What Is Pulse Oximetry (Pulse Ox)?

Most people have worn a pulse ox monitoring system in their doctor's office without even knowing it. Pulse oximetry measures the oxygen level in the blood without the need for a blood sample. A special clip is affixed to a finger or toe of the person to be monitored, and his oxygenation level is recorded by a medical care provider within minutes.
  1. Time Frame

    • Pulse ox came into widespread use in the 1980s. Previously, blood gas levels were monitored by performing blood draws.

    Technology

    • A pulse oximeter uses light waves to determine the blood oxygen levels in hemoglobin. According to Oximetry.org, blood that is oxygenated absorbs high levels of infrared light. Blood that contains less oxygen does not absorb as much of the infrared light. The light absorption is translated to numeric values.

    Accuracy

    • A number of factors play into the accuracy of a pulse oximeter. Oximeter.org reports that motion (of the patient) can compromise accuracy. Amal Jubran reports in the May 18, 1999 issue of "Critical Care" that the oxygen saturation levels of some people who have sickle cell anemia and other forms of anemia may not be accurate. The pulse oximeter cannot always distinguish the substances in the blood in these cases.

    Use

    • Pulse ox is used to monitor a person's blood oxygen levels on a more constant basis than through taking periodic blood draws. "Critical Care" expresses the usefulness in part, due to the ease of implementing the pulse ox monitoring system.

    Cost-Effectiveness

    • Pulse oximetry is more cost effective for medical care providers, according to Amal Jubran's findings in "Critical Care." Monitoring a person's blood gas levels through the non-invasive means of a pulse ox costs less than drawing blood and testing it.

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