In choking, asphyxia is caused by obstruction within the air passages. The manner of death can be natural, homicide, or accident. Natural deaths are seen in individuals with acute fulminating epiglottitis, where there is obstruction of the airway by the inflamed epiglottis and adjacent soft tissue. Such individuals represent medical emergencies and can die literally in front of a physician. The individual develops a sore throat, hoarseness, respiratory difficulty, inability to speak and then suddenly collapses as the airway is completely obstructed. Inhalation of steam can cause a similar picture, with a markedly edematous, beefy-red mucosa in the larynx with obstruction (Figure 8.6).

Figure 8.5 Elderly female smothered with hand. Fingernail marks on nose.
Figure 8.6 Massive laryngeal edema caused by inhalation of steam.

Homicidal deaths by choking are relatively uncommon. In infants, one occasionally sees a newborn murdered by stuffing toilet paper into its mouth. Figure 8.7A illustrates the case of an infant killed by her father by ramming

Figure 8.7 (A) Pacifier rammed into mouth by father (continued).

a pacifier into her mouth. In adults, individuals sometimes die during a robbery or burglary when a cloth or sock is rammed into the mouth to silence the individual. This is often done in conjunction with gagging (Figure 8.7B). This method of gagging individuals is shown quite frequently on television without any harmful consequences, but, unfortunately, in real life, the cloth can work its way backward, completely obstructing the posterior pharynx and causing the individual to asphyxiate.

Most choking deaths are accidental in manner. In 1997, there were approximately 3300 deaths ascribed to unintentional inhalation of food or other objects, resulting in obstruction of the respiratory passages.7 In children, choking usually involves aspiration of a small object into the larynx with occlusion of the airway, e.g., a small rubber ball or a balloon (Figure 8.8). Deaths have occurred in classrooms, where children have choked on the top of ballpoint pens they were biting on.

In adults, choking virtually always involves food (Figure 8.9). Here, it is commonly associated with acute alcohol intoxication, bad-fitting dentures, neurological injury, or senility. The piece of food will wedge in the larnygo-pharynx and larynx, completely obstructing the airway. Such deaths have

Figure 8.9 A 39-year-old male choked on a ham sandwich.

acquired the name of "cafe coronary." The individual is eating, suddenly stops talking, stands up, and collapses. Cardiopulmonary resuscitation is begun in the belief that the individual has suffered a heart attack. In fact, he has choked on food and his airway is completely occluded. Thus, cardiopulmonary resuscitation is ineffective. If the individuals giving mouth-to-mouth resuscitation are observant, they will see that the chest is not rising when they blow into the airway, which indicates obstruction.

Coughing during a collapse suspected of being caused by choking rules out this diagnosis as one must have an open airway to cough. Coughing involves the inspiration of 2 to 2.5 liters of air, followed by closing off of the epiglottis and the vocal cords, contraction of the abdominal muscles to force up the diaphragm, while, at the same time, the expiratory muscles contract. The epiglottis and vocal cords open up and the air is then expelled out of the lungs, under pressure, usually carrying with it any foreign material present in the bronchi and trachea.8 The expelled air can reach velocities of 75 to 100 miles per hour.

Occasionally, choking deaths occur when an individual falls into finely ground material, such as cornmeal or sawdust. There is involuntary inhalation and the airway is completely occluded by this material.

The finding of small amounts of food material in the airway at autopsy does not indicate that the individual choked to death. Approximately 20-25% of all individuals aspirate food agonally, independent of the cause of death.9 One can attribute a death to aspiration only if the airway from the larynx down is completely occluded by food. Death caused by massive aspiration of food is rarely seen in a medical examiner's office. It is most common in comatose patients who have impaired functioning of the central nervous system.

The diagnosis of choking death is made at autopsy when the airway is found occluded. If the individual had an occluded airway and the object or food was removed during resuscitation, the only way to make the diagnosis would be by history. There are no specific autopsy findings indicative of choking except for occlusion of the airway.

Some medical personnel will ascribe a death to choking even though the airway was never completely occluded. They suggest that laryngospasm is the cause of death. There is, however, no objective evidence that this can occur. If laryngospasm did occur, one would expect relaxation of the larynx as the victim became agonal. This, in turn, would lead to opening up of the airway and recovery. Others hypothesize that a fatal "vagal reaction" or "reflex cardiac death," mediated through the parasympathetic nervous system, occurred through hypersensitivity of the larynx to aspirated food. Again, there is just no objective proof that this entity exists.

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