Predictive equation to estimate post-mortem interval using spectrophotometric blood-colour values. (January 2019)

• Record Type: Journal Article
• Authors: Usumoto, Yosuke; Kudo, Keiko; Tsuji, Akiko; Ihama, Yoko; Ikeda, Noriaki
• Is Part Of: Medicine, science and the law. Volume 59:Number 1(2019)
• Page Start: 36
• Page End: 41
• Publication Date: 2019-01
• Subjects: Post-mortem lividity -- spectrophotometer -- blood colour -- post-mortem interval (PMI); Forensic sciences -- Periodicals; Medical laws and legislation -- Great Britain -- Periodicals; 614.105
• DOI: 10.1177/0025802418819611
• Languages: English
• ISSNs: 0025-8024

Abstract

Forensic pathologists use post-mortem phenomena to estimate the post-mortem interval (PMI). We have reported on the usefulness of post-mortem lividity spectrophotometric values to estimate PMIs. Here, we focused on blood colour, looking for associations between blood colour, age and PMI. We generated predictive equations for blood-colour values and the PMI. We included data from a total of 129 cadavers (84 males and 45 females). We measured the colour of 124 left ventricular blood ( L*l, a*l, b*l ), 123 right ventricular blood ( L*r, a*r, b*r ) and 57 femoral blood ( L*f, a*f, b*f ) samples. We found no significant associations between blood colour and age or between blood colour and the PMI, but the values of a*l, b*l, a*r and b*r were significantly increased with increased age, and those of L*f, a*f and b*f were significantly decreased with increased PMI. We created equations to estimate blood colour. The equations for femoral blood colour had higher adjusted R 2 values and lower root mean square error values than those for left and right ventricular blood colours. We generated equations to estimate PMIs using blood-colour values and autopsy findings. Our estimated PMIs up to 67 hours had accuracies within 8.84 hours, without measuring post-mortem lividity colour or considering the age of the deceased. This is the first study to estimate PMIs based on blood-colour spectrophotometric values.