Pulmonary Artery Catheterization

Definition

Pulmonary artery catheterization is a diagnostic procedure in which a small catheter is inserted through a neck, arm, chest, or thigh vein and maneuvered into the right side of the heart, in order to measure pressures at different spots in the heart.

Purpose

Pulmonary artery catheterization is performed to:

• evaluate heart failure
• monitor therapy after a heart attack
• check the fluid balance of a patient with serious burns, kidney disease, or after heart surgery
• check the effect of medications on the heart

Precautions

Pulmonary artery catheterization is a potentially complicated and invasive procedure. The doctor must decide if the value of the information obtained will out-weigh the risk of catheterization.

Description

Pulmonary artery catheterization, sometimes called Swan-Ganz catheterization, is usually performed at the bedside of a patient in the intensive care unit. A catheter is threaded through a vein in the arm, thigh, chest, or neck until it passes through the right side of the heart. This procedure takes about 30 minutes. Local anesthesia is given to reduce discomfort.

Once the catheter is in place, the doctor briefly inflates a tiny balloon at its end. This temporarily blocks the blood flow and allows the doctor to make a pressure measurement in the pulmonary artery system. Pressure measurements are usually recorded for the next 48-72 hours in different parts of the heart. During this time, the patient must stay in bed so the catheter stays in place. Once the pressure measurements are no longer needed, the catheter is removed.

Preparation

Before and during the test, the patient will be connected to an electrocardiograph, which makes a recording of the electrical stimuli that cause the heart to contract. The insertion site is sterilized and prepared. The catheter is often sutured to the skin to prevent dislodgment.

Aftercare

The patient is observed for any sign of infection or complications from the procedure.

Risks

Pulmonary artery catheterization is not without risks. Possible complications from the procedure include:

• infection at the site where the catheter was inserted
• pulmonary artery perforation
• blood clots in the lungs
• irregular heartbeat

Normal results

Normal pressures reflect a normally functioning heart with no fluid accumulation. These normal pressure readings are:

• right atrium: 1-6 mm of mercury (mm Hg)
• right ventricle during contraction (systolic): 20–30 mm Hg
• right ventricle at the end of relaxation (end diastolic): less than 5 mm Hg
• pulmonary artery during contraction (systolic): 20–30 mm Hg
• pulmonary artery during relaxation (diastolic): about 10 mm Hg
• mean pulmonary artery: less than 20 mm Hg
• pulmonary artery wedge pressure: 6–12 mm Hg
• left atrium: about 10 mm Hg

Abnormal results

Abnormally high right atrium pressure can indicate:

• pulmonary disease
• right side heart failure
• fluid accumulation
• compression of the heart after hemorrhage (cardiac tamponade)
• right heart valve abnormalities
• pulmonary hypertension (high blood pressure)

Abnormally high right ventricle pressure may indicate:

• pulmonary hypertension (high blood pressure)
• pulmonary valve abnormalities
• right ventricle failure
• defects in the wall between the right and left ventricle
• congestive heart failure
• serious heart inflammation

Abnormally high pulmonary artery pressure may indicate:

• diversion of blood from a left-to-right cardiac shunt
• pulmonary artery hypertension
• chronic obstructive pulmonary disease or emphysema
• blood clots in the lungs
• fluid accumulation in the lungs
• left ventricle failure

Abnormally high pulmonary artery wedge pressure may indicate:

• left ventricle failure
• mitral valve abnormalities
• cardiac insufficiency
• compression of the heart after hemorrhage

BOOKS

"Pulmonary Artery Catheterization." In The Patient's Guide to Medical Tests, ed. Barry L. Zaret, et al. Boston: Houghton Mifflin, 1997.

Tish Davidson

KEY TERMS

Cardiac shunt—A defect in the wall of the heart that allows blood from different chambers to mix.