Digoxin, magnesium, and potassium levels in a forensic autopsy material of sudden death from ischemic heart disease

In 91 cases where the cause of death was heart disease, digoxin, Mg and K concentrations in serum and ventricular myocardium were measured post mortem. Forty per cent were positive for digoxin in both serum and myocardium. The mean serum level was 5.1 +/- 2.4 nmol/l and the mean myocardial level was 42.6 +/- 27.5 ng/g. Correlation could be established between serum and myocardial concentrations of digoxin. There were statistically significant differences in serum as well as in myocardial digoxin levels in persons on 0.13 mg and 0.25 mg per day, respectively. Myocardial levels of Mg and K were low as generally found in persons with ischemic heart disease. There was no correlation between these levels and myocardial digoxin concentrations. Caution must be exercised in the assessment of digoxin results from cadaver samples because of the postmortem rise of digoxin serum concentrations. Considering this fact, the results still indicate that the prevalence of toxic digoxin concentrations might be more common than previously thought.     

Distribution of digoxin, digitoxin and their cardioactive metabolites in human heart and kidney tissue. A postmortem study

A method was developed for the specific determination of digoxin and digitoxin, as well as their semisynthetic derivatives and dependent cardioactive metabolites, in autopsy samples of heart and kidney. A collective of six patients on long-term treatment with therapeutic doses of beta-acetyldigoxin had a mean myocardial digoxin content of 46.1 +/- 25.0 ng/g (SD); kidney: 50.3 +/- 30.3 ng/g. Digoxigenin bisdigitoxoside represented the second most important metabolite in heart and kidney; digoxigenin monodigitoxoside and digoxigenin follow, respectively. In a collective of seven patients on maintenance treatment with digitoxin, the mean tissue levels were higher but the metabolic pattern was similar (myocardial digitoxin content: 78.9 +/- 38.4 ng/g, renal content: 104.1 +/- 44.1 ng/g). The amount of digoxin formed by hydroxylation under long-term treatment with digitoxin in heart and kidney were approximately 10 ng/g. A case of digoxin intoxication differed both in the tissue content and in the metabolic distribution.     

Interpretation of postmortem digoxin levels: evaluating a "corrective factor" for postmortem blood digoxin concentration

Interpretation of postmortem serum digoxin levels is made difficult above all by a possible prefinal or postmortem rise in digoxin concentrations in the blood. To compensate for this postmortem increase, Eriksson et al. (1984) divided the level of postmortem digoxin in femoral venous blood by a factor of 1.5; in the opinion of these authors, postmortem digoxin levels still exceeding "therapeutic levels" after division by 1.5 are an index of digoxin overdose. The diagnostic value of this "correction factor" was investigated. In 56 cases with documented digoxin medication, samples of postmortem femoral venous blood were taken and the level of digoxin determined. In none of the cases had there been a clinical diagnosis of digoxin intoxication. Fifty percent of the measured values were above "therapeutic levels" (0.7 ng/ml to 2.2 ng/ml). Following division by 1.5, 20% of the cases still showed levels exceeding 2.2 ng/ml; the highest "corrected" value was 4.44 ng/ml. Taking into account the length of time between final dosage and death, individual differences in sensitivity to digitalis glycoside, and the complexity of ante- and postmortem dispersion processes, we concluded for the cases we studied that an (undetected) digoxin overdose was not even likely in those cases whose postmortem values after division by 1.5 lie above "therapeutic levels". The "correction factor" proposed by Eriksson et al. (1984) is only of limited diagnostic value; at best the "corrected" values can give an approximate indication of the corresponding antemortem serum digoxin concentrations. In particular, "corrected" values only a little above "therapeutic levels" could not confirm suspicion of an overdose with sufficient certainty.     

Postmortem redistribution of digoxin in rats

Adult male Wistar rats were treated with either 0.1 or 3 mg/kg body weight X day of digoxin for five days, then killed and stored at 4 degrees C for 12 h in an attempt to mimic the normal preautopsy procedures in our hospital. In rats treated with 0.1 mg/kg body weight X day, the antemortem serum digoxin concentrations (SDC) were 1.1 +/- 0.4 ng/mL while the 12-h postmortem concentration was markedly increased (16.3 +/- 5.9 ng/mL) (P less than 0.01). In rats treated with 3 mg/kg body weight X day, SDC was not changed significantly (11.2 +/- 4.8 ng/mL antemortem and 13.3 +/- 6 ng/mL postmortem). Postmortem redistribution of digoxin was assessed by injection of 125I-labelled digoxin with or without pretreatment with the unlabelled drug. The results indicate that after death passive redistribution of digoxin may take place. When the SDC are within the therapeutic or low toxic range, digoxin may reenter the blood. High antemortem serum concentrations of digoxin may prevent such passive redistribution. Therefore, antemortem digoxin intoxication cannot be reliably inferred on the basis of high postmortem levels of the drug. Digoxin intoxication can be ruled out when postmortem SDC remain within the therapeutic range. The above changes cast doubt on some of the forensic and cardiologic literature, which has in the past been based on incorrect assumptions concerning postmortem behavior of digoxin.     

Digoxin-like immunoreactive substance in postmortem blood of infants and children

A digoxin-like immunoreactive substance (DLIS) has been reported in the serum of infants not receiving digoxin. This study was undertaken to determine if DLIS is present in the postmortem blood and tissues of infants or children and whether the endogenous substance could interfere with forensic toxicological analysis in suspected overdose. Ninety blood specimens taken from the heart at autopsy of children or infants were screened for DLIS using commercial radioimmunoassay kits. The average age at death in these cases was 8.6 months, the median age was 2 months. DLIS equivalent to 0.25 to 2.0 ng/mL digoxin was found in one third of the cases. The incidence of positive findings was 5/6 stillborns, 10/45 Sudden Infant Death Syndrome (SIDS), 10/15 deaths as a result of infection, 4/7 homicides, 1/8 deaths caused by congenital defects, and 0/9 accidental deaths. The body distribution of DLIS was investigated and highest levels were found in the liver. Findings of DLIS in blood were correlated with renal failure, (elevated vitreous urea nitrogen), electrolyte imbalance, and liver trauma. Apparent concentrations were in the equivalent therapeutic range of digoxin and would not be confused with accidental or intentional overdose with digoxin.     

Classification of digoxin concentrations in blood and tissues in cases under suspicion of poisoning

The clarification of a suspicion of poisoning at all times poses a problem to the forensic toxicologist, when a narrow margin of therapeutic safety and a low dosage coincide as in cases of digoxin poisoning. Statistical methods may serve as an aid. The post mortem digoxin concentration in the tissues of heart, kidney, liver and in blood of 45 patients who had received therapeutic daily doses and of 13 cases of fatal poisoning are compared. After logarithmic transformation of the individual concentration values a two modal distribution is obtained. There is one concentration calculated with equal probability of being classified to "therapeutic or toxic", as well as the probability of observing the "critical" concentrations of 400 ng digoxin/g cardiac tissue, 500 ng/g kidney and 250 ng/g liver after therapeutic dosing. Using the discriminant analysis each of the cases clearly falls into one of the two collectives "therapeutic" and "toxic", when taken as a separate observation. Concentration data of fatal poisonings taken from the literature are as successfully classified as the analytical results of some exhumed bodies under suspicion but not poisoned. As expected the power of discrimination increases with the number of parameters. Because of the relatively slow body distribution of digoxin the blood taken from peripheral vessels is of most important evidence.     

Stable isotopic characterization of ammonium metavanadate (NH4VO3)

The diagnosis of fatal anaphylaxis can be difficult for clinical features may not always be evident in necropsy. Therefore post mortem determination of tryptase and other blood parameters can be helpful in verifying the diagnosis. We compared post mortem tryptase, histamine and diamine oxidase (DAO) serum levels of two patients who had died after a Hymenoptera sting and one patient who died of bronchospasm during anaesthesia with data obtained from 55 control subjects who had died from other causes than anaphylaxis. In the three anaphylactic cases, serum tryptase level was 880, 68 and 200 μg/l (normal range in living subjects: <11.4 μg/l), histamine was 37.5, 8.5 and 23.2 ng/ml (normal range: <0.3 ng/ml) and DAO was 1, 30 and 4 U/ml (normal range 10-30 U/ml), respectively. Values in the control group were as follows: tryptase 1-340 μg/l (mean 24.2 ± 58.2), histamine 5.0-22.0 ng/ml (mean 14.7 ± 3.9) and DAO 0-114 U/ml (mean 21.1 ± 27.8). 19/55 (34.5%) of the controls had elevated tryptase levels >11.4 μg/l, with four of them showing values >45 μg/ml. Significantly higher histamine levels were seen in blood samples taken more than 24h post mortem (p<0.05), whereas the timing of blood collection had no effect on tryptase and DAO levels. While moderately elevated tryptase levels are common in post mortem sera, values above 45 μg/l may support the diagnosis of fatal anaphylaxis. Strongly elevated histamine levels might give an additional clue on fatal anaphylaxis, whereas DAO does not seem to be helpful.     

Minimizing analytical interferences from digoxin-like immunoreactive substances (DLIS) in cases of digoxin toxicity

Recently, the value of therapeutic drug monitoring for digoxin has been called into question by the finding of endogenous digoxin-like immunoreactive substances (DLIS) in the serum of individuals, especially premature and full-term neonates, not being treated with digoxin. In some cases, values have been as high as 10 micrograms/L. Levels as high as 20 micrograms/L and 80 micrograms/g can be found in bile and meconium. Because of the magnitude of this interference, it is essential that methods be developed for measuring digoxin in the presence of DLIS. This is particularly important when such analyses are required in forensic science cases of suspected digoxin toxicity. This report outlines the high performance liquid chromatographic (HPLC) and radioimmunoassay (RIA) methods that we used in assessing the relative contribution made by digoxin, its metabolites, and DLIS to serum and tissue digoxin concentrations obtained by RIA in a forensic pediatric case of suspected digoxin toxicity.     

Subacute fatal aluminum poisoning in dialyzed patients: post-mortem toxicological findings

The population of Cura?ao, Netherlands Antilles (133,000) shows a very high prevalence of end-stage renal disease (approximately 1 per 1,000). These patients are often treated chronically with haemodialysis. As the drinking water on the island is prepared by distillation of sea water, the haemodialysis fluid used to be prepared with tap water without further treatment. In 1996, the 27 patients of one of the dialysis centers on the island presented with nausea, vomiting, and hypercalcaemia in a short time span, which was initially diagnosed as 'hard water syndrome'. In spite of treatment with low-calcium dialysate, microcytic anaemia and neurological symptoms developed. Ten patients died of convulsions, sepsis, and coma. As aluminum (Al) intoxication was suspected, Al in serum (AlS) was measured. Ante mortem AlS was 808 microg/l (n = 7; range 359-1189); in the survivors AlS was 255 microg/l (n = 17; range 113-490). Normal AlS is < 10 microg/l, and <50 microg/l in asymptomatic dialyzed patients. The court requested post-mortem toxicological analysis of four patients. Al concentrations in liver, bone, and cerebral cortex were significantly increased as compared with background levels. Al intoxication was, therefore, considered to be the most likely cause of death in these patients. Investigations of the tap water supply revealed that a few weeks before the onset of the symptoms, a water conduit pipe to the dialysis unit had been replaced, which was lined with Al- and Ca-rich cement mortar. These ions leached into the distilled water and caused both Ca- and Al-intoxication through uptake from the dialysate into the patients' circulation. The symptoms of the latter were initially not recognized as they were masked by the symptoms of hypercalcaemia.     

Comparison of nonradioactive microtiter plate enzyme immunoassays for the sensitive detection of fentanyl

Fentanyl is a very strong opioid with analgesic properties that are approximately 80 times stronger than those of morphine and therefore is used in major surgery and treatment of pain in tumor patients. Cases of fentanyl abuse by intravenous injection, inhalation, oral or nasal application have been reported especially in the USA. Therapeutic levels of fentanyl are as low as 1 ng/ml of serum and therefore a screening test must have a detection limit below that concentration. Recently three non-radioactive enzyme immunoassays (EIAs) have become commercially available from COZART, STC and DIAGNOSTIX, all of them supplied by MAHSAN Diagnostika for evaluation with serum samples from forensic and clinical cases. A calibration curve is obtained with samples that contain 0, 0.1, 0.5, 1 and 5 ng fentanyl per ml of negative serum. The calibration curve of COZART is especially in the low range, steeper than those of STC and DIAGNOSTIX. The cut-off for all these EIAs, however, can be set at 0.5 ng/ml. After the administration of therapeutic doses, fentanyl concentrations were between 3 and more than 5 ng/ml as determined with the EIAs. The presence of the typical drugs of abuse, e.g. heroin, methadone, cocaine, cannabinoids and amphetamines including the derivatives of methylenedioxyamphetamine, don't generate false-positive results. No cross-reactivity was also observed at toxic levels of benzodiazepines and paracetamol and therapeutic levels of barbiturates, phenothiazines, antidepressants and analgesics. The EIAs tested so far appear to be suitable for the detection of fentanyl at therapeutic levels. False-positive results or cross-reactivity towards other compounds have not been observed.     

Drugs as markers in identification. Detection of melperon (Buronil) in an adipoceratous corpse

The body of a 76-year old female pensioner was recovered from the Danube as adipoceratous torso after the person had been missing for almost two years. Identification first of all based on comparing postmortem and radiological findings which revealed correspondence of numerous features. The missing woman had been receiving long-term drug therapy of melperone (active substance of the neuroleptic Buronil) in doses of 25 mg three times daily. Combined gas chromatography and mass spectrometry succeeded in detecting the characteristic mass fragment of melperone in the adipoceratously transformed bone marrow of the water-logged corpse; in the remaining soft tissues outside the bones the concentration was below detection range. The reported case exemplifies that demonstration of low drug levels resulting from therapeutic ingestion can contribute to the identification of extensively decomposed bodies and to the correct relating of severed parts.     

An enzyme-linked immunosorbent assay for plasma-paraquat levels of poisoned patients

To investigate the efficacy of medical treatments, plasma-paraquat levels were measured in patients who had ingested the liquid weedkiller, Gramoxon, containing paraquat. We determined the levels by an enzyme-linked immunosorbent assay (ELISA) using a murine paraquat-specific monoclonal antibody developed by Niewola et al. (Clin. Chim. Acta, 148 (1985) 149-156). Using this ELISA, concentrations of paraquat in the range 1.56-100 ng/ml could be measured. This assay method had good precision and was suitable for measurement of low levels of paraquat. The therapeutic treatments were most effective on the day of admission. The plasma-paraquat levels of poisoned patients decreased significantly. However, the levels tended to increase again during the pause period of the haemoperfusion and this increase was serious for fatal cases. It is clear that elimination of poison not only from blood but also from tissues is necessary to lower the mortality rate.     

Comparative evaluation of postmortem serum concentrations of neopterin and C-reactive protein

The cellular immune response is accompanied by the release of neopterin. The level of neopterin in serum is increased in patients suffering from viral infections, autoimmune diseases, systemic inflammation, allograft rejection and malignant diseases, while that of C-reactive protein (CRP) is known to rise during inflammatory diseases and traumas. To investigate postmortem neopterin and CRP concentrations with regard to the cause of death, we examined cardiac and peripheral blood samples in 474 autopsy cases without advanced decomposition (0-96 years of age, 343 males and 131 females), 2.8 h to 3 days (median, 18.0 h) after death. Survival time was 0.1 h to 5 months (median, 3.0 h) for traumatic death, and 0.1-1, 440 h (median, 2.5 h) for natural death. In autopsied subjects, neopterin concentrations were higher than the clinical reference, independent of the time after death, and depended on the survival time. In cases of acute and subacute death due to trauma, the neopterin level in right heart blood was mildly to moderately elevated (about 50-200 nmol/l) except for sharp instrument injury, whereas the CRP concentration usually remained low (<1 mg/dl). However, a moderate rise in the CRP level (around 1-10 mg/dl) was observed in fatal cases of hypothermia (cold exposure). Markedly elevated serum CRP and neopterin levels (>10 mg/dl and >500 nmol/l, respectively) were detected in cases of delayed death due to trauma involving systemic inflammatory response syndrome (SIRS) and of fatal bacterial infections. For sepsis, the serum CRP level was markedly elevated but the neopterin level was low in some cases. Fatal viral infections usually resulted in a marked elevation in the serum neopterin level (>500 nmol/l) with a mild to moderate rise in the CRP level. Combined analyses of neopterin and CRP may be useful to investigate viral infections and delayed traumatic death involving SIRS to support pathological findings.     

Comparison of ethyl glucuronide in hair with phosphatidylethanol in whole blood as post-mortem markers of alcohol abuse

Ethyl glucuronide (EtG) is a direct metabolite of ethanol and has been used as a marker of alcohol abuse in both urine and hair. This study investigated the value of EtG testing in post-mortem hair for diagnostic improvement of alcohol abuse in forensic medicine. Material from 70 consecutive medico-legal autopsies was collected in accordance with the recommendations on ethics by the Swedish National Board of Forensic Medicine. A method for determination of EtG in hair samples was developed using ultra performance liquid chromatography/electrospray tandem mass spectrometry (UPLC/ESI-MS/MS; LOQ, 2.5 pg/mg). The result of the EtG analysis was compared with the findings of phosphatidylethanol (PEth) in femoral whole blood, as measured by high performance liquid chromatography with an evaporative light-scattering detector (HPLC-ELSD; LOQ, 0.22 micromol/l). Evaluation of liver histology and anamnestic evidence of alcohol abuse of the deceased were taken in consideration for the interpretation. Measurable levels of EtG were present in 49 of the 70 autopsy cases whereas PEth was present in 36. Thirty-nine cases had EtG levels above the cutoff limit (> or = 30 pg/mg) compared with 29 for PEth (> or = 0.7 micromol/l). Fifteen cases had EtG as exclusive indicator for alcohol abuse compared with four cases for PEth. These findings suggest that measurements of EtG in hair may provide improved diagnostic information on alcohol abuse, due to a long retrospective time-window for detection and stability of EtG in hair in the decaying cadaver. However, an EtG level below the cutoff does not completely exclude previous alcohol abuse.     

Post-mortem analysis of formic acid disposition in acute methanol intoxication

Fifteen cases of fatal massive methanol intoxication have been investigated. Victims received either no treatment or ethanol therapeutic treatment. Methanol poisoning cases were classified in three groups according to survival time: more than 3 days (group 1), up to 3 days (group 2) and few hours (group 3). Body distribution of methanol and formic acid, as the main metabolite, was analyzed in blood and in different organs (brain, kidney, lung and liver). Relationships between formic acid concentration in the different tissues, survival time and type of treatment applied to victims were studied. Formic acid in blood and tissues was analyzed by head space gas chromatography (head space-GC) with FID detector, previous transformation in methyl formate, essentially as described by Abolin. Formic acid concentration was between 0.03 and 1.10g/l in the samples under study. A good correlation between blood and brain, but poor between blood and the remaining tissues was found. Obtained data suggested that the use of blood and brain could help to improve the analysis of formic acid intoxication. The best correlation among organs was found between lung and kidney for all groups (r(2)=0.91, 0.84 and 0.87, corresponding to groups 1, 2 and 3, respectively). Lethality index was defined as LI = (concentration of formic acid in blood in (g/l)/0.5) x 100, taking into account that 0.5g/l is the concentration reported by Mahieu in severe methanol poisoning. LI parameter was used to estimate formic acid incidence on the lethality of methanol poisoning cases. LI showed a good correlation with total formic acid concentration of the different tissues analyzed (r(2)=0.80). Furthermore, LI allowed us to discriminate between individuals that received therapeutic treatment and survived different periods. LI>100 indicated a severe intoxication and short survival time if the victim was assisted with ethanol therapy and hemodialysis was not applied. With regard to victims who received no therapeutic treatment and died in few hours, LI was in the range 40-100. LI was below 40 for individuals that survived more than 3 days and hemodialysis was not performed. Results showed the importance of performing formic acid analysis to diagnose severe methanol intoxication in post-mortem cases.     

Tissue concentrations at autopsy in infants and children receiving therapeutic digoxin

Therapeutic tissue concentrations of digoxin have been reported for relatively small numbers of infants and children. In forensic medicine, knowledge of these concentration ranges is important for confirming or excluding digoxin overdosage in different age groups. In addition to age and weight, other factors such as dosage, duration of treatment, route of administration, sampling site, time of last dose, and death-autopsy interval may influence tissue concentrations. In this paper we report on tissue concentrations in 36 infants and children who received therapeutic digoxin before death.     

Death during patient-controlled analgesia: piritramide overdose and tissue distribution of the drug

We report about a fatality during patient-controlled analgesia (PCA). Piritramide peripheral blood concentration was measured with 0.1 mg/l and exceeded the normal therapeutic range. Therefore, a fatal overdose was considered as the cause of death with respiratory depression as the underlying pathophysiological mechanism. The tissue distribution was studied; highest concentrations of piritramide were measured in kidney, bile and urine. Due to a large volume of distribution a difference in the drug concentration found in heart and peripheral bloods the phenomenon of drug redistribution was observed. Confronted with toxicological results, investigations revealed, that the PCA pump had been changed during a previous servicing from displaying mg/h to ml/h, therefore, the anesthetist had entered "1.5" assuming mg/h, but actually applying 1.5 ml/h (which was therefore equivalent to 2.25 mg/h, given a concentration in the cartridge of 1.5 mg piritramide/ml). In total, 61.5 ml (instead of 61.5 mg) had been infused, equivalent to 92.25 mg piritramide. This case report is a further example that human errors can play a crucial role in the safety of medical equipment. Experts in anesthesia recommended human factors engineering design principles to improve the safety of medical devices.     

Correlation between 'on admission' blood toluene concentrations and the presence or absence of signs and symptoms in solvent abusers

For 1 year, from June 1987 to June 1988, toluene concentrations in blood samples of patients admitted to a psychiatric hospital after inhaling solvent vapor, collected on admission and 4 h later, were analyzed by gas chromatograph. Toluene levels in the first urine samples collected after admission were also analyzed and case histories were kept listing age, sex and physical and psychiatric effects. In all, 51 cases were studied--34 males and 17 females. (1) The average age of the males was 21.4 years and of the female 16.2 years. (2) The toluene concentrations in the blood collected on admission ranged from 0.3 to 22.8 micrograms/g. (3) Physical signs were observed in 9 patients with an "on admission" blood toluene concentrations of more than 3.0 micrograms/g; twice as many subjects (18), however, with blood toluene concentration greater than 3.0 micrograms/g were without physical signs. (4) The blood toluene concentrations of three cases in the condition known as twilight state were more than 10.0 micrograms/g. (5) In 24 cases with blood toluene concentrations below 3.0 micrograms/g, there were no physical signs. (6) Five subjects with blood toluene concentrations in the 0.8-5.2 micrograms/g range showed neuropsychiatric effects; however, 23 subjects in the same blood toluene concentration range did not exhibit psychiatric effects, and none of the subjects with blood toluene concentrations greater than 5.2 micrograms/g, 15 in all, had such effects.     

Fatality due to ingestion of tramadol alone

A rare case of a fatal intoxication in an adult with tramadol alone is reported. In the peripheral blood, tramadol was measured in a concentration of 9.6 mg/l exceeded at least 30-times the normal therapeutic range of 0.1-0.3 mg/l. The concentration of tramadol in liver and kidney, in relation to blood, failed to suggest a major sequestration of drug in either specimen which is consistent with the volume of distribution of 3 l/kg. The concentration of tramadol in the heart and peripheral blood specimens did not suggest a major difference (ratio of 1.36). Similar to morphine tramadol was accumulated significantly in the bile.