Which sequence is correct for obtaining SpO2 with a pulse oximeter?

• A. Select the site for obtaining the measurement 2. Apply the sensor probe on the chosen site 3. Confirm the pulse rate displayed on the oximeter by palpating the radial pulse 4. Wait 15 seconds and observe the SaO2 percentage displayed on the pulse oximeter
• B. Apply the sensor probe on the chosen site 2. Select the site for obtaining the measurement 3. Confirm the pulse rate displayed on the oximeter by palpating the radial pulse 4. Wait 15 seconds and observe the SaO2 percentage displayed on the pulse oximeter
• C. Select the site for obtaining the measurement 2. Wait 15 seconds and observe the SaO2 percentage displayed on the pulse oximeter 3. Apply the sensor probe on the chosen site 4. Confirm the pulse rate displayed on the oximeter by palpating the radial pulse
• D. Wait 15 seconds and observe the SaO2 percentage displayed on the pulse oximeter 2. Select the site for obtaining the measurement 3. Apply the sensor probe on the chosen site 4. Confirm the pulse rate displayed on the oximeter by palpating the radial pulse

Answer: (A)

Obtaining a reliable SpO2 reading starts with ensuring a good signal path and a stable reading. First, select an appropriate site that has good perfusion, such as a fingertip or earlobe, so the sensor can get a clear signal. Then place the sensor on that site firmly but comfortably to ensure proper contact. After applying, confirm that the device is actually detecting a pulse by palpating the corresponding artery and compare the palpated pulse with the pulse rate shown on the oximeter. If the pulse rate on the display doesn’t match or the signal is weak, reposition or try another site before reading. Finally, wait about 15 seconds for the reading to stabilize and observe the SaO2 value on the display. This order helps prevent artifacts from placement, perfusion, or motion and yields a trustworthy SpO2 reading.