What issue can disrupt light transmission and affect pulse oximetry readings?

The presence of artificial nails can significantly disrupt light transmission, which is crucial for accurate pulse oximetry readings. Pulse oximeters work by passing light through a translucent part of the body, usually a fingertip, and measuring the amount of light absorbed by oxygenated and deoxygenated hemoglobin. If a patient has artificial nails, especially those that are darkly colored or opaque, they can obstruct or alter the light transmission needed for the device to perform its measurements effectively. This can lead to unreliable or erroneous readings, which can impact clinical decisions regarding the patient's oxygen saturation.

In contrast, while cold skin temperature can lead to peripheral vasoconstriction and potentially affect readings, it doesn't fundamentally disrupt the light transmission as artificial nails do. Unsupported patient position can also interfere with vascular circulation but primarily impacts the consistency of the readings rather than the optical properties. Room lighting conditions can occasionally cause interference, but pulse oximeters are designed to filter out ambient light to some extent, making artificial nails the more direct cause of transmission disruption.