title: An objective approach using three indexes for determining fatal hypothermia due to cold exposure; statistical analysis of oxyhemoglobin saturation data.
abstract: Analysis of oxyhemoglobin (O2-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 O2-Hb saturation levels and developed useful diagnostic criteria for fatal hypothermia: O2-Hb saturation in the left heart blood (L-O2Hb) was ⩾36%, the O2-Hb saturation gap between the left and right heart blood (L-R gap) was ⩾13%, and the O2-Hb saturation ratio of the left to right heart blood (L/R ratio) was ⩾1.8. When we used L-O2Hb 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.
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan; Department of Legal Medicine, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba City 260-8670, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yajima
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Asari
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Okuda
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Chikatoshi
authors.initials: C
authors.lastname: Maseda
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Ichimaru
authors.affiliation: Department of Pharmacy, Kyoto University Hospital, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Matsubara
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shiono
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba City 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hirotaro
authors.initials: H
authors.lastname: Iwase
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba City 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Makino
authors.affiliation: Department of Legal Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan. Electronic address: okeichan@asahikawa-med.ac.jp.
authors.forename: Keiko
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy / Q000379:methods*; D003080:Cold Temperature / Q000009:adverse effects; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000209:etiology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000032:analysis*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins
keywords: Difference in color; Hypothermia; Oximeter; Oxyhemoglobin saturation