Postmortem redistribution of lidocaine after epidural injection in beagle dogs.

Objectives: An animal model using beagle dog has been established to investigate the postmortem redistribution of lidocaine.

Materials and methods: 18 dogs were euthanized and injected lidocaine (13 mg/kg) via epidural immediately. An autopsy was performed at 0, 12, 24, 48, 72, 96 hours after drug administration. All animals were stored in supine position at room temperature. For the other groups, lidocaine was given via epidural 6, 12, 24 hours after dogs were euthanized. Followed treatments were as above described. All samples were treated for detection of the concentration of lidocaine.

Results: It was found that lidocaine could diffuse via blood vessel rapidly post administration. And the concentration of lidocaine in the blood from ventriculus sinister increased obviously in a time-dependent manner. Meanwhile, the postmortem tissue distribution of lidocaine was significantly different. However, the process of postmortem redistribution of lidocaine was obviously delayed in dogs which were given drugs after death.

Conclusions: Together results revealed the process of postmortem redistribution of lidocaine via epidural injection, and provided the method to distinguish the lidocaine-induced death and drug administration after death.