Concentration of carbon monoxide (CO) in postmortem human tissues: effect of environmental CO exposure.

We studied how carbon monoxide (CO) is distributed within the human body through quantitation of CO concentrations in postmortem tissue samples from fatalities including possible CO exposure. Stored, frozen tissues were diced, sonicated in water, and 0.01-8.0 mg wet weight (ww) tissues were incubated with sulfosalicylic acid in CO-purged, septum-sealed vials. CO released into the headspace was quantitated by reduction gas chromatography. Mean tissue CO concentrations (pmol/mg ww) from subjects diagnosed to have no known CO exposure (control, N=14), died from fire (N=13), and CO asphyxiation (N=7), respectively, were: adipose (2;13;9), brain (3;13;65), muscle (15;97;297), heart (30;99;371), kidney (22;432;709, lung (54;690;2638), spleen (73;1366;3548), and blood (162;2238;5070). Carboxyhemoglobin concentrations were 1.4%, 25.2%, and 69.1% of total hemoglobin, respectively. We conclude that measurements of CO concentration in a variety of tissues can be used as markers for the degree of exogenous CO exposure and the identification of possible causes of death.

Investigation of sudden infant deaths in the State of Maryland (1990-2000).

The Office of the Chief Medical Examiner (OCME) has recorded a significant decline in the deaths of sudden infant death syndrome (SIDS) in the state of Maryland since 1994. However, infants who died of accidental or non-accidental injuries remained consistent during the same time period. This report focuses on the epidemiological characteristics and scene investigation findings of infant victims who died suddenly and unexpectedly in Maryland between 1990 and 2000. A retrospective study of OCME cases between 1990 and 2000 yielded a total of 1619 infant fatalities. 802 infant deaths were determined to be SIDS, which represented 50% of the total infant deaths in our study population. Five hundred and twenty-three (31.8%) deaths were due to natural diseases, 128 (7.9%) deaths were accidents, and 74 (4.6%) were homicides. The manner of death could not be determined after a thorough scene investigation, review of history and a complete postmortem examination in 92 (5.7%) infants. SIDS deaths most often involved infants who were male and black. The peak incidence of SIDS was between 2 and 4 months of age. The majority of SIDS infants (60%) were found unresponsive on their stomach. Among SIDS infants, 269 (33.4%) were found in bed with another person or persons (bed sharing). Of the bed-sharing SIDS cases, 182 (68%) were African-American. In the past 11 years, 52 infants died of asphyxia due to unsafe sleeping environment, such as defective cribs, ill-fitting mattresses, inappropriate bedding materials. Of the 74 homicide victims, 53 (70%) involved infants less than 6 months of age. Twenty (27%) exhibited the classical abuse syndrome characterized by repeated acts of trauma to the infants.

Distribution of triazolam and alpha-hydroxytriazolam in a fatal intoxication case.

The case of a 77-year-old woman who was found dead in her bathtub with her head clearly above the water line is presented. The decedent had a medical history of depression, liver disease, spinal stenosis, and diabetes mellitus. An empty medication bottle of triazolam was found in the trashcan. At autopsy, no injury or evidence of drowning was found. Toxicological analysis identified triazolam at a concentration of 0.12 mg/L in the heart blood. Triazolam and alpha-hydroxytriazolam were quantitated in the specimens received. The medical examiner ruled that the cause of death was triazolam intoxication and the manner of death was suicide.

Pseudo-subarachnoid hemorrhage of the head diagnosed by computerized axial tomography: a postmortem study of ten medical examiner cases.

In this report, we describe ten cases of pseudo-subarachnoid hemorrhage on computer axial tomography (CT) scan of the head. A pseudo-subarachnoid hemorrhage is a false positive finding by CT of the head in which the scan is interpreted as being positive for a subarachnoid hemorrhage not substantiated by subsequent neuropathologic findings. This study is a retrospective review of postmortem cases brought into the Office of the Chief Medical Examiner for the State of Maryland over a three-year period (from 1997 to 2000). We compared the clinician's impression of the CT scan with the postmortem neuropathology. The clinical diagnosis of subarachnoid hemorrhage was based on misinterpretation of non-contrast CT scans of the head. In six of the ten cases, the reading was performed by a radiologist and in four cases by nonradiologist physicians (emergency room physician, neurologist, or neurosurgeon). All the patients survived between a few hours to a few days after being admitted to the hospital. For most of the cases (80%), the neuropathology showed hypoxic/ischemic encephalopathy. The most common cause of death (four out of ten cases) was narcotic intoxication. This report is submitted so that clinicians and pathologist become more familiar with this entity.

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).

Lung tissue concentrations of nicotine in sudden infant death syndrome (SIDS).

OBJECTIVE: To compare lung concentrations of nicotine and cotinine in cases of sudden infant death syndrome (SIDS) and controls. DESIGN/METHODS: We measured lung tissue concentrations of nicotine and cotinine in SIDS (n = 44) and non-SIDS cases (n = 29) stratified according to household smoking status. RESULTS: When all the SIDS and non-SIDS cases were compared regardless of smoking status, there was a significantly higher nicotine concentration in the SIDS cases than in the non-SIDS cases, (P =.0001). Upon stratifying for smoking status, there was a nonsignificant trend toward more nicotine in SIDS versus non-SIDS lungs that had come from a reported smoking environment. In the nonsmoking group, there were significantly higher nicotine concentrations in SIDS than non-SIDS cases (P =.001). CONCLUSIONS: Children who died from SIDS tended to have higher concentrations of nicotine in their lungs than control children, regardless of whether smoking was reported. These results are based on an objective, biochemical test rather than history, and they further support the relationship between environmental tobacco smoke and the risk of SIDS.

Autopsy study of motorcyclist fatalities: the effect of the 1992 Maryland motorcycle helmet use law.

OBJECTIVES: This study sought to determine the impact of Maryland's all-rider motorcycle helmet law (enacted on October 1, 1992) on preventing deaths and traumatic brain injuries among motorcyclists. METHODS: Statewide motorcyclist fatalities occurring during seasonally comparable 33-month periods immediately preceding and following enactment of the law were compared. RESULTS: The motorcyclist fatality rate dropped from 10.3 per 10 000 registered motorcycles prelaw to 4.5 postlaw despite almost identical numbers of registered motorcycles. Motorcyclists wearing helmets had a lower risk of traumatic brain injury than those not wearing helmets (odds ratio = 0.31, 95% confidence interval = 0.14, 0.68). CONCLUSIONS: Maryland's controversial motorcycle helmet law appears to be an effective public health policy and may be responsible for saving many lives.