Swan-Ganz Catheterization

Definition

Swan-Ganz catheterization, also known as pulmonary artery catheterization, is a diagnostic procedure in which a small catheter is threaded through a vein in the arm, thigh, chest, or neck until it passes through the right side of the heart into the pulmonary artery. The catheter is than able to measure the pressures in the right heart and pulmonary artery.

Purpose

Swan-Ganz catheterization is performed in order to:

• Evaluate heart failure.
• Determine whether pulmonary edema is caused by a weak heart (cardiogenic pulmonary edema) or leaky pulmonary capillaries (non-cardiogenic pulmonary edema or adult respiratory distress syndrome).
• Monitor therapy after a myocardial infarction (heart attack).
• Check the fluid balance of patients in shock as well as those recovering from heart surgery, serious burns, or kidney disease.
• • Monitor the effect of medications on the heart.

Precautions

Pulmonary artery catheterization is an invasive and potentially complicated procedure. The physician must decide if the value of the information obtained outweighs the risks of catheterization.

Description

Swan-Ganz catheterization is usually performed in the hospital 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 into the pulmonary artery. The procedure takes about 30 minutes. Local anesthesia is administered at the catheter insertion site to reduce discomfort.

Once the catheter is in place, the physician briefly inflates a tiny balloon at its tip. This temporarily blocks the blood flow and allows the physician to make a pressure measurement in the pulmonary artery system. This pressure reading is called the pulmonary capillary wedge pressure. Pressure measurements are usually recorded for the next 48-72 hours in different parts of the heart. During this time, the patient must remain in bed so the catheter remains in position. 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 records the electrical stimuli that cause the heart to contract. The insertion site is sterilized and prepared prior to the test. The catheter is often sutured to the skin to prevent dislodgment.

Aftercare

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

Complications

Swan-Ganz catheterization is not without risk. Possible complications from the procedure include:

• lung collapse (pneumothorax)
• infection at the site of catheter insertion
• pulmonary artery perforation
• blood clots in the lungs
• irregular heartbeat

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 capillary wedge pressure: 6-12 mm Hg.
• Cardiac output: 3-7 L/min.

Abnormally high right atrium pressure can indicate:

• pulmonary disease
• right-sided heart failure
• fluid accumulation
• cardiac tamponade (compression of the heart by a pericardial effusion)
• 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 heart wall between the right and left ventricle
• congestive heart failure
• serious heart inflammation

Abnormally high pulmonary artery pressure may indicate:

• 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 ventricular failure

Abnormally high pulmonary capillary wedge pressure may indicate:

• left ventricular failure
• mitral valve abnormalities
• compression of the heart after hemorrhage

Health care team roles

Swan-Ganz catheterization is generally performed in the hospital intensive care or critical care unit by trained physicians. Physicians from a variety of specialties are trained to perform the procedure, including cardiologists, surgeons, anesthesiologists, and critical care specialists. Patients in the intensive care unit are monitored and cared for by critical care nurses, laboratory and radiology technicians as well as other physician specialists such as internists, pulmonologists, and cardiothoracic surgeons.

Patient education

Specially trained nurses assist during catheterization procedures and provide pre-and postoperative education, monitoring, and supportive care.

KEY TERMS

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

BOOKS

Thelan, Lynne A. et al. Critical Care Nursing Diagnosis and Management. St. Louis, MO: Mosby, 1998, pp. 386.

Zaret, Barry, ed. "Pulmonary Artery Catheterization." In The Patient's Guide to Medical Tests. New York: Houghton Mifflin, 1997.

Barbara Wexler