Determination of formic acid tissue and fluid concentrations in three fatalities due to methanol poisoning

Three fatalities caused by methanol ingestion are reported. Admission blood methanol concentrations ranged from 0.28 to 4.6 g/L. Two patients had been admitted after a significant delay (>20 hours), and one patient was observed within 90 minutes following ingestion. Formic acid levels were determined in blood samples at admission and ranged from 302 to 680 mg/L. The patients died 44, 55, and 82 hours after poisoning. Formic acid determinations in postmortem tissues were performed by a gas chromatograph method. The authors found great variability in formic acid distribution among the patients and among organs.     

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.     

Postmortem determination of the biological distribution of formic acid in methanol intoxication.

Two 25-year-old men were fatally intoxicated with methanol. The formic acid levels in their blood, urine, and organs were determined postmortem by headspace gas chromatography. The postmortem concentrations of formic acid in the two patients were the following: 0.32 and 0.23 mg/mL in blood, 2.27 and 0.47 mg/mL in urine, 0.11 and 1.17 mg/g in the brain, 0.54 and 0.51 mg/g in the liver, and 0.13 and 1.19 mg/g in the kidneys. The total amounts of formic acid in the gastric contents were 108 and 23.2 mg.     

Morbus Fahr--considerations on a case of sudden death

This paper presents 21 cases related to cyanide intoxication by oral ingestion. Cyanide concentrations in biological specimens are especially different from the type of postmortem specimens, and very important in interpreting the cause of death in postmortem forensic toxicology. Besides the detection of cyanide in autopsy specimens, the autopsy findings were unremarkable. Biological samples (0.2mL or equal to less than 10μg of cyanide) were analyzed colorimetrically for cyanide. In a series of 21 cyanide fatalities, the concentration ranges (mean±SD) of cyanide in heart blood, peripheral blood and gastric contents were 0.1-248.6mg/L (38.1±56.6mg/L), 0.3-212.4mg/L (17.1±45.1mg/L) and 2.0-6398.0mg/kg (859.0±1486.2mg/kg), respectively. The ranges of the heart/peripheral blood concentration ratio and gastric contents/peripheral blood concentration ratio were 0.3-10.6 (mean 3.4) and 3.4-402.4 (mean 86.0), respectively. From the difference of cyanide concentration and the concentration ratio of cyanide in different types of postmortem specimens, the possibility of the postmortem redistribution of cyanide and death by oral ingestion of cyanide could be confirmed. We reported cyanide fatal cases along with a review of literature.     

Postmortem oxycodone and hydrocodone blood concentrations

There is limited data on postmortem oxycodone concentrations, consisting of three published reports with a total of 11 cases, many of which were polypharmacy cases. This report presents the results of a review of autopsy and coroner's reports from 10 counties for the years 2000 and 2001 to locate cases with oxycodone or hydrocodone exposure as a leading cause of death. Eighty-eight cases were located. Twenty-four deaths were attributed to oxycodone alone. Mean and median postmortem oxycodone blood concentrations were 1.23 mg/L and 0.43 mg/L, respectively. The range was 0.12 to 8.0 mg/L, with 13 cases (54%) < or = 0.5 mg/L. Seventeen deaths were attributed to hydrocodone alone. Mean and median postmortem hydrocodone blood concentrations were 0.53 mg/L and 0.40 mg/L, respectively. The range was 0.12 to 1.6 mg/L, with 11 cases (65%) < or = 0.5 mg/L. There were seven cases where the cause of death was attributed to the effects of a combination of hydrocodone and oxycodone. Mean oxycodone and hydrocodone blood concentrations were 0.34 mg/L and 0.14 mg/L, respectively. Forty cases involved polysubstance overdoses with significant involvement of other drugs and ethanol. Mean oxycodone and hydrocodone blood concentrations were 0.18 mg/L and 0.29 mg/L, respectively. The list of other substances involved was extensive but included ethanol, amitriptyline, methadone, codeine, propoxyphene, and acetaminophen. The findings of this study report oxycodone values associated with a fatality at blood concentrations lower than previously reported. This may represent enhanced information because of the larger sample group. Hydrocodone values associated with a fatality were similar to previously published values.     

Fentanyl concentrations in 23 postmortem cases from the hennepin county medical examiner's office

The purpose of this study was to compare blood fentanyl concentrations in fentanyl-related deaths with fentanyl concentrations found incidentally at autopsy, as well as with fentanyl concentrations found in hospitalized patients receiving fentanyl. Between the years 1997 to 2005, 23 fentanyl-positive postmortem cases were identified. Nineteen of 23 (82.6%) cases were deemed to be drug overdoses. Fentanyl alone was responsible for 8 of the 19 (42.1%) overdose deaths. Mean and median fentanyl concentrations were 36 (SD 38) microg/L and 22 microg/L, respectively, range 5-120 microg/L. Seven of the cases were accidental, one undetermined. The remaining 11 of the 19 (57.9%) cases were mixed drug overdoses. Fentanyl concentrations in these cases were 31 (SD 46) microg/L, range 5-152 microg/L. All of the mixed drug overdoses were determined to be accidental. Four cases where fentanyl was considered an incidental postmortem finding were determined to be natural deaths. In hospitalized inpatients (n = 11) receiving fentanyl 2 of the patients receiving fentanyl for chronic pain for more than 3 months had concentrations of 8.5 microg/L and 9.9 microg/L. The other nine inpatient concentrations were less than 4 microg/L. In conclusion, blood fentanyl concentrations found in cases where fentanyl alone was determined to be the cause of death were similar to cases where fentanyl was part of a mixed drug overdose. There was also considerable overlap between fentanyl concentrations in fentanyl-related overdose deaths compared to hospitalized patients being treated for chronic pain. Fentanyl concentrations in postmortem cases must be interpreted in the context of the deceased's past medical history and autopsy findings.     

Fatal methanol intoxication with different survival times--morphological findings and postmortem methanol distribution

Three corresponding cases of fatal methanol intoxication with different survival times were investigated ante-mortem and postmortem. Ante-mortem serum methanol concentrations were determined during treatment in hospital for 4 days. Furthermore, postmortem distribution of methanol in various tissues and fluids was measured after autopsy. Morphological and toxicological findings are discussed based on the literature. The morphological findings correlated with the different survival times. The results of the toxicological analyses were partly in keeping with previously published data. Interestingly, very high methanol levels were determined in brain with very low concentrations in femoral venous blood. These results may have implications for postmortem toxicological analysis, brain death diagnosis and organ explanation for transplantation.     

Tissue distribution of tramadol and metabolites in an overdose fatality

Tramadol (Ultram) is a centrally acting, synthetic analgesic agent. Although it has some affinity for the opiate receptors, tramadol is believed to exert its analgesic effect by inhibiting the re-uptake of norepinephrine and serotonin. There are several published cases of tramadol's involvement in drug-related deaths and impairment. Reports of deaths involving tramadol alone with associated tissue concentrations are rare. This report documents a case in which tramadol overdose was identified as the cause of death. The following tramadol concentrations were found in various tissues: blood, 20 mg/L; urine, 110.2 mg/L; liver, 68.9 mg/kg; and kidney, 37.5 mg/kg. Tissue distributions of the two primary metabolites, N-desmethyl and O-desmethyl tramadol, are also reported. In each tissue or fluid except urine, the tramadol concentration was greater than either metabolite, consistent with other reports of drug-impaired drivers and postmortem cases. The O-desmethyl metabolite concentration was greater than the N-desmethyl metabolite concentration in all tissues; this is in contrast to other postmortem reports, in which the majority of cases report concentrations of O-desmethyl as less than those of N-desmethyl. This may be useful as an indicator of time lapse between ingestion and death.     

Relationship between the concentration of ethanol and methanol in blood samples from Swedish drinking drivers

Headspace gas chromatography was used to determine the concentration of ethanol and methanol in blood samples from 519 individuals suspected of drinking and driving in Sweden where the legal alcohol limit is 0.50 mg/g in whole blood (11 mmol/l). The concentration of ethanol in blood ranged from 0.01 to 3.52 mg/g with a mean of 1.83 +/- 0.82 mg/g (+/- S.D.). The frequency distribution was symmetrical about the mean but deviated from normality. A plot of the same data on normal probability paper indicated that it might be composed of two subpopulations (bimodal). The concentration of methanol in the same blood specimens ranged from 1 to 23 mg/l with a mean of 7.3 +/- 3.6 mg/l (+/- S.D.) and this distribution was markedly skew (+). The concentration of ethanol (x) and methanol (y) were positively correlated (r = 0.47, P less than 0.001) and implies that 22% (r2) of the variance in blood-methanol can be attributed to its linear regression on blood-ethanol. The regression equation was y = 3.6 + 2.1 x and the standard error estimate was 0.32 mg/l. This large scatter precludes making reliable estimates of blood-methanol concentration from measurements of blood-ethanol concentration and the regression equation. But higher blood-methanol concentrations are definitely associated with higher blood-ethanol in this sample of Swedish drinking drivers. Frequent exposure to methanol and its toxic products of metabolism, formaldehyde and formic acid, might constitute an additional health risk associated with heavy drinking in predisposed individuals. The determination of methanol in blood of drinking drivers in addition to ethanol could indicate long-standing ethanol intoxication and therefore potential problem drinkers or alcoholics.     

Beta-hydroxybutyric acid--an indicator for an alcoholic ketoacidosis as cause of death in deceased alcohol abusers

We analyzed the postmortem blood of a total of 100 fatal cases for beta-hydroxybutyric acid (BHBA). In 25 cases of sudden and unexpected death of alcoholics we found pathologically increased levels of BHBA of 1260 to 47200 (median 8000) micromol/L. This led us to the diagnosis of an alcoholic ketoacidosis (AKA) as cause of death in these cases. The control group of 69 postmortem cases revealed that BHBA concentrations below 500 can be regarded as normal, and values up to 2500 micromol/L as elevated. Our study shows that BHBA values over 2500 micromol/L could lead to death, if no medical attention is sought. During storage we did not find any indication of postmortem formation or decomposition of BHBA in blood in vitro or in the corpses. In our opinion, BHBA should be considered the diagnostic marker of choice for the postmortem determination of alcoholic ketoacidosis (AKA) as the cause of death. The classical indications of such deaths are: unexpected death of a chronic alcoholic; none or only traces of ethanol in the blood; increased acetone blood concentration; and neither autopsy, histology, microbiology, nor toxicology reveal the cause of death. In six further cases a diabetic ketoacidosis (DKA) was diagnosed as the cause of death.     

Postmortem atropine concentrations in resuscitation cases

The medications used during resuscitation are often in and of themselves toxic. Several reports have been published regarding toxicities of these drugs, including lidocaine, procainamide, and atropine. But how does a forensic pathologist or toxicologist differentiate a possible intoxication from therapeutic or resuscitory use especially given that the concentrations of such drugs, when used in the setting of resuscitation, have not been studied? Concentrations of a well-known resuscitation medication, atropine, were assessed in cases where it was administered before death during attempted resuscitation in an effort to address this deficiency. A review of deaths occurring in 2009 was undertaken to identify cases where drugs known to be used during resuscitation were present on toxicological analysis. Autopsy reports and medical records were examined to determine how much atropine was administered, the timing and route of administration, the time the sample was drawn (antemortem and postmortem), the source of the sample, and the ultimate cause of death. Eighty-nine cases were identified in which atropine was given before death during attempted resuscitation and was detected in the blood on postmortem toxicological screening; 11 cases were identified in which atropine was administered before death yet was not detected on the postmortem toxicological screening. Mean age was 41 years, and there were 65 males and 35 females. The overall median dose of atropine given was 3 mg, the median difference between the time of last administration of the atropine to the time of death (or draw for antemortem samples) was 15 minutes, and the median atropine concentration was 0.1 mg/L. Analysis failed to reveal significant differences in the atropine concentration based on the route of administration (intravenous or intraosseus), the cause of death, or the time since administration (within the first 2 hours). Analysis did reveal a difference between the atropine concentrations in peripheral versus central blood sources and with prolonged postmortem interval (>24 hours) suggesting postmortem redistribution.     

Site-dependent postmortem changes in blood cocaine concentrations

When a forensic toxicologist interprets postmortem blood cocaine findings he usually must make assumptions regarding perimortem drug concentrations. In-vitro studies have shown that cocaine rapidly hydrolyzes in unpreserved blood, particularly at elevated temperatures. However, other studies have demonstrated site-dependent postmortem release of some drugs from tissue stores accompanied by increases in drug concentrations in the blood. This study was undertaken to investigate whether blood cocaine concentrations change in the body during the postmortem interval and, if so, to measure the direction and magnitude of the changes. In medical examiner cases in which scene investigation suggested that the decreased was a cocaine user, blood samples were collected as soon after death as possible. At autopsy, a second set of samples was collected. Analysis of paired samples by gas chromatography/mass spectrometry (GC/MS) revealed dramatic differences in the cocaine concentration. The magnitude and direction of the change appears to be site dependent. Usually, but not invariably, cocaine concentration in subclavian vein blood decreases while that in heart, aorta, and femoral vein blood increases during the interval between death and autopsy. The findings emphasize the danger inherent in attempting to estimate the concentration of cocaine in blood at the time of death from postmortem data.     

Fatal Oral Methylphenidate Intoxication with Postmortem Concentrations

Methylphenidate (MPD) is a widely prescribed stimulant used primarily for the treatment for attention‐deficit/hyperactivity disorder (ADHD). Suicide attempts involving MPD ingestion have been well described; however, deaths attributed solely to MPD ingestion have not been reported. A 62‐year‐old woman was found dead on her floor. The only discrepancy in among her medication quantities was that >three hundred 10 mg MPD tablets were missing. Analysis utilizing gas chromatography–mass spectrometry revealed elevated postmortem MPD peripheral and central blood, liver and vitreous humor concentrations. Considering both the central blood to peripheral blood ratio (0.89) and the liver to peripheral blood ratio (3.3), MPD does not appear subject to significant postmortem redistribution. With no other identifiable cause of death, we report what appears to be the first isolated MPD ingestion associated with a fatality.     

Acute cardiovascular fatalities following cannabis use.

We report six cases of possible acute cardiovascular death in young adults, where very recent cannabis ingestion was documented by the presence of tetrahydrocannabinol (THC) in postmortem blood samples. A broad toxicological blood analysis could not reveal other drugs. Similar cases have been reported in the literature, but the toxicological analysis has been absent or limited to urine samples, which represent a much broader time window for cannabis intake. This paper presents six case reports, where cannabis alone was detected in blood. Further, an overview over previously published cases, clinical trials and possible patho-physiological mechanisms are presented.     

“Bath Salts” the New York City Medical Examiner Experience: A 3‐Year Retrospective Review

“Bath salts” are synthetic derivatives of cathinones, compounds found in the leaves of Catha edulis, which possesses amphetamine‐like properties. At the New York City Office of Chief Medical Examiner, we conducted a 3‐year retrospective analysis of deaths in which cathinones were detected. Two categories emerged; those in which cathinones were a contributory cause of death (15 cases) and those in which they were an incidental finding (15 cases). Of the former group, 13 were associated with additional intoxicants; two deaths were attributed solely to cathinone intoxication, both survived 10 h: a man whose postmortem blood methylone concentration was 0.71 mg/L and a woman whose postmortem blood ethylone concentration was 1.7 mg/L. In the latter category, there were several individuals who had higher concentrations of cathinones than the above two, the highest being a blood methylone of 4.8 mg/L. Based upon our data and the literature presented, lethal concentrations of cathinones cannot be established.     

Postmortem blood free and total morphine concentrations in medical examiner cases

This purpose of this study was to determine the relationships between postmortem free morphine and total morphine levels in a large series of medical examiner morphine and heroin related deaths. Free morphine, total morphine, and 6-monoacetylmorphine (6-MAM) concentrations were measured by gas chromatography-mass spectrometry (GC-MS) in 87 medical examiner cases over 20 months. The mean total morphine concentration, mean free morphine concentration, and mean percent free morphine for all cases were: 2.3 mg/L (SD 5.2 mg/L), 0.5 mg/L (SD 1.6 mg/L), and 19.4% (SD 22.8%); respectively. Regression analyses showed weak correlations between total and free morphine concentrations over the entire concentration range (0 to 36.6 m/L, r = 0.603, n = 91) and over a subset concentration range of 0 to 1.0 mg/L (r = 0.369, n = 54). Twenty-three out of 56 (41%) tested positive for 6-MAM, indicative heroin abuse cases. Lower total and free morphine concentrations and a higher percent free morphine were found in individuals with detectable 6-MAM. Comparing blood concentrations for cases with and without detectable 6-MAM demonstrated mean total morphine concentrations of 0.9 mg/L versus 2.1 mg/L (p = 0.05), mean free morphine concentrations of 0.3 mg/L versus 0.4 mg/L (p = 0.21), and mean percent free morphine of 34.7% versus 13.7% (p < 0.003), respectively. Our findings demonstrate higher free to total morphine ratios in individuals with detectable 6-MAM than in individuals without 6-MAM. The database established in this study may assist medical examiners in the evaluation of postmortem blood opiates regarding the cause of death in opiate related ingestion cases.     

Contributory and Incidental Blood Concentrations in Deaths Involving Citalopram

All cases presenting to the New South Wales Department of Forensic Medicine between January 1, 2001 and December 31, 2010 in which citalopram was detected were retrieved. A total of 348 cases were identified. Citalopram contributed to death in 21.0%, and was incidental in 79.0%. Cases in which citalopram was contributory to death had significantly higher blood citalopram concentrations than incidental cases (0.50 mg/L vs. 0.30 mg/L). Citalopram concentrations varied significantly by contributory status: sole citalopram toxicity (median = 1.30 mg/L), citalopram/other drug toxicity (0.50 mg/L), and incidental cases (0.30 mg/L). Citalopram concentrations also varied by suicide status, with the highest concentration found in suicides where citalopram contributed to death (0.70 mg/L) compared with 0.50 mg/L for nonsuicide cases where citalopram contributed to death. In almost all contributory cases (69/73), other psychoactive substances were also detected, most commonly benzodiazepines (47.9%), alcohol (45.2%), and opioids (40.1%).     

One hundred seventy two deaths involving the use of oxycodone in Palm Beach County

Oxycodone is a potent semi-synthetic narcotic prescribed for the management of pain. Previous investigators have reported that the abuse of oxycodone is most frequently seen in conjunction with the abuse of other drugs, although fatalities have been reported with oxycodone alone. We undertook a retrospective review of cases investigated by the Palm Beach County Medical Examiner's Office in which postmortem toxicologic studies indicated the presence of oxycodone. A total of 172 consecutive cases were studied, including 18 in which death was attributed to oxycodone toxicity, 117 to combined drug toxicity, 23 to trauma, 9 to natural causes and 5 to another drug or drugs. The postmortem blood concentrations of oxycodone overlapped among the groups. The mean blood oxycodone concentration among the cases of oxycodone toxicity was 0.69 mg/L, combined drug toxicity 0.72 mg/L and trauma 0.62 mg/L. Concentrations were lower in cases of deaths attributed to natural causes and to another drug or drugs (mean each 0.087 mg/L). Benzodiazepines, detected in 96 cases, were the most common co-intoxicants in the cases of combined drug toxicity, followed by cocaine, which was found in 41. The most frequently encountered benzodiazepine was alprazolam. This study confirms that deaths in which oxycodone is a factor are most commonly cases of combined drug toxicity. The high incidence of alprazolam as a co-intoxicant has not been previously recognized.     

The Difficult Task of Assessing Perimortem and Postmortem Fractures on the Skeleton: A Blind Text on 210 Fractures of Known Origin

The distinction between perimortem and postmortem fractures is an important challenge for forensic anthropology. Such a crucial task is presently based on macro‐morphological criteria widely accepted in the scientific community. However, several limits affect these parameters which have not yet been investigated thoroughly. This study aims at highlighting the pitfalls and errors in evaluating perimortem or postmortem fractures. Two trained forensic anthropologists were asked to classify 210 fractures of known origin in four skeletons (three victims of blunt force trauma and one natural death) as perimortem, postmortem, or dubious, twice in 6 months in order to assess intraobserver error also. Results show large errors, ranging from 14.8 to 37% for perimortem fractures and from 5.5 to 14.8% for postmortem ones; more than 80% of errors concerned trabecular bone. This supports the need for more objective and reliable criteria for a correct assessment of peri‐ and postmortem bone fractures.