Chapter 85 Cardiac Catheterization
Cardiac catheterization is an invasive procedure used to measure the intracardiac pressure of the heart chambers and the great vessels, as well as oxygen saturation. In addition, angiography is performed when contrast or dye is injected to outline the anatomic details of any cardiac malformation. A radiopaque catheter is inserted percutaneously through a large-bore needle into a large artery, such as the femoral artery. Measurements of chamber pressures, oxygen saturation, cardiac output, and shunt flow, as well as pulmonary vascular resistance, are obtained and recorded (Box 85-1). In children, cardiac catheterization is used primarily to accurately diagnose complex cardiac defects.
Box 85-1 Normal Heart Chamber and Great Vessel Pressures and Oxygen Saturations
Heart Chamber and Great Vessel Pressures
The pressures in the systemic circuit, or on the left side of the heart, are normally higher than those in the pulmonary circuit, or on the right side of the heart.
• Superior vena cava mean pressure: 3 to 5 mm Hg
• Right atrium mean pressure: 3 to 5 mm Hg
• Right ventricle systolic/diastolic pressure: 25/3 mm Hg
• Pulmonary artery systolic/diastolic pressure: 25/10 mm Hg
• Left atrium mean pressure: 8 mm Hg
Oxygen Saturation Levels
It is normal for oxygen in the blood to be extracted by the tissues so that blood returns to the right side of the heart with an oxygen level about 30% lower than the level when it entered the left atrium from the lungs. Blood entering the left atrium is less than 97% to 100% saturated because there is mixing with blood passing through pulmonary arteriovenous and other small shunts.
Cardiac catheterization is also performed in an interventional manner, using balloon catheters or coiled stents for such purposes as dilating stenotic valves or vessels, and using coils or umbrella catheters for closing septal defects. Interventional cardiac catheterization can delay or negate the need for surgery. Cardiac catheterization is also performed for electrophysiologic studies to diagnose arrhythmias and treat those that are refractory to medication.
NURSING ASSESSMENT
1. Assess cardiopulmonary status.
2. Assess whether nothing-by-mouth orders were carried out.
3. Assess child’s and parents’ knowledge of procedure and level of anxiety.
NURSING INTERVENTIONS
Preprocedural Care
1. Prepare child and parents for procedure and describe cardiac catheterization room.
2. Administer sedative and monitor child’s response according to institutional guidelines. Allow parents to remain with child until asleep.
3. Mark pulses distal to insertion site.
Postprocedural Care
3. Maintain bed rest for 6 to 12 hours after catheterization if arterial catheterization was performed, and for 4 to 6 hours if venous catheterization was performed (or per order of physician).
4. Begin administration of clear liquids and advance diet as tolerated.
5. Assess for other complications or adverse effects such as pain, hemorrhage, cold stress (infants), arrrhythmias, dye reactions, or nausea and vomiting.
6. Provide opportunities for distraction, relaxation, and play.
Lock JE. Diagnostic and interventional catheterization in congenital heart disease. Boston: Martinus Nijhoff, 1987.
Tremko LA. Understanding diagnostic cardiac catheterization. Am J Nurs. 1997;97(2):16K.
Uzark K. Therapeutic cardiac catheterization for congenital heart disease—A new era in pediatric care. J Pediatr Nurs. 2001;16(5):300.
