Related Experiment Video
Updated: Oct 10, 2026
Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs
Published on: May 21, 2019
Cerebral blood flow monitored during circulatory shock using hemodynamic trend indices: a diffuse correlation
Randolph S Sinahon1, Luis M Gomero2, Meltem Izzetoglu2
1School of Biomedical Engineering and Science, Nick Howley College of Engineering and Computing, Drexel University, 3141 Chestnut Street Philadelphia, PA, 19104, USA.
Background And Objective:
Reliable detection and monitoring of circulatory shock is critical to provide timely and effective treatments. Specifically, continuous cerebral hemodynamic monitoring is essential as cerebral tissues are vulnerable to hypoxic-ischemic conditions. Diffuse correlation spectroscopy (DCS) is a non-invasive optical technique that measures cerebral blood flow (CBF) in microvasculature by calculating a cerebral blood flow index (BFI). Current CBF monitoring by DCS commonly relies on BFI magnitude changes or changes relative to a baseline (rBFI) of optical signals. However, BFI and rBFI are often confounded by robust compensatory mechanisms meant to stabilize CBF, thereby masking potential early indicators of shock. To address this limitation, we applied a cumulative sum approach to develop BFI-derived Hemodynamic Trend Indices (HTIs), to selectively monitor dynamic trends in CBF leading to shock.
Methods:
Newborn piglet models of controlled blood loss (BL) and hypoxia were selected to investigate BFI, rBFI, and HTIs response to shock. Ascending and descending HTIs (aHTI and dHTI) were calculated from two-sided cumulative sum of BFI slopes. Machine learning and statistical models evaluated these biomarkers' shock detection performance and sensitivity to insult progression.
Results:
In hemorrhage and hypoxia groups, HTIs diverged from baseline at earlier insult epochs; HTIs at 10% BL (Hedges' g = -0.85, 1.13) versus BFI at 50% BL, and after only ∼10-30 min of hypoxia, while BFI and rBFI declined after 40 min. In No-Shock vs. Shock classification, dHTI outperformed absolute BFI, achieving ∼0.90 accuracy and >0.8 F1-scores.
Conclusion:
The proposed hemodynamic trend indices can monitor directional changes in CBF during insult progression towards shock, and may be further developed as potential clinical biomarkers for early indication of cerebral hemodynamic decompensation prior to circulatory collapse.
