For the purpose of assessing right-to-left shunting, as in the case of persistent pulmonary hypertension, which of the following sites would render postductal blood?
I. Right arm
II. Left arm
III. Right leg
IV. Left leg

Question

Quizplus · Accepted Answer

In addition, placing pulse oximeters on preductal and postductal sites allows for assessing right-to-left ductal level shunting, as seen with persistent pulmonary hypertension of the newborn. In this case the right arm, or preductal site, will have a higher saturation, while the postductal site, or left arm and lower extremities, will have a lower saturation due to venous admixture occurring postductally.

For the Purpose of Assessing Right-To-Left Shunting, as in the Case