The role of trauma in postmortem blood alcohol determination

In postmortem cases, a blood sample is frequently obtained by transthoracic (TT) puncture. The purpose of this study was to determine if, in traumatic death, blood samples collected by TT provided a valid sample for blood alcohol analysis. A retrospective study (1980-1986) was conducted to evaluate possible contamination of blood by GI alcohol in traumatic death cases. Out of 6000 cases reviewed, 19 cses with BACs > 500 mg/dl were found and 8 of these cases involved traumatic death with GI laceration and/or transection. The results of this study support the hypothesis that blood samples from the 8 cases had been contaminated, resulting in a falsely elevated BAC. A transthoracic study (1987-1989) was conducted under controlled conditions, where blood alcohol content of TT blood samples was compared with samples collected from the intact heart chamber. Seven out of 28 cases of traumatic injury revealed trauma to the GI tract. The results showed that when GI traumatic injury occurs and unabsorbed ethanol is present in the stomach, contamination of TT blood samples occurs and artificially elevated BACs are obtained. It is recommended that, in cases of traumatic injury, heart blood samples from the intact heart chamber, as well as samples of additional biological fluids, be collected to rule out the possibility of contamination and to ensure that the BAC used for forensic interpretation is accurate.