[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
(TFT) this is a test, this is only a test
Ed. Note: Nov 5th, 2008 has turned out to be a WEIRD fiat in my apotheosis
which aint going as smoothly as Homers from what Dali painted. On the mundane
side, I purchased two IBM ThinkPads', a 760XL and a 760E, for $20.00.
Having formally served as machines for the Heads of the Nursing dep. at the
county hospital for Clatsop, OR, I was expecting a bunch of trash (too me)
files and the like. I was pleasantly surprised to discover the babies to be in
admirable condition, and this little gem was one of only four such 'garbage'
files left stray. I leave it as I came across it, IMHO the thing speaks for
itself.
Also worth noting, I've set 1pt dam = 100ft.lbs[ref1], and 1pt ST = 5.5lbs @
1fps.[ref2]
[ref1] Barbae {sp?} used a corpse and the formula 2 * the cos of the angle of
the arms / body wt., to determine a rough force of 88lbs to tear through the
palms w/nail.
[ref2] This figure, having been extracted from my neathers, has a value of
about 55 kuricks, or 137.5lbs of excrement, or a 25 ST load of crap. Also note
1pt ST = 1/100th Horsepower, and ~ 1/10 peck.
The Horsepower figure applies to vehicles, the peck applies to a days work as
well as a days energy requirements.
All the babble at the bottom is me consolidating several hundred pages of
notes.
PHTLS - 2001
Kinematics of Trauma
2-1A Introduction
Myself
Ed. Note: Mr. Dan Clark
Kinematics of Trauma: As EMS and ED personnel, we have to have
an understanding of the Kinematics of trauma. We have to
be able to identify both obvious and hidden injuries.
2-1B Predicting Injuries:
You have the ability to identify 90% of patients' injuries before you
even touch them - by obtaining a complete and accurate
history of the traumatic even, and properly interpreting that
information.
2-2 Objectives
2-3 Energy Exchange:
In all trauma there is an exchange of energy - between a moving
object and the tissue of a trauma victim - or between a moving trauma victim
and an object.
Kinetic Energy:
*Kinetic Energy is that energy of an object that results from its
motion, and is equal to HALF the product of its mass (or weight) and
the square of its velocity (or speed).
*So while you're not going to whip out your notepad at the scene and use this
formula to calculate the amount of kinetic energy was
involved in your trauma, your knowledge of KE will help you to
predict injuries and raise your index of suspicion.
2-4 Examples:
A 150 lb person traveling 30 mph will have 67,500 KE units
2-5 Examples:
And if you plug in different weights and speeds - it's obvious which
variable is the most significant
2-6 VELOCITY
2-7 Newton's First Law:
An object at rest will stay at rest. An object in motion will remain in
motion unless
Unless it's acted on by an outside force.
2-8 This slide illustrates Newton's First Law as related to trauma:
The car and occupant are moving forward - the car stops when it
strikes the pole, the occupant continues to move forward, until it's
stopped by the steering wheel - the posterior body and organs
continue to move forward.
2-9 The Law of Conservation of Energy:
States energy cannot be created or destroyed, but can change form.
Example:
As a driver applies the brakes in a car, braking creates friction.
This causes a change in the form of energy to heat, or thermal energy.
2-10 How does the Law of Conservation of Energy apply to trauma?
Example??
So a 150 lb person traveling 30 mph would have 67,500 units of KE
to convert to another form: the energy takes the form of damage to
the vehicle and injury to the person in it.
Stopping Distance:
Is another important factor. If the stopping distance is prolonged -
the person was able to brake, for example, converting the energy of
motion to thermal energy, the force of deceleration is decreased and damage is
decreased.
2-11 In Deceleration and Acceleration, 2 forces are involved:
Compression
Shearing
Both are a result of an organ, object or part of an organ
changing speed faster than another.
Compression occurs when the moving body comes to a stop by impacting an
object. A temporary cavity is created - where the chest strikes the steering
wheel for example. The organs or tissues inside
collide with one another or with the wall of the cavity and are compressed and
damaged.
Head: the skull can be fractured and compressed.
Thorax: compression can cause rib fractures, flail chest,
pneumothorax, pulmonary and cardiac contusions.
The "Paper Bag" effect is when the victim sees
the accident coming and instinctively takes a deep
breath and holds it. Upon impact the lungs can burst.
Abdomen: solid organs frequently compressed by the
vertebral column and the steering column include
the pancreas, spleen, liver and kidneys.
*Increased build-up of pressure in the abd can cause
tearing or rupture of the diaphragm, impacting
respiration, and causing herniation of the abd contents
into the chest.
2-12 Shearing:
Shearing occurs when the moving body comes to a stop by impacting
an object - and organs that have points of attachment are torn from
the structures that support them:
Head: if the skull stops its forward motion, the brain keeps
going. The portion of the brain furthest from the
impact is separated from the skull with tearing and
lacerations of the vessels, causing epidural, subdural
and subarachnoid hemorrhages.
Chest: if the anterior chest is impacted, all the organs
continue to move forward. The descending aorta is
attached to the posterior thoracic wall and vertebral
column. Since the heart, ascending aorta and aortic
arch continue to move forward the result can be a
partial or complete aortic tear. Most die at the scene.
Abdomen: The organs that shear are the kidneys, small and
large intestines, and spleen.
2-13 What injuries?
If you arrived on scene and saw the starred windshield, what injuries
would you suspect?
Skull fx
Neck injury
Contusions and lacerations (soft tissue injuries)
Brain injury
Cord damage
** coup and contrecoup injuries: at the point of impact and
the are of the brain opposite (Dowlatdad)
2-14 (above answers)
2-15 Torso Injuries:
Rib fx
Heart and lung damage
Abdominal organ damage
Major vessel damage
2-16 Extremity Injuries:
fractures
ligamentous
soft tissue
2-17 Types of MVCs:
Each of these collisions cause different kinds of damage. Look at the
vehicle to determine which of the types of collision the car was
involved in:
head on or frontal impact
lateral or side impact
rotational impact
rear impact
rollover
**Remember that the vehicle collides with an object, the unrestrained
occupant collides with the inside of the vehicle, and the occupant's
internal organs collide with one another or with the cavity that
contains them.
**When occupants are ejected, they are subjected to a second impact
as the body strikes the ground or another object. The risk of death is
much greater that for those not ejected.
2-18 Frontal impact injuries:
Occupants will follow 2 paths:
Down-and-under
Up-and-over
This will determine injuries
2-19 Up and Over Pathway:
Forward motion carries the unrestrained occupant up and over the
steering wheel, usually leading with the head.
2-20 Head (strikes the windshield or frame of windshield)
Spine
Chest strikes steering (fx, pneumo, hemo, contusions, great vessel inj)
2-21 Abdominal (solid organs, hollow organs, diaphragm)
Pelvis - fx
2-22 Down and Under Pathway:
The unrestrained occupant continues to move downward into
The seat and forward into the dashboard or steering column.
2-23 Injuries:
The knees have 2 possible impact points: the femur and tibia, with
varying injuries: Look for knee imprints on the dashboard ASAP
(they may disappear quickly).
Posterior knee dislocation
Occur when the tibia is the point of impact, and can
result in popliteal artery tear
Posterior hip dislocation and/or femur fx (pg 15)
can occur when the femur is the point of impact.
Lower extremity fx - the foot can twist if planted
Pelvic
2-24 Rear Impact:
Energy from the impact is converted to acceleration - so the vehicle
shoots ahead upon impact. What injuries?
Neck hyperextension if the head rest is poorly positioned,
otherwise as the vehicle slows to a stop the head moves with
the seat, minimizine injury.
**If the vehicle strikes another object or vehicle, injuries will
be as those seen in a frontal impact.
2-25 Lateral Impact:
Struck from the side. The occupant may be injured in 2 ways:
By the movement of the car
By the door's intrusion into the passenger compartment.
2-26 Injuries:
Neck: from lateral flexion and rotation of the Cspine. Fractures
are more common in a lateral impact that in a rear impact.
Chest: lateral compression injuries like rib fxs, flail chest, pulmonary
contusion or injury to solid organs: If on the driver's side of
the vehicle - splenic injury. If on the passenger's side of the
vehicle - liver injury.
Pelvic: the pelvis and femur are frequently struck by the door.
Head/scalp injuries
**Be aware of secondary collisions with other occupants - heads strike
2-27 Rotational Impact:
Occurs when one corner of the car strikes an immovable object or the
corner of another vehicle moving 90 degrees to it or a slower car
traveling in the opposite direction. The corner of the car stops while
the rest of it continues moving.
**Results in injuries that are a combination of those seen in head-on
and lateral impact collisions.
2-28 Rollover:
The vehicle may undergo several impacts at many different angles.
Injuries are unpredictable.
2-29 Lap Restraint Device
When the lap belt is properly positioned, the pressure of the impact is
absorbed by the pelvis. But if worn alone, the upper body may rotate into
the steering wheel or other structures. If the lap belt is positioned
incorrectly, may cause compression injuries of the abdominal organs,
increased intraabdominal pressure that can rupture the diaphragm,
anterior compression of the lumbar spine.
**lap belts work best with shoulder restraint
2-30 Lap and Shoulder Restraint system:
If only the shoulder harness is used, the victim submarines, or moves
down and under. Severe neck injuries can occur, including decap.
**Shoulder restraints must be used with lap belts
If only the lap restraint is used, the victim moves up and over.
2-31 Air Bag Deployment:
Airbags absorb energy slowly by increasing the occupant's stopping
distance. They are effective in head on collisions, but work best with
lap and shoulder restraints. Airbags alone will not prevent serious
injuries.
When they deploy, you will see minor injuries like abrasions or the
arms, chest and face, foreign bodies to the face and eyes or injuries
caused by glasses.
**Airbags deflate immediately after impact and wouldn't be of
benefit in a second collision.
**Remember to check under the deployed airbag for vehicle structure
damage.
2-32 Air Bag Deployment:
Air bag deployment may cause severe or fatal injuries in small
patients and children in car seats.
2-33 (part 2) Motorcycle Collisions:
Helmets absorb much of the impact, decreasing injur to the face, skull
and brain. Helmets provide only minimal protection for the neck, but
doesn't cause neck injuries.
2-34 Types of Impacts (motorcycle): ??how many collisions??
Frontal - because the bike's center of gravity is above and behind the
front axle, the motorcycle will tip forward and the rider will
crash into the handlebars.
Head, chest, abd, pelvis or bilat midshaft femurs
(whichever strikes the handlebars)
Ejection - The rider is thrown from the bike like a missile - until he
hits something else. Injury occurs at the point of impact and
will radiate to the rest of the body as energy is absorbed.
2-35 Lateral or Angular - the bike hits an object at an angle. The cycle
will collapse on the rider or cause the rider to be crushed
between the bike and the object struck.
Injuries to upper and lower extremities and abdominal
Cavity
2-36 Pedestrian vs. Motor Vehicle:
Adults will generally turn away from an oncoming vehicle while a
Child will turn and face the vehicle.
An adult's injuries will tend to be limited to the lower extremities
And head injuries from striking the pavement.
A child's injuries can be more severe due to the height of the vehicle
In relationship to the height of the child (i.e., chest and abd).
2-37 Falls:
The nature and severity of injuries from falls are related to the height
of the fall and the surface on which the victim lands.
The harder the surface, the greater the injury
The greater the height, the greater the injury
Falls from a distance of more than three times the patient's
height produce critical injuries.
Determining which part of the body hit first is important.
e.g. Brad
2-38 Falls - Deceleration injuries: think about the abdominal organs
subject to
shearing and compression: liver, aorta, spleen, kidney.
2-39 Landing Feet First (Don Juan syndrome):
(only in the movies can people jump from high places, land on their
feet and walk away).
Bilat heel fx
Ankle fx
Distal tib/fib
Knee dislocations
Femur fractures
Hip fractures
Spine compression fractures
2-40 Landing Arms/Hands First:
Colles fractures of the wrists
Shoulder dislocations
Clavicle fractures
2-41 Landing Head First:
Commonly occurs in shallow water diving injuries
Cervical spine injuries
Facial injuries
CNS damage
2-42 Sports and Recreational Activity Mechanisms:
Many recreational participants lack the training, conditioning
and protective equipment. Injuries are caused by:
sudden deceleration forces
or by excessive compression,
twisting
hyperextension
or hyperflexion
What do we have?
Bicycling
Surfing
Wind surfing
Hiking
2-43 Predicting Sports-related injuries:
Kinematics & forces involved
Equipment contributing to injury
Broken or damaged equipment & relative damage to body
Helmet, skis
Involvement of protective equipment
Was it worn and removed prior to EMS arrival?
Nature of the sport
High velocity sports like skiing, waterskiing, bicycling
Skateboarding
Collision sports like mountain biking, ATV
2-44 Blast Injuries:
The incidence of blast injuries increases during warfare - for us
training at Camp Rilea has provided us with patients.
Recent events have also brought warfare to our country.
Blasts may injure 70% of the people in the vicinity.
Other sources of blast injuries (as listed)
2-45 Blast-Related Injuries:
Three phases of an explosion:
Primary, Secondary, Tertiary
2-46 Primary - primary injuries are caused by the pressure wave of the
blast.
Usually occur in gas containing organs like lungs and GI tract from
pressure waves rupturing and tearing small vessels and membranes:
Pulmonary bleeding
Pneumothorax
Air emboli
Perforation of GI organs
Burns from the heat, common
2-47 Secondary - occur when victim is struck by flying debris
Lacerations
Fractures
Burns
2-48 Tertiary - occurs when the victim becomes a missile and is thrown
against an
object. Injury occurs at the point of impact.
2-49 Penetrating Trauma:
Physics
Weapon velocity
Bullet design
2-50 Newton's Law (an object in motion) and the law of conservation of
energy
apply to ballistics.
The chemical energy changes to heat then to motion then to injury
2-51 Low-Energy Injuries:
Low energy weapons include hand-driven weapons like knives, ice
picks and scissors.
They produce damage only with their sharp points or cutting edges.
Because they are low-velocity, there is usually less secondary
Damage - usually limited to the depth and area of penetration.
Men tend to stab with an upward thrust, women tend to stab
downward.
Look for more than 1 wound.
2-52 Low-Energy Penetrating Wounds:
An attacker may stab his victim and then move the knife
around inside the body. The entrance wound may be
small, but the damage inside may be extensive.
Longer weapons increase the potential for greater depth and a
greater area of damage.
2-53 Assessment of Low-Energy Injuries:
Type of weapon involved - length of blade
Path of weapon
Depth of penetration
Number of wounds
Underlying anatomy
2-54
And there it stops.
Yeah, it's me again.
I just love this kinda stuff.
Jung said Synchronicity.
So I have the following information to add to the "lecture".
The average human body is between 14 to 18ft^2 in area.
In classical art the human male is proportionally 8 heads in height, and
traditionally considered 6ft. tall and 3 heads wide at the shoulders (male
figure, female has more mass at the hips and a lower center of g).
1 hex is described as = 1.3m from side to side (sts).
1m = 39.37in.
1.3m = 51.181in, or ~52in (4'4").
4.3ft * 4.3ft = 18.49ft^2 or ~ 18.5ft^2.
A hex presents about twice the area as a human facing front-on.
The square hex I've described previously is 16 squares on quarter inch graph.
Each square can be considered as roughly 13 by 13 inches or 169in^2.
This is obviously 1/16th the area of a hex and ~ 1/8th the area of a human
silhouette.
This is sufficiently detailed enough to describe hit locations.
Divide each hex-square into 16, 3 1/4in by 3 1/4in scale-squares for underling
anatomy, armor, etc.
Anatomy from Grays, visible man, etc.
Armor as follows.
1ft^2 = 144in^2
1in^3 = 32in^2 @ 1/32nd inch thick
4.5in^3 = 1ft^2 @ 1/32nd inch thick
16ft^2 ~ 72 cubic inches @ 1/32nd inch thick
Ductile materials are defined by their elastic limit, yield point, and
ultimate strength.
The elastic limit can be thought of as the point at which a material
deformation permanently sets or in other words dents.
Stresses applied below a materials elastic limit don't leave dents, force
above said limit causes dents, and unit stresses exceeding a materials
ultimate strength leave holes.
For structural steel I have figures of 36,000lbs per inch for an elastic
limit, and 70,000psi for ultimate strength.
This dents 1/32nd inch thick steel @ > 11pts dam and breaches @ > 21pts dam.
Oh yeah, 1 cubic inch = 16.3871 cubic cm.
Iron = 55.874 ~5.5g per cm^3
Tin = 118.69
Nickel = 58.71
Lead = 207.19
Copper = 63.546
Zinc = 65.37
Carbon = 12.01115
Silver = 107.868
Platinum = 195.09
Gold = 196.967 or 19.32 g per cm^3
So to encase a human (~ 16ft^2) in 1/16th inch thick iron takes about 30lbs of
material.
22pts dam to dent, 42pts to pierce.
Of course armor isn't a single sheet of metal, but this allows design of
pieces.
Think Blondie at the end of "A Fist Full of Dollars".
Wood
Very Weak = 50 to 60 pST per ft^3
(walls)
Balsam Poplar 26lbs per ft^3 material weight
Northern White Cedar 22
Weak = 60 to 70 pST
(walls, shingles)
Hemlock 28
Black Spruce 28
Basswood 26
Eastern Red Cedar 33
Western Red Cedar 23
Redwood 28
Cypress 32
Aspen 26
Cottonwoods 24-28
Balsam Fir 25
Fair = 70 to 90 pST
(general use)
White Pine 25
Ponderosa Pine 28
Jack Pine 27
Red Pine 34
Tamarack 36
Yellow Poplar 28
Soft Elm 37
Soft Maple 38
White Birch 34
Black Ash 44
Strong = 90 to 110 pST
(floors, joists)
Douglas Fir 34
Yellow Pines 36-41
White Ashes 38-41
Beech 45
Rock Elm 44
White Oaks 47
Red Oaks 44
Sugar Maple 44
Very Strong = 110 to 130 pST
(furnature)
Black Locust 48
Yellow Birch 44
White Ash 41
Shag Hickory 51
Nonductile materials like wood have poorly defined elastic limits and no yield
point.
Structural Lumber E (modulus of elasticity) ~ 1,600,000psi from a range of
something around 1,000,000psi to under 2,000,000psi.
Wood from specific locations can be assigned significantly different factors
from the average, allowing for things like "Old Ironsides" or English
Longbows.
So a Wizards Staff made outta Cedar blocking a blow from a Wizards Staff made
from Hickory...
The following information comes from Petersen's Hunting Magazine 2009 edition
ballistics guide.
The data is for centerfire rifle cartridges w/factory loads.
.17 Rem.
Velocity
4250 fps @ muzzle (note that this JUST breaches 1/16th inch steel w/>50lbs
force left, or half a point of Damage.)
3594 fps @ 100yrds ~70hexes
3028 fps @ 200yrds ~140hexes
2529 fps @ 300yrds ~209hexes
2081 fps @ 400yrds ~279hexes
1684 fps @ 500yrds ~349hexes
Energy
8pts dam @ muzzle
6pts dam @ 100yrds
4pts dam @ 200yrds
3pts dam @ 300yrds
2pts dam @ 400yrds
1pt dam @ 500yrds
Trajectory (200yrd zero)
+ is a rise and - is a drop from zero
+0.6 @ 100yrds
-4.5 @ 300yrds
-14.4 @ 400yrds
-32.6 @ 500yrds
Petersen's Hunting Magazine 2009 edition ballistics guide provides info on
1200+ loads.
Domestic violence notes, Dan Sheridan
Forensic = pertaining to the law
What we write or do not write has forensic implications of tremendous
importance. Contemplate what we write in notes before we write it.
Terms:
Abrasions = scrape = rubbing or scraping of skin or mucous membranes
Avulsion = tearing away of a structure or part
Partial avulsion
Bruise = caused by blunt force trauma. Superficial discoloration due to
hemorrhaging into the tissue from the ruptured blood vessels from beneath the
skin surface without the skin itself being broken
Bruise also is an injury without breakage of the skin that causes swelling,
tenderness and discoloration.
Cut = incision
Eccyhymosis is NOT a bruise or contusion. Frequently misused term.
Hemorrhagic spot larger than petechiae forming non-elevated rounded or
irregular blue or purplish patch of the skin or mucous membrane.
Cause = spontaneous bleed (usually a hematological problem).
Hemoptysis = coughing /spitting up blood, usually bright frothy pink/red.
Hematemesis = vomiting blood. Blood in stomach, may be from epistaxis
(swallowing blood) or from esophagus or bleeding from the stomach
Epistaxis = bleeding from the nose
Hemorrhage = bleeding, internal or external or into organs.
Incision = cut - smooth edge, clean wound. Made by sharp instrument or
object.
Laceration = is not a term to be used for any general open and bleeding wound.
Laceration is not usually straight - jagged, depth differs, irregular, not a
clean edged wound. Act of tearing. Often blunt impact.
Patterned injury = (not all patterned injuries are abuse). Reasonable
certainty of the object that caused the injury or by what mechanism an injury
was caused. E.g. Glove burn (immersion)
Pattern of injury = Injuries in various stages of healing, new and old scars,
contusions, wounds. (may not fit the given history). Not necessarily abuse.
Petechiae = minute round nonraised purplish-red spots caused by intradermal or
submucosal hemorrhage that may turn blue/yellow.
`Strangulation When strangled, the venous blood return is cut off, but the
high pressure arteries are still delivering blood to the area, causing the
capillaries to burst. Common in faces. Or if BP cuff left on too long
(unless the cuff pressure was high enough to cut off the arterial flow, too).
Other causes: childbirth, pushing (see in faces, conjunctiva).
Choke = eg piece of meat stuck in throat
Strangulation = ligature/hands around neck DON'T CONFUSE THESE TERMS
Puncture = the act of piercing or penetrating with a sharp pointed object.
Patterned injuries/patterns of injuries:
Looped welts - electrical cord "patterned looped cord-like contusion"
"Patterned heel-like contusion" (shoe print)
***assess organs underneath marks***
"patterned punch-like contusions" most people when they punch have a little
bit of a round house punch - circular to oval contusions
"patterned fingernail scratch-like abrasions to right lateral neck" ?whose
fingernails? Scrape hers, and scrape his in jail ` evidence
If she turns into a hostile witness - there is a growing trend for evidence-
based prosecution (she may not want to prosecute because she's forgiven him,
or maybe he's threatened her or the kids). The charges are now filed by the
state, not the wife. They have the 911 tape, the record, the photos, etc.
"patterned punch-like contusions" see a lot of left arms - most people are
right handed - punch with right. Right handed people unconsciously offer up
their left side when defending themselves. Also when not at home, abuse can
occur in cars. Elbow or punching (depending on size of car)
Does the history fit the injury??
Laceration? Use care as to the terminology you use. A batterer can go free
over definitions. If not sure what to call it, call it a 4" lineal wound
(eg)
Bruise ages: NEVER age a bruise. Everybody heals at different rates. Age,
location, nutrition, anti-coagulants. Valproic acid - thrombocytopenic
affects. Please describe by size, shape, and color. Palpate - is it tender
or not?
Eg brown bruise - "my boyfriend hit me 1 hour ago - look what he did?"
You can say injury not consistent with history.
Look at patterned defense injuries / contusions.
If hit with a ring with a stone will give you a circular or U/horseshoe shaped
abrasion. Possible skin or blood on ring/setting.
Traumatic alopecia - hair pulling. Hard to photograph alopecia. Run comb
through hair. Lots of hair in comb, take photo of comb with hair next to pt.
Very painful.
Raccoons eyes "bilateral periorbital ecchymosis" is not the correct term.
These are contusions.
Triage
A.B.C.
Airway
Priorities:
1 Sweep a finger deep into the mouth to remove clotted blood, vomitus, teeth,
etc.
2 Raise tongue away from back of throat.
The method depends on weather the tongue is swollen, or the patient has a
suspected neck injury.
3 Suction, insert tube, or do the pocketknife / pen bit.
Breathing
Priorities:
1 Ausculitate breath sounds billaterally.
2 mouth to mouth or other ventilation.
Circulation
Priorities:
1 Control major hemorrhage
2 CPR
3 Control shock
____________________________________________________________
Click here to become a professional counselor in less time than you think.
http://thirdpartyoffers.netzero.net/TGL2231/fc/PnY6rc21PaVr8P8vrnZjqlWcRKkYPj
epGKMdr7X5s9FUh1lCbmVMq/
=====
Post to the entire list by writing to tft@brainiac.com.
Unsubscribe by mailing to majordomo@brainiac.com with the message body
"unsubscribe tft"