| OBJECTIVE: 1.To establish the models of postmortem redistribution in dogs with an intravenous, a subarachnoid or an epidural administration of lidocaine hydrochloride. 2. To compare the distribution of lidocaine in the cardiac blood, peripheral blood, liver and cerebrum of anesthesia accident death dogs in different times at room temperature, and provide a scientific evidence for the forensic identification of the epidural anesthesia accident caused by lidocaine. 3. Investigate whether there was a postmortem distribution of lidocaine in anesthesia accident death dogs,and discuss its mechanism. METHOD: 1. Animal model: Twenty seven dogs were randomly allocated to one of three groups (n=9 per group ) .Six dogs in each group was given an intravenous injection, a subarachnoid anesthesia ,or an epidural anesthesia with an even speed in ten minutes for 5×15mg/kg weight of lidocaine hydrochloride(n=6 per group), and the other 3 dogs in each group was given the same volume of physiological salt solution(n=3 per group). 2. Record of vital signs: By a biological function system,the vital signs such as electro cardia, blood pressure and respiration of dogs from the beginning of the administration to the death were recorded. 3. Collection of samples: A dog died from anesthesia was placed at room temperature, collected cardiac blood, peripheral blood, liver and cerebrum in 0,1,4,8,24,48,72 hours after the death and was analyzed. 4. Analysis method: These obtained samples were extracted by ether. Analysis was performed with a GC equipped with a NPD and a GC-MS. Qualitative analysis was based on retention time in the chromatographic system coupled with the ion fragmentation spectrum in the mass spectrometer. Quantitative analysis was based on an internal standard method. RESULTS: 1. Symptom Pupil decrease, respiratory arrest, opisthotonos, incontinence of urine and excrement, and extensive sensory occurred at 1~2 min after the intravenous administration of lidocaine. The symptom of the subarachnoid anesthesia and epidural anesthesia were similar with intravenous administration. 2. Postmortem redistribution of lidocaine in anesthesia accident death dogs: Anesthesia accident dogs showed different changes of lidocaine concentration in cardiac blood, peripheral blood, liver and cerebrum after the intravenous administration, the subarachnoid anesthesia or the epidural anesthesia, which showed the most remarkable change in the acardiac blood. Postmortem cardiac blood lidocaine concentrations were decreased from 123.5±14.5μg/ml to 32.1±4.6μg/ml in 72h after the intravenous administration death. There was also no significant difference between the antenortem and after death for 8 hours lidocaine concentrations in peripheral blood, liver and cerebrum. After the death for 48 h ,the cardiac blood lidocaine concentration in subarachnoid anesthesia dogs was the highest. There were no significant changes of peripheral blood or liver lidocaine concentration in them. Liver and cerebrum lidocaine levels were steadier than cardiac and peripheral blood in epidural anesthesia. Peripheral blood lidocaine concentrations were similar with cardiac blood. CONCLUSION: 1. The study has established the postmortem redistribution models of intravenous administration, subarachnoid anesthesia and epidural anesthesia with lidocaine. Marked differences between heart and femoral blood, liver and cerebrum lidocaine concentrations were observed in both of the above-mentioned models. Each model has characteristic of itself, this study has demonstrated that an anesthesia accident should be think about postmortem redistribution. The chosen site and time for postmortem matrices sampling can greatly influence the concentration of lidocaine measured. 2. The data of postmortem redistribution in different matrices after intravenous suharachonid and epidural application in dogs may apply to the study on forensic identification.
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