Hypoxia-related brain dysfunction in forensic medicine.

Blood gases levels imbalances belong to important factors triggering central nervous system (CNS) functional disturbances. Hypoxia can be illness-related, like in many COPD patients, or it may be caused by broad range of external or iatrogenic factors - including influence of drugs depressing respiration, failure to keep the patient's prosthesis-supported airways patent, or a mistake in the operation of medical equipment supporting patient's respiration. Hypoxia, especially when it is not accompanied by rapid carbon dioxide retention, can go unnoticed for prolonged times, deepening existing CNS disorders, sometimes rapidly triggering their manifestation, or evoking quite new conditions and symptoms - like anxiety, agitation, aggressive behavior, euphoria, or hallucinations. Those, in turn, often result in situations raising interest in law enforcement institutions which need forensic medicine specialist's assistance and opinion. The possibility of illness or drug-related hypoxia, especially in terminal patients, is used to raise questions about the patients' ability to properly express their will in the way demanded by law - it also must be considered as a factor limiting the patients' responsibility in case they commit crimes. The possibility of hallucinations in hypoxia patients limits their credibility as witnesses or even their ability to report crime or sexual abuse they have been subjected to.

Death as a result of violent asphyxia in autopsy reports.

Violent asphyxia can be subdivided into various kinds according to the mechanism, so that the resuscitation techniques are different in each case. The purpose of the present article was to analyze the autopsy reports of the Department of Forensic Medicine of the Medical University in Wroclaw, Poland of 2010, in which the established cause of death was violent asphyxia. We found that among the 890 autopsies performed, there were 164 cases of death due to violent asphyxia caused by drowning, choking on food, gastric fluid, or blood, hanging, manual strangulations, immobilization of the chest (positional asphyxia), environmental asphyxia due to substitution of the oxygen-rich air for some other gas, and others. The most common cause of death in the group was hanging, mostly suicidal hangings of alcohol-intoxicated males. Despite an early medical treatment consisting of removing the noose from the neck and suction the fluids from the mouth and bronchial tree to safe the central nervous system from imminent hypoxia, there were negative outcomes in most cases due to the development of critical brain ischemia, with deaths followed after several days spent in the intensive care units. No connection to gender or age of the deceased was noted. We conclude that violent asphyxia remains to be a quite commonly cause of death in the practice of forensic pathologists - among all the autopsies performed in 2010 every sixth was of an asphyxia victim.