NHA Certified Clinical Medical Assistant (CCMA)Clinical Patient CareMedium
A medical assistant is performing a pulse oximetry reading on a patient. Which of the following factors can lead to an inaccurate reading?
- ABright ambient light
- BWarm fingers
- CNormal hemoglobin levels
- DRecent exercise
Show answer & explanationAnswer & explanation
Correct answer: A. Bright ambient light
Bright ambient light, such as from examination lights or sunlight, can interfere with the light sensors of a pulse oximeter, leading to inaccurate readings. The device relies on light absorption to measure oxygen saturation, and external light can disrupt this process.
Why the other options are wrong
- B. Warm fingers generally improve blood flow and can lead to more accurate readings, not inaccurate ones.
- C. Normal hemoglobin levels are necessary for accurate oxygen transport and do not cause inaccurate pulse oximetry readings.
- D. Recent exercise may temporarily increase heart rate and oxygen consumption, but it does not directly cause an inaccurate pulse oximetry reading in terms of sensor function unless there's excessive motion artifact.
Pulse Oximetry Accuracy Factors
Several factors can interfere with the accuracy of pulse oximetry readings, including bright ambient light, nail polish, poor peripheral circulation, and patient motion.
- Bright light causes interference.
- Nail polish can block light.
- Poor circulation affects signal.
- Motion leads to artifacts.
Memory trick: Oxy's Light Fight: Nail Polish, Cold Fingers, Bright Light, & Motion's Blight.