MULTIPLE CHOICE QUESTION
Q. How much force an assailant could have used?
II. ATYPICAL DROWNING 1. Dry drowning
• In dry drowning, water does not enter the lungs due to laryngeal spasm induced by small amounts of water entering the larynx.25
• Seen in 1-2% of cases.
Flow chart 10.4: Mechanism of fresh and sea water drowning
Fig. 10.14: Mechanism of death in fresh water drowning
• Death may be extremely rapid and time elapsed is insufficient for typical drowning to occur. Two mechanisms have been postulated:
i. Reflex cardiac arrest due to vasovagal stimulation.
ii. Laryngeal spasm due to airway closure causing lethal hypoxemia.
• In these cases, autopsy findings and biological tests for drowning are negative and the lung fields are dry.
2. Immersion syndrome (Hydrocution, submersion inhibition or cold water drowning)26
• The syndrome occurs as a result of:
i. Cold water stimulating the nerve endings of the surface of the body.
ii. Water striking the epigastrium.
iii. Cold water entering eardrums, nasal passages, pharynx and larynx.
iv. Falling or diving into water with feet first or duck diving by the inexperienced.
• Mechanism: Sudden immersion in cold water may initiate cardiorespiratory reflexes lasting about 2-3 min which is termed as 'cold-shock' response. The initial response include an immediate reflex peripheral vasoconstriction, increase in heart rate and increase in cardiac output with resulting increase in arterial and venous pressure. These significantly increase the workload of the heart and coupled with concomitant increased catecholamine levels which may induce fatal arrhythmias.
• The findings of typical drowning are absent because aspiration of water into the lungs does not occur.
• The syndrome particularly affects the middle-aged or elderly men who have ingested some amounts of ethanol. Underlying cardiac disease could increase the risk of sudden collapse.
3. Near drowning (post-immersion syndrome or secondary drowning)
• Near drowning refers to survival beyond 24 h after a submersion episode.
• Death is caused by complications or sequelae (e.g.
ARDS, pneumonia, sepsis, hypoxic-ischemic encepha- lopathy, cerebral edema and DIC).
• Secondary drowning sometimes refers to a victim who initially responds well to resuscitation but then suffers respiratory decompensation.
4. Shallow water drowning (submersion of the unconscious):
Alcoholics, drugged, epileptics, infants, children and unconscious persons may die due to drowning in shallow water in a pit or drain.
Epidemiology
• Drowning victims are predominantly male (> 65%). It occurs in the summer months, more frequently seen in rivers, lakes, ponds and creeks.
• The age groups affected are the children (< 4 years) and young adults (15-24 years). Drugs and alcohol abuse among the teenagers are other associated factors.
Fig. 10.15: Mechanism of death in sea water drowning
Asphyxia 157
Cause of Death
i. Asphyxia: Most common cause of death.
ii. In fresh water drowning, death results from ventricular fibrillation. While in salt water, it is due to cardiac arrest from fulminant pulmonary edema and associated changes.
iii. Vagal inhibition due to impact with water.
iv. Laryngeal spasm.
v. Concussion/head injury.
vi. Apoplexy: Subarachnoid hemorrhage from rupture of Berry aneurysm or cerebral hemorrhage by rupture of cerebral vessels from sudden on-rush of blood to the brain due to excitement or sudden fall from height into cold water.
vii. Secondary causes
• Septic aspiration pneumonia
• Sudden bursting of aneurysm
Symptoms: Apart from recalling of memory of past events, there may be mental confusion along with auditory and visual hallucinations, tinnitus and vertigo.
In wet drowning, there is chest pain.
Treatment: First and immediate step consists of application of artificial respiration with closed chest cardiac massage, even in absence of pulse and respiration and irrespective of injuries sustained during drowning.
Defibrillator should be used when there is ventricular fibrillation.
Fatal period
• Fresh water drowning: 4-5 min.27
• Sea water drowning: 8-12 min.
Postmortem Examination
• The diagnosis of drowning is one of exclusion.
• Most of the signs are not specific of death due to drowning and are rather signs of submersion of body underwater for some period. Any dead body, whatever the cause of death, will develop signs of immersion, if left for a sufficient time in water.
• Moreover, some of the signs are not appreciable in case of putrefaction.
When freshly removed from water, the body and clothes will be wet. There will be sand and mud particles on the body, hair and clothes. This finding is not specific of antemortem drowning or death due to drowning.
External Findings
i. Face is pale, becomes bloated and discolored with putrefaction. Cyanosis is present.
ii. Eyes are found half open or closed, conjunctiva suffused and pupils are dilated. Sub-conjunctival hemorrhages may be present in lower eyelids.
iii. Tongue may be swollen and protruded.
iv. Postmortem lividity: Light pink in color, present over face, neck, front of upper part of chest, upper and lower limbs as the body usually floats with face down, buttocks up, legs and arms hanging down in front of the body (Fig. 10.16). With onset of putrefaction, skin of head and neck become dark with 'tete de negre' appearance.
v. Froth: Presence of fine, copious white 'shaving- lather' like froth at the mouth and nostrils is the most characteristic antemortem external finding.28,29 Production of this tenacious, fine, lathery foam is a vital phenomenon.
• The mass of foam, consisting of fine bubbles, does not collapse when touched with the point of a knife.
• It may be absent when wiped off, but reappears again by itself or by applying simple pressure on chest.
Mechanism of production of froth: The inhalation of water irritates the mucous membrane of air passages due to which the tracheal and bronchial glands secrete large quantities of tenacious mucus and the alveolar lining cell irritation produces edema fluid.
Vigorous agitation of the seromucoid secretion, surfactant, aspirated water and retained air converts the mixture of endogenous and drowning medium into froth.
Other conditions in which froth is seen:
• Strangulation • Electric shock
• Putrefaction • Acute pulmonary edema
• Epileptic fit • Opium/OPC poisoning In all these cases, froth is not fine, not of such large quantity or tenacious in nature as in drowning.
vi. Cutis anserina (goose skin/goose flesh/goose bumps) is a state of puckered and granular appearance of
Fig. 10.16: Position of a submerged dead body
skin of the extremities immersed in cold water due to contraction of erector pilorum muscles. It can occur on submersion of the body in cold water immediately after death while the muscles are still warm and irritable, and also produced by rigor mortis of erector muscles.30
vii. Washerwomen's hand is the wrinkled, sodden, bleached appearance of palms, palmer aspect of fingers and soles of feet including plantar surface of toes due to submersion of the body. Maceration of skin occurs due to imbibation of water into its outer layers. It is first seen in the fingertips by 3-4 h and whole hand by 24 h.
viii. Scrotum and penis get retracted in contact with cold water in winter months.
ix. Grass, gravel, mud, sand, weeds or aquatic vegetations held firmly in clenched hands due to cadaveric spasm which is a vital proof of antemortem drowning. The material clenched in the hands indicates the place of submersion.
x. Rigor mortis appears early, especially when a violent struggle for life has taken place before death.
xi. Antemortem injuries might be sustained during fall into water, along the tank, or by striking against a hard object while diving in shallow water.
Examination of the skin for blunt injuries should be delayed until the body is dry. Abrasions are easily seen after drying which becomes brownish in color.
• Tete-de-negre is the French name for a dessert, a pastry covered with black chocolate. According to Harrap's French-English dictionary, tete-de-negre literally means 'nigger-brown' color.
• Cutis anserina (Latin cutis: skin, anser: goose): Another term for this is 'horripilation' (Latin horrere: to stand on end, pilus: hair).
Internal Findings 1. Lungs
i. Lungs are voluminous, distended and show ballooning, i.e. bulge out of chest on removal of sternum (Diff.
10.3). Tenacious, lathery froth in trachea and bronchi is present. In case of laryngeal spasm, there will be no ballooning.
ii. Distended lungs will show indentations of ribs on the pleural surface because of pressure on increased volume of lungs.
iii. Lungs feel heavy, boggy and doughy; will easily indent on pressure by fingers because of water logging and edematous condition.
iv. Lungs may be congested, but are often pale gray in appearance because of forcing out of blood from lungs and compression of vessels in the interalveolar septa by the trapped air and water in lung alveoli.
v. Tardieu's spots over the subpleural tissues are few or none due to compression of blood vessels in interalveolar septa.
vi. There may be mottled areas of red and gray distended alveoli, alternating with few bigger areas of extravasation known as Paltauf's hemorrhage, from tracking of effused blood along the interlobular septa; mostly seen over the anterior surface and margins of lungs.31
vii. Cut section of lungs will exude copious amount of frothy bloodstained liquid due to presence of water within alveoli and bronchioles.
viii. Pleural cavities may contain bloodstained fluid, either by permeation through pleura or postmortem disintegration of lungs and pleurae.
• The overall picture of lungs and respiratory passage in wet drowning has been described as emphysema aquosum (emphyseme hydroaerique) as it resembles the pulmonary hyperinflation seen in obstructive lung disease. There is dilation of alveoli, thinning of alveolar septae and compression of alveolar capillaries.
• When the person is unconscious at the time of drowning, edema aquosum develops. It is a state of mere flooding of lungs with the airless water and no formation of froth. Emphysema aquosum develops
Differentiation 10.3: Lungs in fresh water and sea water drowning
S.No. Feature Fresh water drowning Sea water drowning
1. Size and weight Ballooned, but light Ballooned and heavy
2. Color Pinkish Purplish or bluish
3. Consistency Emphysematous Soft, jelly-like
4. Shape after removal from body Retained, do not collapse Not retained, tend to flatten out 5. On cut section Crepitus is heard, little froth No crepitus, copious fluid and froth
and no fluid
Asphyxia 159 only when the conscious victim of drowning struggles
for survival.
• When a dead body is thrown into water, even though hydrostatic lungs (due to hydrostatic pressure water passes into the lungs) are produced, yet there will be no classical signs of drowning lungs. A drowning lung together with frothy fluid is diagnostic.
2. Larynx, trachea and bronchioles
i. Presence of sand, mud, slit, dirt, aquatic vegetations, classical water flora, algae and diatoms in the trachea and lower bronchial tree are characteristic positive findings of antemortem drowning.
ii. Fine white froth, at times blood tinged in the lumen of trachea and bronchi, interspersed with foreign material as above, is highly suggestive of death from antemortem drowning.
iii. Mucosa of larynx, trachea and bronchioles may be red and congested.
iv. Vomit reflex due to medullary hypoxia may result in regurgitation of gastric contents into larynx, trachea and bronchioles.
3. Heart and blood vessels: Like in other forms of asphyxia, left side of heart will be usually empty; the right heart will be full with the venous system engorged with dark blood, unusually fluid in consistency because of admixture with water.
Gettler test: Normally the chloride content of the right and left side of heart is nearly same, about 600 mg/
100 ml. If difference is 25 mg% or more, it is suggestive of antemortem drowning.32
• In case of fresh water drowning, the chloride content of the blood of left heart will be lower than that in right because of dilution by water.
• In case of salt water drowning, chloride content of left heart will be greater than right heart because of hemoconcentration and mixing with salt water.
• No change in chloride content of heart is seen in persons dying of laryngeal spasm or vagal inhibition, putrefaction, patent foramen ovale or if the saline content of drowning medium approximates that of blood.
Plasma magnesium: A high level of plasma magnesium in left heart blood is observed than in right heart blood and is due to absorption of magnesium from the drowning medium, particularly salt water.
4. Stomach and small intestines
• Stomach contains water in 70% of cases, but it is possible that the victim might have drunk the same
water before death. When a disagreeable liquid is found which could not be swallowed voluntarily and which corresponds to drowning medium, like muddy water, it is a valuable indication of antemortem drowning.
• Water is not found in the stomach, if the person died from shock, syncope, putrefaction and was already dead (postmortem submersion).
• Small intestine may contain water in about 20% cases.
This is regarded as positive evidence of death by drowning as it depends on peristaltic movement which is a vital phenomenon.
Water may enter the mouth and pass down into the stomach passively if the water is turbulent, rather that the victim actively swallowing it. It may also be due to the postmortem relaxation of the gastroesophageal sphincter which allows water to enter the stomach.
5. Brain: Congested gray matter, softening and loss at the gray-white junction.
6. Liver, spleen and kidneys are congested.
7. Middle ear: Presence of water and hemorrhage in middle ear is claimed to be one of the positive proof of antemortem drowning. Hemorrhages in petrous temporal bone or in mastoid air cells may be seen. Temporal bone hemorrhages are also seen in death due to hanging, head injury and carbon monoxide poisoning.
8. Ethmoid and sphenoid sinuses: Water may enter the respiratory sinuses; the jugum sphenoidale may be removed to expose the contents of the sphenoid sinus.
9. Diatom test: Diatoms belong to the class Bacillario- phyceae and are microscopic unicellular algae which secrete silicon skeletons called frustules; they are chemically inert and almost indestructible, being resistant to strong acids (Fig. 10.17). During drowning, diatoms (size upto 60 enter the circulation via the lungs through the ruptured alveolar walls, lymph channels and pulmonary veins into left heart and then into general circulation, when the person is alive (Fig.
10.18).33
• Presence of diatoms in the lung substance, blood stream, brain, liver, kidneys, bone marrow of femur (best site for analysis)34 or humerus or in the skeletal muscle has been claimed to be suggestive proof of antemortem drowning.35
• Since diatoms resist putrefaction, diatom test may have some value in examination of decomposed bodies.
• The test is negative in dead bodies thrown in water and in dry drowning.
Procedure: A sample of tissue is carefully retrieved to avoid surface contamination. Approximately 50 g of tissue is taken and placed in 50 ml of concentrated nitric acid in a boiling flask. The flask is heated for
48 h, cooled and the liquid is centrifuged for 20-30 min. The supernatant is discarded and the sediment is re-centrifuged. The final residue is aspirated and placed on a clean glass slide and air dried. It is then examined for silica skeletons of diatoms which are birefringent using phase-contrast microscopy or dark ground illumination. A water sample is collected at the time of body retrieval in a clean container and similarity of different species of diatom is compared.
Interpretation
The presence of diatoms supports the diagnosis of drowning, while the absence of diatoms does not exclude it as a cause. The diatom test is valid only if it can be shown that:
• Deceased did not drink this water immediately before submersion.
• Species recovered from specimen are present in the sample from site of drowning.
• The various species are present in same order of dominance for the admissible size range and in approximately same proportions.
The test is limited by the difficulty of excluding the possibility of environmental contamination. Diatoms are ubiquitous in the environment and may enter the Fig. 10.17: Different types of diatoms
Fig. 10.18: Principle of diatom test
Asphyxia 161 circulation via the GIT (as contaminants of foods, such
as salads, watercress and shellfish) or via the respiratory tract (diatoms are normally present in small numbers in the air, in some paints, building plasters and dusts).
Medico-legal Questions