Near infrared spectroscopy (NIRS) may be utilized in conjunction with a vascular occlusion test to quantify a tissue bed's ability to re-oxygenate by measuring continuous tissue oxygen saturation recovery rate. We hypothesize that NIRS recovery slope will be associated with expression of endothelial biomarkers, thus, making it a feasible bedside surrogate for assessing endothelial activation/dysfunction in patients with sepsis. A secondary analysis of a prospective, multicenter, observational study was done on a convenience sample of adult patients at four university emergency departments consisting of patients with septic shock, sepsis without shock and patients without infection. At enrollment we measured the NIRS-derived measurements and collected plasma to assay biomarkers of endothelial activation. 186 patients were enrolled in the study. The mean age was 63 (±16) years with 60 % male gender. Univariate analysis assessing the linear relationship between the recovery slope with endothelial biomarkers, found a weak but statistical significant association between NIRS recovery slope and soluble fms-like tyrosine kinase-1 (sFLT-1) and tPAI-1 (r = -0.08, p < 0.0001 and r = -0.06, p = 0.002). When adjusting for diabetes, age and sequential organ failure assessment score at enrollment, only sFLT-1 persisted having a statistically significant association (r = -0.04, p = 0.01). We found a weak, but statistically significant relationship between NIRS-derived measurements and biomarkers of endothelial activation/dysfunction in patients with sepsis. This study fails to support the use of NIRS-derived measurements as a clinical or research tool to identify patients with endothelial cell activation/dysfunction and informs researchers that this is not a robust option for identifying this lesion at the bedside.
Bibliographical noteFunding Information:
Conflict of interest This project was funded in part by an investigator initiated research grant from Hutchinson Technology (Hutchinson, MN, USA). Dr. Shapiro has received research grants from Hutchinson Technologies, Cheetah Medical, and Inverness Medical. Dr. Trzeciak receives research support from Ikaria and serves as a consultant to Spectral Diagnostics, but does not receive any personal remuneration from any commercial interest.
Acknowledgments Dr. Skibsted is supported from a research grant from Aarhus University, Denmark. Dr. Shapiro is supported in part by National Institutes of Health grants HL091757, GM076659, and 5R01HL093234-02. Dr. Trzeciak is supported by NIH grant GM083211. Dr. Aird is supported by National Institutes of Health grants HL091757 and GM088184.
- Endothelial biomarkers
- Near infrared spectroscopy