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EMT Exam Review – Shock, Trauma & Environmental Emergencies

Scene Safety & Universal Precautions

  • Absolute first priority on any scene: Scene safety
    • Ensure no hazards (fire, electrocution, violence, traffic, unstable structures, secondary devices, etc.)
  • Second, don appropriate PPE / BSI (gloves, eye protection, mask, gown as needed)
  • Personal decision: If no gloves immediately available and life-threatening bleed exists, many providers will still apply pressure—risk–benefit decision
  • Be alert for unusual threats (e.g., arsonist ambush, shootings at responders)

Patient Assessment Priorities

  • Primary assessment = ABCs with simultaneous c-spine control when mechanism warrants
  • Rapid transport for all critical patients; most interventions performed en route ("load & go")
  • Time-sensitive interventions that can NOT wait:
    • Direct pressure for life-threatening hemorrhage
    • Immediate airway suctioning / obstruction removal
    • Sealing an open chest wound (then reassess for tension pneumothorax)

Shock – Overview

  • Definition: State of hypoperfusion—inadequate circulation to meet metabolic needs
  • Waste products of metabolism
    • Aerobic: \text{CO}2 + \text{H}2\text{O}
    • Anaerobic: Lactic acid (causes muscle soreness, metabolic acidosis)
  • Stages
    • Compensated: tachycardia, vasoconstriction, normal BP
    • Decompensated: absent peripheral pulses, falling BP, AMS
    • Irreversible: cellular death despite resuscitation

Types of Shock & Hallmark Findings

  • Hypovolemic
    • Hemorrhage or plasma/fluid loss (e.g., burns lose plasma)
    • Pale, cool, diaphoretic; tachycardia; narrow pulse pressure
  • Cardiogenic (pump failure)
    • Causes: bradycardia, poor contractility, MI
    • NOT caused by increased preload (that actually helps)
  • Neurogenic (spinal cord injury)
    • Warm, dry skin; relative bradycardia; hypotension (loss of SNS tone → vasodilation)
    • Often accompanied by hypothermia (loss of thermoregulation)
    • Treatment: c-spine, airway, oxygen/ventilation, thermal management, slightly elevate legs/backboard foot if tolerated
  • Septic
    • Systemic infection; skin hot & moist; tachycardia; history of surgery or UTI in elderly females common
  • Anaphylactic
    • Unique sign: wheezing / bronchospasm; treat with \text{Epi}_{1:1,000} IM (EMT only in anaphylaxis)
  • Psychogenic (vasovagal)
    • Temporary widespread vasodilation → syncope; assess for secondary injuries

Stroke Review

  • Two major types:
    • Ischemic (≈80–88 %) – clot/embolus like "brain heart attack"
    • Hemorrhagic – vessel rupture
  • Prehospital cannot differentiate without CT → NO aspirin for possible stroke
  • Rapid transport, perform FAST / Cincinnati exam (face, arm, speech, time)

Glasgow Coma Scale (GCS) Refresh

  • Example given: Eyes to pain (2), incomprehensible/mumbling speech (2), decorticate flexion (3) → GCS = 7
  • Use early and repeat; declining score suggests rising intracranial pressure (ICP)

Traumatic Brain Injury & ICP

  • Cushing’s triad = hypertension (widening pulse pressure), bradycardia, irregular respirations (Biot/Cheyne-Stokes)
  • Other signs: unequal pupils, CSF from ears/nose, decerebrate posturing
  • Epidural vs. Subdural vs. Intracerebral bleeding
    • Epidural – arterial, above dura
    • Subdural – venous, below dura
    • Intracerebral – bleeding within brain tissue itself

Airway & Ventilation Pearls

  • Rapid, shallow respirations → inadequate tidal volume → assist with BVM
    • May start NRB and switch to BVM if no improvement
  • Severe facial trauma + gurgling → manual c-spine, suction, airway adjunct, oxygen
  • Inhaled object removal only IF
    • Visible and reachable with forceps / finger sweep
    • Or causing total obstruction in unconscious patient

Thoracic Injuries

  • Open chest wound → occlusive dressing taped on 3 sides; if patient deteriorates (cyanosis, tachycardia, ↑ dyspnea) suspect tension pneumothorax → lift corner to vent
  • Flail chest = ≥2 ribs fractured in ≥2 places; paradoxical motion; treat with bulky dressing, oxygen, possible CPAP if protocols allow
  • Pericardial tamponade → Beck’s triad (JVD, muffled heart tones, narrowing pulse pressure)
  • Commotio cordis – sudden blunt chest blow during repolarization → VF; treat with CPR/AED

Abdominal & Pelvic Trauma

  • Distended, tender, rigid belly suggests internal bleeding
  • Flank bruising after blunt trauma → kidney injury
  • Evisceration: cover with moist sterile dressing, occlusive layer on top, but address ABCs first
  • Pelvic fracture risk: bladder injury; consider pelvic binder

Musculoskeletal Injuries & Splinting

  • Femur fracture can conceal ≈ 1\text{ L} blood loss (≈20 % of total 5!–!6\text{ L})
  • Closed bilateral femur fx: bind legs together with padding, scoop to backboard; no traction (takes too long)
  • Splint before move UNLESS life-threats demand immediate transport
  • Open fracture = any overlying skin break, even if bone re-seated
  • Colles’ fracture – distal radius (“dinner-fork” deformity)
  • Amputation: control bleeding with direct pressure → tourniquet high & tight; wrap severed part moist cool (avoid direct ice)

Burns

  • Rule of nines (adult): each arm = 9 %, each leg = 18 %, anterior trunk = 18 %, posterior trunk = 18 %, head = 9 %, genitalia = 1 %
    • Palm (including fingers) = 1 %
  • Pediatric burns more serious: larger surface-area-to-mass, poorer thermoregulation
  • Burn shock = plasma loss, not blood loss

Environmental Emergencies

Heat

  • Heat exhaustion: moist, pale skin; normal/slightly elevated temp; dizziness, cramps
  • Heat stroke: hot, dry skin, temp >40!°\text{C}, altered LOC – emergency cooling & transport
  • High humidity impairs evaporative cooling (sweating)

Cold / Hypothermia

  • Shivering = involuntary heat production via ↑ metabolic rate
  • Hypothermia worsens bleeding (coagulopathy)
  • Obtain rectal core temp if possible
  • Diving reflex: cold water submersion → bradycardia, ↓ metabolic demand (especially in children)

Drowning & Water Incidents

  • Any unwitnessed water incident: suspect c-spine injury until proven otherwise

Snake Bites & Envenomation

  • Pit vipers: rattlesnake, cottonmouth (water moccasin), copperhead
  • NOT a pit viper: coral snake (neurotoxic; red-on-yellow, kill a fellow)

Mechanisms of Injury (MOI)

  • Rollover MVC: highest risk partial/total ejection
  • Lateral (T-bone) collisions – highest incidence aortic tears; body built for fore-aft forces, not side forces
  • Rotational + rollover collisions → multiple impacts
  • Three collisions concept: car vs. object, body vs. interior, organs vs. skeleton; internal injuries (e.g., aortic rupture) occur in third collision
  • Blast injuries
    • Primary (pressure wave) – hardest to detect; organ barotrauma (ear, lung, GI)
    • Secondary – shrapnel
    • Tertiary – body displacement

Head, Face, Neck & Eye

  • Neck vessel laceration: apply pressure above & below wound; avoid bilateral carotid compression
  • Unequal pupils in alert patient: ask if baseline (old injury, surgery)
  • Chemical eye burn: remove contacts, irrigate with water/NS ≥20 min; document start time
  • Hyphema = blood in anterior chamber (red eye) – indicates significant ocular trauma
  • Clothesline/laryngeal trauma: airway swelling, subcutaneous emphysema, cyanosis → high-flow O₂, rapid transport

Neurology Quick Hits

  • Retrograde amnesia = can’t recall events before injury; Anterograde (antegrade) = can’t form new memories after injury
  • Reflex arc: sensory neuron → spinal cord → motor neuron (bypasses brain)
  • Helmet removal: only if interferes with airway or prevents proper spinal immobilization

Pediatric Considerations

  • Children compensate (tachycardia, vasoconstrict) longer; by the time hypotension appears they may have lost ≥50 % blood volume – ominous
  • Larger surface area → greater heat loss, higher burn severity

Miscellaneous Physiology & Anatomy

  • CSF located in subarachnoid space; cushions brain & spinal cord
  • Meningeal layers (outer → inner): dura mater → arachnoid → pia mater
  • Sympathetic hormones: epinephrine & norepinephrine
  • Adult vertebral counts: Cervical 7, Thoracic 12, Lumbar 5, Sacrum & Coccyx fused (total ≈33)
  • Atrophy = muscle wasting due to disuse/denervation
  • Bone marrow: produces RBCs, WBCs, platelets
  • Ligaments connect bone-to-bone; tendons attach muscle-to-bone

Formulas & Numbers to Remember

  • Adult blood volume ≈ 70 \text{mL·kg}^{-1} (≈ 5!–!6 \text{L} total)
  • Significant adult blood loss ≈ \ge 20 \% (≈ 1 \text{L})
  • Acceptable capillary refill: ≤ 2 s in all ages (per instructor)
  • Rule of nines percentages (see Burns section)
  • GCS ranges 3 !\to! 15; < 8 = severe TBI ("<8, intubate")

Treatment Themes & Key Actions

  • Rapid transport is the single most repeated answer for multisystem trauma, suspected internal bleeding, stroke, airway compromise, neck lacerations, laryngeal trauma
  • During transport: ongoing ABC monitoring, high-flow oxygen, BP/SpO₂, reassess every 5 min (critical) / 15 min (stable)
  • Maintain body temperature: blankets, warm ambulance, prevent hypothermia-induced coagulopathy
  • Document times: irrigation start, tourniquet application, vitals, interventions