When should a Umbilical Arterial Catheter (UAC) be used versus a Umbilical Venous Catheter (UVC)?

UAC vs UVC: When to Use Each

Use an Umbilical Arterial Catheter (UAC) primarily for continuous blood pressure monitoring and frequent arterial blood gas sampling, while an Umbilical Venous Catheter (UVC) should be used for central venous access to deliver medications, fluids, parenteral nutrition, and emergency resuscitation.

Primary Indications

Umbilical Arterial Catheter (UAC)

• Continuous arterial blood pressure monitoring in critically ill neonates requiring hemodynamic assessment 1
• Frequent arterial blood gas sampling to minimize repeated peripheral arterial punctures 1
• Cardiac catheterization procedures requiring arterial access with UFH prophylaxis (100 units/kg bolus) 1

Umbilical Venous Catheter (UVC)

• Central venous access for administration of medications, fluids, and parenteral nutrition 2
• Emergency vascular access during delivery room resuscitation 2
• Infusion of vasoactive medications requiring central venous delivery 2
• Total parenteral nutrition in the first days of life 2

Key Technical Considerations

UAC Placement

• Position the UAC in a high position (between T-6 and T-10) rather than a low position to reduce thrombotic complications 1, 3
• Maintain patency with low-dose UFH infusion (heparin concentration 0.25-1 unit/mL, total dose 25-200 units/kg per day) 1
• Remove as soon as clinically feasible since longer duration significantly increases thrombosis risk (adjusted OR 1.2 per additional day, 95% CI: 1.1-1.3) 4

UVC Placement

• Position the tip in the right atrium to ensure central location and prevent complications 3
• Use ultrasound guidance for tip location verification, as up to 40% of UVCs placed without ultrasound are malpositioned 2
• Consider for longer-term use compared to UAC, as UVC-associated thrombosis is significantly less common (4.1% vs 32.3%) 4

Thrombotic Risk Profile

UAC Carries Higher Thrombotic Risk

• Abdominal aortic thrombosis occurs in 32.3% of infants with UAC vs only 4.1% inferior vena cava thrombosis with UVC 4
• Infants with UAC have 7.6 times higher odds of developing thrombosis compared to those with UVC alone (95% CI: 1.1-325.5) 4
• Duration is the primary modifiable risk factor - each additional day increases thrombosis risk by 20% 4

Management of Catheter-Related Thrombosis

• For symptomatic UAC-related thrombosis, initiate therapeutic UFH or LMWH acutely, with LMWH preferred for longer-term treatment 1
• Consider thrombolysis for symptomatic non-occlusive (>50% occlusion) aortic thrombosis, bilateral renal artery thrombosis, or limb/organ/life-threatening conditions 1
• Treatment duration varies from <2 weeks to 3 months depending on severity, with most experts recommending 4-6 weeks 1

Concurrent Use Considerations

When Both Catheters Are Needed

• Infants receiving both UAC and UVC have the same elevated thrombosis risk as those with UAC alone (OR: 7.6) 4
• Enteral feeding is practiced by 51% of NICUs with UVC in place (trophic feeds) and 49% with UAC in place, though evidence for safety is limited 5
• More complete enteral nutrition is provided by 44% of NICUs with UVC and 36% with UAC, despite theoretical concerns 5

Removal Timing

UAC Removal

• Remove immediately when no longer needed for blood pressure monitoring or blood gas sampling, given the 1.2-fold daily increase in thrombosis risk 4
• Screen all infants with 2-D ultrasonography within 48 hours after UAC removal to detect abdominal aortic thrombus 4

UVC Removal

• Can remain in place longer than UAC due to lower thrombotic risk (4.1% vs 32.3%) 4
• Remove when central access no longer required or when transitioning to peripherally inserted central catheter (PICC) for longer-term needs 6

Common Pitfalls to Avoid

• Do not use UAC solely for venous access - the thrombotic risk is not justified when UVC provides safer central venous access 4
• Do not leave UAC in place "just in case" - duration is the strongest modifiable risk factor for thrombosis 4
• Do not place UVC without ultrasound confirmation - 40% will be malpositioned without imaging guidance 2
• Do not use subclavian vein as alternative to umbilical access in neonates - it causes stenosis in >80% of pediatric patients 7