血中碳氧血红蛋白饱和度测定影响因素的研究

目的 考察血中碳氧血红蛋白饱和度(HbCO％)测定的影响因素,为其结果评定和所需样品保存条件提供实验依据。方法 利用三种分光光度法,测定30d内不同条件下保存的CO阳性血的HbCO％的变化。结果 还原双波长法、双波长法测定结果比较稳定,单波长法抗干扰能力较差;尸检所取血样的保存条件包括温度、保存时间及与空气接触程度对HbCO％的测定均有影响,其中温度影响较为显著。结论 利用还原双波长法与双波长法,并结合光谱扫描观察峰形变化可得到比较可靠的结果。30d内4℃条件下,密闭容器中血样接触少量空气不影响其HbCO％的测定。     

Suicidal asphyxiation by inhalation of automobile emission without carbon monoxide poisoning

Reported herein is the suicidal asphyxiation of a young man due to exhaustion of oxygen in the interior of a sealed automobile into which the exhaust emissions were diverted. His blood carboxyhemaglobin concentration was less than 5% saturation. The car was equipped with a catalytic converter and when tested, the exhaust carbon monoxide concentration was 0.01%.     

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.     

一氧化碳中毒致死之案例研究

通过两例一氧化碳中毒致死特殊案例的分析,探讨一氧化碳中毒原因,中毒机理,中毒致死量。案例分析表明,只有通过详细认真的现场勘查,专业性的尸体检验及检材采取,科学的富有逻辑性的案件分析论断,才能准确为案件定性,解答死者家属疑问,以避免冤案错案的产生。     

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.     

血液保存中碳氧血红蛋白稳定性研究进展

通过分析近年来有关血液样品中碳氧血红蛋白稳定性方面的研究资料,发现血液中碳氧血红蛋白的稳定性受到盛放容器、保存温度、容器顶部空气体积、初始HbCO饱和度及防腐剂的添加与否的影响,其中保存温度、容器顶部空气体积及初始HbCO饱和度则是其主要影响因素。     

Subarachnoid Hemorrhage and Carbon Monoxide Exposure: Accidental Association or Fatal Link?

This case study reports a fatal subarachnoid hemorrhage (SAH) with concomitant accidental carbon monoxide (CO) exposure in 32‐year‐old man. Autopsy results indicated an antemortem aspiration of smoke, and a massive SAH was identified as the cause of death. Intriguingly, the carboxyhemoglobin level was 30%, suggesting that CO could have played a specific role. Intracranial hemorrhages following CO exposure in brain areas and tissues such as the basal ganglia, globus pallidus, or white matter are rare, but well characterized, whereas SAH related to CO exposure has not been previously described. In this case report, the possible role of CO, either as a primary cause or as a facilitating factor, in the pathogenesis of SAH is discussed. In particular, we propose the hypothesis that the excessive vasodilating effects produced by CO on the cerebral endothelium results in consequential loss of microvascular integrity.     

大鼠血液中HbCO随吸入CO浓度和时间的变化

目的研究不同一氧化碳(carbon monoxide,CO)浓度下中毒大鼠的行为学特征、存活时间、碳氧血红蛋白(carboxyhemoglobin,HbCO)饱和度变化规律,为法医学实践中CO中毒死亡案件提供实验依据。方法将160只SD大鼠随机分为4组。自制染毒装置,使大鼠分别在CO浓度为1 250、3 750、6 250 mg/m~3及持续通入CO状态下染毒致死亡。观察不同CO浓度中毒大鼠的行为学特征,记录存活时间,采用分光光度法检测心血HbCO饱和度,并提取脑、心脏、肺、肝等器官进行组织病理学观察。结果 CO中毒大鼠的行为学特征表现为肢体瘫软、反应迟钝。随着CO浓度的升高,大鼠存活时间逐渐缩短,心血HbCO饱和度逐渐升高。在CO浓度为1 250 mg/m~3条件下,发现3例心血HbCO饱和度明显低于致死饱和度,其余各组未发现心血HbCO饱和度低于致死饱和度的情况。结论建立的不同浓度下CO中毒死亡动物模型,操作简单,重复性好,为进一步研究CO中毒及其他吸入性有毒气体的法医学研究奠定了基础。     

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.     

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.