Kohei Tsuda

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.

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.

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.

Labor-related fatalities in forensic postmortem investigations during the past 6 years in the southern half of Osaka city and surrounding areas

To investigate fatal factors involved in labor-related accidents and events, forensic postmortem cases (n=874) during the past 6 years (1996-2001) at our institute were reviewed. Among them, there were 67 labor-related fatalities, showing a varied annual incidence (6-15 cases per year). All the victims were males (19-68 years of age). The most common sites of the accidents were manufacturing factories (n=21, 31.3%), warehouses (n=14, 20.9%), construction and demolition sites (n=11 and n=5, 16.4 and 7.5%, respectively). There were some characteristic types of accidents: falls from heights at work during construction and maintenance, and crushes by heavy materials and moving vehicles in transportation, by collapsing structures at demolition sites or by working machinery in factories. The most severely injured body regions were usually the head in falls (n=13/23) and the chest/abdomen in crushes (n=19/32). Most of the victims (n=54, 80.6%) died within 24 h. Alcohol was detected only in four cases. Most accidents were considered to be due to carelessness and simple fault of the workers without any significant relationship to their professional training and career.

Hemorrhages in the root of the tongue in fire fatalities: the incidence and diagnostic value

Hemorrhages in the root of the tongue have been considered to be a finding associated with asphyxiation. The aim of the present study was to examine the incidence and diagnostic value of the lingual hemorrhages in fire fatalities with reference to the related pathological and toxicological findings, in comparison with asphyxiation and drowning cases. In fire fatalities (n=90), small to marked hemorrhages were observed in 26 cases (28.9%). In the reference groups (asphyxiation and drowning), the hemorrhages were frequently observed in ligature strangulation (n=10/15), manual strangulation (n=5/7) and traumatic asphyxia (n=4/5). In fire fatalities, the hemorrhages were closely associated with a lower blood carboxyhemoglobin (COHb) level, suggesting an influence of fatal burns: n=16/32 (50.0%), n=8/26 (30.8%) and n=2/32 (6.2%), respectively, in cases of COHb<30%, 30-60% and >60%. These findings suggested possible acute hemodynamic disturbance in the head including brain (cranial congestion) in the dying process due to fires. A careful differentiation from neck compression may be necessary in such cases.