Umbilical Venous Catheterization (UVC) and Umbilical Arterial Catheterization (UAC)

Catheter Type	Position	Calculation Formula
UVC (Umbilical Venous Catheter)	High-Lying	UVC Depth (cm) = (3 × BW (kg) + 9) / 2 + 1
	Low-Lying	UVC Depth (cm) = (3 × BW (kg) + 7) / 2 + 1
UAC (Umbilical Arterial Catheter)	High-Lying	UAC Depth (cm) = 3 × BW (kg) + 9 + 1
	Low-Lying	UAC Depth (cm) = 3 × BW (kg) + 5 + 1

Umbilical Venous Catheterization (UVC)

Indications for UVC Insertion

• Venous Access

  • Administration of intravenous fluids, total parenteral nutrition (TPN), or medications in neonates.

  • The preferred route for hypertonic solutions (e.g., TPN, dextrose >12.5%).

• Resuscitation

  • Provides urgent vascular access for medications like adrenaline or volume expansion during neonatal resuscitation.

• Exchange Transfusion

  • Route during procedures for exchange transfusion in neonates with severe hyperbilirubinemia or polycythemia.
    

Contraindications for UVC Insertion

• Omphalitis

• Abdominal wall defects (e.g., Gastroschisis, Omphalocele)

• Necrotizing enterocolitis (NEC)
  

Placement of UVC

• Tip Position: The tip of the UVC should ideally be positioned correctly within the venous system, with reference points visible on a chest X-ray (AP view).

• Low-Lying UVC: The catheter tip is located below the diaphragm but not beyond the liver. On a chest X-ray, this would typically be below the level of the 10th thoracic vertebra (T10).

• High-Lying UVC: The catheter tip is around the diaphragm, ideally positioned at the level of the 8th-9th thoracic vertebrae (T8-T9), but not extending into the inferior vena cava (IVC) or right atrium (RA).
  

Depth Calculation for UVC Insertion

The depth for inserting a UVC can be calculated using the following formula:

UVC Depth (cm)=[( 3× BW(kg) +9​)/2] +1

Where:

• BW = Birth Weight in kilograms

• 1 = Stump depth
  

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Umbilical Arterial Catheterization (UAC)

Placement of UAC

High Position:

• Tip Position: The tip of the UAC should be located at the level of the diaphragm, typically between the T6 and T9 vertebrae.

• Rationale: This positioning ensures the catheter tip is in the descending aorta above the major branches such as the celiac trunk, superior mesenteric artery (SMA), and renal arteries, reducing the risk of vascular complications.

Low Position:

• Tip Position: The tip of the UAC should be located between L3 and L5 vertebrae.

• Rationale: This positioning ensures the catheter is below the major abdominal branches but above the aortic bifurcation, avoiding interference with the renal arteries.

Avoiding Major Branches:

• Celiac Trunk: Typically arises at the level of T12.

• Superior Mesenteric Artery (SMA): Typically arises at the level of L1.

• Inferior Mesenteric Artery (IMA): Typically arises at the level of L3.
  

Specific Vertebral Landmarks

• Celiac Trunk:

  • Level: T12

  • Details: Supplies blood to the stomach, liver, spleen, and pancreas. UAC tip should be well above this level if in the high position.

• Superior Mesenteric Artery (SMA):

  • Level: L1

  • Details: Supplies blood to the small intestine and part of the colon. UAC tip should be above this level in the high position and below in the low position.

• Inferior Mesenteric Artery (IMA):

  • Level: L3

  • Details: Supplies blood to the lower part of the colon. UAC tip in the low position should be above this level.
    

Depth Calculation for UAC Insertion

The depth for inserting a UAC can be calculated using the following formula:

UAC Depth (cm)=[( 3× BW(kg) +9​)] +1

Where:

• BW = Birth Weight in kilograms

• 1 = Stump depth
  

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Additional Notes

• The placement and depth of both UVC and UAC should always be confirmed with an X-ray to ensure proper positioning and to avoid complications.

• Continuous monitoring and follow-up are essential to ensure the catheters remain in the correct positions and function effectively without causing harm.