Changes in tissue oxygenation of the porcine liver measured by near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is a novel method for the measurement of tissue oxygenation and may have a role in monitoring liver oxygenation and viability, The aim of this study is to validate the application of NIRS for monitoring hepatic tissue oxygenation. Large Landrace pigs (n = 12) underw ent laparotomy and liver exposure, Total hepatic blood flow (THBF) was meas ured by the Transonic Medical Flowmeter system. NIRS probes were placed on the liver surface to continuously record changes in hepatic tissue oxyhemog lobin (HbO(2)), deoxyhemoglobin (Hb), and the reduction-oxidation state of cytochrome oxidase (Cyt Ox). Reduction of hepatic tissue oxygenation was ac hieved by hepatic vascular inflow occlusion (n = 6) or reduction of inspire d oxygen (FIO2; n = 6), The THBF changes correlated significantly with hepa tic HbO(2) (r = 0.84; P < .001) and Cyt Ox (r = 0.88; P < .001), With reduc tion of FIO2, a significant correlation was found between arterial oxygen s aturation and hepatic HbO(2) and Hb (r = 0.99 and r = -0,99, respectively; P < .0001), NIRS measurement of liver parenchymal oxygenation correlates we ll with changes in liver blood flow and arterial oxygenation, Copyright (C) 1999 by the American Association for the Study of Liver Diseases.