Br. Soller et al., Simultaneous measurement of hepatic tissue pH, venous oxygen saturation and hemoglobin by near infrared spectroscopy, SHOCK, 15(2), 2001, pp. 106-111
Citations number
31
Categorie Soggetti
Aneshtesia & Intensive Care","Cardiovascular & Hematology Research
The purpose of this study was to investigate the feasibility of using near
infrared (NIR) spectroscopy of the liver to simultaneously assess oxygen co
ntent in combination with tissue pH, an indicator of anaerobic metabolism.
Six anesthetized swine were subjected to 45 min of hemorrhagic shock follow
ed by resuscitation with blood and crystalloid. Calibration models between
NIR spectra and reference measurements of tissue pH, hepatic venous oxygen
saturation (SvO2), and blood hemoglobin concentration (Hb) were developed u
sing partial least-squares regression. Model accuracy was assessed using cr
oss validation. The average correlation (R-2) between NIR and reference mea
surements was 0.87, 0.68, and 0.93, respectively for pH, Hb, and SvO2. Esti
mated accuracy, the root mean squared deviation between spectral, and refer
ence measurements was 0.03 pH units, 0.3 g/dL, and 6%. NIR determination of
hepatic oxygen content and tissue pH during shock and resuscitation demons
trated that there can be a variance between hepatic venous oxygenation and
regional tissue acidosis. NIR spectroscopy provides a technique to explore
the implications of post-shock depression of tissue pH and evaluate new met
hods of resuscitation.