Key result
Increasing the oxygen content in inhaled gas from 21% to 100% in calves significantly increased intramyocardial oxygen saturation from 19% to 28% (p<0.001).
Diffuse reflectance spectroscopy can successfully estimate intramyocardial oxygenation and chromophore tissue fractions during respiratory and hemodynamic changes in a calf model.
Answers are grounded in this paper and cite their sources.
Hyperoxia augments myocardial saturation in calves; validates spectroscopy for oximetry but leaves human translation open.
Intramyocardial oxygen transport was assessed during open-chest surgery in calves by diffuse reflectance spectroscopy using a small intramuscular fiber-optic probe. The sum of hemo- and myoglobin tissue fraction and oxygen saturation, the tissue fraction and oxidation of cytochrome aa3, and the tissue fraction of methemoglobin were estimated using a calibrated empirical light transport model. Increasing the oxygen content in the inhaled gas, 21%-50%-100%, in five calves (group A) gave an increasing oxygen saturation of 19+/-4%, 24+/-5%, and 28+/-8% (p<0.001, ANOVA repeated measures design) and mean tissue fractions of 1.6% (cytochrome aa3) and 1.1% (hemo- and myoglobin). Cardiac arrest in two calves gave an oxygen saturation lower than 5%. In two calves (group B), a left ventricular assistive device (LVAD pump) was implanted. Oxygen saturation in group B animals increased with LVAD pump speed (p<0.001, ANOVA) and with oxygen content in inhaled gas (p<0.001, ANOVA). The cytochrome aa3 oxidation level was above 96% in both group A and group B calves, including the two cases involving cardiac arrest. In conclusion, the estimated tissue fractions and oxygenation/oxidation levels of the myocardial chromophores during respiratory and hemodynamic provocations were in agreement with previously presented results, demonstrating the potential of the method.
No takes yet. Share an insight, caveat, or question.
Lindbergh et al. (2010) studied Intramyocardial oxygen transport assessment (n=9). Increasing oxygen content in inhaled gas and LVAD pump speed vs. Baseline (21% oxygen) or lower pump speed was evaluated on Intramyocardial oxygen saturation (p=<0.001). Increasing the oxygen content in inhaled gas from 21% to 100% in calves significantly increased intramyocardial oxygen saturation from 19% to 28% (p<0.001).
Synapse has enriched 10 related papers. Consider them for comparative context: