quite long power point

1. Myth and Mechanisms of Firearm Injuries Dr. Joel Turner, CCFP, FRCP 3 McGill University January 12, 2000

3. "A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed ” 2d Amendment to the U.S. Constitution

5. Monday 11 October 1999 Man faces charge in friend's shooting A 21-year-old man is to be charged in connection with a fatal shooting in Notre Dame de Grace early yesterday morning ALLISON LAMPERT .

7. Objectives: 1. Epidemiology of Firearm-related injuries/deaths 2. Basic anatomy and terminology 3. Ballistics of firearms 4. Role of the EP

8. 1. Epidemiology/Statistics Firearm death rate (per 100,000) for young males in 12 selected countries (Center for Disease Control. Births & Death, 1995)

10. Firearms Deaths (per 100,000) by Mode of Death for Children <15 Years of Age - Top 10 Countries C.D.C. Rates of Homicide, Suicide, and firearm- Related death among children. MMWR, 1997 -Firearms are the 2 nd leading cause of death of children in the U.S.  Number 1 cause of death in young blacks

11. Canadian numbers… United States Canada (Hurg K, Firearm Statistics. Dept of Justice, March, 1999) Year Total firearm deaths Homicides Suicides Accidents Police Misc 1982 33,086 13,841 16,573 1,756 376 540 1993 39,595 18,940 18,571 1,521 1997 32,436 13,623 17,515 981 Canada (89-96) 1,385 187 1013 56 Quebec (89-96) 337 66 291 17 Year Total firearm deaths Homicides Suicides Accidents Police Misc 1982 1,530 213 1,197 56 6 58 1993 1,286 173 1,053 44 5 11 1997 1,131 177 881 46

12. Canadian numbers… (Canadian Firearm Centre- Statistics Canada)

13. Canadian numbers… (Canadian Firearm Centre – Angus Reid Group, May 1998)

14. Canadian numbers… (Canadian Firearm Centre- Statistics Canada. Homicide Survey, 1997)

15. 1989-1995: 9,995 people shot in Washington State -29%  ED care only -29%  Admitted to hospital & survived -42%  died Hospital Visits and admissions 1988-1996: average 1,217 admissions/year Canada: Quebec: 1988-1996: average 287 admissions/year (23.6%) 43.6% - firearm accidents 28.2% - self-inflicted 22.0% - inflicted by others (Cummings, et al. Annals of Emergency Medicine, 1998) (Canadian Institute for Health Information)

16. 2. Terminology & Anatomy of Firearms A. The Gun:

17. Action Chamber Barrel Rifling Bore Caliber Muzzle Hammer Magazine (Clip) Anatomy of the Gun

19. The derringer

20. The Revolver

21. Semi-automatic pistol

22. Rifles

23. Shotguns

24. Anatomy of the Cartridge Shotgun Handgun Rifle Primer Flash Hole Powder bullet Powder Primer Wad Shot

25. Small arms powder made of: 1. Nitrocellulose base, or 2. Nitrocellulose / nitroglycerine mix -Smokeless powder is NOT an explosive (black powder IS) -Grains come in different shapes and sizes -The smaller the grain the faster it burns Some Powder basics :

29. A little bit of physics… I. Internal Ballistics – what affects what?

30. II. External Ballistics – gun to target

31. II. External Ballistics – gun to target

32. III. Terminal Ballistics – Wound Ballistics What happens when the bullet hits the target?

33. Bullets produce damage in 3 ways: 1. Laceration and crushing 2. Cavitation: a) permanent cavity: b) temporary cavity. (tissue splash) 3. (Shock waves) (U.S. Dept of Defense ) III. Terminal Ballistics – Wound Ballistics

35. .32 Cal. Silvertip Winchester -soft lead -Non-fragmenting, expanding -Velocity: 940 fps (similar to present day .22 cal) Neck A. Handguns and Rifles IV. Wounding mechanisms – Wound Profiles Fackler, et al. Annals of Emergency Medicine . 1996

36. M-80 7.62 mm NATO cartridge : -Full Metal Jacket -Non-fragmenting, Non-expanding -Velocity = 2800 fps IV. Wounding mechanisms – Wound Profiles

37. Mannlicher Carcano 6.5 mm -Full metal Jacket -Non-deforming, Non-fragmenting -Velocity = 2085 fps IV. Wounding mechanisms – Wound Profiles

38. .45 Cal Automatic pistol - full metal jacket - velocity = 870 fps IV. Wounding mechanisms – Wound Profiles

39. M-16 .22 Cal Military Rifle -Full Metal Jacket -Fragmenting rifle bullet -Velocity = 3035 fps IV. Wounding mechanisms – Wound Profiles

40. Winchester .308 Caliber Hunting Rifle (civilian) -civilian equivalent of military M-16 -Soft Point bullet -Fragmenting bullet -Velocity = 2,900 fps IV. Wounding mechanisms – Wound Profiles

41. B. Shotguns 12 gauge shotgun - 1 oz slug - Velocity = 1510 fps IV. Wounding mechanisms – Wound Profiles

42. 12 gauge shotgun - 27 pellet #4 buck shot - Velocity = 1350 fps IV. Wounding mechanisms – Wound Profiles

43. 12 gauge Shotgun -169 pellets, #4 shot - Velocity = 1200 fps IV. Wounding mechanisms – Wound Profiles (Letterman Army Institute of Research)

44. IV. Wounding mechanisms – Wound Profiles

45. V. Myths of Firearm Injuries and Wound Ballistics : a) Myth of High Velocity : False dogma: 1. Tissue damage is directly related to bullet velocity. 2. High vel. missile injuries require aggressive resection. 3. Low vel. missile injuires require little or no treatment. 1960’s – Vietnam war, introduction of M-16 rifle (bullet speed = 3100 fps): - GSW severity increased significantly - The M-16: “massively destructive” “ devastating wounding power” - High velocity became synonymous with “devastating killing power” Rich, et al. JAMA . 1967 Dimond, et al. J Trauma . 1967

46. 1974 – Rybeck, et al. - High vel. Injuries cause temporary cavity 30x diameter of missile. - this tissue “would not survive” -  core of tissue would have to be excised!! -  equates to an amputation of almost any wound to arm/leg a) Myth of High Velocity…. V. Myths of Firearm Injuries and Wound Ballistics : 1975 - The Nato Handbook: Emergency War surgery (U.S. Govt. Printing Office) Rybeck, et al. Acta Chir Scand . 1974

47. V. Myths of Firearm Injuries and Wound Ballistics : BUT: History of small arms development shows us differently: -Late 1880’s  largest increase in vel. of small arms projectiles. - From 1,100 to 2,400 fps - Invention of smokeless gun powder and jacketed bullets - striking decrease in wounds severity reported from all battlefields !!

48. .38 Special Velocity = 880 fps Remington .357 Magnum Velocity = 1400 fps V. Myths of Firearm Injuries and Wound Ballistics :  Despite the 60% increase in velocity, the shape and size of both temporary and permanent cavities are very similar, Fackler, Emergency Medicine Clinics of North America . 1998

50. b) Shock waves and Injury V. Myths of Firearm Injuries and Wound Ballistics : 1940’s: Harvey, et al. Surgery . 1947 1980’s: Suneson, et al. J Trauma . 1987, 1988, 1989 1990’s: Ordog, et al. J Trauma . 1994 Present day lithotriptor:

52. V. Myths of Firearm Injuries and Wound Ballistics : d) Size of temporary cavity determines tissue disruption: .308 Winchester: 2800 fps 7.65 mm Browning: 900 fps -Most temporary cavities are relatively shallow compared to permanent cavity. -Temporary cavity is of very short duration. -Type of tissue significantly affects the wounding potential of temporary cavity: Lung Muscle Liver/Spleen/Brain Bone Fluid filled organs -In general, a faster bullet will produce a larger temporary cavity.

54. 4. Clinical Evaluation of G.S.W. – Role of E.P. The Emergency physician: - in ideal position to evaluate and document wounds before they are distorted by surgical intervention. - must resist temptation to make assumptions about findings  interpretations are correct in only 47% of cases 1 . - do not describe wound as “entrance” or “exit” without indicating physical features of each. - must provide complete documentation of all wounds  in 59 patients, only 75% of all actual wounds was documented 2 .  in 258 GSW’s, accurate anatomical locations were described in only 37% of wounds 1. Busuttil A, et al. Police Surgeon. 1990. 2. Marlowe AL, et al. Proc Am Acad For Sci 1996.

55. Clinical Evaluation of G.S.W. – Role of E.P. Exit Entrance

59. 3. Entrance Wounds – Intermediate range Clinical Evaluation of G.S.W. – Role of E.P. - Tattooing is pathognomonic  Tattooing cannot be wiped away. (soot can)  Density of tattooing is dependent on the distance & caliber -Generally found at distances of 60 cm or less.

63. ” A meticulous evaluation and written description of gunshot wounds by the E.P. can save a very long and tiring process of legal testimony brought on by criminal events”

64. The End.