Yasunobu Kamikodai

Possible postmortem serum markers for differentiation between fresh-, saltwater drowning and acute cardiac death: a preliminary investigation

The aim of the present study was to investigate the differences in postmortem blood biochemistry between fresh-, saltwater drowning and acute myocardial infarction/ischemia (AMI) (n=11, n=15 and n=23, respectively; postmortem interval <48 h). Left and right cardiac blood samples were examined for the serum markers: sodium (Na), chloride (Cl), magnesium (Mg), blood urea nitrogen (BUN), creatinine (Cr), pulmonary surfactant-associated protein A (SP-A) and cardiac troponin T (cTn-T). The most efficient markers were the left-right cardiac BUN ratio for determination of drowning (hemodilution) and the left heart blood Mg level for differentiation between fresh- and saltwater aspiration. A characteristic feature of saltwater drowning was a low left-right BUN ratio and a marked elevation in the serum Cl, Mg and Ca levels of the left heart blood. Serum cTn-T level was usually low in drownings, showing a difference from most cases of AMI. Freshwater drowning showed a significant elevation of serum SP-A, although there was considerable overlapping with saltwater drowning and AMI. These findings suggested the usefulness of serum markers in the investigation of death from drownings.

Postmortem lung weight in drownings: a comparison with acute asphyxiation and cardiac death

There are several controversial findings and arguments about the lung weight as a marker of drowning. The aim of the present study was to examine the difference in the lung weight and the amount of pleural effusion between freshwater and saltwater drownings (n=70 and n=75, respectively), in comparison with asphyxiation (n=85) and acute cardiac death (n=82), for the diagnosis of drowning. In drowning cases, a gradual postmortem time-dependent decrease in the lung weight and a reciprocal increase in the pleural effusion suggested postmortem transudation from the lungs. The decrease in the total value of the combined lung weight and the amount of pleural effusion was marked in saltwater immersion after 3 days postmortem, suggesting a leakage of the effusion out of the thoracic cavity under an osmotic effect of the immersion medium. In cases within 3 days postmortem, when the combined lung weight and amount of pleural effusion were added to estimate possible combined lung weight at the time of death, there was a gross difference among the causes of death: the value was the largest in saltwater drowning, followed by freshwater drowning, acute cardiac death and asphyxiation. However, the value depended on the gender and age of the subjects, suggesting a relation to the individual physical constitution and survival time or vital activity. These factors should be taken into consideration in evaluation of the lung weight in the diagnosis of drownings.

Post-mortem urinary myoglobin levels with reference to the causes of death.

To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia.

Cardiothoracic ratio in postmortem chest radiography with regard to the cause of death

It is difficult to examine the intact in situ status of thoracic organs, including the heart and lungs, after opening the chest at autopsy. The present study investigated the pathological diagnostic significance of the cardiothoracic ratio (CTR) with regard to heart and lung weight in postmortem plain chest radiography. The pathological diagnostic significance of the CTR in postmortem plain chest radiography using serial forensic autopsy cases of adults (>19 years of age, n=367, within 72 h postmortem) was retrospectively investigated. In natural deaths, CTR was larger for heart diseases, and was smaller for pulmonary infection and gastrointestinal bleeding, showing correlations to the heart weight except in cases of hemopericardium. In traumatic deaths, CTR was larger in cases of fire fatality and acute methamphetamine intoxication, and varied in cases of blunt injury, showing correlations to the heart weight. However, CTR was smaller for sharp instrument injury and drowning, independently of the heart weight. These findings suggest that postmortem CTR (median, 55.6%, measured using a mobile X-ray apparatus) primarily depends on the heart weight, but is substantially modified during the process of death: the CTR may be enlarged by cardiac dilatation due to terminal congestive heart failure, but may be reduced by inflated lungs in drowning or hypovolemia due to fatal hemorrhage. CTR showed a mild correlation to the right diaphragm level, which was also related to the cause of death, but was independent of the left diaphragm level. Plain chest radiographic findings may also be helpful in investigating the pathophysiology of death, and are to some extent comparable with clinical findings. This also suggests the potential usefulness of postmortem CT and MRI for analysis of terminal cardiac function.

Analysis of postmortem biochemical findings with regard to the lung weight in drowning

To clarify drowning death, positive evidence for aspiration of the immersion medium and the subsequent fatal mechanism is necessary. This study investigated biochemical findings with regard to lung weight in drowning cases of adults (n=56, >18 years of age, <48 h postmortem: salt water, n=19; fresh water, n=21; brackish water, n=16), using acute cardiac death cases (n=240) as controls. The biochemical markers used in this study were urea nitrogen (UN), sodium (Na), chloride (Cl), calcium (Ca) and magnesium (Mg) in the blood and pericardial fluid (PCF). The left-to-right ratio of cardiac blood UN levels was lower for drowning, showing an inverse correlation to the total lung weight. There was a mild postmortem decrease in serum and PCF Na and Cl levels; however, left cardiac serum and PCF Na, Cl, Ca and Mg levels were higher for saltwater drowning, and left cardiac serum Na and Cl levels were lower for fresh water drowning. Correlation of the left cardiac serum level with lung weight was positive for Na, Cl and Mg in saltwater and brackish water drowning, and was also positive for Ca in saltwater drowning. There was an inverse correlation with lung weight for PCF Na and Cl levels in freshwater drowning. These findings suggest that analyses of serum and pericardial markers in relation to lung weight are useful for evaluating the composition and amount of aspirated medium when investigating drowning death.

Lung–heart weight ratio as a possible index of cardiopulmonary pathophysiology in drowning

The aim of the present study was to investigate the lung-heart weight ratio in fresh- and saltwater drowning (n=67 and n=75, respectively) as a possible index of cardiopulmonary pathophysiology, in comparison with acute myocardial infarction/ischemia (AMI, n=75) and asphyxiation (n=85). In drowning cases, the total value of the combined lung weight and the amount of pleural effusion was regarded as a possible total lung weight. The median value of the combined/total lung weight was the highest in saltwater drowning, which was followed by freshwater drowning, AMI and asphyxiation, showing a tendency to be mildly increased depending on the heart weight. The lung-heart weight ratio was significantly higher in fresh-/saltwater drownings (3.944+/-1.538 and 4.825+/-2.242, respectively) than in asphyxiation (2.846+/-1.042) and AMI (2.641+/-0.916) (P<0.0001), showing a tendency to be higher in saltwater than freshwater drowning. However, the value depended on the gender and age of the subjects, and the difference between freshwater drowning and asphyxiation was insignificant in females. These results suggested that the lung-heart weight ratio may be an index for investigating the influence of aspirated immersion medium in drownings.

Pathological and biochemical analysis of the pathophysiology of fatal electrocution in five autopsy cases

Five autopsy cases involving electrocution were examined to determine the pathophysiology of death. Cases 1-4 (industrial accidents: about 160-3800 V-AC) showed pathological findings of acute death, whereas Case 5 (suicide: 100 V-AC) showed those of subacute death. Electrical marks were observed as collapsed blisters with/without charring in Cases 1-4, and markedly charred burns with erythema in Case 5. There was evident cardiomyolysis in Cases 3 and 4, and marked congestive edema of the lungs in Cases 3 and 5. In postmortem biochemistry, a peculiar elevation of creatine kinase-MB in the heart blood was seen in Cases 1 and 2, suggesting myocardial cytoplasmic membrane injury. In Cases 3 and 4, showing cardiomyolysis, cardiac troponin I was markedly elevated in the heart and peripheral blood, suggesting cardiac myofibrillary injury. Case 5 showed findings of prolonged hypoxia and skeletal muscle injury involving elevations in serum uric acid and creatinine, and a typical pattern of acute respiratory distress in pulmonary surfactant immunostaining. These findings suggest that the main fatal factors were acute circulatory failure following myocardial injury in Cases 1 and 2, more advanced myocardial injury in Cases 3 and 4, and respiratory failure due to skeletal muscle injury in Case 5. The present study suggested that the mode of death due to electrocution might be closely related to the macromorphology of electrical marks.

Potential risk factors for sudden cardiac death: An analysis of medicolegal autopsy cases

Chronic kidney disease and elevated serum C-reactive protein (CRP) have been suggested as clinical risk factors for cardiac attacks. The present study investigated postmortem blood urea nitrogen (BUN), creatinine (Cr) and CRP levels in the peripheral blood of sudden cardiac death cases. Adult autopsy cases of ischemic heart diseases (n=153, >20 years of age), including acute myocardial infarction (AMI, n=71), recurrent myocardial infarction (RMI, n=47), acute ischemic heart disease without infarction (AIHD, n=27) and chronic ischemic heart disease (CIHD, n=8), were examined and compared with chronic congestive heart disease (CHD, n=24), spontaneous cerebral hemorrhage (SCH, n=17) and mechanical asphyxiation (n=32). BUN was slightly higher for RMI and CHD, although Cr was slightly higher for SCH. CRP was higher for AMI than for AIHD. The correlation between BUN and Cr levels was significant for AMI, AIHD and CHD, but insignificant for RMI and CIHD. Heart weight was larger for all heart diseases and SCH than for asphyxiation, and was larger for RMI and CHD but lower for AIHD and CIHD among them. Body mass index (BMI) was slightly higher for AMI, RMI, AIHD and CHD, remaining within the reference interval in most cases, but was lower for CIHD. These findings suggest different risk factors or etiologies, including active atherosclerosis, latent renal failure, dehydration and cardiac hypertrophy, for sudden deaths due to these heart diseases.

Inca bone in forensic autopsy: A report of two cases with a review of the literature

Complete tripartite and complete asymmetric bipartite bones were, respectively, found in the interparietal region of the occipital bone in two forensic autopsy cases that we encountered. These isolated bones are called the Inca bones, or interparietal bones, which occasionally occur as a result of incomplete fusion of the ossifying nuclei during the developmental course. The Inca bones were detectable on ante-mortem cranial radiographs in these two cases. We review the embryological background of this variation, discuss the significance of this variation in forensic medicine, and additionally, present a review of the frequencies of other non-metrical characteristics of the skulls that may be detectable at the time of autopsy.

Fatal traumatic rupture of an aortic aneurysm of the sinus of Valsalva: an autopsy case

This report describes an autopsy case of a rare type of aortic sinus of Valsalva aneurysm, which caused fatal rupture from a blunt chest impact. A 51-year-old male was hit in the chest with a fist, lost consciousness after about 15min and died after approximately 7h. The postmortem examination revealed a large saccular aneurysm of the right coronary sinus bulging on the right atrium, which had a full laceration causing pericardial hematoma (cardiac tamponade). A related chest wall injury was observed in the right outer mammary region. A rare type of bulging onto the right atrium and subsequent sclerosis of the right coronary artery appeared to have greatly contributed to the fatal rupture.