Drowning:

Drowning is a form of asphyxia due to the aspiration of fluid into air passages, caused by submersion in water or other fluid.

1) Wet drowning:

In this, water is inhaled into the lungs and the victim has severe chest pain. This is also known as primary drowning (typical drowning), in which death occurs within minutes of submersion secondary to cardiac arrest or ventricular fibrillation.

2) Dry drowning:

In this type, water does not enter the lungs, but death results from immediate sustained laryngeal spasm due to the inrush of water into the nasopharynx or larynx. Thick mucus, foam, and froth may develop, producing a plug.

3) Secondary drowning (post- immersion syndrome or near-drowning):

Near drowning refers to a submersion victim who is resuscitated and survives for 24 hours. The person may or may not be conscious. These persons may develop hypoxemia resulting in brain damage, electrolyte disturbances, pulmonary edema, hemoglobinuria, sepsis, metabolic acidosis, chemical pneumonitis, cerebral edema, cardiac arrhythmias, and myocardial anoxia.

4) Immersion syndrome (hydrocution or submersion inhibition):

Death results from cardiac arrest due to vagal inhibition as a result of

(a) cold water stimulating the nerve endings of the surface of the body,

(b) water striking the epigastrium,

(c) cold water entering eardrums, nasal passages, and the pharynx and larynx which cause stimulation of nerve endings of the mucosa.

5) Shallow water drowning

Alcoholics, epileptics, infants, children, and unconscious persons may die due to drowning- ing in shallow water, in a shallow pit, or a drain In shallow water drowning, the whole body need not be submerged. Submersion of the face alone is sufficient to cause drowning if the mouth and the nose remain under the water.

 

Causes of drowning

a) For swimmer - exhaustion or other adversities.

b) For a non-swimmer - incapability to utilize the buoyancy of the body to keep the nose and mouth above the surface level of the water.

 

Cause of death in drowning

• Asphyxia
• Ventricular fibrillation
• Laryngeal spasm
• Vagal inhibition
• Exhaustion
• Injuries

 

Causes of death

1. In dry drowning - laryngeal spasm

2. In wet/primary drowning In freshwater drowning - ventricular fibrillation - results in heart failure In saltwater drowning - pulmonary edema leading to asphyxia

3. In post-immersion syndrome/secondary drowning - pulmonary infection. During drowning, death has not occurred. After drowning, being rescued- die due to complications of drowning.

4. In immersion syndrome - vagal inhibition leading to cardiac arrest.

In complete submersion- death occurs within 5 minutes.

Death usually occurs in 4 to 5 minutes in fresh water and 8 to 10 minutes in seawater.

 

Mechanism of drowning in freshwater

Water enters the lung

Increase in blood volume.

Hemodilution

Hemolysis

Increase in K+ level leading to hyperkalemia.

Ventricular arrhythmia ie. Ventricular fibrillation

Heart failure Death

 

Mechanism of drowning in saltwater

Water enters in the lung

The high osmolarity of inhaled water

Water movements occur from blood to lung

Leading to pulmonary edema

Hemoconcentration

Hypovolemia circulatory shock

Death

 

Positive finding of Antemortem drowning

1. Cadaveric spasm of hand with the presence of sand, mud, gravel, weeds in the grip

2. Presence of copious fine white froth near the mouth and the nasal opening.

3. Presence of similar froth in the lumen of the respiratory tract.

4. The lungs are voluminous, edematous, have a balloon-like appearance with marks of indentation over the surface by ribs.

5. Discharge of copious froth fluid in blood on the cut side of lungs.

6. Presence of water, sand mud in the stomach, small intestine.

7. Presence of diatoms in distant organs or tissues similar to those in water where the body was submerged.

The presence of diatoms in the lung substance, bloodstream, brain, liver, kidneys, bone marrow of femur (best site for analysis) or humerus or in the skeletal muscle has been claimed to be suggestive proof of antemortem drowning.

 

Postmortem finding in Drowning

Externally

1. Cadaveric spasm of hand with the presence of sand, mud, weeds in hand

2. Presence of copious fine white froth near the mouth and the nasal opening

3. Development of cutis anserina (goose skin-like appearance of the surface of the body

4. The skin becomes sodden, thickened, wrinkled, and white in color, known as "washerwoman's hands".

5. Liver Mortis on the dependent part.

Internally

1. The lungs are voluminous, edematous, have a balloon-like appearance with marks of indentation over the surface by ribs. When incised, the cut surfaces ooze out white, copious, lathery frothy thin fluid blood.

2. Lungs become hyper expanded & waterlogged lungs called emphysema a quorum.

3. Sand, mud water in stomach & water.

4. Hemorrhage in the middle war, mastoid ear cells

 

Cutis anserina or goose-skin or goose-flesh, in which the skin has granular and puckered appearance may be seen. It is produced by the spasm of the erector pilae muscles, attached to each hair follicle, and can occur in living when the skin comes in contact with cold water.

Washer woman's hands: Soddening of the skin occurs due to absorption of water into its outer layer. The skin becomes sodden, thickened, wrinkled, and white in color, known as "washerwoman's hands".

The alveolar walls may rupture due to increased pressure during forced expirations, and produce hemorrhages, which when present subpleural are called "Paltauf's hemorrhages".

 

Diatoms

These are unicellular algae that have inert silicone coating around them. These are present in all-natural water sources, more abundantly in pond water or in a lagoon, or where the water is stagnant. They are less frequent in streams or in rivers where the water is frequently polluted by chemicals and industrial refuge.

When a drowning person inhales water and when the alveoli get distended with water and air, the alveolar walls may get ruptured exposing the capillaries which are also ruptured along with. The water from the alveolar sacs along with diatoms it contains enters the circulation and is carried to distant organs and tissues. Hence, in a body removed. from water, if diatoms can be demonstrated in the tissues of some distant organs (distant from the lungs and the body surface, to exclude the chance of contamination of the tissue by surface diatoms), then it goes strongly in support of death due to drowning. 

 

Test for the presence of diatoms

1. By histological examination diatoms can be demonstrated in the lungs or rarely in some other tissue, provided that plenty of diatoms were present in the submerging water and a good number of them entered in the circulation.

2. Diatoms can be demonstrated, alternatively and comparatively more easily, by acid digestion of the bone marrow (considered most suitable for the collection of contamination if the sample of tissue and for most satisfactory interpretation), brain tissue, or tissue from other organs.