What action should a nurse take to ensure accuracy of a pulse oximeter reading in a postanesthesia care unit?

Placing the probe on a finger or earlobe is the most effective action to ensure an accurate pulse oximeter reading, particularly in the postanesthesia care unit setting. These areas have good blood flow and are commonly used sites for monitoring oxygen saturation because they allow for reliable readings.

Fingers, especially the index finger, are often recommended for adult patients due to their accessibility and the presence of a rich vascular supply. Similarly, earlobes can also yield accurate results while being less prone to interference from factors such as nail polish or cold extremities.

In contrast, the accuracy of readings can be impacted when the probe is attached to the toe, as peripheral circulation might not be as strong, leading to potential inaccuracies. Using a wristwatch to compare readings does not provide any clinically relevant data for verifying the accuracy of a pulse oximeter, and placing the probe on the forehead is not a standard practice, as the forehead may not reliably reflect peripheral oxygenation levels like the finger or earlobe would.