Development of a New Index for Mortality Prediction Due to Hemorrhagic Shock using Lactate Concentration and Perfusion in S-D Rats

ABSTRACT

PURPOSE: We proposed a new index for predicting death resulting from hemorrhagic shock, which was calculated by dividing measured lactate concentration by perfusion. METHODS: Using 24 Sprague-Dawley (S-D) rats, we induced uncontrolled hemorrhage and then measured blood lactate concentration and perfusion in addition to vital signs such as heart rate, blood pressure, respiration rate and temperature. Perfusion and lactate concentration were measured by laser Doppler flowmetry and a lactate concentration meter, respectively. We collected the data for 15 min, which consisted of 3 intervals after homeostasis, and thus obtained a new index. RESULTS: The proposed index revealed an earlier death prediction than lactate concentration alone with the same timing as perfusion. The new index showed generally better sensitivity, specificity and accuracy than lactate concentration and perfusion. Using a receiver operating characteristic curve method, the mortality prediction with the proposed index resulted in a sensitivity of 98.0%, specificity of 90.0%, and accuracy of 93.7%. The mortality prediction with the proposed index resulted in a sensitivity of 98.0%, specificity of 90.0% and accuracy of 93.7%. CONCLUSION: This index could provide physicians, in emergency situations, with early and accurate mortality predictions for cases of human hemorrhagic shock.