|SOFT - TIAFT 1998||Scientific Session 4||Thursday October 8, 1998|
|POSTMORTEM DIAGNOSIS OF COCAINE TOXICITY:THE UTILITY OF BRAIN CONCENTRATION MEASUREMENTS|
|Steven B. Karch1, Lee Hearn2, Deborah Mash3, James Ruttenber4|
1. Assistant Medical Examiner, City and County of San Francisco
|In 1985, Spiehler and Reed first suggested that brain is a better sample for postmortem cocaine quantification than either blood or liver, because (1) cocaine distributes evenly in the brain, eliminating problems of site dependency, (2) brain concentrations "...are representative of the drug at the site of action at the time of death," and (3) "information on the recent or remote use of cocaine can be obtained from the relative concentration of cocaine and benzoylecgonine (BE) in blood and brain tissue." PET studies have shown that cocaine is not as evenly distributed as once thought, but the fundamental correctness of their conclusions has been repeatedly confirmed. Yet brain cocaine concentrations are rarely determined. We present here data from 15 decedents where both blood and brain concentrations were determined.
Decedents were 73% male, 80% white, with a mean age of 38.5 years, and a mean postmortem interval of 14.9 hours. Mean values for blood cocaine and benzoylecgonine were 3.1 ± 4.2 and 3.0 ± 3.1 mg/L, respectively. In the brain the concentrations were 8.7 ± 11.4 and 1.7 ± 1.3 mg/Kg. Five of the decedents died with classic symptoms of excited delirium, the remainder with a variety of medical conditions (hemorrhagic pulmonary edema, cardiomegaly, hemorrhagic pancreatitis, and seizures). In each instance, when the absolute drug concentrations and ratios for cocaine:benzoylecgonine in the brain were considered in relation to the autopsy findings and scene reports, a plausible mechanism for the cause of death could be constructed. Similar attempts based on blood concentration measurements, could not always distinguish the cause of death. Autopsy and scene findings must be related to measured drug concentrations at the time of death, and the only way to estimate those is to quantitate the amount of drug and metabolite in the brain.