Occurrence of acetone concentrations > 0.10 g/L in post-mortem femoral blood and association with ethanol and isopropanol concentrations

The analysis of volatiles in post-mortem blood by gas chromatography sometimes shows the presence of acetone at concentrations exceeding 0.10 g/L, which is the analytical cut-off used in many laboratories. Whether these results reflect ante-mortem ingestion of isopropanol and subsequent oxidation to acetone or if the deceased suffered from a metabolic disorder (diabetes and/or ketoacidosis) is not always obvious. To throw more light on this question, we made a retrospective survey of ∼45,000 post-mortem blood samples and found that in 1366 cases (3%) acetone concentrations were > 0.10 g/L; mean (median) and highest 0.26 g/L (0.19 g/L) and 2.4 g/L, respectively. Of these 1366 blood samples, there were 256 (19%) that contained isopropanol at mean (median) and highest concentrations of 0.30 g/L (0.15 g/L) and 3.1 g/L. Blood-ethanol was positive (> 0.10 g/L) in 500 cases (37%) and the mean (median) and highest concentrations were 1.1 g/L (0.68 g/L) and 6.2 g/L. The concentrations of acetone and isopropanol in blood were highly correlated, r = 0.52 (P < 0.001), although there were no significant correlations between acetone vs ethanol (r = −0.16) and ethanol vs isopropanol (r = −0.04). Relatively low concentrations of acetone in blood (> 0.10 g/L but < 0.30 g/L) probably reflect a disturbed carbohydrate metabolism or starvation ketosis during the last days of life. Under these circumstances, acetone is reduced to isopropanol in a NADH-NAD+ biochemical reaction. Analytical results showing higher concentrations of acetone in blood (> 0.30 g/L), with or without isopropanol present, are more likely caused by ante-mortem ingestion of isopropanol and/or acetone for intoxication purposes.