Carbon monoxide concentrations in the 2009 Victorian Bushfire disaster victims

Blood was available for the estimation of carboxyhemoglobin saturation (COHb) in 30 of the 173 persons who died in the Victorian bushfires in February 2009. The ages of these 30 deaths ranged from 3 to 80 years and there were 8 females. 13 cases (43%) were considered negative (less than 5% COHb), 12 (40%) were between 5 and 40% COHb, 2 (6.7%) between 40 and 50% and 3 (10%) were greater than 50% COHb. There were 6 persons either found within a building or a car and the COHb in these cases ranged up to 69% (mean 50%). There were 5 cases where the location was unable to be determined as either indoor or outdoor due to the extensive nature of the fire. The remaining 19 deceased persons were all located outside in the open and the concentration of COHb in these cases ranged up to 30% (mean 19%). Hydrogen cyanide was only detected in two deceased persons at concentrations of 0.5 and 2.7 mg/L, respectively. 13 deceased were found to have soot in the airways following necropsy but this did not correlate with the COHb levels.     

Acute and subacute fetal CO-poisoning

The main principles of placental CO exchange in cases of CO intoxications of pregnant women are shown. Fetal COHb lags behind maternal COHb by several hours depending on the exposure pattern. During CO elimination the fetal COHb levels again lag behind the mother's. A case of a lethal CO intoxication of a pregnant woman, mens IX, with exposure time of 10-12 h and COHb of 75% for the mother and 46% for the fetus allows to make conclusions about process of intoxication and about different times of death for mother and fetus. In highly acute lethal intoxications of the mother COHb in fetal blood is low or negative. A vital danger of the fetus is not probable when mother survived a short CO exposure.     

Rapid determination of carboxyhemoglobin in blood by Oximeter

Different methods to determine carboxyhemoglobin (COHb) in blood are described in the literature. In our laboratory three methods to analyze COHb in post-mortem blood samples were compared: the spectrophotometric method of Maehly, a gas chromatographic method with a thermal conductivity detector (GC-TCD) and the Oximeter. Several COHb containing blood samples of deceased persons were analyzed. Results of all three methods were comparable for low concentrations (ca. 10% COHb) as well as for high concentrations (ca. 80% COHb) regardless of the viscosity of the blood samples. The advantages of the Oximeter when compared to Maehly's method and GC-TCD are extreme short time of analysis (<1min), very small blood volume required (<0.1ml) and easy handling. In our opinion application of the Oximeter is not limited to analyses of blood samples from living persons (e.g. in clinical toxicology); it can as well be used for the determination of COHb in post-mortem blood samples. Hence it is a useful and time saving tool in forensic toxicology.     

Atherosclerotic and Hypertensive Cardiovascular Disease are Associated with Death at Sublethal Carboxyhemoglobin Levels: A Postmortem Study

Residential fires are a significant cause for morbidity and mortality in the United States. Death is often the result of soot and smoke inhalation causing carbon monoxide (CO) toxicity. The approximate lethal level of carboxyhemoglobin (COHb) in healthy adults has been well described. However, a significant number of medical examiner cases involve infirmed decedents, often elderly, with complex cardiovascular disease burdens. It is well known that death in these cases will occur at sublethal levels of COHb; however, increased lethality has been largely documented via anecdotal experience and lacks quantification. Fifty-five cases were identified where death resulted from smoke and soot inhalation suffered in a residential fire. The control group, with no cardiovascular disease, had an age-adjusted mean COHb level of 61.6% at the time of death. Presence of hypertensive cardiovascular disease showed a 30% reduction in COHb (age-adjusted mean 43.2%), atherosclerotic disease showed a 33% reduction (age-adjusted mean 41.5%), and combined disease presentation accounted for 41% reduction (age-adjusted mean 36.3%). When controlling for age, atherosclerotic and hypertensive cardiovascular diseases were each associated with statistically significant decreases in COHb (p < 0.01). Increasing age was associated with decreased COHb levels at 2.8% per 10 years of life (p < 0.01), even when modeled with hypertensive and atherosclerotic disease. These findings carry important public health significance, as well as practical significance for the medical examiner when interpreting COHb levels in cases of suspected deaths due to smoke and soot inhalation.     

不同来源一氧化碳中毒死亡者血液中COHb含量分析

目的探索一氧化碳中毒存在的个体差异性,分析女性可能存在的抵御一氧化碳中毒的机制。方法收集207例不同来源的一氧化碳中毒死亡者血液,测量COHb含量,将案例按照不同的因素分类进行统计学分析。结果不同一氧化碳的来源对于死者的COHb浓度影响显著,而性别对于COHb浓度影响不显著,少年儿童和老年人有可能对COHb的抵御能力差于成年人。     

Hydrogen cyanide and carbon monoxide in blood of convicted dead in a polyurethane combustion: a proposition for the data analysis

Carbon monoxide is a well-known toxic component in fire atmospheres. However, the importance of hydrogen cyanide as a toxic agent in fire causalities is under discussion. A tragic polyurethane mattress fire provoked death of 35 convicts in a prison (Unit I, Olmos, Penitenciary Service of Buenos Aires Province, Argentina), in 1990. There is no report of any investigation carried out with such a large amount of victims in Argentina. Carboxihemoglobin (COHb) and hydrogen cyanide (HCN) were quantified in victims blood to elucidate the cause of the death. Saturation of COHb ranged between 4 and 18%, and HCN 2.0-7.2mg/l. These latter values were higher than the lethal levels reported in literature. Other toxic components routinely measured (ethanol, methanol, aldehydes and other volatile compounds) gave negative results on the 35 cases. Neither drugs of abuse nor psychotropics were detected. Statistical chi(2) analysis was applied to find differences between HCN and COHb concentrations. Saturation of COHb and HCN in blood were not independent variables (chi(2)=8.25). Moreover, the ratio COHb/HCN was constant (0.47+/-0.04). In order to evaluate the contribution of each toxic to the diagnosis, a lethal index was defined for each toxic (LI(CO) and LI(HCN)). The most probable cause of death could be inferred by a suitable plot of both indexes. The results indicated that death in the 35 fire victims was probably caused by HCN, generated during the extensive polyurethane decomposition provoked by a rapid increase of temperature.     

Failure to detect elevated levels of carboxyhemoglobin in infants dying from SIDS

Carboxyhemoglobin (COHb) levels were determined in stored blood samples from 91 infants diagnosed to have died from the sudden infant death syndrome (SIDS) (0.59+/-0.41%, excluding one outlying value of 10.83%); 48 age-matched controls (0.53+/-0.38%); and three individuals who died from fire related causes (41+/-20%). No statistical differences in COHb levels were detected between blood from SIDS and control infants (p = 0.43).     

二阶导数光谱双波长法测定血中碳氧血红蛋白饱和度的研究

本文将双波长法用于二阶导数光谱中,提出一种新的COHb饱和度测定方法。用本法测定了已知COHb饱和度的标准血样和未知COHb饱和度的检血,都得到了比较满意的结果。     

Interaction between carbon monoxide and ethanol in fire fatalities.

Impairment due to ethanol is clearly a risk factor in deaths due to fire. However, it is less clear whether there is a physiological interaction between ethanol and carbon monoxide (CO) that would alter the carboxyhemoglobin saturation level (COHb sat.) that accounts for death. In an attempt to explore this issue further, 196 fire fatalities investigated by the Office of the Chief Medical Examiner, State of Maryland over a 3-year period were examined. COHb sat. and blood ethanol concentrations (BAC) were tabulated. Twelve cases positive for therapeutic or abused drugs other than lidocaine or atropine were excluded; 184 cases were included. The data indicate that ethanol does not affect the COHb sat. that accounts for death, since the percentage of cases positive for ethanol at a given COHb range shows no trends. Therefore, we conclude that although ethanol remains a risk factor in fire fatalities, the risk appears to be related to the impairment that it produces as opposed to a direct interaction with CO.     

A comparison of carboxyhemoglobin saturation values in postmortem heart blood and peripheral blood specimens

The following is a study conducted to determine whether there was any significant difference in carboxyhemoglobin (COHb) saturation levels between the heart blood and blood collected from a peripheral site. The average heart blood to peripheral blood COHb saturation level ratio in the 42 cases studied was 1.09. Sixty-two percent (26 of 42) of the cases had a heart blood to peripheral blood ratio between 0.9 and 1.1; 74% (31 of 42) had a ratio between 0.8 and 1.2. Eighty-three percent (35 of 42) had a ratio between 0.7 and 1.3. There were four cases where the heart blood to peripheral blood ratio was either below 0.6 or greater than 1.4. The differences between the two sites were not statistically significant.     

Determination of total hemoglobin in forensic blood samples with special reference to carboxyhemoglobin analysis

For the determination of total hemoglobin (Hb) in blood containing elevated carboxyhemoglobin (COHb), a newly developed reagent containing a 100-fold concentration of ferricyanide (20 g/l) and a 2-fold concentration of Sterox SE was compared with a standard reagent (0.2 g/l ferricyanide), the reagent of van Kampen and Zijlstra, using forensic blood samples and experimentally heated blood samples. There were no significant differences between the spectra of hemiglobincyanide (HiCN) solution produced with our reagent and the van Kampen and Zijlstra reagent using experimentally heated blood samples. Although the spectra of HiCN changed gradually with increased heating time and with the passage of time after mixing, the absorbance at 540 nm (A540) did not change until at least 120 min for both the reagents. When forensic blood samples containing elevated COHb were mixed with the van Kampen and Zijlstra reagent, total-Hb concentrations determined 5 min after mixing were 10-20% higher than those determined after 180 min. The overestimates of total Hb determined after 5 min resulted in comparable underestimates of percentage saturation of COHb (COHb%) when COHb% was obtained from the ratio of COHb content, determined by gas chromatogrpahy, to total-Hb concentration in blood. However, there was an extremely good correlation between the values of total Hb in forensic blood samples determined with the van Kampen and Zijlstra reagent after 180 min and those determined with our reagent after 5 min. From the results obtained, our reagent proved to be suitable for the determination of total Hb in forensic science practice.     

The happy land homicides: 87 deaths due to smoke inhalation

We reviewed all 87 deaths from the Happy Land Social Club fire. All deaths were due to smoke inhalation. The carboxyhemoglobin (COHb) concentrations ranged from 37 to 93% with a mean of 76.5%. The vast majority (97%) of the decedents had a COHb concentration over 50%. Cyanide blood concentrations ranged from 0 to 5.5 mg/L with a mean of 2.2 mg/L. Nine decedents had no cyanide detected, and seven had cyanide concentrations of less than 1 mg/L. Fewer than one third of the decedents had thermal injuries, and most were partial thickness burns involving less than 20% body surface area. Ethanol was detected in 72% of decedents with a range of 0.01 to 0.29 g% and a mean blood concentration of 0.11 g%. Cocaine or cannabinoid use was identified in 9% of the decedents. All decedents were visually identified, and all had soot in the airway extending to the major bronchi. Carboxyhemoglobin concentrations corresponded well with deaths from smoke inhalation. Cyanide concentrations did not correspond with the extent of smoke inhalation, and the role of cyanide in contributing to these deaths is doubtful. Hydrogen chloride inhalation, as evidenced by comparison of the pH of tracheal mucosa to controls, was not a factor.     

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.     

"First pass phenomenon" of inhaled gas in the fire victims

We investigated the differences in the levels of carboxyhemoglobin (COHb), cyanide (HCN) and petroleum fuels (gasoline and kerosene) between left and right ventricular bloods from fire victims. COHb was slightly, and HCN and petroleum fuels were markedly higher levels in the left than those in the right. These effects were so called 'first pass phenomena' due to the circulation, diffusion and metabolization before the deaths of fire victims.     

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.     

顶空气质联用法测定腐败血、肝检材中CO

目的研究CO中毒腐败血、肝组织检材中CO的HS/GC/MS检测。方法用HS/GC/MS法分析碳氧血红蛋白(COHb)血的线性范围。配制10%、30%、50%、70%浓度COHb血样,分别在室温、冷藏、冷冻条件下保存,分别在当日、第4、14、45d进行测定,比较实验结果。腐败肝组织由雄性健康家兔通CO气体致死,当天解剖,家兔肝常温隔绝空气保存并放35d至腐败,期间进行不定期顶空测定分析。结果制备的COHb血在0-100%之间有良好的线性关系Y=2.4X+2.2(r=0.9995)。以此方法测定家兔CO中毒致死的COHb新鲜血的浓度和4℃下放置45dCOHb腐败血,结果表明温度对血样中COHb%的测定影响最大。采用HS/GC/MS法检测,每次只需0.25ml血样或1g肝脏,分析一次时间只需3min,均可检测出新鲜检材和常温放置45d的腐败肝组织检材CO的含量。结论HS/GC/MS法能检出CO中毒的腐败生物检材中CO。     

The prevalence of drugs in carbon monoxide-related deaths: a retrospective study, 2000-2003

The objective of this study was to review demographic characteristics and drugs detected in carbon monoxide (CO)-related deaths from cases received by the Office of the Cuyahoga County Coroner in Cleveland, Ohio, from 2000-2003. Postmortem reports were reviewed, and decedents for which CO was listed as the cause of death were included. The data were compiled into 3 groups according to the official coroner's verdict as to the manner of death: accident, suicide, and homicide. Included in this study were 122 cases: 84 (69%) accidental, 31 (25%) suicide, and 7 (6%) homicide. Accident decedents were typically white males, aged 40-59 years, residing in Cleveland. Suicide decedents were also middle-aged, white males but residing in the suburbs. Homicide decedents under the age of 6 were characteristically black (N=2), while decedents over the age of 39 were predominately white (N=3). Carboxyhemoglobin (COHb) levels in suicide cases were higher than concentrations measured in accidental deaths. The highest percentage of suicide decedents (36%) had a COHb level>70% saturation, accident decedents (36%) between 50% and 69% saturation, and homicide decedents (71%) below 50% saturation. Ethanol (N=34) was detected in 28% of deaths, and therapeutic and/or abused drugs (N=50) were detected in 41% of deaths. Illicit drugs were detected in 11% of cases (cocaine/metabolites; THC/metabolites), other drug positives were therapeutic medications. The most common drugs detected were antidepressants and antihistamines in suicides and pain medications and antihistamines in accidents.     

Validity of CO-oximetric determination of carboxyhaemoglobin in putrefying blood and body cavity fluid

Most commercial CO-oximeters pose warning flags in their measured carboxyhaemoglobin (COHb) levels when total haemoglobin (tHb) concentrations in the samples are below a certain threshold, typically about 3-4gdl. The warning flags acknowledge the fact that the haemoglobin levels are outside the ranges these instruments are designed (or validated) for. By using a parallel GC method and special sample treatment methods prior to CO-oximetric measurements, this study demonstrates that CO-oximeters could actually produce valid COHb results for samples with tHb as low as 1g/dl, and that the warning flags have no bearing to the accuracy and precision of the measurements. This study also indicates that warning flags due to high methaemoglobin (MetHb) and sulphaemoglobin (SHb), and often turbidity did not affect the validity of the CO-oximetric measurements.     

Complex suicide by ethanol intoxication and inhalation of fire fumes in an old lady: interdisciplinary elucidation including post-mortem analysis of congener alcohols

An 88-year-old woman committed suicide by drinking a toxic amount of highly concentrated alcohol and setting two rooms of her flat on fire. As there was not enough oxygen, the fire went out, however. At autopsy, no thermal lesions were found on the body, but soot depositions in the airways and a COHb value of 14% pointed to the inhalation of fire fumes. The ethanol concentration in femoral blood was 6.62 per mille. The gastric mucosa was fixed by the ingested alcohol and showed hardly any autolytic changes despite a post-mortem interval of five days. Congener analysis of the gastric contents and the femoral blood indicated the uptake of a fruit distillate or its foreshot.     

Toxic environmental factors in sudden infant death (SIDS)

The increasing number of discussions on the influence of toxic environmental factors, including SIDS, prompted systematic postmortem chemical-toxicological investigations to be carried out on 54 SIDS cases and 2 control cases of the same age group. Tissue levels of arsenic, lead, cadmium, mercury, and pentachlorphenol, as well as other organic noxious agents, were measured in several organs. In addition, the COHb concentrations were determined. In spite of the widely scattered values, the extreme levels measured and the arithmetic means and median averages of As, Pb, Cd, Hg, PCP, and COHb had no more range in concentrations than can be expected for toxic effects - according to present knowledge anyway. It was observed that infants from an urban environment showed no greater concentration of noxious agents than did infants from rural regions. There were also no differences between SIDS cases and the controls, nor was there a correlation between infections of the respiratory system that are often morphologically detected - including laryngitis - and higher concentrations of these agents in the organs of SIDS cases.