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- This is a chart showing the body's systemic inflammatory response to trauma.
- First Hit = Traumatic injuries trigger the systemic inflammatory response syndrome (SIRS), followed by a recovery period mediated by the counter-regulatory anti-inflammatory response (CARS).
- Second Hit = Surgery can act as a second hit. The impact on the patient's biological reserve varies based on the type and timing of surgery.
- Understanding this chart led to the development of Damage Control Orthopaedics (DCO), as opposed to Early Total Care (ETC).
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- It is the immune response mounted by the body in response to trauma.
- It is defined by having 2 or more of: Tachycardia, Low PaCO2, High or low WBC, High or low Temperature
- If it exceeds a certain threshold, patients may develop Acute Respiratory Syndrome (ARDS) and Multi-Organ Dysfunction Syndrome (MODS)
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- Interleukin 1, 6, 8, 10 and TNF-alpha
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- Hypothermia, Hypercoagulopathy, Metabolic Acidosis
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- It means "Early Total Care," which advocates early definitive management of ALL fractures. However, this approach was found to affect the second hit phenomenon.
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- Damage control orthopaedics was a term coined by the US Navy in reference to keeping a badly damaged ship afloat
- DCO involves providing temporary stabilization with external fixation of long bone and pelvic fractures to reduce major pain, fat emboli, SIRS, lethal triad and the second hit phenomenon.
- It stands in contrast to "Early Total Care"
- Most literature on DCO focuses on femoral shaft fractures. Pape et al. suggested that femoral shaft fracture patients can be classified into stable, borderline, unstable and extremis groups based on markers of shock, coagulation, temperature and soft tissue injuries
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- Vallier recently proposed a new approach to polytrauma known as Early Appropriate Care
- It recommends definitive management of mechanically unstable fractures within 36 hours of injury, provided the patient has demonstrated response to resuscitation based on 3 biochemical markers:
- Lactate < 4
- pH > 7.25
- If markers remain deranged, a DCO strategy is used.
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vallier2013.pdf435.7KB
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- This is an ebb and flow chart of metabolic response to injury, which consists of 3 phases
- Ebb phase = decreased metabolic rate during early shock (first 24-48 hours after injury)
- Flow phase = catabolic phase (2-7 days)
- Provides a compensating response to the initial trauma and volume replacement in all but minor injuries
- Increased body oxygen consumption and metabolic rate are key features of this phase
- Late Flow phase = Anabolic phase (8 days to several weeks/months)
- Characterized by gradual restoration of body protein and fat stores, and normalization of positive nitrogen balance as the metabolic response to trauma resolves
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- New Berlin Classification (Pape 2014) combines anatomic and physiological parameters.
- Abbreviated Injury Scale (AIS) ≥ 3 for two or more different nine body regions
- Plus one or more of these five physiologic parameters:
- SBP ≤ 90 mm Hg
- GCS score ≤ 8
- Base excess ≤ 6.0
- INR ≥ 1.4 or partial thromboplastin time ≥ 40 s
- Age ≥ 70 years
- Alternatively, it can be defined by an Injury Severity Score (ISS) greater than certain threshold values (15, 16, 18, or 25 have been cited in literature)
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- Score ranges from 0-75 points [calculated as 3 × (5²)]. Based on the square of AIS scores from the 3 most severely injured body regions (rated 1-6 based on severity). A score of 75 is automatically assigned if any region is rated as unsurvivable.
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- Lancet CRASH-2 trial: multicenter study of 20,000 patients
- Administration within 3 hours reduces risk of death from bleeding (1g/10min loading dose, then 1g/8hr)
- After 3 hours, no benefit and paradoxically increased risk of death
CRASH 2 trial.pdf255.9KB
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- ATLS
- MTP = 1:1:1 = Packed red cells, Plasma, Platelets (PROPPR Trial in JAMA 2015
- "Permissive Hypotension" - to avoid disrupting blood clots
- IV TXA
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- Shock has 4 classes:
- Class 1: Normal vital signs
- Class 2: Tachycardia
- Class 3: Low blood pressure
- Class 4: Altered mental status, poor urine output
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- Larger head:body ratio - head injuries more common
- Bones have higher elasticity → mainly soft tissue injuries. However, pelvic fractures indicate very high-energy trauma
- Children are usually hemodynamically more stable
- Due to children's vessels being able to vasoconstrict more readily than the atherosclerotic, friable vessels of adults
- Smaller diameter vessels that can vasoconstrict rapidly
- Also due to bone elasticity, fractures are usually limited to a single bone
FAT EMBOLISM
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- Typically presents within 24-72 hours after injury
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- Gurd Criteria - requires either 2 major criteria OR one major plus 4 minor criteria
- Major Criteria:
- Respiratory insufficiency (hypoxemia PaO2< 60 mm Hg, FiO2= 0.4)
- CNS depression disproportionate to hypoxemia
- Pulmonary edema
- Axillary or sub conjunctival petechiae
- Minor Criteria
- Tachycardia > 110 bpm
- Pyrexia > 38.5°C
- Emboli present in the retina on fundoscopy
- Fat globules present in urine
- Jaundice
- Oligoanuria
- Sudden drop in Hemoglobin > 20%
- Sudden thrombocytopenia > 50%
- Increased Erythrocyte Sedimentation Rate (ESR) > 71 mm/hour
- Fat globules present in the sputum
- Fat Macroglobinemia
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- The condition is self-limiting and treatment is mainly supportive, including respiratory support when needed
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The Lord possessed me at the beginning of his work, the first of his acts of old. Proverbs 8:22