Background and Goal of Study: In time-resolved spectroscopy (TRS), the optical path lengths is directly measured, resulted in enabling determination of the hemoglobin (Hb) concentration, and tissue oxygenation.The aim of this study was to investigate whether in adults the liver can be detected by TRS placed on the skin above the liver surface, and the hepatic oxygenation can act as a noninvasive monitoring for early detection of intestinal ischemia.
Materials and Methods: With approval of the local Hospital Ethics Committee and informed consent, 6 volunteers aged 28.8 years, and 5 patients with chronic renal failure (CRF) aged 70.6 years were studied. In volunteers, following the echography, TRS (TRS-10, Hamamatsu Photonics K.K., Japan) probe consisting of a near-infrared light, was placed 4 cm apart on the skin above the liver or the intestine. After the monitoring by TRS, the total Hb (tHb) concentration, and oxygen saturation (SO2) in the liver were compared with those in the intestine.
In patients with CRF, following the echography, TRS probes were placed 4 cm apart on the skin above the liver surface, and the Hb and SO2 in the liver was continuously monitored during hemodialysis (HD).
Results and Discussion: The values of tHb was significantly higher in the liver than in the intestine (80.6±26.81 vs 44.6±23.1mM, P=0.0017), while the SO2 in the liver was nearly the same as that in the intestine (71.5±3.6% vs 73.6±4.6%, P=0.19). One of 5 patients with CRF complained of the severe abdominal pain during HD, and the SO2 in the liver was decreasing from 53% to 22%, but the pain relief occurred following cessation of HD, and SO2 recovered to the baseline (Fig. 1).
Conclusion(s): In adults the liver can be detected by the TRS placed on the skin above the liver surface, and the hepatic oxygenation can act as a noninvasive monitoring for early detection of intestinal ischemia.