Medical Aspects of Urban Search

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Medical Aspects ofUrban Search Rescue

• David C. Cone, MD
• Associate Professor and Chief
• Division of EMS
• Section of Emergency Medicine
• Yale University School of Medicine
• Medical Team Manager
• Connecticut Urban Search Rescue Task Force

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Objectives

• 1. Introduce the U.S. federal response system for
  USR incidents
• 2. Introduce confined space medicine

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USR Definition

• The process of locating, extricating, and
  providing medical treatment to victims trapped as
  a result of structural collapses and other
  natural or man-made catastrophes.

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USR Definition Contd.

• USR also has application toward a wide range of
  other advanced technical rescue incidents such as
  rescuing victims from floods, swift-water,
  high-rise fire incidents and cave-ins as well as
  rescuing survivors of confined space, trench
  collapse, mass-transportation, climbing and
  industrial machinery accidents

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CSM Definition

• An emerging body of knowledge concerned with
  treatment and rescue of victims in a collapsed
  structure with limited access and egress, and
  unfavorable environmental conditions.

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Part 1U.S. USR System

• I am not trying to sell this system
• I am not trying to suggest that the U.S. system
  is better than any other system
• Im just describing it as it currently exists

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FEMA USR Task Forces

• 28 teams variability in structure, composition,
  policies, etc.
• Fully self-sufficient for first 72 hours
• Food, potable water, shelter, etc.
• Functional for at least 10 days

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Task Force Structure

• Incident Command System
• 62 persons ( canines) in two shifts
• Five components
• Medical 2 physicians, 4 medics/nurses
• Search canines, specialized
• Rescue 4 squads of six, heavy rigging
• Logistics communications, logistics
• Planning hazmat, structural, law enforcement,
  information

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Equipment Cache

• 60,000 pounds
• Pre-packaged on pallets
• www.fema.gov/pdf/usr/tfcache2000.pdf

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Task Force Missions

• Recon assess damage, determine needs, survey
  hazmat and structural
• Physical search rescue
• Emergency medical care for response personnel and
  limited of victims
• 10 critical, 15 moderate, 25 minor
• Communications support (military compatible
  equipment)

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Caring For Our Own

• Providing for the health and medical needs of the
  team is the 1 priority of the medical component
  of the team
• We do this by ensuring that all aspects of
  medical care are provided by us

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Prospective Roles

• Health and fitness standards
• Immunizations
• Medical records
• Training
• Medical cache maintenance
• Medical check-in before departure
• Medical intelligence gathering
• Starts before departure

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Medical Intelligence Gathering

• Likely numbers and types of victims
• Weather
• Hazardous materials
• Status of local medical resources
• Is the EMS system intact?
• Are the hospitals and EDs intact?
• Can we re-stock our supplies

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Arrival On Scene

• Quickly establish and staff a dedicated medical
  area, and be sure everybody knows where it is
• Establish and staff a forward medical area,
  once it is known where the team will be operating

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On-Scene Medical Duties

• Up-front care for team members
• Enforcing hydration, hygiene, rehab
• Ensuring shelter, sanitation, food
• Care for victims
• Care for teams search dogs
• Media relations
• Relations with local medical resources (if any)

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Interaction with local EM/EMS

• Availability of EMS resources
• is there somebody to hand patients off to?
• hand-off to less sophisticated level of care is
  FEMA policy, to maintain integrity of medical
  team and equipment at site
• Availability of ED/hospital resources

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Retrospective Roles

• Injury and exposure follow-up
• Medical cache reconstitution
• Paperwork, paperwork, paperwork

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Part 2Confined Space Medicine

• CSM and the treatment of victims is a very small
  part of USR medicine
• Care of the team must be the primary function of
  the medical component of USR task force

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CSM Two general categories

• A confined space that is intact power vaults,
  grain silos, sewers
• 35 of victims are would-be rescuers
• A structural collapse building, trench, highway

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Why is it hard to operate?

• Poor lighting, ventilation, temperature control
• Exposure to blood/body fluids, liquids
• Tight spaces
• Need for PPE
• Crime scene

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Situational Considerations

• Atmosphere (90 of non-collapse injuries and
  deaths)
• Oxygen-deficient
• CO from fires and tools
• Broken gas lines
• Hazardous materials
• Risk of secondary collapse / device
• shoring, stabilizing

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Basic CSM Principles

• Forget scoop and run
• Prevention of renal failure secondary to crush
  syndrome is the biggest advance in reducing
  morbidity and mortality in urban search rescue
• Team must expect to spend hours in the hole
  with the patient

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Anticipate prolonged mgmt

• Expect hypothermia, dehydration
• Possible blood loss, third spacing
• Patient may be contaminated with own urine and
  stool
• Complications not typically seen in the
  pre-hospital setting may have already begun

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Limited Exam

• May begin assessment before patient is reached
• May begin treatment with only part of the victim
  accessible

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How we decrease MM

• Rapid stabilization in the hole
• Expedite extrication
• immobilize only as needed
• provide pain control
• improve patient cooperation
• anatomic / physiologic advice for disentangling
  and moving patient
• prepare patient for hand-off to EMS

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Unusual medical problems

• Crush injury / crush syndrome
• Dust airway impaction
• Hazmat exposure / injury
• Traumatic amputations
• Blast injury
• Dehydration/starvation
• Hypothermia/hyperthermia

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Dust

• Building materials contain silica, calcium,
  asbestos, wood, mineral fibers
• Masonry, sheet rock, plaster, tiles, insulation
• Impair both ventilation and gas transfer
• Major cause of death in Kobe earthquake

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Respiratory Problems

• Airway obstruction (blood, teeth, vomitus, etc)
• Airway contamination (dust)
• Provide all patients with dust masks
• Ventilation problems (debris limiting chest wall
  expansion, pneumothorax, hemothorax, pulmonary
  contusion

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Inhalation Injuries

• Displacement/consumption of oxygen
• e.g. methane from ruptured gas line
• Thermal injury - hot gases gt edema
• Noxious gases / particulates
• Cellular toxins (CO, cyanide)

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Blast Injury

• Air-filled organs at greatest risk (lungs,
  stomach, intestines, tympanic membranes)

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Blast injury

• Significantly higher morbidity and mortality if
  occurs in an enclosed space than if out in the
  open
• Frequent complications
• air embolism
• ARDS
• splenic rupture
• pneumoperitoneum
• ocular injury

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Infection Considerations

• Open wounds sepsis and wound infection
• Contamination with air- and water-borne agents,
  as well as own stool and/or vomitus
• Pulmonary coccidiomycosis following Northridge
  earthquake

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Field Considerations for ID

• Drain abscesses if delay in extrication
• Local wound care and antibiotics for other
  infections
• Oral, IM, or IV antibiotics

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Orthopedic Injuries

• All open fractures get splints and IV antibiotics
• Be generous with pain meds
• Immobilize spine only if necessary
• Field amputation is a last resort

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Crush Syndrome

• Post-extrication deterioration and death from
  treatable mechanisms
• Essential to begin treatment before the crush is
  relieved
• Death by hypovolemia and arrhythmia (early),
  renal failure and infection (late)

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Cellular effects of crush

• Local arterial blood flow interrupted
• Cells switch from aerobic to anaerobic, produce
  lactic acid
• Cell membrane disrupted
• Cellular contents leak out (potassium, CK,
  myoglobin, phosphorous, leukotrienes)
• Calcium leaks in
• Capillaries leak, causing edema

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Releasing compressionEarly effects

• Capillary leak gt hypovolemia, shock
• Metabolic acidosis gt ventr. fibrillation
• Increased serum potassium gt various arrhythmias
• Serum hypocalcemia and hyperphosphatemia
  contribute to cardiac instability

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Calcium

• Serum calcium level falls
• Intracellular calcium rises in the injured muscle
  tissue
• Increased mitochondrial calcium impairs cellular
  respiration and ATP production
• Activation of phospholipase A2, causing
  activation of leukotrienes, prostaglandins,
  lysophopholipase

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Should you give calcium?

• Not unless absolutely necessary to treat
  ventricular ectopy
• will only transiently correct hypocalcemia
• will be deposited in the injured muscle

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Late effects renal

• Traumatic rhabdomyolysis
• 1. Ferrihemate and other decomposition products
  of myoglobin
• 2. Direct tubule obstruction by CPK, myoglobin,
  and uric acid crystals
• 3. Hypovolemia

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Myoglobin

• Overflow appears in urine - red/brown color
• At high levels, myoglobin precipitates in kidney
  tubules
• Detect with urine dip-stick
• Solubility in urine is pH-dependent
• 0 precipitates at pH gt 7.5
• 73 precipitates at pH lt 5.0

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Post-release signs of trouble

• Agitation
• Severe pain
• Paralysis of affected limb
• Progressive, marked swelling
• These should all be prevented with adequate
  pre-release care!

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Hypovolemia

• Have good IV access in place before release
• Use normal saline (lactated Ringers contains
  potassium and lactate)
• Carefully monitor fluid status vital signs,
  urine output, chest sounds, edema, etc

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Hyperkalemia Acidosis

• Sodium bicarbonate IV
• Insulin dextrose
• Beta-2 agonists

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Renal Injury

• Maximize renal perfusion with IV fluids
• Carefully alkalinize urine with sodium
  bicarbonate or acetazolamide
• Monitor both amount and pH (prefer gt6.5)

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Crush Injury Cocktail

• 500 cc crystalloid per hour (after initial bolus,
  if needed)
• Add 1 amp NaHCO3 per liter
• Give mannitol if UO lt 300 ml/hr
• Give acetazolamide if pH lt 7.45

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Care of the compressed limb

• Protect open wounds
• Non-compressive splint
• Monitor for signs of compartment syndrome
• Provide adequate pain control

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Contact Information

• david.cone_at_yale.edu
• Yale Emergency Medicine
• Suite 260
• 464 Congress Avenue
• New Haven CT 06519-1315 USA