The therapist is setting pulse oximetry to determine the presence of right-to-left shunt in an infant suspected of having a heart defect.Where should the therapist place the pulse ox probe to obtain the most accurate measure of preductal oxygen saturation?

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Quizplus · Accepted Answer

Pulse oximetry is a fundamental monitoring device in children with congenital heart disease.In addition to measuring systemic oxygenation,it can also be used to measure the degree of right-to-left shunting in lesions where this is a possibility.This is done by measuring preductal and postductal saturations.Preductal saturations are measured by placing the pulse oximeter on the right upper extremity.Postductal saturations are reflected by placing the pulse oximeter on any other extremity,though the lower extremities are preferred as preductal and postductal blood may be incompletely mixed at the left upper extremity.If postductal saturations are 5% to 10% lower than preductal saturations,then right-to-left shunting should be suspected.

The Therapist Is Setting Pulse Oximetry to Determine the Presence