'Lingering' opiate deaths? Concentration of opiates in medulla and femoral blood.

'Lingering death' cases occur when the circumstances of death indicate an opiate overdose, but measured opiate blood levels are only in the therapeutic range; death results from cardiac and respiratory depression. This study examined the relative concentration of opiates in femoral blood and in the medulla oblongata (sites for cardiac and respiratory control) from 41 cases to determine whether a difference in opiate concentration might explain lingering deaths. Opiates from blood and medulla were analyzed using GC-EI-MS in selective ion monitoring mode. Results were correlated with gross and microscopic findings of the lungs and with cause and manner of death. Opiate concentrations for morphine, codeine and 6-acetylmorphine (6-AM) were higher in the medulla than in blood. The brain: blood ratio for the analytes demonstrated an increasing ratio from morphine, to codeine, to 6-AM (1.42, 2.48 and 4.86), which corresponds to the relative lipophilicity of these analytes. The average right and left lung weights were 762 and 668 g, respectively. Histologic examination showed edema, and/or polarizable microemboli, acute bronchopneumonia and acute bronchitis. The preferential distribution of opiates to medulla suggests that lingering opiate deaths may be explained, at least in part, because of higher relative concentrations of drug in brain, compared with femoral blood.