Snapshot A 35-year-old male presents to the ED C-collared on a backboard after being hit in a motor vehicle accident. He breathes spontaneously without any frank bleeding, but bruises are noted throughout his hip and abdomen. His blood pressure is 90/60 mmHg, pulse is 110/min, respirations are 20/min, and SaO2 is 95% on room air. After 1 L Lactated Ringer's and some pain medications are administered, the radiology technician takes images of his C-spine, chest, and pelvis. The pelvic radiograph is shown. Introduction to Mechanisms of Trauma Trauma is the leading cause of death in patients < 45 years old (accident, homicide, suicide) causes more deaths in children/adolescents than all diseases combined Timeline of trauma mortality is important for prognosis minutes: death usually at scene early: death within 4-6 hours without intervention days-weeks: death from multiple organ dysfunction, sepsis, etc. Broadly, trauma is either blunt or penetrating blunt is more common Knowing mechanism is important to anticipate injuries for appropriate triage Beyond managing trauma, underlying cause must always be sought (6 S's) Presentation of Mechanisms Motor vehicle collison head-on: head/facial, thoracic (aortic), lower extremitiy (LE) injury lateral/T-bone: head, cervical, thoracic, abdominal, pelvic, LE injury rear-end: hyper-extension of cervical spine (whiplash injury) rollover accidents: most fatal Pedestrian-automobile impact children: high risk of run-over injury (multisystem) Waddell's triad: tibia-fibula or femur fracture, intrathoracic/abdominal injury, contralateral head injury adult: generally lower extremity injury, but also truncal and head injury from impact Falls landing position important vertical: LE, pelvic, spine, head injury (impact ascends through skeleton) horizontal: facial, UE, rib fractures; intrathoracic and abdominal injuries Gunshot wounds (GSW) injury depends on weapon used, location of GSW(s), and underlying structures handgun: low/medium velocity, extent of damage may be limited to small area hunting rifle: high velocity, widespread injury shotgun: widespread tissue damage at close range, wadding deposition in wound Stab wounds (SW) injury depends on weapon used (length in particular), location of SW(s), underlying structures type of penetration can vary (stab, slash, impalement) Amputation transport amputated appendage wrapped in moist gauze, put in a plastic bag, placed on ice Dental trauma avulsed tooth should be immediately gently cleaned (rinse, do not scrub) and replaced in the socket as soon as possible transport medium for avulsed tooth milk or special tooth solution Evaluation and Management Primary and secondary surveys with resuscitation as needed type and cross for potential transfusions as soon as possible for penetrating injuries, do NOT remove object if present in body may be tamponading vessel remove in operating room Imaging Doppler ultrasound perform to assess vascular injury or compromise the presence of distal pulses does not rule out vascular injury radiography (XR/CT) based on mechanism of injury Amputated body part wrap amputated body part in saline-moistened sterile gauze and sealed in sterile plastic bag Summary Trauma does not cause isolated injuries as suggested in Waddell's triad above, think about other possible injuries to anticipate necessary interventions (and possible test question answer choices!) Principles chief concern: vascular compromise consider nearby vasculature if no nearby vasculature next best step: cleaning + tetanus ppx if nearby vasculature and stable vitals next best step: doppler studies or CT angiogram if clear vascular injury (absent pulses, worsening hematoma) next best step: surgical exploration injury to bone, artery and nerve next best step: repair the bone first - this is rough work second step: vascular repair third step: nerve repair ppx: fasciotomy to protect from compartment syndrome shotgun, military contraband injuries tend to be high velocity and cause a large area ("cone") of tissue destruction next best step: surgical debridement, amputation if severe, antibiotics, tetanus crushing injuries worry about hyperkalemia, myoglobinemia/uria, renal failure and compartment syndrome next best step: IV fluids, mannitol, alkalinization of the urine and management of severe electrolyte abnormalities as presented The next best step is never management of the pathology if the patient's vitals are unstable or could lose an airway - never forget ABCs of resuscitation! References Amputated body part wrap amputated body part in saline-moistened sterile gauze and sealed in sterile plastic bag