Pulse spectrum analysis, a faster and easier way to predict outcome of sepsis?

In order to provide a faster and easier way for outcome prediction of sepsis, this study aimed to characterize the pattern of arterial pulse spectrum by a rat cecum ligation and puncture (CLP) model and explore whether specific harmonic components of pulse spectrum are associated with the mortality of CLP rats, followed by the comparison of accuracy between these specific variables and IL-6. Nineteen Sprague-Dawley rats receiving CLP were analyzed. Femoral artery of each rat was catheterized for blood pressure recording and blood sampling in the first 24 hours after CLP. The former was for off-line pulse spectrum analysis, and the latter for IL-6 assay. These rats were observed for 3-day mortality after CLP, and were divided into survivor or non-survivor groups. Differences of the hemodynamic profile, IL-6, and changes of the harmonics between the 2 groups were analyzed by using the Mann-Whitney test. Kaplan-Meier curves were constructed to characterize cumulative survival with the best prognostic cutoff point. The characteristic changes of pulse spectrum were different between survivors and non-survivors. The percentage differences of the 2nd harmonic proportion (C2) increased significantly from the 10th hour after CLP, and was higher in the non-survivors. Serum levels of IL-6 were also higher in the non-survivor group. Analyzed by Kaplan-Meier survival curve for 3-day mortality, C2 had a higher accuracy than IL-6 as a predictor. The pulse spectrum analysis may be applied to evaluate the prognosis of CLP rats, and the rapidly and highly elevated C2 harmonic had a strong association with the 3-day mortality of CLP rats.