Relationship between postmortem blood and vitreous humor ethanol levels

Area of Science:

• Forensic Toxicology
• Postmortem Alcohol Analysis

Background:

• Understanding postmortem ethanol distribution is crucial for accurate toxicological assessments.
• The vitreous humor offers a protected biological matrix for ethanol analysis.

Observation:

• The study analyzed blood to vitreous humor (B/V) and urine to blood (U/B) ethanol ratios in 200 postmortem cases.
• A bimodal distribution was observed, with a U/B ratio of 1.20 distinguishing early absorption from later phases.
• Ethanol distribution patterns were consistent across various causes of death, including those with head injuries.

Findings:

• Early absorption phase: Average B/V ratio of 1.29 (range 0.71-3.71, SD 0.57).
• Late absorption/elimination phases: Average B/V ratio of 0.89 (range 0.32-1.28, SD 0.19).
• Formulated equations for estimating blood ethanol: B = 1.29V (early) and B = 0.89V (later).

Implications:

• Vitreous humor ethanol levels can aid in estimating blood alcohol concentration, particularly in cases with head trauma.
• The established ratios provide a basis for more accurate postmortem alcohol estimations.
• This research supports the utility of vitreous humor in forensic investigations involving alcohol consumption.