Acute Respiratory Distress
Syndrome, Fat Embolism, &
Thromboembolic Disease in the
Orthopaedic Trauma Patient
Steve Morgan, MD & Scott Adams, MD
Original Authors: Steve Morgan, MD; March 2004;
New Authors: Steve Morgan, MD & Scott Adams, MD;
Revised January 2007 and November 2011
Objectives
• Define
– ARDS
– FES
– Thromboembolic Disease
• Understand Etiology &
Physiology of each
Condition
• Understand
–
–
–
–
Prevention
Diagnosis
Treatment
Outcomes
ARDS
Acute Respiratory Distress Syndrome
• Acute respiratory failure in the post traumatic
period characterized by a decreased PaO2 and
a diffuse and often massive extravasations of
fluid from the pulmonary vasculature to the
interstitial space of the lungs.
ARDS Clinical Definition
– Acute onset of symptoms
– Ratio of PaO2 to FIO2 of 200 mm Hg or less
– Bilateral infiltrates on CXRs
– Pulmonary arterial wedge pressure of 18 mm Hg or less
or no clinical signs of left atrial hypertension
– American-European Consensus Conference (AECC) on ARDS, 94
ARDS
• Incidence 5% – 8% after polytrauma
– Much lower in isolated fracture
• Mortality up to 40%
• Uncommon in Children and the Elderly
ARDS
Common Causes
•
•
•
•
•
•
Trauma
Massive Transfusion
Embolism
Sepsis
Aspiration
Abdominal Distension
• Pulmonary Edema
• Prolonged LOC
• Cardiopulmonary
Bypass
• Pancreatitis
• Major Burns
MULTIFACTORAL
ARDS Etiology
• ARDS related to MODS
Trauma
Inflammatory
Mediators
Organ
Injury
• Release of inflammatory mediators results
in organ dysfunction
ARDS
PATHOPHYSIOLOGY
• Systemic
Inflammatory
Mediators
• Damage to Endothelial
Lining
• Increased Capillary
Permeability
• Fluid Extravasation
• Alveolar Collapse
• Decreased Pulmonary
Compliance
• Ventilation Perfusion
Abnormalities
• Arteriolar Hypoxemia
ARDS
Chest Radiograph
Autopsy Specimen
ARDS Chest CT Scan
ARDS
Prevention
• Limiting Blood Loss
• Decreasing Transfusion
Requirements
• Early Stabilization Of
Unstable Fractures
• Early Prophylactic
Mechanical Ventilation
Temporary Ex-Fix For Stabilization
ARDS
Treatment
• Ventilator Support
– Acceptable ABG’s
– Avoid further alveolar damage
• Toxic FIO2
• Barotrauma
• General Organ Support
• Research
– Optimal ventilator settings
– Pharmalogical agents
ARDS
Outcome
• Significant Cause of Mortality
• Major Cause of Death in Patients with the
Lowest ISS scores
• 30% - 40% Mortality Rate
– Mortality Rate Slowly Decreasing with
Changing & Improving Therapy
Fat Embolism Syndrome
(FES)
• A condition characterized by hypoxia,
confusion and petechiae presenting soon
after long bone fracture and soft tissue
injury.
• Diagnosis of Exclusion
FES
• Often Placed in the Category of ARDS
– May share common pathological pathways
• R/O other Causes of Hypoxia & Confusion
• Index Patient
– young adult with isolated LE injury seen after long
transfer with no supporting therapy or splintage.
FES
• Occurs in 0.9 – 8.5% of all fracture patients
• Up to 35% of the multiply injured
• Mortality 2.5%
• Rare in upper limb injury and children
Etiology
• The likely pathogenetic reaction of lung tissue to
shock, hypercoagulability and lipid metabolism
• Mechanical Theory
• Biochemical Theory
Mechanical Theory
• Fracture Liberates Fat
• Intravasation - Fat Enters Venous System
• Fat Causes Mechanical Obstruction
Mechanical Theory
FES To Brain On MRI
• Systemic Fat Embolization
– Patent Foramen Ovale
– Pulmonary Pre-Capillary
Shunts
– Skin petechiae, CNS signs
Biochemical Theory
• Neutral Fat and Chemical Mediators
Released at Time of Fracture
• Neutral Fat Metabolized by Lipases releases
Free Fatty Acids
• Free Fatty Acids Result in Endothelial Lung
Damage
FES Diagnosis
• Major Criteria
–
–
–
–
• Minor Criteria
–
–
–
–
–
–
–
Hypoxemia
CNS Depression
Petechial Rash
Pulmonary Edema
Gurd et al
Tachycardia
Pyrexia
Retinal Emboli
Fat in Urine
Fat in Sputum
Thrombocytopenia
Decreased Hematocrit
FES Diagnosis
• Gurd & Wilson Criteria
• At least 1 Major Sign
• 4 Minor Signs
Gurd et al
FES Prevention
• Appropriate
Splinting
• Early Fracture
Stabilization
• Oxygen Therapy
FES Prevention
• Therapies
–
–
–
–
–
–
Fluid Loading
Hypertonic Fluid
Alcohol
Heparin
Dextran
Aspirin
• None Shown to be Effective
FES Treatment
• Supportive
– Oxygen Therapy to maintain PaO2
– Mechanical Ventilation
– Adequate Hydration
FES Treatment Steroids
• Steroids
– Decrease endothelial damage
– 30mg/kg initial dose repeated @ 4 Hours, 1gm
dose repeated @ 8 Hours: Total 3 Doses
• Complications - Frequent
– Infection
– GI
• Steroid Therapy Avoided Secondary To Poor Risk
Benefit Ratio
Systemic Effects of Trauma
Second Hit in susceptible patients
ARDS
MODS
Threshold
Post Injury
Inflammatory
Response in
2 Patients
24 hours
Injury (First Hit)
48 hours
IM Nailing as a Cause of Secondary Systemic Injury
Fracture Fixation Technique
-Controversial• Early Total Care
– Definitive Early
Fixation
• Nail or Plate
• Damage Control
– Temporary Stability
• External Fixator
– Limit Further Blood
Loss
– Limit Anesthetic Time
– Delay Definitive
Fracture fixation
Effect of IM Nailing
• Increased IM Pressure
• Embolic Showers On Echocardiograms
• Caused by
– Canal Opening
– Reaming
– Nail Insertion (both reamed & unreamed)
Fracture Fixation Technique
-Controversial• IM Nail - Reamed vs Un-Reamed
– Decreased with Unreamed Technique
• Pape et al
– No Difference
• Keating et al
• Canadian OTS
• IM Nail Reamed vs Plate Osteosynthesis
– No Difference In Pulmonary Dysfunction
• Bosse et al
DVT Incidence
• DVT occurrence
60% if ISS >9.
• 35%-60% DVT in
pelvic fracture
• PE-Most common
preventable cause of
death in trauma.
Virchow Triad
Hypercoaguability
•
•
•
•
Tissue Thromboplastin
Activated Procoagulants
Decreased Fibrinolytic Activity
Ineffective Heparin Clearance of Activated
Clotting Factors
• Catecholamine Release
Endothelial Injury
• Direct Trauma to Vein at time of Injury
• Compression of the Vein Secondary to
Fracture Position
• Vein Manipulation at Time of Fracture
Fixation
Venous Stasis
• Immobilization
• Hypotension
• Venous Occlusion
– Edema
– Fracture Position
• Tourniquet
DVT Prevention
Goals
•
Clinically significant events
– PE
– Post Thrombotic syndrome
• Low Complication Rate
• High Compliance Rate
• Cost Effective
DVT Prevention
Mechanical
Non Pharamcologic
Pneumatic
Compression
Vena Cava
Filter
Elastic
Stockings
DVT Prevention
Pharamcologic
Unfractionated
Heparin
LMWH
Heparin
Warfarin
Oral
Anticoagulants
Pentasacharides
Elastic
Stockings
Prophylaxis
• Elastic Stockings
• Mechanical
Compression
Devices
• Early Mobilization
•
IVC Filter (PE Prophylaxis)
• Pentasaccharide
• Low Molecular
Weight Heparin
• Heparin
• Aspirin
• Warfarin
Mechanical Methods
• Activity
• Compression
Stockings
• Sequential
Compression Device
• Pedal Pumps
Mechanism of Action
• Decrease Stasis
•  Fibrinolytic Activity
IVC Filter Indications
• Anticoagulation
Prohibited
• High Risk Patients
• DVT Prior to
Necessary Surgery
• PE Despite
Anticoagulation
IVC Filter
Advantages
• Prevents Major PE
• Low Morbidity
– 96% Patent
– 8% Migration
– 4% PE
• Filter insertion in the
ICU
Disadvantage
•
•
•
•
•
Expensive
Invasive
Does not treat DVT
Venous Insufficiency
Filter Occlusion
ACCP Recommendation on Vena
Cava Filter
• No Recommendation
for Vena Caval Filter
Pentsaccharide
• Selective Inhibitor of Activated Xa
– Decreased DVT rate with no change in major
bleeding rate compared to LMWH
• Eriksson B I et al N Engl J Med 2001
– Increased risk of minor bleeding
• Delay administration for several hours after surgery
and removal of epidural catheter
Low Molecular Weight Heparin
(LMWH)
• Potentiates Antithrombin III
• Inhibits Factor Xa & II
• Minimal effects on other Factors
LMWH
Advantages
•
•
•
•
No Monitoring
Increased Efficacy
Longer 1/2 life
Predictable
Response
• Lower risk of
thrombocytopenia
Disadvantage
• Parenteral
Administration
• Cost
Heparin
• Heparin Potentiates Anti-Thrombin III
Activity
• Complex Inhibits
– Thrombin (IIa), IXa, Xa
• Heparin effect relative short duration
– Reversed with Protamine Sulfate
• Significant hemorrhage risk
SQ Heparin
Advantages
•
•
•
•
Low Cost
No Monitoring
Convenient
Relatively Low
Incidence of
Bleeding
Disadvantage
• Insufficient
Efficacy in High
Risk Patients
• Unpredictable
Responses
• Heparin Induced
Thrombocytopenia
Aspirin
•
•
•
•
Advantages
Disadvantage
Oral Administration
Tolerated well
In-expensive
No Monitoring
• ? Efficacy when used
alone
• GI Intolerance
• Prolonged anti-platelet
effect
Aspirin
• Inhibits cyclooxygenase
• Decreases Platelet Adherence
• ? Effectiveness in Musculoskeletal Trauma
– Venous clots not typically found to have
Platelet aggregates
ACCP Recommendation on Aspirin
• No Recommendation
For The Use of
Aspirin
• Recommend Against
The Use of Aspirin
For Any Indication
Warfarin
•
•
•
•
•
Blocks Vit K conversion in Liver
Effects Vit K Dependent Factors
Effects the Extrinsic Clotting System
Factor VII Effected first, Short Half Life
Monitored with Pro-Time
– INR 2.0-2.5
• Reversed With Vitamin K or FFP
Warfarin
Advantages
• Effective
• Oral Administration
• Inexpensive
Disadvantage
• Requires Monitoring
• Difficult to Reverse
• Increased Bleeding
Complications in
Elderly
EAST Guidelines
• Guidelines based on
qualitative review of the
current scientific literature
improve uniformity of
opinion and prescribing
practices
– Watts JBJS B 05
• Risk Factors
• Level I Evidence – Major
Significance
– Spinal Fracture
– Spinal Cord Injury
• Level II – No Major
Significance
–
–
–
–
Advanced Age
ISS Score
Blood Transfusion
Long Bone, Pelvis, Head
Injury
ACCP Guidelines
• Guidelines based on
qualitative review of the
current scientific literature
improve uniformity of
opinion and prescribing
practices
– Watts JBJS B 05
• Risk Factors
• Level I Evidence – Major
Significance
–
–
–
–
Spinal Cord Injury
Major Trauma
Hip Fractures
Complex Lower-extremity
Fracture
– Pelvic Fracture
– Prolonged Immobility
– Delay in Commencement Of
Thromboprophylaxis
ACCP Guidelines on Hip
Fractures
• Recommend Routine
Thromboprophylaxis
•
•
•
•
Fondaparinux
LMWH
Warfarin (INR 2.5)
LDUH
ACCP Guidelines on Spinal
Cord Injury
• Recommend Routine
Thromboprophylaxis
• LMWH Once
Hemostasis Obtained
• IPC and/or GCS
– While Obtaining
Hemostasis
ACCP Guidelines on Isolated
Injuries Distal To The Knee
• No Routine
Thromboprophylaxis
Duration of Prophylaxis
ACCP Guidelines Duration of
Therapy Hip Fractures
• 10 to 35 Days
• Agents
– LMWH
– Fondaparinux
– Warfarin
ACCP Guidelines on Duration of
Therapy for Trauma Patients
• Up to Hospital
Discharge
• Agents
– LMWH
– Fondaparinux
– Warfarin
ACCP Guidelines Length of
Prophylaxis
Trauma Population
• Exception
– Impaired mobility
who undergo
inpatient
rehabilitation
– Thromboprophylaxis
– LMWH
– Warafarin INR, 2.5
DVT screening
•
•
•
•
Physical Exam
Ascending venography
Duplex Ultrasonography
Magnetic Resonance Venography
Physical Examination
•
•
•
•
Calf Swelling
Palpable Venous Cords
Calf Pain
Homan’s Sign
• All Unreliable
Ascending Contrast Venography
• Sensitive for detection
• Invasive
• Dye Problems
(allergies, renal)
• Injection Site Irritation
• Poor Pelvic Vein
Evaluation
• Gold Standard
*Invasiveness,expense make ACV a poor screening tool
Doppler/Duplex Ultrasound
•
•
•
•
Comparable to Venogram
Non Invasive
No Morbidity
Poor Axial (i.e Pelvic)
Vein Evaluation
• Operator Dependent
• Good Screening Tool
– Noninvasive, reproducible
Magnetic Resonance Venography
• Non Invasive
• Good Visualization of
Pelvic Veins
• Difficult in Polytrauma
Patient
• Excellent specificity and
sensitivity for suspected
DVT
• Controversial for screening
Pulmonary Embolism
Clinical
Shortness of breath, agitation, confusion
Laboratory
 PaO2,  A-a gradient
Diagnostic studies
V/Q scans
Pulmonary Angiogram, CT PA
Ventilation Perfusion Scan
• Ventilation Perfusion mismatch
• Results
– Low probabiltity
• 15% False Negative
– Medium
• Need Angiogram
– High probability
• 15% False Positive
• Screening Tool
Pulmonary Angiogram
• Angiographic Evaluation of
pulmonary vascular tree
• Allows Placement of IVC
Filter in same setting if
indicated
• Sensitive - Standard in PE
Detection. Diagnostic
Treatment PE
• Anticoagulation
• Filter for recurrent
event despite
anticoagulation
• Thrombectomy
– Serious Acute PE
– Patient in extremous
– Large identifiable PE
Treatment DVT/PE
• Heparin
– Bolus 10-15K units
– Continuous Infusion
• 1000Units/Hr
– Goal  PTT 2x Control
• Prevent Clot
propagation and
recurrent PE
– Discontinue when
Therapeutic on Warfarin
• LMWH / Pentasaccharide
–
–
–
–
Mass related dose SQ inj
Single daily dose
No monitoring necessary
Discontinue when
Therapeutic on Warfarin
Treatment DVT/PE
• Warfarin
– INR 2.0-3.0
– 3-6 Month Duration
– Contraindicated in:
• Pregnancy
• Liver insufficiency
• Poor Compliance
– Prolonged Therapy may decrease recurrence rates
DVT/PE Outcome
• No Diagnosis and Treatment
– 30% Mortality
• Correct Diagnosis and Therapy
– 11% Mortality in First Hour
– 8% Mortality After First Hour
DVT/PE Outcome
• Post Thrombotic Syndrome
–
–
–
–
Valvular Incompetence
Venous Stasis
Edema
Cutaneous Atrophy
• Recurrent DVT
– 20% of Patients
Bibliography FES/ARDS
•
•
•
•
Gurd AR, Wilson RI Fat-embolism syndrome Lancet. 1972 Jul
29;2(7770):231-2
Giannoudis PV, Pape HC, Cohen AP, Krettek C, Smith RM. Review: systemic
effects of femoral nailing: from Küntscher to the immune reactivity era. Clin
Orthop Relat Res. 2002 Nov;(404):378-86
Bosse MJ, MacKenzie EJ, Riemer BL, Brumback RJ, McCarthy ML, Burgess
AR, Gens DR, Yasui Y. Adult respiratory distress syndrome, pneumonia, and
mortality following thoracic injury and a femoral fracture treated either with
intramedullary nailing with reaming or with a plate. A comparative study. J
Bone Joint Surg Am. 1997 Jun;79(6):799-809
Canadian Orthopaedic Trauma Society.Reamed versus unreamed
intramedullary nailing of the femur: comparison of the rate of ARDS in
multiple injured patients. J Orthop Trauma. 2006 Jul;20(6):384-7
Bibliography DVT/PE
•
Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR,
Colwell CW; American College of Chest Physicians Prevention of venous
thromboembolism: American College of Chest Physicians Evidence-Based
Clinical Practice Guidelines (8th Edition). Chest. 2008 Jun;133(6
Suppl):381S-453S
•
Rogers FB, Cipolle MD, Velmahos G, Rozycki G, Luchette FA Practice
management guidelines for the prevention of venous thromboembolism in
trauma patients: the EAST practice management guidelines work group. J
Trauma. 2002 Jul;53(1):142-64
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