凍死の診断における血中および尿中のアセトン検出の有用性

Abstract

Ketone bodies, such as acetone, are often detected during autopsy in the bodily fluids of those who have died from fatal hypothermia and malnutrition. However, the association between ketone body detection and cause of death has not been fully examined. In this investigation, we assessed the relationship between fatal hypothermia and the detection of acetone in blood or urine. In 446 out of 1,070 autopsies performed in our laboratory over the past six years (January 2011-February 2017), acetone was detected in either blood or urine. In 240 out of 446 cases, acetone was detected in both blood and urine. Among these 240 cases, the most frequent causes of death were cardiovascular disease (20.8%), fatal hypothermia (19.6%), and asphyxia (15.4%). In 1070 cases, the highest rate of acetone detection was associated with fatal hypothermia (76.6%) followed by pneumonia (57.9%)，liver disease (44.4%), and starvation (38.1%). Fatal hypothermia was the cause of death in 47 out of the 240 cases. Acetone was detected in 36 of these 47 cases in both blood and urine. Among the 240 cases, 22 showed acetone values of 0.15mg/mL or more in blood or urine. Of the 22 cases, 6 were associated with fatal hypothermia. Acetone levels in blood and urine did not change until 50 days after death in these 22 cases. The body mass index of those with fatal hypothermia did not differ among those with and with out acetone detection. The appearance rate of Wischnewski spots in the gastric mucosa was twice as high in the cases with acetone detection compared to the cases without. These results suggest that the detection rate of acetone in fatal hypothermia is high, and that acetone levels can remain stable for a relatively long time after death. These findings are meaningful as they can help identify the cause of death in patients with fatal hypothermia.