Summary Response:
Since myoglobin absorbs light similarly to hemoglobin, the InSpectraTM StO2System cannot distinguish them. Research suggests that myoglobin does not significantly influence the correlation of StO2 to microvascular hemoglobin oxygen saturation.1 For example, Mancini’s research showed that myoglobin does not release its oxygen until hemoglobin is significantly deoxygenated.2 Whatever its effect, myoglobin measurement did not prevent StO2 from being prospectively proven as a clinically reliable indicator of hypoperfusion in trauma patients.3
Background:
Animal research suggests that myoglobin does not significantly influence the correlation of StO2 to micro vascular hemoglobin oxygen saturation.2 Clinical research has shown that myoglobin does not release its oxygen until hemoglobin is significantly deoxygenated.3 Studies from other investigators suggest that myoglobin effects on StO2 cannot be discounted.4
References:
1Myers DE, Anderson LD, Seifert RP, Ortner JP, Cooper CE, Beilman GJ, Mowlem JD. Noninvasive method for measuring local hemoglobin oxygen saturation in tissue using wide gap second derivative near-infrared spectroscopy. J Biomed Optics. 2005;10:1-18.
2Mancini DM, Bolinger L, Li H, Kendrick K, Chance B, Wilson JR. Validation of near-infrared spectroscopy in humans. J Appl Physiol. 1994;77:2740-2747.
3Cohn SM, Nathens AB, Moore FA, Rhee P, Puyana JC, Moore EE, Beilman GJ. Tissue Oxygen Saturation Predicts the Development of Organ Dysfunction During Traumatic Shock Resuscitation. J. Trauma. 2007;62:44-55.
4Ward KR, Ivatury RR, Barbee W, Terner J, Pittman R, Torres Filho IP, and Spiess B. Near infrared spectroscopy for evaluation of the trauma patient: a technology review. Resuscitation. 2006;68:27-44.