COPE Health Scholars Practice Test

What should the red light of the pulse ox indicate?

1. It should face the palm

2. It should be under the fingernail

3. It should be on the top of the fingernail

4. It should be blinking fast

The correct answer is: It should be on the top of the fingernail

The correct indication regarding the placement of the red light of a pulse oximeter is that it should be on the top of the fingernail. This positioning is crucial because the sensor relies on the effective transmission of light through the finger to measure the levels of oxygen saturation in the blood. When the red light is placed properly on the top of the fingernail, it allows the pulse oximeter to detect the light absorption characteristics of oxygenated versus deoxygenated blood, thus providing an accurate reading. Proper alignment of the pulse oximeter's light source ensures that the light can penetrate through the finger properly. If the device were positioned differently, such as facing the palm or placed under the fingernail, it could obstruct or misdirect the light, leading to inaccurate readings. The rate at which the light blinks is not typically used to assess the positioning of the pulse oximeter; rather, a steady response is expected for accurate pulse and oxygen saturation measurements.