Postmortem diagnosis of ketoacidosis: Levels of beta-hydroxybutyrate, acetone and isopropanol in different causes of death

Abstract

Data from 496 autopsy cases with positive beta hydroxybutyrate (BHB), acetone or isopropanol in blood were investigated. The cases were divided into different groups according to cause of death. Cases with cause of death due to diabetic ketoacidosis (DKA, n=54) had the highest levels of BHB (median 1085mg/L) and acetone (median 330mg/L). Cases with cause of death due to alcoholic ketoacidosis (AKA, n=57) had high levels of BHB (median 500mg/L) and acetone (median 110mg/L). Cases with cause of death due to hypothermia (n=12) had similar BHB and acetone levels as the AKA group (median BHB 520mg/L and acetone 80mg/L). Cases with cause of death due to isopropanol intoxication (n=17) had high levels of isopropanol (median 430mg/L) and acetone (330mg/L), but undetected or low levels of BHB. Cases with cause of death due to other than the above mentioned (n=349) had median BHB levels of 100mg/L and median acetone levels of 20mg/L.

BHB analysis is crucial for the diagnosis of postmortem ketoacidosis, since it is the main marker of ketoacidosis and helps distinguish between different causes of death. Acetone levels correlate with BHB levels in endogenous ketoacidosis, so acetone can be used as an initial screening marker to identify cases where BHB analysis should be performed, but positive acetone threshold should be maximum 20mg/L. Positive BHB is proof of endogenous ketoacidosis, whereas negative BHB indicates isopropanol intoxication or postmortem acetone/isopropanol formation by microorganisms in cases of decomposition. There is no correlation between BHB and the postmortem interval, and no sign of postmortem formation, so BHB analysis is useful even in cases of severe decomposition.