Pulse oximetry measures:

Pulse oximetry measures:

• A. Arterial blood pressure
• B. Arterial oxyhemoglobin saturation
• C. Venous oxygen saturation
• D. Cardiac output

Answer: (B)

Pulse oximetry estimates the arterial oxyhemoglobin saturation (SpO2) noninvasively by shining light through a perfused tissue and measuring how much is absorbed at two wavelengths. The device uses the pulsatile nature of arterial blood to separate arterial signals from venous and tissue signals, then compares the absorption of red and infrared light to distinguish oxyhemoglobin from deoxyhemoglobin. The resulting percentage represents how much of the arterial hemoglobin is bound to oxygen. It does not measure arterial blood pressure, venous oxygen saturation, or cardiac output. Readings can be affected by factors like poor peripheral perfusion, movement, cold extremities, nail polish or artificial nails, ambient light, and certain conditions such as carbon monoxide poisoning or methemoglobinemia.

Pulse oximetry estimates the arterial oxyhemoglobin saturation (SpO2) noninvasively by shining light through a perfused tissue and measuring how much is absorbed at two wavelengths. The device uses the pulsatile nature of arterial blood to separate arterial signals from venous and tissue signals, then compares the absorption of red and infrared light to distinguish oxyhemoglobin from deoxyhemoglobin. The resulting percentage represents how much of the arterial hemoglobin is bound to oxygen. It does not measure arterial blood pressure, venous oxygen saturation, or cardiac output. Readings can be affected by factors like poor peripheral perfusion, movement, cold extremities, nail polish or artificial nails, ambient light, and certain conditions such as carbon monoxide poisoning or methemoglobinemia.