Cardiac Output by N. Braudis | OPENPediatrics

Learn about normal cardiac output in pediatric patients and obtaining accurate cardiac output readings in this lecture.
0:41 Chapter 1: Blood Flow During the Cardiac Cycle
1:49 Chapter 2: Cardiac Metabolism
2:28 Chapter 3: Cardiac Output
4:19 Chapter 4: Cardiac Saturations

Initial publication: January 5, 2015.
Last reviewed: July 11, 2019.


OPENPediatrics™ is an interactive digital learning platform for healthcare clinicians sponsored by Boston Children's Hospital and in collaboration with the World Federation of Pediatric Intensive and Critical Care Societies. It is designed to promote the exchange of knowledge between healthcare providers around the world caring for critically ill children in all resource settings. The content includes internationally recognized experts teaching the full range of topics on the care of critically ill children. All content is peer-reviewed and open access-and thus at no expense to the user.

Please note: OPENPediatrics does not support nor control any related videos in the sidebar, these are placed by Youtube. We apologize for any inconvenience this may cause.

My name is Nancy Braudis and I am a clinical nurse specialist in the Cardiac ICU at Children’s Hospital Boston. The topic today is cardiac output. These slides represent our practice here at Children’s Hospital Boston, and you may have to modify for your own individual institutions.

Blood Flow During the Cardiac Cycle.

Blood flow during the cardiac cycle. The pumping action of the heart consists of the contraction and relaxation of the heart muscle. Each contraction and relaxation is one cardiac heart cycle. During the contraction of the heart, called systole, the blood is pumped out of the ventricles and into the circulation. At this time, the mitral and tricuspid valves are closed and the aortic and pulmonic valves are open. The closing of the mitral and tricuspid valves creates the first heart sound, also known as S1. During relaxation of the heart, called diastole, blood fills the ventricles. At this time the mitral and tricuspid valves are open and the aortic and pulmonic valves are closed. The closing of the aortic and pulmonic valves creates the second heart sound, also known as S2.

Cardiac Metabolis.

Cardiac metabolism. The oxygen supply of the heart is delivered by the coronary arteries. 70 to 75% of the oxygen from the coronary arteries is used immediately by the heart muscles, leaving little oxygen reserves. Increased energy needs of the heart can only be met by increasing coronary blood flow. Oxygen consumption by the heart increases during exercise and fever. In the immediate postoperative period, fever can have a negative impact on the function of the heart.

Cardiac Output.

Calculating cardiac output. Cardiac output is the volume of blood ejected from the heart in one minute, expressed as liters per minute. Normal cardiac output in children is 200 mls/kilogram. Cardiac index most often used in children is obtained by dividing the cardiac output by the body’s surface area. A normal cardiac index is 3.5 to 4.5 liters per minute per meter squared. Children have a much higher cardiac output than adults.