Drowning

Drowning

Aim of this 2 parts class:

• 1. To give you guys attendance.• 2. Theoretical, conceptual & practical know how• 3. To able you to understand the burden,

mechanism, morphological, micro features• 4. To differentiate between freshwater and

saltwater drowning• 5. To differentiate between AM and PM

drowning• 6. To estimate the duration & Site of incidence.

Drowning Vs Sinking

Home-work

• Difference b/w Drowning and Immersion?

Specific Gravity and Density

• Specific gravity is defined as the ratio of the density of a substance to the density of water.

• Water has a specific gravity of 1.0

• Any object with a specific gravity less than1.0 will float in water and anything greater than 1.0 will sink

• The human body has a density slightly less than that of water and averages a specific gravity of 0.974. Therefore, we float.

• Lean body mass has a typical density near 1.1

• Fat mass has a density of about 0.9.

Am I a stud?

SEQUENCE OF EVENTS IN DROWNING

• 1. SENSE OF PANIC– Expressed by:

• Violent struggle• Automatic swimming movements

– Usually followed by:

• 2. PERIOD OF VOLUNTARY APNOEA• Duration: 1-2 minutes.• Hypoxemia, hypercapnia, R & M acidosis.

• 3. ATTEMPT AT TAKING A BREATH• WATER:

• May be freely inhaled• Or, may cause glottic spasm due to impingement.

• In 10-15 % victims: glottic spasm severe asphyxia water may not enter the lungs unless subcouncious.

Dry drowning

• In 85-90 % victims: water is swallowed inducing vomiting, gasping & aspiration of water into lungs. When expiratory effort is made: fine froth, sometimes blood stained (due to overdistension of liquid coloumn)

Wet drowning

• 4. Cessation of constant struggling

• 5. Stage of convulsive spasms, twitching, dilation of pupils

• 6. Clinical death

Freshwater Drowning

» The Mechanism + Resp Pathophysiology

Freshwater moves rapidly across A.C.mb

into circulation

disrupts & denatures surfactant

Surface tension increased

compliance decreased

atelectasis

More liquid in the circulation

Hemodilution, decrease in Na+, Cl & Ca conc.

Liquid/ water goes inside RBCs

Hemolysis

Release of K+

Increase in K+ conc.

• Marked Ventilation perfusion mismatch• Shift Acute hypervolemia• Experimental Vs Reality

Increase in K+ irritates myocardium

Arrythmias (VF) occurs

Effect on CVS

• Increase in circulatory volume but till plateau.

• Decrease in blood density• Dec in Na, Cl

Salt water Drowning

• Pulling out of water Hemoconc. Inc. in Na, Cl and Mg

• No hemolysis, No VF

• Death within 5-12 minutes (later than freshwater)

• Pulmonary edema within minutes• Shift Hypovolemia

Hypertonic liquid

Draws water out through mb

Into pulmonary alveoli

Damage to basement mb + Dilution & washing out of Surfactant

compliance decreased

Pulmonary edema X ray

Effect on CVS

CVS effects are secondary to:

• 1. Changes in arterial oxygen tension• 2. Changes in acid base balance.

Acute hypoxemia Catecholamine release Transient tachycardia and hypertension.

Followed by bradycardia and hypotension as hypoxemia intensifies.

Hypoxemia may directly reduce myocardial contractility

Hypoxia + Acidosis: increase the risk for arrythmias( VT, VF, Asystole)

Note: VF as an immediate cause of death is uncommon in both forms of human drowning.

Effects on Brain

• Hypoxia ischemic damage to brain

• Window period of 4-6 minutes before irreversible neuronal damage.

Effects on other organs

• Acute renal and hepatic insufficiency• GI injuries• DIC

Complications

Immediate Complications

Cardiac Arrhythmias (VF, Asystole)

Cardiogenic Shock

Delayed Complications

1. Liquiddamages pulmonary ARDS Primary pulmonary edema

2. Cerebral hypoxia Neurogenic pulm edema

3. Hypoxic encephalopathy Brain death

4. Pneumonia (aspiration, chemical, bacterial)

5. Sepsis6. Multi Organ failure

Types of drowning

• 1. Wet drowning= primary drowning• 2. Dry drowning= 10-15%, laryngospasm, thick mucous foam

plug, panoramic views of past life, pleasant dreams without distress.

• 3. Secondary drowning= post immersion syndrome= near drowning; Secondary drowning is death due to chemical or biological changes in the lungs after a near drowning incident ; resuscitated and survives for 24 hours, +/- conscious, hypoxemia brain damage, electrolyte disturbances, pulmonary edema, hemoglobinuria, chemical pneumonitis

• 4. Immersion syndrome= hydrocution= submersion inhibition; cold water n. endings +/ strike epigastrium +/ entering ear drums, nasal passages. – Horizontal entry (dive) pressure on abdomen– All these Vagal inhibition Cardiac arrest death

RESPIRATORY SYSTEM

• In humans: As little as 1 to 3 ml/kg produces profound alteration in pulmonary gas exchange and decreases pulmonary compliance by 10 to 40%

Causes of death

• 1. Asphyxia• 2. VF: disturbed Na/ K ratio (freshwater)• 3. Laryngeal spasm• 4. Vagal inhibition: cold water, emotions?,

unexpected immersion.• 5. Exhaustion• 6. Injuries: # skull, cervical vertebrae.

MACRO-MORPHOLOGICAL CHANGES

• 1. FOAM/ FROTH: – 1. Mushroom like froth from mouth, nostrils.– 2. Foam inside mouth, in upper airways.

• Drowning liquid+ edema liquid+ fine air bubbles (resistant to collapse)

• Blood stained: mechanism?

– 3. External foam: most valuable finding• D/D:

» 1. Cardiogenic PE» 2. Epilepsy» 3. Drug intoxication» 4. Electrical shock

Mechanism of foam formation

• Clothing: wet• Skin: wet, moist, pale ?• Mud, silt, algae on body• PM lividity: light pink in color• Face: +/- cyanotic• Conjunctivae: congested• Pupils: dilated

• Tongue: may be protruded or swollen• Cutis Anserina: goose flesh?• Reaction Phenomenon?• Weed, grass, gravel in hand: due to cadaveric

spasm.

• Soddening of skin of hands, feet/ shoes. Wrinkling Bleaching of epidermis in 4-8 hrs Washerwoman’s hands and feet 24-48 hrs.

Long standing Washer man/woman’s feet

• 2. LUNGS:• Emphysema Aquosum• Imprints of ribs on pleural surface• lung SR: Pale, mottled, red and grey areas• Cut Section: Oozing of foamy liquid• Subpleural hges (Paltauf’s spots): 5-60% of drownings• Lung weight: if taken alone, has little diagnostic value.• Dry lungs: with no signs of aqueous emphysema (10-

15%)

Comparison of forensic pathology of lungsTrait Fresh water drowning Sea water drowning

1. Size and weight Balloned but light Balloned and heavy; weight upto 2kg

2. Color Pale pink Purplish or bluish

3. Consistency Emphysematous Soft and jelly like

4. Shape after removal from the body

Retained but do not collapse

Not retained; tend to flatten out

5. Sectioning Crepitus is heard.Little froth and no fluid

No crepitus. Copius fluid and froth.

Over distension

and overlapping of anterior

lung margin

Paltauf’s spots

• 3. PLEURA: • PE: a relatively common finding• Due to diffusion of liquid into thoracic cavity.

4. TEMPORAL BONE: • Gross hges in the petrous and mastoid region of

temporal bone• Reasons:

• 1. Barotrauma• 2. Penetration• 3. Increased capillary & venous pressure

• 5. SINUSES:• Aqueous liquid inside sinuses.• Sign of permanence, can occur PM too.

• 6. SPLEEN:• controversial• Cut off value 0.2% body weight.• Decrease in weight due to (proposed): symp.

Stimulation V/c Contraction of the spleen capsule and trabeculae

• 7. MUSCLES:• Hges are seen, mostly in Resp & Aux resp ms > neck &

back ms > ms of shoulder girdle > upper arm ms.

• Causes: Convulsions, hypercontraction, overexertion.

• 8. GI:• Laceration of GI mucosa: vague

When the body starts floating?

Alterations in blood

Gettler Test:• Normally, Cl content R=L, 600 mg/100 ml• F.W.D= blood gets diluted by as much as 72 %

in 3 minutes blood in the left side: Cl is 50 % lower than usual.

• S.W.D= Cl conc increases (due to hemoconc)• 25% difference= significant• Value of the test= doubtful

Diatoms

• Microscopic, unicellular algae

• Siliceous skeleton = frustule

• Resist heat and acid.• Active circulation brings

diatoms into intestine, liver, brain, bone marrow.

• Technique: HNo3 or enzymatic digestion Centrifuge deposit PC or DGI Microscopy

Thank you, for your patience

• Pressure• is applied using the heel of one hand with the other• hand on top, to depress the sternum 1 in. to 11/4 in.• with each stroke in adults, followed by release of• pressure, at the rate of about 60 per minute.• The application of artfficial respiration and• cardiac massage should be continued for at least• 15 minutes• If spontaneous respiration• and restoration of the circulation do not occur• within 15 minutes, further efforts are probably• fruitless. If there is discernible evidence of active• circulation, artificial respiration should be continued• until spontaneous respiration is restored. On• the other hand, marked body cooling or evidence• of early rigor mortis indicates the futility of continued• efforts in this direction. The presence of• fixed dilated pupils persisting for 15 minutes is• suggestive of clinical death.

• In fresh-water• drowning, this consists of 1000 c.c. of 3% saline,• which is repeated in three to six hours if the serum• sodium level is below 110 mEq./l. The deficit in• serum calcium may need to be corrected by an• infusion of calcium gluconate.• Transfusion with whole blood, alternating with

bleeding, may be• needed later.

• In salt-water drowning, intravenous• therapy is carried out with 5% dextrose-never• saline, whole blood or plasma. Venesection

may be• needed later.

• anesthetic machine• using intermittent pressure and pure oxygen.

• If the cardiac• status is unsatisfactory, injections of epinephrine• have been employed by some workers. If ventricular• fibrillation has occurred, the use of external• stimuli such as a quick blow over the heart, the• application of electrodes with one or more shocks• using 480 volts for .25 second,

• In victims of fresh-water drowning the urinary• output must be carefully observed; the

hemolysis• of red cells may cause renal tubular nephrosis.

• under circumstances• which induce emotions such as fear or

surprise,• the swimmer may be in such a state that an• ordinarily innocuous stimulus will cause vagal

inhibition• and immediate cardiac arrest.