NICU Vascular Access: Umbilical Catheters, Neonatal PICC, and Peripheral IV in Neonates

Vascular access in the neonatal intensive care unit (NICU) is among the most technically demanding and highest-stakes procedures in clinical medicine. Neonates — particularly preterm infants at the physiologic limits of viability — have extremely small and fragile veins, unique anatomic access routes unavailable in any other population (umbilical vessels), and age-specific physiologic vulnerabilities that affect every aspect of vascular access decision-making.

Parent guide: Vascular Access Special Populations: Complete Reference

Vascular Access Options in the NICU: Overview

The neonate has access routes not available in any other patient population:

Umbilical Venous Catheter (UVC)

Anatomy and Indication

The umbilical vein provides unique immediate central access in the first days of life. The vein travels from the umbilicus through the liver via the ductus venosus to the inferior vena cava. A properly positioned UVC provides central venous access for medication administration, parenteral nutrition, and blood product administration.

Indications:

• Resuscitation in the delivery room
• TPN administration in preterm or critically ill neonates
• Administration of hyperosmolar medications
• Exchange transfusion
• Central venous pressure monitoring

UVC Tip Position

Target position: Junction of the inferior vena cava and right atrium (IVC-RA junction), confirmed radiographically at the level of the diaphragm to the right atrium.

Radiographic landmark: On anterior-posterior chest radiograph, the UVC tip should be visible at the level of T8–T10 (right heart border). The tip should NOT be in the portal system (liver), ductus venosus, or hepatic vasculature — malposition in portal/hepatic circulation can cause hepatic injury, portal hypertension, and liver necrosis from infusate.

Verification: Chest and abdominal radiograph after insertion. The UVC should course centrally toward the diaphragm (upward path), distinguishing it from a UAC which takes a distinctive caudal-then-cephalad course.

UVC Insertion Technique

1. Prepare umbilical stump: cut cord 1–2 cm from skin; identify the single large-lumen umbilical vein (thin-walled, oval or irregular) and two smaller arterial vessels (round, thick-walled)
2. Insert catheter to estimated depth (birth weight in kg + 1 + 1 = estimated UVC depth in cm — more precise estimates use body length/shoulder-umbilicus measurements)
3. Confirm with radiograph before use
4. Do not advance/withdraw without radiographic confirmation if catheter has been in use
5. Secure with suture/umbilical bridge; bridge securement preferred over tape

UVC Dwell and Transition

INS standard: UVC dwell should not exceed 14 days (risk increases for hepatic vessel injury, hepatic portal hypertension, and line-associated infection). Most NICUs aim for transition to neonatal PICC within the first 7–10 days when possible.

Do not leave a malpositioned UVC in use. A UVC with tip in the portal circulation, hepatic veins, or heart is associated with serious complications. Reposition (pull back to safe position if feasible) or remove and replace.

Umbilical Arterial Catheter (UAC)

Purpose and Anatomy

The umbilical arteries (two vessels, thick-walled) course caudally from the umbilicus into the iliac arteries and descending aorta. A UAC advances from the umbilicus → iliac artery → descending aorta, enabling continuous arterial blood pressure monitoring and arterial blood sampling.

Indications:

• Continuous arterial blood pressure monitoring in critically ill neonates
• Frequent arterial blood gas sampling
• Exchange transfusion

UAC Tip Positions

High position (preferred): Tip at T6–T9 (above the celiac, SMA, and renal arteries). This position avoids mesenteric ischemia from vasospasm near mesenteric vessels.

Low position (acceptable alternative): Tip at L3–L4 (below the renal arteries, above the aortic bifurcation). This position is used when high position is technically difficult.

Avoid mid-aortic positions (T10–L2, near the renal and mesenteric arteries) — associated with higher risk of renal and mesenteric ischemia.

Verification: Radiograph after insertion. The UAC courses caudally into the iliac arteries before turning cephalad into the aorta — this “U-shaped” course on x-ray distinguishes the UAC from the UVC.

UAC Dwell and Monitoring

Recommended maximum dwell: 7–10 days (some institutions limit to 5–7 days due to infection and thrombus risk).

Monitoring: Assess lower extremities for signs of vascular compromise — blanching, mottling, cyanosis, or asymmetric limb temperature — at minimum every 4 hours. Vasospasm in the lower extremities should be treated by removing the UAC.

Heparin in UAC flush solutions: Low-dose heparin (0.25–1 unit/mL in normal saline) is used in UAC infusion fluids at most institutions to maintain patency and reduce fibrin deposition. This is UAC-specific — not applicable to other neonatal access.

Neonatal PICC Lines

Role in NICU

Neonatal PICCs are the standard central access device for neonates requiring more than 7–14 days of central access, particularly for:

• Long-term parenteral nutrition
• Prolonged antibiotic therapy
• Highly osmolar or vesicant medications

Anatomic Sites for Neonatal PICC

Gauge Selection

• 1.9 Fr (double-lumen): standard neonatal PICC for most NICUs; smallest dual-lumen catheter
• 1.9 Fr or 2 Fr single-lumen: for very small/preterm neonates
• 3 Fr: older infants approaching transition to standard PICC sizes

Neonatal PICC Insertion Technique

Neonatal PICC insertion requires specialized training beyond adult PICC insertion. Key differences:

Measurement: Measure from insertion site to the SVC-RA junction using anatomic landmarks. External measurement correlates less reliably with actual tip position than in adults — radiographic confirmation is mandatory.

Vessel visualization: Transillumination (bright light held against the extremity) was the historical technique; ultrasound guidance is increasingly used but challenging given vessel size (1–2 mm in preterm neonates).

Stylet and catheter: Neonatal PICCs have extremely thin, delicate catheters. Stylet tips are not as stiff as adult PICC stylets. Advancement is done with gentle, steady pressure — never force.

Confirm with radiograph: ALL neonatal PICCs require post-insertion radiograph to confirm tip at SVC-RA junction or IVC-RA junction (lower extremity PICC).

Neonatal PICC Tip Position: Cavoatrial Junction Standard

Per INS 2021 and CEVAD 2020 consensus: neonatal PICCs tip position targets the SVC-RA junction (cavoatrial junction) for upper extremity lines, and the IVC-RA junction for lower extremity lines. Tip placement in the mid-SVC is associated with higher rates of thrombosis and pericardial effusion in neonates.

Pericardial effusion / cardiac tamponade: A recognized life-threatening complication of neonatal PICCs, particularly with tips malpositioned in the atrium or pericardium. In neonatal PICC tamponade, the clinical presentation may be subtle — sudden deterioration, tachycardia, muffled heart tones, hypotension. Emergent pericardiocentesis is required.

Malposition rates in neonatal PICCs are substantially higher than adult PICCs due to small vessel size, thin walls, and limited margin for tip adjustment.

Peripheral IV in Neonates

Site Selection

Standard sites (in order of preference):

1. Dorsum of hand
2. Dorsum of foot
3. Forearm (cephalic/basilic)
4. Antecubital fossa (avoid in neonates when possible — positional instability)
5. Scalp veins (frontal, temporal) — last resort for peripheral access in neonates

Gauge

• 24G or 26G for all neonatal PIVs
• 22G acceptable in larger neonates for specific indications (blood products)

Neonatal Skin Protection

Neonatal skin — especially in preterm infants <28 weeks — is extremely thin, fragile, and highly permeable. The stratum corneum is functionally immature until 28–34 weeks.

Adhesive products: Use only hydrocolloid, silicone, or foam adhesive products (not standard medical tape) for catheter securement and dressing. Standard adhesive removers cause significant skin trauma.

MARSI (Medical Adhesive-Related Skin Injury): Neonates are at extreme risk. Change securement devices carefully; soak adhesive with saline before removal; consider skin barrier products.

Transepidermal absorption: Many topical agents penetrate immature neonatal skin and cause systemic effects. Avoid alcohol-based skin preparations in very preterm neonates (<28 weeks).

Antisepsis Considerations by Gestational Age

Note: Chlorhexidine absorption through extremely preterm skin has been associated with chemical skin burns and systemic absorption. Most NICUs have age-specific protocols.

Filtration in the NICU

Standard NICU practice: All IV infusions in neonates should be administered through a 0.22 μm in-line filter (INS 2021, NICU practice standards). Neonatal patients are uniquely vulnerable to particulate matter — their small circulating volumes mean even minor particulate loads have larger relative impact.

Exception: Lipid emulsion and 3-in-1 TNA → 1.2 μm filter (same as adults). Blood products are never filtered through 0.22 μm.

Heparin-Free Protocols in the NICU

Heparin exposure in neonates carries risks not present in adults:

• Neonatal coagulation system differs from adults; heparin pharmacokinetics are unpredictable
• Cumulative heparin exposure from multiple heparin flushes is significant relative to neonatal circulating volume
• Heparin-induced thrombocytopenia (HIT), while rare, can occur in neonates

Trend: Many NICUs have moved toward heparin-free or minimized-heparin protocols for peripheral IVs and PICCs. Saline-only locking is acceptable for neonatal PICCs per INS 2021 when institutional protocols support it.

Exception: UAC infusion fluids (see above) and hemodialysis circuits use heparin.

Light Protection for Neonatal PN

Vitamins A (retinol) and tryptophan in parenteral nutrition formulations degrade with light exposure. This effect is clinically most significant in neonates because:

• Neonatal PN infusion durations are long (18–24 hours/day)
• Vitamin requirements relative to circulating volume are high
• Neonates cannot compensate for vitamin deficiency through enteral intake when NPO

Recommended: Use amber-colored PN bags and tubing, or foil-wrapped covering, for all neonatal PN containing vitamins.

Related Resources

Related guides:

• Pediatric Peripheral IV Guide
• Infusion Filtration Guide
• Parenteral Nutrition and Vascular Access
• Vascular Access Special Populations

Patient education:

• Parent Guide: NICU Vascular Access

References

1. Gorski LA, et al. (2021). INS Infusion Therapy Standards of Practice (Standards 17, 30, 42, 64). J Infus Nurs, 44(Suppl 1).
2. Wyckoff MH, et al. (2022). 2022 International Consensus on Cardiopulmonary Resuscitation (neonatal resuscitation). Circulation, 146(25):e450–e495.
3. Sharpe E, et al. (2017). Neonatal peripherally inserted central catheter practices and providers. Adv Neonatal Care, 17(3):209–221.
4. Ades A & McCurnin D. (2019). The National Association of Neonatal Nurses (NANN) neonatal skin care practice guideline. Adv Neonatal Care, 19(6):S1–S18.
5. O’Grady NP, et al. (2011). CDC Guidelines for Prevention of Intravascular Catheter-Related Infections. MMWR, 60(RR-1).