Pulse oximetry

Abstract

Pulse oximetry is universally used for monitoring patients in the critical care setting. This article updates the review on pulse oximetry that was published in 1999 in Critical Care. A summary of the recently developed multiwavelength pulse oximeters and their ability in detecting dyshemoglobins is provided. The impact of the latest signal processing techniques and reflectance technology on improving the performance of pulse oximeters during motion artifact and low perfusion conditions is critically examined. Finally, data regarding the effect of pulse oximetry on patient outcome are discussed.

Pulse rate variability compared with heart rate variability in children with and without sleep disordered breathing

“…Pulse-to-pulse variability, called pulse rate variability (PRV), can be calculated from peak to peak time intervals of the PPG signal. The AC component of the PPG signal is overlaid on a large DC component which varies slowly due to respiration [2].…”

Acute Favism: Methemoglobinemia May Cause Cyanosis and Low Pulse Oximetry Readings

“…Third, transcutaneous pulse oximeters are unreliable when a variant Hb is present [6,7]. The oximeters measure absorbance of red and infrared light corresponding to reduced Hb and oxy-Hb and convert the ratio to a saturation using an algorithm derived from healthy persons [7].…”

“…The oximeters measure absorbance of red and infrared light corresponding to reduced Hb and oxy-Hb and convert the ratio to a saturation using an algorithm derived from healthy persons [7]. The results are valid only when all Hb is normal.…”

On being human: reflections on a daily error

“…Apart from comorbidity, RR is the strongest predictor of death in acutely hospitalised patients over 75 years 8. There is no surrogate for RR, not even pulse oximetry,9 which lacks specificity 10…”