Pulse Oximeter

4.23 Pulse Oximeter

Pulse oximeters are used for the detection of hypoxemia in arterial oxyhemoglobin. Peripheral oxygen is obtained by placing a sensor probe on the peripheral capillary bed.

  1. Attach the appropriate sensor to the patient's finger or toe. Remove any nail polish.
  2. Turn on the pulse oximeter unit.
  3. Evaluate the results:
    • Normal range: oxygen saturation of 92-100%
    • Mild distress: oxygen saturation of 90-92%
    • Moderate distress: oxygen saturation of 80-89%
    • Severe distress: oxygen saturation of less than 80%
  4. Oxygenate the patient with the appropriate delivery device based on the reading and the patient's condition.
  5. Evaluate the patient for possibly false high readings:
    • Carbon monoxide poisoning: Elevated carboxyhemoglobin can falsely elevate saturation readings because carboxyhemoglobin modulates light similar to oxyhemoglobin as it passes through the tissue.
    • Trauma: Despite a normal saturation level, severe hemorrhage can cause the patient to not have enough blood to perfuse the organs, so that the patient is hypoxic.
  6. Evaluate the patient for possibly false low readings:
    • Deeply pigmented patients: may diminish light transmission.
    • Nail polish or fake nails: may diminish light transmission.
    • Patient movement: may cause the pulse oximeter to not register.
    • Low blood flow states: may cause the pulse oximeter to not register.
  7. Continuously monitor and document readings.