THE ROLE OF TRAUMA IN POSTMORTEM BLOOD-ALCOHOL DETERMINATION

In postmortem cases, a blood sample is frequently obtained by transtho racic (TT) puncture. The purpose of this study was to determine if, in traumatic death, blood samples collected by TT provided a valid sampl e for blood alcohol analysis. A retrospective study (1980-1986) was co nducted to evaluate possible contamination of blood by GI alcohol in t raumatic death cases. Out of 6000 cases reviewed, 19 cses with BACs > 500 mg/dl were found and 8 of these cases involved traumatic death wit h GI laceration and/or transection. The results of this study support the hypothesis that blood samples from the 8 cases had been contaminat ed, resulting in a falsely elevated BAG. A transthoracic study (1987-1 989) was conducted under controlled conditions, where blood alcohol co ntent of TT blood samples was compared with samples collected from the intact heart chamber. Seven out of 28 cases of traumatic injury revea led trauma to the GI tract. The results showed that when GI traumatic injury occurs and unabsorbed ethanol is present in the stomach, contam ination 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 add itional biological fluids, be collected to rule out the possibility of contamination and to ensure that the BAC used for forensic interpreta tion is accurate.