Effects of Cold-Storage Temperature on the Accuracy of Death Interval Estimation Using the Thanatochemical Dynamics of Vitreous Humour and Synovial Fluid
Authors: Prasad Patra Ambika 
Published: October 2024

Background: Accurate death interval (DI) estimation is crucial in forensic investigations. Various methods, including temperature-based techniques, postmortem changes, and circumstantial evidence, have been employed for this purpose. Thanatochemistry, which focuses on the biochemical changes after death, offers a promising approach. Body fluids such as vitreous humour and synovial fluid have been extensively studied for their potential in PMI estimation. The use of biochemical markers from body fluids such as vitreous humour and synovial fluid has been widely studied, but the effects of cold storage on these estimates remain a challenge. Objective: This study aimed to evaluate the impact of cold storage on PMI estimation using regression equations based on potassium, sodium, chloride, and glucose levels in vitreous humor and synovial fluid. Methods: A 2-year prospective analysis of 170 hospital autopsy cases with known death time was conducted on those bodies exposed to cold storage temperature (4-7oC) before the autopsy. Biochemical analyses were conducted on vitreous humor and synovial fluid samples from bodies subjected to cold storage. Electrolyte/chemical levels (sodium, potassium, chloride, and glucose) were measured in both fluids, and their correlation with death interval was assessed. Regression equations were derived to estimate DI, providing reliable estimates within specific time frames. Regression equations were applied to estimate the death interval (DI) at zero hours of actual death time. The correlations between these chemical markers and PMI were analysed, focusing on the influence of cold storage. Results: Potassium levels in both vitreous humour and synovial fluid showed a positive correlation with PMI, leading to an overestimation of DI by 1.2 to 1.5 hours. Sodium and chloride levels demonstrated a negative correlation, resulting in International Journal of Forensic Sciences 2 Patra AP, et al. Effects of Cold-Storage Temperature on the Accuracy of Death Interval Estimation Using the Thanatochemical Dynamics of Vitreous Humour and Synovial Fluid. Int J Forens Sci 2024, 9(3): 000406. Copyright© Patra AP, et al. underestimations ranging from 5 to 31 minutes. Glucose levels showed minimal and statistically insignificant variations, indicating limited utility as a PMI marker in cold-stored bodies. Conclusion: The study findings contribute to understanding the reliability of vitreous humour and synovial fluid analysis in estimating PMI, even in cases where bodies have undergone cold storage. Cold storage significantly affects the accuracy of PMI estimation using biochemical markers. Potassium remains a valuable indicator but tends to overestimate PMI under cold conditions. Sodium and chloride provide supplementary information but are prone to underestimation, while glucose is less reliable. A multi-marker approach, considering the specific environmental conditions, is recommended for more accurate PMI estimation. Further research is needed to refine the regression models for cold storage effects