Faculty Collaboration Database

Hepatic artery flow, inspired oxygen, and hemoglobin determine liver tissue saturation measured with visible diffuse reflectance spectroscopy (vis-DRS) in an in vivo swine model. Pediatr Transplant 2022 Jun;26(4):e14230

Date

01/23/2022

Pubmed ID

35064720

DOI

10.1111/petr.14230

Scopus ID

2-s2.0-85123506404 (requires institutional sign-in at Scopus site)   1 Citation

Abstract

BACKGROUND: Prompt diagnosis of vascular compromise following pediatric liver transplantation and restoration of oxygen delivery to the liver improves organ survival. vis-DRS allows for real-time measurement of liver tissue saturation.

METHODS: The current study used vis-DRS to determine changes in liver saturation during clinically relevant conditions of reduced oxygen delivery. In an in vivo swine model (n = 15), we determined liver tissue saturation (S_t O₂ ) during stepwise reduction in hepatic artery flow, different inspiratory oxygen fraction (FiO₂ ), and increasing hemodilution. A custom vis-DRS probe was placed directly on the organ.

RESULTS: Liver tissue saturation decreased significantly with a decrease in hepatic artery flow. A reduction in hepatic artery flow to 25% of baseline reduced the S_t O₂ by 15.3 ± 1.4% at FiO₂ 0.3 (mean ± SE, p < .0013), and by 8.3 ± 1.9% at FiO₂ 1.0 (p = .0013). After hemodilution to 7-8 g/dl, S_t O₂ was reduced by 31.8% ± 2.7%, p < .001 (FiO₂ 0.3) and 26.6 ± 2.7%, p < .001 (FiO₂ : 1.0) respectively. Portal venous saturation during low hepatic artery flow was consistently higher at FiO2 1.0. The gradient between portal venous saturation and liver tissue saturation was consistently greater at lower hemoglobin levels (7.0 ± 1.6% per g/dl hemoglobin, p < .001).

CONCLUSIONS: Vis-DRS showed prompt changes in liver tissue saturation with decreases in hepatic artery blood flow. At hepatic artery flows below 50% of baseline, liver saturation depended on FiO2 and hemoglobin concentration suggesting that during hepatic artery occlusion, packed red blood cell transfusion and increased FiO₂ may be useful measures to reduce hypoxic damage until surgical revascularization.

Author List

Voulgarelis S, Fathi F, Yu B, Palkovic B, Chatzizacharias NA, Allen KP, Stucke AG

Authors

Kenneth Paul Allen DVM Associate Professor in the Research Office department at Medical College of Wisconsin
Astrid G. Stucke MD Professor in the Anesthesiology department at Medical College of Wisconsin
Bing Yu PH.D. Assistant Professor of Biomedical Engineering in the Biomedical Engineering department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Hemoglobins
Hepatic Artery
Humans
Liver
Oxygen
Spectrum Analysis
Swine