title: Estimation of time since death by vitreous humor hypoxanthine, potassium, and ambient temperature.
abstract: Measurement of vitreous humor potassium (K(+)) has since the 1960s been recognized as an adjunct for estimation of time since death. In 1991 we introduced hypoxanthine (Hx) as a new marker. Furthermore we demonstrated that time since death estimation was more accurate when ambient temperature was included in the calculations, both for K(+) and for Hx. In this paper we present a refined method. The subjects consist of 132 cases with known time of death and ambient temperature. One sample from each subject was used in the calculations. Vitreous humor Hx levels were available in all subjects, while K(+) was measured in 106 of the subjects, due to insufficient volume of vitreous humor. Linear regression analysis was applied to model the correlation between vitreous humor Hx and K(+), taking the interactions with temperature into consideration. The diagrams published in 1991, which also included ambient temperature, estimated median time since death with range between the 10th and 90th percentile, whereas the linear regression analysis presented in this paper estimates mean time since death with a corresponding 95% interval of confidence. We conclude that time since death may be estimated with relatively high precision applying vitreous humor Hx and K(+) concentrations combined with ambient temperature.
authors.affiliation: Department of Pediatric Forensic Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, 0403 Oslo, Norway.
authors.forename: T O
authors.initials: TO
authors.lastname: Rognum
authors.affiliation: Institute of Clinical Medicine, University of Oslo, P.O. Box 1072 Blindern, 0316 Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Holmen
authors.affiliation: Department of Pediatric Forensic Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, 0403 Oslo, Norway.
authors.forename: M A
authors.initials: MA
authors.lastname: Musse
authors.affiliation: Department of Pediatric Forensic Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, 0403 Oslo, Norway.
authors.forename: P S
authors.initials: PS
authors.lastname: Dahlberg
authors.affiliation: Department of Pediatric Forensic Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, 0403 Oslo, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Stray-Pedersen
authors.affiliation: Institute of Clinical Medicine, University of Oslo, P.O. Box 1072 Blindern, 0316 Oslo, Norway; Department of Pediatric Research, Oslo University Hospital, P.O. Box 4950 Nydalen, 0424 Oslo, Norway.
authors.forename: O D
authors.initials: OD
authors.lastname: Saugstad
authors.affiliation: Department of Pediatric Forensic Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, 0403 Oslo, Norway. Electronic address: siri.hauge.opdal@fhi.no.
authors.forename: S H
authors.initials: SH
authors.lastname: Opdal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D019075:Electrophoresis, Capillary; D005260:Female; D049429:Forensic Pathology; D006801:Humans; D019271:Hypoxanthine / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011180:Postmortem Changes; D011188:Potassium / Q000378:metabolism; D013696:Temperature; D014822:Vitreous Body / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019271:Hypoxanthine; D011188:Potassium
keywords: Hypoxanthine; Post mortem interval; Potassium; Time of death estimation