Cardiac output in children under the age of 5 years is dependent ...

[jwb375]

Cardiac output in children under the age of 5 years is dependent on which of the following factors?
 
  1. Heart rate
   2. Preload
   3. Contractility
   4. Afterload

Question 2

The nurse is checking peripheral perfusion to a child's extremity following a cardiac catheterization. If there is adequate peripheral circulation, the nurse would find that the extremity:
 
  1. Has a capillary refill of greater than three seconds.
   2. Has a palpable dorsalis pedis pulse but a weak posterior tibial pulse.
   3. Has decreased sensation with a weakened dorsalis pedis pulse.
   4. Is warm, with a capillary refill of less than three seconds.

[Tabitha_2016]

Answer to Question 1

1
Rationale:
1. Cardiac output in newborns and young children depends primarily on heart rate until the heart muscle is fully developed at 5 years of age.
2. The undeveloped muscle fibers in the myocardium are unable to expand their stretch to increase the ventricular volume or preload.
3. The heart muscle fibers are unable to expand until age 5.
4. The heart muscle is not fully developed until age 5, and cannot alter afterload effectively.

Answer to Question 2

4
Rationale:
1. If the capillary refill is over three seconds; if any of the pedal pulses are absent and/or weakened; or if the extremity is cool, cyanotic, or lacking sensation, circulation might not be adequate.
2. If the capillary refill is over three seconds; if any of the pedal pulses are absent and/or weakened; or if the extremity is cool, cyanotic, or lacking sensation, circulation might not be adequate.
3. If the capillary refill is over three seconds; if any of the pedal pulses are absent and/or weakened; or if the extremity is cool, cyanotic, or lacking sensation, circulation might not be adequate.
4. The nurse checks the extremity to determine adequacy of circulation following a cardiac catheterization. An extremity that is warm with capillary refill of less than three seconds has adequate circulation. Other indicators of adequate circulation include palpable pedal (dorsalis and posterior tibial) pulses, adequate sensation, and pinkness of skin color.
Assessment
Physiological Integrity
Analysis
Learning Outcome 26.2 List three differences in cardiac functioning between infants and adults.