Exploration of Vitreous Biochemical Markers for Postmortem Discrimination of Carbon Monoxide Toxicity: Insights from Animal Model

Abstract

This study investigates the potential of postmortem vitreous biochemical parameters as biomarkers for distinguishing between drowning and deaths disguised as drowning. The purpose of the study is to explore the discriminatory power of selected vitreous biochemical parameters in forensic autopsy to resolve disputed causes of death. The study aims to assess and compare the postmortem levels of sodium, potassium, chloride, calcium, total protein, albumin, globulin, glucose, cholesterol, triglycerides, urea, creatinine, uric acid, creatine kinase, and lactate dehydrogenase in rabbits that died from different causes. Using a completely randomized block design (CRBD), 96 male rabbits were divided into four groups: two treatment groups (one for drowning and one for strangulation followed by drowning) and two control groups. After a 24-hour postmortem interval, vitreous humor samples were analyzed using ion-selective electrode and standard biochemical methods.The results showed significant differences (P≤0.05) in the biochemical parameters between the drowning and strangulation groups. The postmortem levels of sodium in the drowning group were 145 ± 5 mmol/L, compared to 133 ± 4 mmol/L in the strangulation group. Potassium levels were 4.8 ± 0.5 mmol/L in the drowning group, significantly higher than 3.2 ± 0.4 mmol/L in the strangulation group. Chloride levels were 105 ± 7 mmol/L in the drowning group, while the strangulation group had 90 ± 6 mmol/L. Calcium levels were 2.5 ± 0.2 mmol/L in the drowning group, compared to 1.8 ± 0.3 mmol/L in the strangulation group. Total protein concentrations were 72 ± 3 g/L in the drowning group and 55 ± 4 g/L in the strangulation group. Creatinine levels were 72 ± 8 µmol/L in the drowning group, higher than 48 ± 7 µmol/L in the strangulation group. Creatine kinase and lactate dehydrogenase levels in the drowning group were 120 ± 10 U/L and 420 ± 30 U/L, respectively, whereas in the strangulation group, they were 85 ± 8 U/L and 300 ± 25 U/L.These biochemical markers were identified as potential biomarkers for distinguishing between deaths caused by actual drowning and those disguised as drowning. The study recommends the further development and validation of vitreous biochemical analysis as a reliable, non-invasive alternative to blood analysis for forensic investigations, particularly in cases of suspected drowning-related homicides. This approach holds promise for improving the accuracy of postmortem diagnostics and enhancing the justice system’s ability to resolve controversial death cases.