renal arteries and mesenteric vasculature
  • Perforation of vessel during placement should be suspected when the umbilical arterial catheter projects over no known arterial vessel
  • Umbilical arterial catheter tip thrombosis which can extend into any adjacent arterial vessel