Determining the state of the deceased during cardiopulmonary resuscitation from tissue distribution patterns of intubation-related lidocaine

The objective of this study was to determine whether the concentrations of lidocaine, used for endotracheal intubation, in body fluids and tissues reflect the state of the circulation of the deceased during cardiopulmonary resuscitation. The tissue distribution of lidocaine was investigated in seven individuals (Cases 1-7) who underwent medical treatment with endotracheal intubation using Xylocaine jelly (a 2% lidocaine hydrochloride preparation), before being pronounced dead. Six patients (Cases 1-6) had cardiopulmonary arrest on arrival at hospital. In Cases 1-4, there was no restoration of heartbeat during cardiopulmonary resuscitation. However, systemic distribution of intubation-related lidocaine was observed and the kidney-to-liver ratios of lidocaine were less than 1. In Cases 5 and 6, the heartbeat resumed temporarily with cardiac massage, and a kidney-to-liver lidocaine ratio greater than 1 was observed. In Case 7, where the patient was comatose upon admission to hospital, the kidney-to-liver ratio of lidocaine was also greater than 1. These phenomena were substantiated in animal experiments. Our results indicate that the absorption of tracheal lidocaine during the artificial circulation resulting from cardiopulmonary resuscitation results in a kidney to liver ratio of less than 1, whereas absorption during natural circulation gives a ratio greater than 1. The kidney-to-liver ratio of intubation-related lidocaine may give useful information on the state of a patient during cardiopulmonary resuscitation.     

Potential for error when assessing blood cyanide concentrations in fire victims.

The present study explores toxicologic significance of blood cyanide concentrations in fire victims. Headspace gas chromatography was used for cyanide detection. Analysis of blood samples from ten fire victims (postmortem interval = 8 h to 3 to 5 d) detected zero to 11.9 mg/L of cyanide and a large difference in cyanide concentrations among victims. Carboxyhemoglobin (COHb) saturation was in the range of 24.9 to 84.2%. To examine the effects of methemoglobinemia and postmortem interval on blood cyanide concentrations in fire victims, an experiment was carried out using rabbits as the animal model. The rabbits were sacrificed by intramuscular injection of 1 mL/kg 2% potassium cyanide 5 min after intravenous injection of 0.33 mL/kg of 3% sodium nitrite (Group A, n = 3) or physiological saline (Group B, n = 6). Average methemoglobin contents immediately before potassium cyanide administration were 6.9 and 0.8% in Groups A and B, respectively. Average cyanide concentrations in cardiac blood at the time of death were 47.4 and 3.56 mg/L, respectively. When blood-containing hearts of the rabbits (n = 3 for Group B) were left at 46 degrees C for the first 1 h, at 20 to 25 degrees C for the next 23 h and then at 4 degrees C for 48 h, approximately 85 and 46% of the original amounts of blood cyanide disappeared within 24 h in Groups A and B, respectively. After the 72-h storage period, 37 and 10%, respectively, of the original amounts of cyanide remained in the blood. When the other three hearts in Group B were left at 20 to 25 degrees C for the last 48 h without refrigeration, cyanide had disappeared almost completely by the end of the experiment. The present results and those published in the literature demonstrate that the toxic effects of cyanide on fire victims should not be evaluated based solely on the concentration in blood.     

Comparative studies on tissue distributions of organophosphorus, carbamate and organochlorine pesticides in decedents intoxicated with these chemicals

This paper describes the tissue distributions of dichlorvos, an organophosphate, chlorpyrifos-methyl, an organophosphorothioate, methomyl, a carbamate, and endrin, an organochlorine, in three individuals (Cases 1-3) who died after ingesting insecticidal preparations containing these chemicals. In Case 1 involving dichlorvos and chlorpyrifos-methyl, no dichlorvos was detected in most of the blood and tissue samples. Tiny amounts of dichlorvos (0.067 mg/L and 0.027 mg/L) were detected in the vitreous humor and cerebrospinal fluid, respectively. The chlorpyrifos-methyl concentrations in the blood samples were very site-dependent with a range of 0.615-2.24 mg/L. The tissue concentrations of chlorpyrifos-methyl were within the range 0.379-8.60 mg/kg. The total amounts of dichlorvos and chlorpyrifos-methyl in the stomach were 879 and 612 mg, respectively. The serum cholinesterase activity was 3 IU/L/37 degrees C. In Case 2 involving methomyl, the methomyl concentrations in the blood samples were very site-dependent with a range of 0.56-4.75 mg/L. The tissue concentrations of methomyl were 2.61 mg/kg or less, no methomyl being detected in the spleen, liver and kidney. The methomyl concentrations in the cerebrospinal fluid and vitreous humor were 5.37 and 4.75 mg/L, respectively. The stomach contained 85 mg methomyl. The serum cholinesterase activity was 73 IU/L/37 degrees C. In Case 3 involving endrin, the victim underwent medical treatment for 7 h after ingesting an endrin preparation. The differences in the endrin concentrations among the blood samples were small, with a range of 0.353-0.615 mg/L. The tissue concentrations of endrin were within the range 0.467-13.3 mg/kg. The endrin in the stomach (66 mg) was adsorbed almost completely on the activated charcoal that was administered for medical treatment.     

Postmortem production of ethanol and n-propanol in the brain of drowned persons

We examined endogenous ethanol and n-propanol levels in the brain in 29 drowning cases in which ethanol consumption was excluded. Based on the stage of putrefaction of the brain, our cases were classified into 4 groups: pulpified brain (PB, n = 11), softened brain (SB, n = 6), discolored brain (DB, n = 2), and normal brain (NB, n = 10). The endogenous ethanol and n-propanol levels (mg/g), respectively, in the brains from these groups were 1.06 +/- 0.401 and 0.076 +/- 0.032 in PB, 0.195 +/- 0.136 and 0.012 +/- 0.009 in SB, and 0.053 +/- 0.032 and 0.001 +/- 0.001 in DB. Ethanol and n-propanol were not detected in NB. The concentration ratios of ethanol to n-propanol were 16.2 +/- 7.1 in specimens with ethanol levels > or = 0.50 mg/g (n = 10), and 17.6 +/- 13.5 in specimens with ethanol levels of 0.10 to 0.49 mg/g (n = 9). Drinking may strongly be suspected when (1) ethanol concentration in the brain is > or = 0.50 mg/g and cerebral ethanol to n-propanol ratio is > or = 40; and (2) the concentration of ethanol is 0.10 to 0.49 mg/g and the ethanol to n-propanol ratio is > or = 60.     

Tissue distribution of nitrazepam and 7-aminonitrazepam in a case of nitrazepam intoxication

We report a case of nitrazepam poisoning in which the distribution of nitrazepam and 7-aminonitrazepam was determined in body fluids and tissues. A 52-year-old woman was found dead in a shallow ditch (approximately 5 cm in depth), in the winter. Ambient temperature was 2-8 degrees C. The postmortem interval was estimated to be approximately 1 day and no putrefaction was observed. The cause of death was thought to be drowning due to nitrazepam overdose and cold exposure. Blood concentrations of nitrazepam and 7-aminonitrazepam were very site dependent (0.400-0.973 microg/ml and 0.418-1.82 microg/ml). In addition, the concentration of the same analytes in the bile were 4.08 and 1.67 microg/ml, respectively, and in the urine: 0.580 and 1.09 microg/ml, respectively. A high accumulation of both substances was observed in various types of brain tissue (2.17-6.22 microg/g and 2.49-5.11 microg/g). Only small amounts of nitrazepam and 7-aminonitrazepam were detected in the liver (0.059 and 0.113 microg/g, respectively). Large differences in the observed concentrations of nitrazepam and 7-aminonitrazepam among arterial and venous blood samples were thought to be mainly due to dilution of arterial blood by water entering the circulation through lungs at the time of death. Bacterial metabolism of nitrazepam may also have contributed to the observed differences.