How to Measure the Pressure of the Portal Vein

Measuring pressure in the portal vein is a useful tool in assessing liver function. When the liver is damaged, the pressure in the portal vein and the hepatic vein will result in increased resistance, causing blood to be shunted to smaller, collateral vessels. The liver will enlarge due to congestion of the blood in both the hepatic and portal veins. Pressure exceeding greater than 22 mm Hg in the portal vein or a pressure difference between the portal vein and the hepatic vein of greater than 12 mm Hg will result in portal hypertension. Measuring portal pressure involves inserting a catheter into the portal vein. The procedure is extremely short and involves the administration of a local anesthetic.

Instructions

Measure Portal Vein Pressure

• 1

  Give anesthetic for this catheterization procedure. Local anesthetic is given to the patient in order to successfully numb the site where the catheter is inserted for the procedure.

• 2

  Lay the patient flat on his back. Stabilize the patient and insert a catheter through one of the following: the internal jugular, femoral, or medial antecubital vein. These vessels are the best way to access the hepatic and portal veins.

• 3

  Insert the catheter through the hepatic vein, closing it off with a balloon at the end of the catheter. The vein becomes blocked and stops blood flow from the hepatic vein to the portal vein.

• 4

  Calculate the hepatic wedge pressure in the portal vein. Patients with cirrhosis or portal hypertension have a similar wedge pressure created by the occluded balloon catheter in the hepatic vein. This allows physicians to indirectly estimate the pressure in the portal vein.

• 5

  Once portal vein pressure has been calculated, gently remove the catheter from the patient. Apply pressure at the site of insertion to prevent any bleeding. Monitor patient vitals signs after procedure is completed.