Estimation of the early post-mortem interval: a multicentre comparison of the analysis of vitreous humour and the Henssge’s Nomogram method. A cross-sectional, correlational study

Abstract

Background: Estimating the Post-Mortem Interval (PMI) is a daily forensic task. It is especially important in those cases where a violent death has occurred in order to verify the suspects’ alibis around this period of time. This estimation is also important for heritage purposes if victims are family related. Nowadays, the medical examiner applies different PMI methods, such as body cooling or Rigor mortis, alongside witnesses’ statements so as to increase the precision of death time estimation as much as possible. So far, the only objective-quantitative method used in the regular forensic practice is the Henssge’s Nomogram method which is based in the post-mortem body cooling. Academically, a promising objective-quantitative method has been studied: the PMI extrapolation from the analysis of the vitreous humour’s potassium concentration. Forensic field studies are needed in order to demonstrate the real applicability of a PMI method: to be precise, to be reliable and to give immediate results. Objective: Our main goal is to assess whether the analysis of vitreous humour is more accurate than the Henssge’s Nomogram method in estimating the early PMI in violent deaths occurred within the Institut de Medicina Legal i Ciències Forenses de Catalunya’s jurisdiction. Method: We are going to carry out a multicentre cross-sectional, correlational study. During the regular forensic practice, both methods will be applied to the same corpse at the same time. At the crime scene, the necessary data will be duly and systemically collected in order to calculate the early PMI subsequently. The early-PMI’s estimations will be then compared with the exact PMI, the Gold Standard. During 12 months, the data collection process will be done by forensic Doctors from every division of the Institut de Medicina Legal i Ciències Forenses de Catalunya alongside the Laboratory Personnel from the Biochemical Department of Hospital Clínic (Barcelona)