A New Approach for the Carbon Monoxide (CO) Exposure Diagnosis: Measurement of Total CO in Human Blood Versus Carboxyhemoglobin (HbCO)

The aim of the study is to present the application of a headspace–gas chromatography–mass spectrometry (HS‐GC‐MS) method for the determination of the carbon monoxide (CO) blood concentration and to compare it with carboxyhemoglobin (HbCO) saturation. In postmortem cases, the HbCO measured by spectrophotometry frequently leads to inaccurate results due to inadequate samples or analyses. The true role of CO intoxication in the death of a person could be misclassified. The estimation of HbCO from HS‐GC‐MS CO measurements provides helpful information by determining the total CO levels (CO linked to hemoglobin (HbCO) and CO dissociated from hemoglobin). The CO concentrations were converted in HbCO saturation levels to define cutoff blood CO values. CO limits were defined as less than 1 μmol/mL for living persons, less than 1.5 μmol/mL for dead persons without CO exposure, and greater than 3 μmol/mL for dead persons with clear CO poisoning.     

Comparison of Different Analytical Methods for the Determination of Carbon Monoxide in Postmortem Blood

The determination of carbon monoxide (CO) and carboxyhemoglobin (COHb) is of utmost importance in forensic toxicology to determine the cause of death in cases of CO poisoning, fire, and explosions. To this end, reliable and updated analytical methods are required. In this paper, four different methods for the determination of carbon monoxide in postmortem blood samples were compared: (i) the spectrophotometric determination of COHb applying the method proposed by Rodkey and modified by Beutler–West, (ii) the spectrophotometric determination of CO using a micro-diffusion-based method, (iii) the determination of CO by gas chromatography coupled to a TCD detector, and (iv) the determination of COHb by blood gas analysis. Three postmortem blood samples were analyzed with all methods, and the results were comparable. The applied methodologies showed different features depending on the sensitivity, sample preparation, and volume. The HS-GC/TCD method in our hand was the most appropriate, on postmortem samples, and versatile to apply. Unfortunately, only a limited number of postmortem blood samples were available for this study due to the rarity of that kind of intoxication in our jurisdiction.     

Production of carbon monoxide in cadavers

Carbon monoxide (CO), total hemoglobin (Hb) and carboxyhemoglobin (HbCO) in the blood and reddish discolored body cavity fluids of cadavers which had not been exposed to fire and CO were analyzed. In 13 cadavers found on land, the maximum saturation of HbCO in the blood was 3.6%, and was 10.1% in the body cavity fluids. There was only one case in which the HbCO saturations in the body cavity fluids were more than 10%. In seven drowned bodies found in fresh water, the highest HbCO saturation in the blood was 6.1%, and was 44.1% in the body cavity fluids. There were three cases in which the HbCO saturations in the body cavity fluids were more than 10%. In 12 drowned bodies found in sea water, the HbCO saturations in the blood were not more than 6.2%, and the maximum saturation of HbCO in the body cavity fluids was 83.7%. There were eight cases in which the HbCO saturations in the body cavity fluids were more than 10%. The results seem to indicate that the interpretation of HbCO saturation in the blood would not be affected significantly by the postmortem formation of CO, and that body cavity fluids should not be used for CO determination.     

The role of environmental factors in the causation of sudden death in infants: two cases of sudden unexpected death in two unrelated infants who were cared for by the same babysitter

We report two cases of sudden unexpected death in two unrelated African American female infants, 2 months and 4 months old. Both infants were attended to by the same babysitter in the same apartment and died 39 days apart in the same bed and in the same bedroom. The autopsy of the first infant revealed sudden unexplained death in an infant. Toxicologic analysis for carbon monoxide (CO) was not performed because it was not suspected. When the second infant died, investigation into the ambient air quality within the apartment revealed high levels of CO emanating from a poorly ventilated and defective hot water heater, which was located across a hallway from the bedroom where the two babies died. CO saturation levels in the postmortem blood samples of the two babies were elevated and were similar (13% and 14%). Nicotine and cotinine were not detected in the blood sample of the two infants. Cherry-red livor mortis was absent. Acute CO intoxication was determined to be the underlying cause of these two unexpected deaths. These two cases underscore the need to integrate ambient air analysis and postmortem CO analysis as routine components of the comprehensive death investigation of infants who die suddenly and unexpectedly.     

Carbon monoxide poisoning without cherry-red livor

Carbon monoxide (CO) poisoning typically causes so-called cherry-red livor of the skin and viscera. The authors report a case of CO poisoning in which cherry-red livor did not develop. The decedent was a 75-year-old white man who was found dead in his car during a cold winter. Blood CO saturation was 86%. The death was attributed to CO poisoning, and the manner of death was designated suicide. The curious absence of cherry-red livor was studied. The decedent's tissue and blood specimens were tested at different temperatures. There was no tendency for either type of specimen to develop cherry-red color at cold or warm temperatures. The antemortem response of the skin to cold possibly sequestered CO-saturated blood in the cadaver. As regards the viscera, there are other proteins to which CO can bond, and possibly these proteins contribute to the development of visceral cherry-red livor. In this case, the absence of cherry-red livor could have led to misclassification of the cause and manner of death. The medicolegal and social consequences of such misclassification can be significant, and psychiatric history, which may be useful to surviving family members, could be lost.     

Homicidal Paraquat Poisoning

Paraquat poisoning usually results from suicide, occupational, or accidental exposure. Herein, we report a rare fatal case of homicidal paraquat poisoning. A 58‐year‐old man was poisoned by taking paraquat‐mixed medicine and wearing paraquat‐soaked underwear. In the absence of a history of paraquat exposure, the patient was misdiagnosed with pulmonary infection and scrotal dermatitis and died of respiratory failure 24 days after the initial exposure to paraquat. Ultra‐performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) was applied to detect and quantify paraquat in postmortem specimens. The concentration of paraquat in postmortem specimens from high to low is lung (0.49 μg/g), brain (0.32 μg/g), kidney (0.24 μg/g), liver (0.20 μg/g), cardiac blood (0.11 μg/mL), and stomach wall (<LOQ). Identification of homicidal paraquat poisoning is not easy for a clinician or a forensic pathologist, it is important to consider the possibility of paraquat poisoning when patients suffer from rapidly aggravating pneumonia of unknown origin.     

Experimental study on postmortem formation of carbon monoxide

Rats were drowned and kept immersed for 1 month in either boiled city water, or boiled or unboiled fresh water collected from a river. A small amount of carbon monoxide (CO) formed after death and a low carboxyhemoglobin (HbCO) saturation was found in blood and thoracic cavity fluid of the animals immersed in boiled city water and in boiled fresh water. A considerable amount of CO and a high HbCO saturation was observed in blood and thoracic cavity fluid in two out of three rats immersed in unboiled fresh water at 4-6 degrees C, and in one out of three at 6-16 degrees C. It is suggested that microorganisms in the water, in which the rats were drowned and kept immersed, and low temperatures of around 5 degrees C during storage, played an important role in the postmortem formation of carbon monoxide.     

Spectrophotometric evaluation of postmortem lividity

Under low ambient temperatures normally bluish postmortem lividity adopts a bright red or pink colour due to resaturation of haemoglobin with O2. The most important differential diagnosis in the presence of pink hypostasis is carbon monoxide poisoning. To answer the question if objective measuring methods allow differentiation of hypostasis with regard to cold exposition or carbon monoxide poisoning, spectrophotometric measurements were performed and the colorimetric measures as well as the spectral reflectance curves of the postmortem lividity were determined. The colorimetric measures CIE-L*a*b* showed similar values for all bright red livores mortis; differentiation between CO intoxication and cold exposition was not possible. Reflectance curves of pink hypostasis after cold storage showed the typical pattern of O2-rich blood with reflectance minima at wavelengths 541 nm and 576 nm and a reflectance maximum at 560 nm. Pink hypostasis because of carbon monoxide poisoning showed a shift of the reflectance maximum toward 555 nm and a flattened curve in all cases with COHb concentrations exceeding 52%, whereas these changes were not regularly observed with lower COHb levels.     

Accuracy and Usefulness of the AVOXimeter 4000 as Routine Analysis of Carboxyhemoglobin

The measurement of blood carboxyhemoglobin (CO‐Hb) is important to determine the cause of death. The AVOXimeter 4000 (AVOX), a portable CO‐oximeter, has the advantages of a low purchase price and operating cost, ease of operation, and rapid results. Little information is available on the usefulness of AVOX in the forensic sample, and the previous study investigated only six samples. Therefore, in this study, we confirmed the usefulness of the AVOX through a comparison of its re s ults with data previously obtained using the double wavelength spectrophotometric method in autopsies. Regression analysis was performed between CO‐Hb levels measured by the AVOX and those measured by the conventional double wavelength spectrophotometric method in postmortem blood samples: a significant correlation was observed. This study suggests the usefulness of the AVOX to analyze postmortem blood, and the AVOX is suitable for routine forensic analysis and can be applied at the crime scene.     

Fatal Fentanyl Patch Misuse in a Hospitalized Patient with a Postmortem Increase in Fentanyl Blood Concentration

Opioid‐related mortality happens, even in healthcare settings. We describe serial postmortem fentanyl blood concentrations in a hospital inpatient who fatally abused transdermal fentanyl. This is a single‐patient case report. A 42‐year‐old man with lymphoma was started on transdermal fentanyl therapy while hospitalized for chronic abdominal pain. The patient was last seen awake 1.3 h prior to being found apneic and cyanotic. During the resuscitation attempt, a small square‐shaped film was removed from the patient's oropharynx. Femoral blood was collected 0.5 and 2 h postmortem, and the measured fentanyl concentration increased from 1.6 to 14 ng/mL. Study limitations include potential laboratory or collection errors and missing data. (i) Providers must be vigilant for signs of fentanyl patch abuse. (ii) Postmortem blood concentrations are not static postmortem, likely secondary to decreasing pH, increased aqueous solubility, and tissue redistribution, and are therefore unlikely to accurately represent antemortem blood concentrations.     

Postmortem formation of carbon monoxide

Since carbon monoxide (CO) production after death was suggested in a drowned body, CO and carboxyhemoglobin (HbCO) levels in blood and body cavity fluids of cadavers which were not exposed to fire and CO have been analyzed. CO released from the tissues was determined by gas chromatography and gas chromatography-mass spectrometry, and the total concentration of hemoglobin (Hb) was measured as cyanmethemoglobin (CNmHb). The HbCO level was calculated by the ratio of CO content and CO-binding capacity. CO levels (ml/100 g at STP) of the seven cases in which blood and body cavity fluids could be collected ranged from 0.13 to 0.87 in blood and 0.02 to 0.80 in body cavity fluids. HbCO levels in blood and body cavity fluids were from 0.3 to 6.0% and from 2.3 to 44.1%, respectively. In a typical case showing postmortem formation of CO, the CO levels in body cavity fluids were higher than that in blood. It is suggested that CO in a putrefied body is due to CO in blood prior to death and the CO formed by the decomposition of Hb, myoglobin and other substances during putrefaction. The significance of HbCO levels in body cavity fluids of cases with marked postmortem decomposition seems difficult to interpret without the value of HbCO in blood.     

便携式血液中CO检测仪的研制与应用研究

目的 依据分光光度计还原法原理,利用微型锂电池、传感器、全分析系统,研制特定波长便携式血液中CO检测仪.方法 选择以发光二极管(LED)为光源的单光源模式,以比色皿为样品池,设置内部参比,对光强进行校正.整个系统进行集成,实现数据采集、信号处理和运算一体化,直接显示测定结果.结果 最终形成体积小、质量轻、操作简便、检测...     

Acute Benztropine Intoxication and Fatality

A woman was found unresponsive with an empty bottle of Cogentin^® prescribed to another. Admitted to an area hospital, her condition steadily declined until death 29 h after admission. Following toxicological screening on hospital (admission) whole blood, the only significant compound detected was benztropine. Benztropine was confirmed at 0.28 mg/L – the highest antemortem blood concentration recorded in a case of toxicity or fatality uniquely associated with benztropine. A second serum antemortem specimen showed a benztropine concentration of 0.19 mg/L. Despite over 24 h in the hospital, benztropine was also found in the postmortem specimens collected at autopsy. Peripheral blood, central blood, liver, and gastric concentrations were 0.47 mg/L, 0.36 mg/L, 9.6 mg/kg, and 44 mg, respectively. These results indicate that benztropine exhibited a potential difference between whole‐blood and serum (plasma) concentrations. Additionally, in consideration of literature data, benztropine was found indicative of a compound prone to at least some postmortem redistribution.     

Clocapramine-related fatality. Postmortem drug levels in multiple psychoactive drug poisoning

A suicide caused by ingestion of multiple psychoactive drugs is reported. A 42-year-old man with a history of psychosis was found dead in a blood pool in his room. The forensic autopsy revealed two stab wounds on his chest. However, these wounds could not explain the cause of death. Eighty-six tablets were found in his stomach. Four psychoactive drugs; clocapramine (CC), chlorpromazine (CP), promethazine (PM) and clotiazepam (CT) were detected in blood and tissues. The concentrations of CC, CP, PM and CT in the femoral vein (FV) blood were 0.39, 0.61, 1.23 and 0.09 microg/ml, respectively. The cause and manner of death were attributed to suicidal multiple psychoactive drug poisoning.Postmortem drug redistribution showed great site-dependent variations with the lowest level in the FV blood. Remarkable variations were observed in CC, CP and PM, but not in CT compared to other three drugs. The variations were dependent on the volume of distribution (Vd) of the drugs. Our human case has demonstrated drugs with higher Vd values showed higher degree of postmortem redistribution of the drug and vice versa.     

A Fatal Case of Poisoning with Fentanyl Transdermal Patches in Japan

Fentanyl transdermal patches have been used to treat cancer‐ and noncancer‐related chronic pain. However, its inappropriate or illegal application may cause fatal poisoning. We herein present the case of a Japanese woman in her 40s who was found dead with seven 25‐μg/h fentanyl transdermal patches on her body. We established a detailed toxicological analysis procedure to quantify fentanyl, and its metabolite norfentanyl, and other drugs (acetaminophen, allylisopropylacetylurea, celecoxib, estazolam, promethazine, and sertraline) in human whole blood by ultra‐high‐performance liquid chromatography–tandem mass spectrometry. The measured fentanyl and norfentanyl concentrations in the femoral and cardiac blood were 0.051 and 0.072 μg/mL and 0.033 and 0.076 μg/mL, respectively. The decedent's fentanyl concentrations were consistent with previously reported postmortem blood levels for fatal cases of poisoning by fentanyl transdermal patches. Based on the decedent's case history, autopsy findings, and toxicological analyses, the cause of death was identified as intoxication with transdermal fentanyl.     

大鼠口服敌敌畏和呋喃丹急性中毒后血液胆碱酯酶体外自动复能的动态观察

作者测定了中毒鼠血胆碱酯酶活性在体外室温下的动态变化,观察研究胆碱酯酶自动复能的特点。结果表明中毒鼠血胆碱酯酶活性体外自动复能在72小时内达最大值;敌敌畏中毒鼠血胆碱酯酶自动复能较呋喃丹组幅度大而下降也快;至第17天,与对照组相比,敌敌畏中毒鼠血胆碱酯酯活性仍有显著性差异。根据实验结果就中毒鼠血胆碱酯酶自动复能的法医学意义作了讨论。     

Evaluation of the Role of Toxicological Data in Discriminating Between H2S Femoral Blood Concentration Secondary to Lethal poisoning and Endogenous H2S Putrefactive Production

Hydrogen sulfide is a colorless gas and has a strong odor of rotten eggs. It is absorbed by the upper respiratory tract mucosa, and it causes histotoxic hypoxemia and respiratory depression by exerting an inhibitory effect on cytochrome oxidase. To evaluate the role of toxicological data in distinguishing between the H₂S blood concentration secondary to lethal poisoning and the endogenous H₂S produced during putrefaction, we compared the postmortem H₂S concentrations of six fatal H₂S poisoning cases (8.7–28.6 mg/L) with the postmortem concentrations of endogenous H₂S of 12 subjects who died from other causes (traffic‐related deaths) (2.2–32.7 mg/L). These results will be of interest to the forensic community as it underlines the importance of considering circumstantial evidence along with the toxicological and pathological findings in the identification of H₂S lethal poisoning.     

Methanol Detected in a Subdural Hematoma as an Embalming Artifact

Analysis of subdural hematomata has been used to suggest antemortem drug concentrations, with the assumption that materials within the hematoma are less subject to metabolism or degradation during any survival period and postmortem interval. We report the case of an 87‐year‐old woman whose death had not been reported to the coroner's office until postembalming. Autopsy revealed a traumatic brain injury with subdural hematoma causing a mass effect. Testing of the clot indicated a methanol concentration of 51.8 mg%. No additional analyses were detected. These findings suggest that methanol can be present in a postmortem hematoma sample, yet not represent a poisoning. Our findings also suggest that while the interior of hematomata do not necessarily represent completely “protected space” from postmortem diffusion of some blood constituents, such diffusion is not facile, and analysis may still provide useful indications of antemortem drugs present, if not actual concentrations.     

High performance liquid chromatographic determination of alcohols with reference to body distribution of methanol.

A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80-90%. The reproducibility of the results was always greater than 90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.     

甲氰菊酯在家兔体内的死后分布研究

目的建立甲氰菊酯家兔灌胃染毒致死模型和生物检材中甲氰菊酯的气相色谱和气相色谱-质谱联用检测方法,研究甲氰菊酯在家兔体内的死后分布规律。方法家兔6只,甲氰菊酯经口灌胃染毒,死亡后迅速解剖,取心血、外周血、肝等组织,气相色谱和气相色谱-质谱联用法检测甲氰菊酯含量;部分组织经甲醛固定,HE染色,光镜观察其病理改变。结果家兔染毒后2～3h出现中毒表现,染毒后4.5～8h死亡。气相色谱和气相色谱-质谱联用法均检测到甲氰菊酯。甲氰菊酯在家兔体内死后分布为胃壁（458.92±32.82）μg/g、肾（46.47±6.30）μg/g、肝（35.79±20.11）μg/g、大脑（28.77±10.52）μg/g、心（26.49±4.10）μg/g、脾（22.23±5.37）μg/g、胆汁（10.87±1.42）μg/mL、肺（10.32±0.78）μg/g、周围血（8.14±1.12）μg/mL和心血（8.20±1.83）μg/mL。结论甲氰菊酯的灌胃染毒致死模型、气相色谱和气相色谱-质谱联用检测方法及死后分布规律可应用于甲氰菊酯中毒死亡案件的法医学鉴定及法医毒物动力学研究。