Choking, Signs Of

Determination of the cause of death is an important facet of a forensic investigation. Some causes of death are easily apparent. A gunshot wound or stab wound are two such examples. Other causes of death, such as poisoning and choking, can be less obvious. To a skilled investigator, even the less than obvious causes of death will leave telltale clues. Choking is defined as the complete obstruction of the airway. Choking can occur when an excessively large piece of solid food such as a piece of meat is swallowed. The object can become lodged in the airway, plugging the flow of air. Even reflexive gagging may be insufficient to free the obstruction.

Food is a common cause of choking. As well, especially when the victim is in a supine position, vomit can puddle in the airway in sufficient quantity to block air flow. Unless the obstruction can be cleared, air cannot enter the lungs and death can ensue within about four minutes.

Signs of choking are obvious in a conscious person. A victim may be unable to talk, cry out, breathe, or cough. Initially, a person may grasp at their throat, in an instinctive although futile attempt to clear the blockage. As the full comprehension of what is happening dawns, a person can become very anxious and even panicked in behavior. As oxygen limitation becomes accentuated, skin color can change from the normal pinkish hue to blue or dusky. Finally, a loss of consciousness can occur.

Once a person is unconscious and unable to communicate their plight, recognition of the severity of the situation and the application of emergency relief becomes more difficult. All the while, however, oxygen deprivation is causing a loss of brain function. If the airway obstruction is not soon removed, death will result.

In an unconscious or dead victim, another sign of choking is the inability to push air into the lungs when artificial respiration is attempted. This failure is evident by the inability of the lungs to artificially inflate with air and visibly expand when air is blown into the mouth.

In a deceased person, the task then becomes to establish that choking did occur. A forensic investigator will search out eyewitnesses to the choking event. Recollections of the aforementioned behaviors by eyewitnesses provide a clue as to what might have happened. Additionally, a change in skin pallor associated with oxygen deprivation may still be evident in a corpse, such as a bluish tint around the lips.

Observation of the scene around the victim can provide clues. For example, choking may lead to loss of consciousness, causing the victim to fall. A resulting blow to the head on a table or other object can occur. A cut on the scalp, bloodstain near the head, and signs of impact with furniture can all be clues to choking.

A prudent investigator would look for signs of a meal such as food or food debris, plates, and cutlery. Observation of vomit should be taken as at least a suspicion that choking occurred.

When someone is unconscious but still alive, clearance of the airway, either by sweeping of the mouth or modified Heimlich maneuver, is essential. As well, a forensic investigator who suspects choking will attempt to identify and recover the blocking object from the airway.

In both cases the procedure is the same. The mouth is opened by grasping the tongue and lower portion of the jaw between the thumb and fingers, then lifting. With the jaw elevated, the upper portion of the airway is visible. An obstruction in the upper airway can sometimes be swept out of the airway using a hooked index finger.

In the case of a forensic examination of a corpse, if choking is suspected but no object is recovered, it is prudent to probe for an obstruction deeper within the airway upon autopsy . Imaging techniques such as x rays or CT scanning can also confirm an airway obstruction in a deceased person.

see also Antemortem injuries; Asphyxiation (signs of); Crime scene investigation; Death, mechanism of; Hypoxia; Lividity.