What factor can significantly affect the accuracy of pulse oximetry readings?

Pulse oximetry is a non-invasive method used to measure the oxygen saturation level of hemoglobin in the blood. The accuracy of pulse oximetry readings can be significantly affected by various physiological factors.

Cardiac arrest can lead to severe alterations in blood flow and perfusion, impacting the ability of the pulse oximeter to detect and analyze oxygen saturation effectively. During cardiac arrest, the cessation of effective cardiac output results in inadequate blood circulation, affecting peripheral perfusion. This can yield erroneous pulse oximeter readings, leading to false lows or inaccurate saturation levels.

In contrast, while peripheral vascular disease, respiratory infections, and anemia can also impact pulse oximetry to some extent, the dramatic and acute changes associated with cardiac arrest present a more immediate and severe challenge to the accuracy of pulse oximetric assessments. Thus, the acute state of cardiac arrest is particularly critical in evaluating the reliability of oxygen saturation readings.