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For students of gian sagar medical college: forensic files/ powerpoint slides:

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  1. 1. Drowning<br />
  2. 2. Aim of this 2 parts class:<br />1. To give you guys attendance.<br />2. Theoretical, conceptual & practical know how<br />3. To able you to understand the burden, mechanism, morphological, micro features<br />4. To differentiate between freshwater and saltwater drowning<br />5. To differentiate between AM and PM drowning<br />6. To estimate the duration & Site of incidence.<br />
  3. 3. Drowning Vs Sinking<br />
  4. 4. Home-work <br />Difference b/w Drowning and Immersion?<br />
  5. 5. Specific Gravity and Density<br />Specific gravity is defined as the ratio of the density of a substance to the density of water.<br />Water has a specific gravity of 1.0 <br />Any object with a specific gravity less than1.0 will float in water and anything greater than 1.0 will sink<br />The human body has a density slightly less than that of water and averages a specific gravity of 0.974. Therefore, we float. <br />Lean body mass has a typical density near 1.1 <br /> Fat mass has a density of about 0.9. <br />
  6. 6. Am I a stud?<br />
  7. 7. SEQUENCE OF EVENTS IN DROWNING<br />1. SENSE OF PANIC<br />Expressed by: <br />Violent struggle<br />Automatic swimming movements<br />Usually followed by:<br />2. PERIOD OF VOLUNTARY APNOEA<br />Duration: 1-2 minutes.<br />Hypoxemia, hypercapnia, R & M acidosis.<br />
  8. 8. 3. ATTEMPT AT TAKING A BREATH<br />WATER:<br />May be freely inhaled<br />Or, may cause glottic spasm due to impingement.<br />In 10-15 % victims: glottic spasm severe asphyxia water may not enter the lungs unless subcouncious.<br />Dry drowning<br />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)<br />Wet drowning<br />
  9. 9. 4. Cessation of constant struggling<br />5. Stage of convulsive spasms, twitching, dilation of pupils<br />6. Clinical death<br />
  10. 10. Freshwater Drowning<br />The Mechanism + RespPathophysiology<br />
  11. 11.
  12. 12. More liquid in the circulation<br />Hemodilution, decrease in Na+, Cl & Ca conc.<br />Liquid/ water goes inside RBCs<br />Hemolysis<br />Release of K+<br />Increase in K+ conc.<br />
  13. 13. Marked Ventilation perfusion mismatch<br />Shift Acute hypervolemia<br />Experimental Vs Reality<br />Increase in K+ irritates myocardium<br />Arrythmias (VF) occurs<br />
  14. 14. Effect on CVS<br />Increase in circulatory volume but till plateau.<br />Decrease in blood density<br />Dec in Na, Cl<br />
  15. 15. Salt water Drowning<br />Pulling out of water  Hemoconc. Inc. in Na, Cl and Mg<br />No hemolysis, No VF<br />Death within 5-12 minutes (later than freshwater)<br />
  16. 16. Hypertonic liquid<br />Pulmonary edema within minutes<br />Shift Hypovolemia<br />Draws water out through mb<br />Into pulmonary alveoli<br />Damage to basement mb + Dilution & washing out of Surfactant<br />compliance decreased<br />
  17. 17. Pulmonary edema X ray<br />
  18. 18. Effect on CVS<br />CVS effects are secondary to:<br />1. Changes in arterial oxygen tension<br />2. Changes in acid base balance.<br />Acute hypoxemia Catecholamine release Transient tachycardia and hypertension.<br />Followed by bradycardia and hypotension as hypoxemia intensifies.<br />Hypoxemia may directly reduce myocardial contractility<br />Hypoxia + Acidosis: increase the risk for arrythmias( VT, VF, Asystole)<br />Note: VF as an immediate cause of death is uncommon in both forms of human drowning.<br />
  19. 19. Effects on Brain<br />Hypoxia ischemic damage to brain<br />Window period of 4-6 minutes before irreversible neuronal damage.<br />
  20. 20. Effects on other organs<br />Acute renal and hepatic insufficiency<br />GI injuries<br />DIC<br />
  21. 21. Complications <br />
  22. 22. Types of drowning<br />1. Wet drowning= primary drowning<br />2. Dry drowning= 10-15%, laryngospasm, thick mucous foam plug, panoramic views of past life, pleasant dreams without distress.<br />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<br />4. Immersion syndrome= hydrocution= submersion inhibition; cold water n. endings +/ strike epigastrium+/ entering ear drums, nasal passages. <br />Horizontal entry (dive) pressure on abdomen<br />All these  Vagal inhibition Cardiac arrest death<br />
  23. 23. RESPIRATORY SYSTEM<br />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%<br />
  24. 24. Causes of death<br />1. Asphyxia<br />2. VF: disturbed Na/ K ratio (freshwater)<br />3. Laryngeal spasm<br />4. Vagal inhibition: cold water, emotions?, unexpected immersion.<br />5. Exhaustion<br />6. Injuries: # skull, cervical vertebrae.<br />
  25. 25. MACRO-MORPHOLOGICAL CHANGES<br />1. FOAM/ FROTH: <br />1. Mushroom like froth from mouth, nostrils.<br />2. Foam inside mouth, in upper airways.<br />Drowning liquid+ edema liquid+ fine air bubbles (resistant to collapse)<br />Blood stained: mechanism?<br />3. External foam: most valuable finding<br />D/D: <br />1. Cardiogenic PE<br />2. Epilepsy<br />3. Drug intoxication<br />4. Electrical shock<br />
  26. 26. Mechanism of foam formation<br />
  27. 27. Clothing: wet<br />Skin: wet, moist, pale ?<br />Mud, silt, algae on body<br />PM lividity: light pink in color<br />Face: +/- cyanotic<br />Conjunctivae: congested<br />Pupils: dilated<br />
  28. 28. Tongue: may be protruded or swollen<br />Cutis Anserina: goose flesh?<br />Reaction Phenomenon?<br />Weed, grass, gravel in hand: due to cadaveric spasm.<br />Soddening of skin of hands, feet/ shoes. Wrinkling Bleaching of epidermis in 4-8 hrs Washerwoman’s hands and feet 24-48 hrs.<br />
  29. 29. Long standing Washer man/woman’s feet<br />
  30. 30. 2. LUNGS:<br />Emphysema Aquosum<br />Imprints of ribs on pleural surface<br />lung SR: Pale, mottled, red and grey areas<br />Cut Section: Oozing of foamy liquid<br />Subpleuralhges (Paltauf’s spots): 5-60% of drownings<br />Lung weight: if taken alone, has little diagnostic value.<br />Dry lungs: with no signs of aqueous emphysema (10-15%) <br />
  31. 31. Comparison of forensic pathology of lungs<br />
  32. 32. Over distension and overlapping of anterior lung margin<br />
  33. 33. Paltauf’s spots<br />
  34. 34. 3. PLEURA: <br />PE: a relatively common finding<br />Due to diffusion of liquid into thoracic cavity.<br />4. TEMPORAL BONE:<br />Gross hges in the petrous and mastoid region of temporal bone<br />Reasons:<br />1. Barotrauma<br />2. Penetration<br />3. Increased capillary & venous pressure<br />
  35. 35.
  36. 36. 5. SINUSES:<br />Aqueous liquid inside sinuses.<br />Sign of permanence, can occur PM too.<br />6. SPLEEN:<br />controversial<br />Cut off value 0.2% body weight.<br />Decrease in weight due to (proposed): symp. Stimulation V/c  Contraction of the spleen capsule and trabeculae<br />
  37. 37. 7. MUSCLES:<br />Hges are seen, mostly in Resp & Aux resp ms > neck & back ms > ms of shoulder girdle > upper arm ms.<br />Causes: Convulsions, hypercontraction, overexertion.<br />8. GI:<br />Laceration of GI mucosa: vague<br />
  38. 38. When the body starts floating? <br />
  39. 39. Alterations in blood<br />Gettler Test:<br />Normally, Cl content R=L, 600 mg/100 ml<br />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.<br />S.W.D= Clconc increases (due to hemoconc)<br />25% difference= significant<br />Value of the test= doubtful<br />
  40. 40. Diatoms<br />Microscopic, unicellular algae<br />Siliceous skeleton = frustule<br />Resist heat and acid.<br />Active circulation brings diatoms into intestine, liver, brain, bone marrow.<br />Technique: HNo3 or enzymatic digestion Centrifuge deposit PC or DGI Microscopy<br />
  41. 41.
  42. 42. Thank you, for your patience <br />
  43. 43.
  44. 44. Pressure<br />is applied using the heel of one hand with the other<br />hand on top, to depress the sternum 1 in. to 11/4 in.<br />with each stroke in adults, followed by release of<br />pressure, at the rate of about 60 per minute.<br />The application of artfficial respiration and<br />cardiac massage should be continued for at least<br />15 minutes<br />If spontaneous respiration<br />and restoration of the circulation do not occur<br />within 15 minutes, further efforts are probably<br />fruitless. If there is discernible evidence of active<br />circulation, artificial respiration should be continued<br />until spontaneous respiration is restored. On<br />the other hand, marked body cooling or evidence<br />of early rigor mortis indicates the futility of continued<br />efforts in this direction. The presence of<br />fixed dilated pupils persisting for 15 minutes is<br />suggestive of clinical death.<br />
  45. 45. In fresh-water<br />drowning, this consists of 1000 c.c. of 3% saline,<br />which is repeated in three to six hours if the serum<br />sodium level is below 110 mEq./l. The deficit in<br />serum calcium may need to be corrected by an<br />infusion of calcium gluconate.<br />Transfusion with whole blood, alternating with bleeding, may be<br />needed later.<br />
  46. 46. In salt-water drowning, intravenous<br />therapy is carried out with 5% dextrose-never<br />saline, whole blood or plasma. Venesection may be<br />needed later.<br />
  47. 47. anesthetic machine<br />using intermittent pressure and pure oxygen.<br />If the cardiac<br />status is unsatisfactory, injections of epinephrine<br />have been employed by some workers. If ventricular<br />fibrillation has occurred, the use of external<br />stimuli such as a quick blow over the heart, the<br />application of electrodes with one or more shocks<br />using 480 volts for .25 second,<br />
  48. 48. In victims of fresh-water drowning the urinary<br />output must be carefully observed; the hemolysis<br />of red cells may cause renal tubular nephrosis.<br />
  49. 49. under circumstances<br />which induce emotions such as fear or surprise,<br />the swimmer may be in such a state that an<br />ordinarily innocuous stimulus will cause vagal inhibition<br />and immediate cardiac arrest.<br />