Resonance Raman Spectroscopy Derived Tissue Hemoglobin Oxygen Saturation in Critically Ill and Injured Patients

Abstract

Background: In this study, we examined the ability of resonance Raman spectroscopy to measure tissue hemoglobin oxygenation (R-StO 2 ) noninvasively in critically ill patients and compared its performance with conventional central venous hemoglobin oxygen saturation (ScvO 2 ). Methods: Critically ill patients (n ¼ 138) with an indwelling central venous or pulmonary artery catheter in place were consented and recruited. R-StO 2 measurements were obtained by placing a sensor inside the mouth on the buccal mucosa. R-StO 2 was measured continuously for 5 min. Blood samples were drawn from the distal port of the indwelling central venous catheter or proximal port of the pulmonary artery catheter at the end of the test period to measure ScvO 2 using standard co-oximetry analyzer. A regression algorithm was used to calculate the R-StO 2 based on the observed spectra. Results: Mean (SD) of pooled R-StO 2 and ScvO 2 were 64(7.6) % and 65(9.2) % respectively. A paired t test showed no significant difference between R-StO 2 and ScvO 2 with a mean(SD) difference of À1(7.5) % (95% CI: À2.2, 0.3%) with a Clarke Error Grid demonstrating 84.8% of the data residing within the accurate and acceptable grids. Area under the receiver operator curve for R-StO 2 's was 0.8(0.029) (95% CI: 0.7, 0.9 P < 0.0001) at different thresholds of ScvO 2 ( 60%, 65%, and 70%). Clinical adjudication by five clinicians to assess the utility of R-StO 2 and ScvO 2 yielded Fleiss' Kappa agreement of 0.45 (P < 0.00001). Conclusions: R-StO 2 has the potential to predict ScvO 2 with high precision and might serve as a faster, safer, and noninvasive surrogate to these measures.

Resonance Raman Spectroscopy Tissue Oxygenation Measurements in Neonates

“…Studies in adults found that changes in perfusion and oxygenation in the oral mucosa and gastrointestinal tract reflect whole-body oxygenation [18,19]. In the first arm of the study, we found that the buccal mucosa and the thenar eminence are equally suitable sites for the measurement of RRS, supporting previous studies showing good correlation of buccal/sublingual and skin RRS-StO2 with S CV O 2 in animal models [12,13] and in humans [14]. Because the thenar eminence is relatively devoid of any pigment, it is likely an optimal site for analysis.…”

“…The splanchnic saturation of RRS-StO2 and NIRS measured simultaneously in a hemorrhagic pig model shows that RRS-StO2 is an earlier predictor of tissue dysoxia compared to NIRS [13]. Recently, RRS applied in adults showed a good correlation of RRS-StO2 measured in the buccal mucosa against S CV O 2 [14]. A similar study carried out in newborns to correlate S CV O 2 with RRS-StO2 in the lower extremity did not find a correlation [15].…”

Performance of Oral Cavity Sensors: A Systematic Review

“…The study reported a Clarke Error Grid where 84.8% of the data was within the accurate and acceptable grids. The clinical utility yielded an agreement of 0.45 [ 64 ]. The other study evaluated the agreement between commercial electronic thermometers against a gold-standard arterial thermometer in estimating the body temperature of patients in critical care (see Table S4 of the Supplementary Material ).…”

What's New in Shock, July 2021?

“…We continue our theme of resuscitation as Tiba et al invite readers to consider a new perspective on tissue perfusion (5). These authors emphasize the importance of surrogate markers for tissue oxygenation in the management of the critically ill patient.…”