Anatomy and Physiology Flashcard 4
Rationale
C. Rationale: The left upper and lower extremities are mixed with poorly oxygenated blood due to the right-to-left shunting of the fetal circulation that is still apparent in the newly born because the ductus arteriosus is still open. Therefore, experts recommend that the team measure oxygen saturation in the preductal circulation (before the ductus arteriosus) on the right upper and lower extremities.
Question
Why is measuring oxygen saturation in the left upper or lower extremities a poor representation of the arterial oxygen status of the newly born?
a. Blood flow increases in these areas
b. Pulses are weak in these areas
c. The blood flowing in these regions is mixed with poorly oxygenated blood
d. All of the above
Answer
c. The blood flowing in these regions is mixed with poorly oxygenated blood