SUFFOCATION

Death from suffocation is said to result from any impediment to the respiration which does not act by compressing the larynx or trachea.

Suffocation may therefore be caused by pressure on the chest, as in persons crushed in a crowd. It may also be due to the respiration of certain gases, or to the presence of pulverulent substances in the air, which act by choking up the air-passages. Imprisonment in any confined space may cause death from suffocation, and abscesses bursting into the trachea, or vomiting matters in drunken persons lodging in the windpipe, may be attended with a like result. Pressure on the umbilical cord whilst the child is in the maternal passages causes death from suffocation.

Signs of Death by Suffocation.—The first effect of arrest to the passage of air into the lungs is the stagnation of blood in the capillaries of the lungs. Non-arterial blood then goes to the brain and consciousness is soon lost. The respiratory sensation is then arrested by the circulation of venous blood. The left side of the heart becomes emptied, and then weak; the right side full and engorged. The great venous trunks are also more or less full, and the abdominal viscera, liver, spleen, and kidneys congested. The arrest of the heart‘s action is a secondary effect; the right side is paralysed by being too full, the left by being empty. These signs may be said to be typical, or, rather, are to be expected in death due to suffocation, but it must be distinctly stated that they are not always present. The right side of the heart is not in all cases engorged with blood; and Christison warns medical men against expecting “strongly marked appearances in every case of death from suffocation.” The heart, moreover, continues to contract after the lungs have ceased to perform their duty. Death is thus due to apnœa—that is, death beginning at the lungs—and not to syncope. Death in some cases is from neuro-paralysis or nervous apoplexy. In death by shock, which in most cases is instantaneous, both sides of the heart are equally filled. Death, the result of disease, may present all the signs of death from suffocation, and no suspicion may be aroused as to the cause of death from the post-mortem appearances, especially if putrefaction have set in.

The following table is given as an aid to diagnosis in this form of death:

Points to be noticed in forming a
Diagnosis of Death by Suffocation

1. The Blood.—There is unusual fluidity of the blood found in death by suffocation, however produced. This condition is sometimes present in deaths due to certain diseases, fevers, &c., and in cases of narcotic poisoning. Even with the blood in this condition, the presence of coagula in the cavities of the heart is not infrequent. The colour of the blood is changed to a dark purple, but in suffocation by carbon monoxide it is red.

2. Animal Heat.—In persons who have died from suffocation the animal heat is long retained.

3. Cadaveric Rigidity.—Other things being equal, the rigor mortis is as well marked in this kind as in other forms of death.

4. The Lungs.—Hyperæmia of the lungs is rarely absent. In most cases both lungs are engorged in about equal proportions. Hypostasis—post-mortem stains—must not be mistaken for capillary engorgement.

5. The Heart.—Engorgement of the right side of the heart, the left being empty, or nearly so. It is advisable always to examine the heart first, and then the lungs. The pulmonary artery is also much congested.

6. Capillary Ecchymoses.—These appear as purplish-red spots on the pulmonary pleuræ, on the surface of the heart, aorta, in the thymus, and on the diaphragm. They may appear on the above-mentioned parts in a fœtus suffocated in utero by pressure on the cord. These ecchymoses are rarely seen on adults, most frequently on infants, due probably to the thinness of the coats of the capillaries, which are ruptured in the efforts made to breathe. They are not a positive sign of death from suffocation, as they have been seen in death due to cholera, typhus, and other diseases. They are present also where death is due to hanging, drowning, &c.

7. Condition and Appearance of the Trachea.—The mucous membrane of the trachea is injected, and appears of a cinnabar-red colour. This is present in every case of death by suffocation, and must not be confounded with the dirty cherry-red or brownish-red coloration due to putrefaction. Remember also that the trachea putrefies early. If suffocation be slowly produced, a quantity of frothy mucus may be found in the windpipe, and also in the smaller tubes of the lungs. Always examine, especially in cases of supposed infanticide, the trachea for foreign bodies, the presence of soot, &c. The presence of sand, ashes, &c., in the œsophagus and stomach in persons buried in these materials, is presumptive of the person having been placed in them prior to death.

8. Kidneys, Vena Cava, &c.—The quantity of blood in the kidneys is always considerable. The abdominal veins are all more or less congested, and the external surface of the intestines presents numerous traces of venous congestion.

9. The Brain.—Apoplexy of the brain, as secondary to the pulmonary apoplexy, may be more or less present, attended by its well-known appearances.

10. Face, Tongue, and Mouth.—The expression of the face is not characteristic of death by suffocation, and differs in no particular from that common to other forms of death, being more frequently pale than turgid; and the starting of the eyes, popularly ascribed to this form of death, is not often seen. The tongue may or may not be protruded beyond the teeth. The presence of froth about the mouth is not constant, and is of common occurrence in those dying from natural causes. The tympanum may be ruptured.

Was the suffocation homicidal, suicidal, or accidental?—Suffocation may occur accidentally during the act of swallowing, and by foreign bodies placed carelessly in the mouth and then drawn suddenly into the windpipe, or by blocking the pharynx or œsophagus, also from being smothered by sinking into sand, grain, mud, and such-like, or by the bed-clothes in cases of epilepsy during a fit. Examine the lips for the presence of ecchymosis and other marks of violence. A man, some years ago, was accused of having caused the death of his wife by strangulation, for which he was indicted, and tried before the High Court of Justiciary in Scotland. The post-mortem examination revealed the cause of death as due to suffocation, and the following injuries were found on dividing the windpipe, which contained a quantity of frothy mucus: in the interior of the larynx there was a considerable extravasation of blood lying beneath the investing membrane, and passing up on both sides and behind, as far as the chink of the glottis, and above that opening into the ventricles of the larynx. There was here, also, a fracture of the right wing of the thyroid cartilage, by which its lowest horn was wholly detached, and the cricoid cartilage was broken in two places at opposite sides of its ring. The defence was that she had fallen accidentally while in a state of drunkenness, and had thus produced the fatal injuries.

The man was acquitted, the legal opinion in favour outweighing the medical opinion against the theory of accident. The above case created some discussion at the time, and induced Dr. Keiller to make several experiments as to the possibility of fracturing the cartilages of the larynx. The following are his conclusions:

1. That ordinary falls on the human larynx are apparently not capable of producing fractures of its cartilages, and even falls from a height with superadded force appear to be unlikely to do so.

2. That severe pressure applied from before backwards, so as strongly to compress the larynx against the vertebral column, or violent blows inflicted over the larynx by means of a heavy body, are sufficient to cause fractures of the larynx. Fractures so produced, however, will be most discernible on the internal surface, and generally in or near the mesial line.

3. Violent compression applied to the sides of the larynx (as in ordinary manual throttling or strangulation by grasping), is, of all applied forces, the most likely to produce fractures of the alæ of the thyroid cartilage, or even of the cricoid cartilage, and fractures so produced are most perceptible, as well as most extensive, on the external surface of the larynx. By this lateral mode of applying force, the hyoid bone is almost most readily broken.

4. That the condition of the larynx in regard to the absence or presence of ossific deposit materially influences its liability to fracture from external violence. If altogether cartilaginous, partial slits or splittings may be produced. If partly ossified, fractures may be produced by a comparatively moderate degree of applied violence, and if extensively or entirely ossified, extreme violence will generally be required to produce laryngeal fracture (Edinburgh Medical Journal, 1855-56).

Homicidal suffocation may be due to forcibly introducing foreign bodies into the air-passages, especially in children; adults suffocated thus are generally under the influence of alcohol or drugs, or enfeebled from disease. Suicidal suffocation by these means is generally limited to lunatics.

Fig. 16.—The pulse in this case became slower than normal. Five minutes after the drop the type reached that of bradycardia, then recovered itself, and even 14½ minutes after the drop was beating with normal frequency, but in the meantime had become very feeble.

Fig. 17.—The pulse in this case became accelerated and then fell again, but was feeble throughout.

Fig. 18.—In this case the pulse rate increased, and then fell to 72 per minute towards the end.

Homicidal suffocation by compression of the chest has been effected in infants; in adults it is combined with the covering of the nose and mouth. The victims are generally old or enfeebled. Suffocation of infants may be homicidal, or accidental, due to “overlaying”; in the latter the greatest mortality is amongst the youngest infants. A child ten months old may struggle and free itself or awaken the mother.

In France a favourite mode of committing suicide by suffocation is the use of irrespirable gases—carbonic acid, carbon monoxide, and the like. Collateral circumstances must be taken into consideration, and will more or less help to point to the true cause of death.

The cause and nature of the death in all of its forms just mentioned are in general the same. Pressure on the trachea—thus arresting respiration—and also on the important vessels and nerves of the neck, results in death, which may be brought about in four different ways:

The following table will show the relative frequency of each form of death:

Remer. Casper.
Apoplexy   9 9
Asphyxia 614
Mixed6862
8385

Traumatic asphyxia occurs when a heavy weight such as a fall of earth or masonry compresses the chest, and thoracic respiration is impossible. The head and neck appear ecchymosed, the purplish-blue lividity generally ending abruptly at the lower part of the neck or upper part of the thorax, about the level of the clavicles. The conjunctivæ are ecchymosed, and there may be epistaxis. This discoloration does not disappear on pressure by the finger, indicating its petechial character. If the person survive long enough, the discoloration gradually disappears, passing through the colour changes of an ordinary ecchymosis.

The effects on the eyes may be such as to be followed by changes in the retina, and optic atrophy leading to loss of vision.

Parts of the neck pressed upon by clothing may escape ecchymosis, and present a white mark of almost normal skin.