An objective approach using three indexes for determining fatal hypothermia due to cold exposure; statistical analysis of oxyhemoglobin saturation data

摘要

Analysis of oxyhemoglobin (O-2-Hb) saturation levels in the left and right heart blood is useful in the assessment of exposure to cold surroundings before death. We quantified conventional subjective visual evaluation of O-2-Hb saturation levels and developed useful diagnostic criteria for fatal hypothermia: O(2)Hb saturation in the left heart blood (L-O(2)Hb) was >= 36%, the O-2-Hb saturation gap between the left and right heart blood (L-R gap) was >13%, and the 02-Hb saturation ratio of the left to right heart blood (L/R ratio) was >1.8. When we used L-O(2)Hb of >36% as a basic criterion and applied a further criterion of an L R gap of >13% or an L/R ratio of >1.8, these criteria registered a sensitivity level of >86% and specificity level of >93% for the diagnosis of fatal hypothermia. This method can be useful for determining fatal hypothermia in connection with conventional autopsy findings, as well as histological and biochemical markers. (C) 2015 Elsevier Ireland Ltd. All rights reserved.