Why might overnight pulse oximetry be performed?

Overnight pulse oximetry is performed primarily to estimate oxygen saturation levels in the blood. This non-invasive procedure utilizes a small device typically placed on a fingertip or earlobe to measure the oxygen saturation (SpO2) of arterial blood over time. It provides critical data that can indicate whether a person is experiencing any episodes of hypoxemia (low blood oxygen levels) during sleep, which is particularly important for diagnosing sleep disorders such as obstructive sleep apnea.

In contrast, measuring blood pressure levels requires different equipment and techniques, making it irrelevant to pulse oximetry. Assessing heart rate variability generally involves an ECG or specialized heart rate monitors, rather than pulse oximeters. Monitoring brainwaves involves an EEG, which is also distinct from the functions of a pulse oximeter, as it focuses on electrical activity in the brain rather than blood parameters. Thus, pulse oximetry is specifically aligned with estimating oxygen saturation, which is critical in evaluating respiratory function during sleep.