AUTHOR=Guyon Peter W. , Karamlou Tara , Ratnayaka Kanishka , El-Said Howaida G. , Moore John W. , Rao Rohit P. TITLE=An Elusive Prize: Transcutaneous Near InfraRed Spectroscopy (NIRS) Monitoring of the Liver JOURNAL=Frontiers in Pediatrics VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2020.563483 DOI=10.3389/fped.2020.563483 ISSN=2296-2360 ABSTRACT=

Introduction: We postulate a relationship between a transcutaneous hepatic NIRS measurement and a directly obtained hepatic vein saturation. If true, hepatic NIRS monitoring (in conjunction with the current dual-site cerebral-renal NIRS paradigm) might increase the sensitivity for detecting shock since regional oxygen delivery changes in the splanchnic circulation before the kidney or brain. We explored a reliable technique for hepatic NIRS monitoring as a prelude to rigorously testing this hypothesis. This proof-of-concept study aimed to validate hepatic NIRS monitoring by comparing hepatic NIRS measurements to direct hepatic vein samples obtained during cardiac catheterization.

Method: IRB-approved prospective pilot study of hepatic NIRS monitoring involving 10 patients without liver disease who were already undergoing elective cardiac catheterization. We placed a NIRS monitor on the skin overlying liver during catheterization. Direct measurement of hepatic vein oxygen saturation during the case compared with simultaneous hepatic NIRS measurement.

Results: There was no correlation between the Hepatic NIRS values and the directly measured hepatic vein saturation (R = −0.035; P = 0.9238). However, the Hepatic NIRS values correlated with the cardiac output (R = 0.808; P = 0.0047), the systolic arterial blood pressure (R = 0.739; P = 0.0146), and the diastolic arterial blood pressure (R = 0.7548; P = 0.0116).

Conclusions: Using the technique described, hepatic NIRS does not correlate well with the hepatic vein saturation. Further optimization of the technique might provide a better measurement. Hepatic NIRS does correlate with cardiac output and thus may still provide a valuable additional piece of hemodynamic information when combined with other non-invasive monitoring.