Postmortem Redistribution Of Lidocaine After Illegal Use

Lidocaine is the most common local anesthetics used for para cervical block to reduce pain associated with surgical abortion. Topical form of lidocaine and its contents have been used for illicit purposes and suicidal intentions. Analysis of lidocaine in different body organs is important for us as a toxicologist to help determine the postmortem redistribution of lidocaine and to avoid misleading of the high lidocaine concentrations. We present two case reports of lidocaine related death. All samples were extracted using solid phase extraction and lidocaine was identified and quantified by gas chromatography with mass spectrometry (GCMS). First case (Case 1) was 25-year-old pregnant women who was undergoing criminal abortion during the first trimester and she died before reaching hospital. Second case (Case 2) was 30-year-old man who ingested of solution contain 10% lidocaine from Avocaine spray 50 ml bottle resulting in seizures and subsequently died. Post-mortem investigations and autopsy show no clear finding. Lidocaine concentrations were detected all analyzed samples with lethal levels. The concentrations of lidocaine were as follows: Case 1 blood 17 mg/l, brain 19 mg/kg, liver 7 mg/kg, kidney 14 mg/kg, and stomach 3 mg/kg. Case 2 blood 63.05 mg/l, urine 21 mg/l, oral swap 9.6 mg/l, brain 29.5 mg/kg, liver 67 mg/kg, kidney 19.2 mg/kg, and stomach 110.2 mg/kg. Our results represent that blood and tissues lidocaine levels were above the lower level of lethal range, therefore, the possibility of lidocaine overdose is expected and considering lidocaine as the cause of death in both cases cannot rule out. Distribution of lidocaine was different in both cases, suggesting, the effect of route of administration. Toxicological findings and factors affecting lidocaine postmortem redistribution and results interpretation are discussed.