Detection of hypoxia by near-infrared spectroscopy and pulse oximetry: a comparative study

Significance: Pulse oximetry is widely used in clinical practice to monitor changes in arterial oxygen saturation (SpO(2)). However, decreases in SpO(2) can be delayed relative to the actual clinical event, and near-infrared spectroscopy (NIRS) may detect alterations in oxygenation earlier than pulse oximetry, as shown in previous cerebral oxygenation monitoring studies. Aim: We aim to compare the response of transcutaneous muscle NIRS measures of the tissue saturation index with pulse oximetry SpO(2) during hypoxia. Approach: Episodes of acute hypoxia were induced in nine anesthetized Yucatan miniature pigs. A standard pulse oximeter was attached to the ear of the animal, and a transcutaneous NIRS sensor was placed on the hind limb muscle. Hypoxia was induced by detaching the ventilator from the animal and reattaching it once the pulse oximeter reported 70% SpO(2). Results: Twenty-four episodes of acute hypoxia were analyzed. Upon the start of hypoxia, the transcutaneous NIRS measures changed in 5.3 +/- 0.4 s, whereas the pulse oximetry measures changed in 14.9 +/- 1.0 s (p < 0.0001). Conclusions: Transcutaneous muscle NIRS can detect the effects of hypoxia significantly sooner than pulse oximetry in the Yucatan miniature pig. A transcutaneous NIRS sensor may be used as an earlier detector of oxygen saturation changes in the clinical setting than the standard pulse oximeter. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License.

Automated summary

In this study, researchers compared the response of transcutaneous muscle NIRS measures with pulse oximetry SpO(2) during hypoxia in Yucatan miniature pigs. They found that transcutaneous muscle NIRS detected the effects of hypoxia significantly sooner than pulse oximetry. This suggests that a transcutaneous NIRS sensor may be a useful tool in clinical settings for detecting changes in oxygen saturation earlier than the standard pulse oximeter.