Which factor would most likely lead to unreliable pulse oximeter readings?

Which factor would most likely lead to unreliable pulse oximeter readings?

• A. Poor perfusion
• B. Proper probe placement
• C. Warm hands
• D. Nail polish removed

Answer: (A)

Pulse oximetry relies on detecting a strong, pulsatile arterial signal to estimate oxygen saturation. When perfusion to the monitoring site is poor, the pulsatile signal becomes weak or inconsistent, making it hard for the device to distinguish arterial blood from surrounding tissue and noise. This leads to unreliable or absent readings. Proper probe placement, warm hands to improve blood flow, and removing nail polish to allow light to pass can all help improve accuracy, but the factor most likely to cause unreliable results is reduced perfusion.

Pulse oximetry relies on detecting a strong, pulsatile arterial signal to estimate oxygen saturation. When perfusion to the monitoring site is poor, the pulsatile signal becomes weak or inconsistent, making it hard for the device to distinguish arterial blood from surrounding tissue and noise. This leads to unreliable or absent readings. Proper probe placement, warm hands to improve blood flow, and removing nail polish to allow light to pass can all help improve accuracy, but the factor most likely to cause unreliable results is reduced perfusion.