Postmortem biochemical investigations in hypothermia fatalities

Abstract

Despite the progress made during the past several decades in forensic pathology, the possibilities for the postmortem diagnosis of hypothermia remains relatively limited. Aside from histology and immunohistochemistry, numerous authors have investigated the postmortem biochemistry of hypothermia fatalities. Several biochemical markers (e.g., glucose, electrolytes, hormones, ketone bodies, and neurotransmitters) and various biological samples (e.g., blood, urine, heart, liver, skeletal muscle as well as pericardial and cerebrospinal fluids) have been proposed as potentially useful markers to improve the insufficient diagnostic efficacy of macroscopic and microscopic findings. The aim of this article is to review the medicolegal literature covering the postmortem biochemical investigations that are associated with hypothermia cases as well as report our own research results on this topic where possible.

Postmortem diagnosis of hypothermia

“…Several histologic findings associated with hypothermia fatalities have been described in medicolegal literature including depletion of hepatic glycogen, fatty degeneration of the renal tubular epithelium (subnuclear vacuolization of renal tubular epithelial cells or Armanni-Ebstein phenomenon), pancreatic changes (focal necrosis of pancreatic and peripancreatic adipose tissue, hemorrhagic and nonhemorrhagic pancreatitis, adenocyte vacuolation), vacuolization of anterior pituitary gland cells, hepatocytes, adrenal cells and renal cells, hypoxic cardiac changes as well as fatty changes of cardiac myocytes and hepatocytes. A strong correlation among frost erythema, Wischnewski spots, and basal vacuolization of renal tubular epithelial cells has been observed by some authors who postulated that the Armanni-Ebstein phenomenon might be considered the most "indicative" histological finding of hypothermia fatalities [7,9,13,[23][24][25][26][27][28].…”

“…These include the lungs, myocardium, anterior pituitary gland, adrenal medulla, hypothalamus, midbrain periaqueductal gray matter, renal tubular epithelium, distal and collecting renal tubules, glomerular podocytes, brain parietal lobe, hippocampus, and cerebral cortex, with extremely promising results in some cases. However, immunohistochemistry has still not provided significantly reliable diagnostic criteria for the postmortem diagnosis of hypothermia [24,[28][29][30][31][32][33].…”

“…Since then, numerous molecules have been measured, and postmortem samples other than blood have been collected and analyzed in order to better understand the metabolic and biochemical changes occurring during hypothermia and find the most helpful combination of biomarkers to allow a reliable diagnosis of fatal hypothermia to be made. In addition, these investigations aimed to identify alternative biological fluids should blood prove insufficient or unavailable at autopsy [24].…”

“…There is a general consensus in the literature that increased levels of blood β-hydroxybutyrate, acetone, isopropyl alcohol, and glucocorticosteroids as well as increased urine adrenaline and cortisol concentrations should be considered potential biochemical hallmarks of fatal hypothermia [24,[34][35][36][37].…”

Victims of lethal hypothermia have decreased levels of thrombomodulin in myocardium and urine

“…Many different biochemical substances and sample types have been studied in order to find an indicator of ante-mortem hypothermia or cold exposure [20]. After analysing several proposed markers in hypothermia deaths, Palmiere et al [21] concluded that the best indicators of hypothermia are increased levels of ketones and isopropyl alcohol in blood, adrenaline in urine, and cortisol in serum and urine.…”