Oxygen saturation (SO2), colloquially referred to as sats, is a measure of the percentage of hemoglobin binding sites occupied by oxygen in the blood stream.

  • Peripheral oxygen saturation (SpO2) is commonly measured with a pulse oximeter and gives an estimate of the oxygen saturation of the blood.
  • Tissue oxygen saturation (StO2) is measured by near infrared spectroscopy.
  • Venous oxygen saturation (SvO2) can be measured to calculate how much body the oxygen is consuming.