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

To evaluate pathophysiological significance of post-mortem urinary myoglobi n levels in determining the cause of death, we investigated 210 forensic au topsy cases, partially in comparison with serum levels. Post-mortem serum m yoglobin levels were extraordinary high in most cases possibly due to post- mortem change. Urinary myoglobin levels did not correlate with the serum le vels, showing possible post-mortem elevation in cases of a prolonged post-m ortem period over 48 h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), sl ight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary my oglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the h ighly elevated cases were those with a survival time over 24 h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin le vel was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48 h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myo globinuria over 100 ng/ml was more frequently and markedly observed in case s with COHb below 60% than over 60%, suggesting muscle damage in fatal burn s. 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 infarc tion. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemorte m massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.