Near-Infrared Spectroscopy-Derived Dynamic Cerebral Autoregulation in Experimental Human Endotoxemia—An Exploratory Study

Cerebral perfusion may be altered in sepsis patients. However, there are conflicting findings on cerebral autoregulation (CA) healthy participants undergoing the experimental endotoxemia protocol, a proxy for systemic inflammation sepsis. In current study, newly developed near-infrared spectroscopy (NIRS)-based CA index is investigated an study population, together with of focal oxygenation. Methods: Continuous-wave NIRS data were obtained from 11 receiving continuous infusion bacterial endotoxin 3 h ( ClinicalTrials.gov NCT02922673) under extensive physiological monitoring. Oxygenated–deoxygenated hemoglobin phase differences (very)low frequency (VLF/LF) bands and Tissue Saturation Index (TSI) calculated at baseline, during inflammation, end experiment 7 after initiation administration. Results: The median (inter-quartile range) LF difference was 16.2° (3.0–52.6°) baseline decreased to 3.9° (2.0–8.8°) p = 0.03). increased 27.6° (12.7–67.5°) 0.005). No significant changes VLF observed. TSI (mean ± SD) 63.7 3.4% 66.5 2.8% 0.03) remained higher (67.1 4.2%, 0.04). Further analysis did not reveal major influence several covariates such as blood pressure, heart rate, PaCO 2 , temperature, although some degree interaction could excluded. Discussion: A reversible decrease NIRS-derived seen infusion, small, sustained increase TSI. These suggest that administration reversibly impairs CA, accompanied by microvascular vasodilation.