Final answer:
Adequate oxygen saturation (SpO2) for a child breathing room air is 95-100 percent, as measured by a pulse oximeter. Readings below this range may indicate hypoxemia, and if significantly low, could signify hypoxia, signaling the need for further medical evaluation.
Step-by-step explanation:
Oxygen saturation indicates the level of oxygen carried by hemoglobin in the blood. A normal SpO2 indicating adequate oxygenation for a child breathing room air typically ranges from 95-100 percent. Pulse oximetry is the non-invasive method used to measure percent saturation, where a device known as a pulse oximeter is placed on a thin part of the body, like the fingertip, to monitor this value. Lower percentages may indicate hypoxemia, which is a state of low blood oxygen, while severe drops can be a sign of hypoxia, a more general term for low oxygen levels across tissues. It should be noted that in cases where the pulse oximetry reading is below the expected range, clinical evaluation and further assessment of oxygenation through arterial blood gas analysis might be warranted, especially to measure the partial pressure of oxygen (PO2).