Monitoring Oxygen Saturation
Pulse oximetry, using a pulse oximeter, is used to measure the percentage of oxygen saturation in the blood and appears as a percentage of hemoglobin saturated with oxygen (Figure). Pulse oximetry readings are recorded using the percentage and then SpO2 (e.g., 95 to 99 percent SpO2). Pulse oximetry should be used as an added tool for victim care, as it is possible for victims to show a normal reading but have difficulty breathing or to have a low reading but appear to be breathing normally. When treating the victim, all symptoms should be assessed, along with the data provided by the device.
The pulse oximeter reading never should be used to withhold oxygen from a victim who appears to be in respiratory distress or when it is the standard of care to apply oxygen despite good pulse oximetry readings, such as in a victim with chest pain.