Upload
quentin-warner
View
213
Download
0
Tags:
Embed Size (px)
Citation preview
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
ARDSCommon 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
• Release of inflammatory mediators results in organ dysfunction
Trauma InflammatoryMediators
OrganInjury
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
ARDSPrevention
• 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
ARDSOutcome
• 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
• Systemic Fat Embolization
– Patent Foramen Ovale
– Pulmonary Pre-Capillary Shunts
– Skin petechiae, CNS signs
FES To Brain On MRI
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
Gurd et al
FES Diagnosis
• Major Criteria– Hypoxemia
– CNS Depression
– Petechial Rash
– Pulmonary Edema
• Minor Criteria– Tachycardia
– Pyrexia
– Retinal Emboli
– Fat in Urine
– Fat in Sputum
– Thrombocytopenia
– Decreased Hematocrit
Gurd et al
FES Diagnosis
• Gurd & Wilson Criteria
• At least 1 Major Sign
• 4 Minor Signs
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
Injury (First Hit)
24 hours 48 hours
Post InjuryInflammatoryResponse in2 Patients
Second Hit in susceptible patients
ARDSMODSThreshold
IM Nailing as a Cause of Secondary Systemic Injury
• 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
Fracture Fixation Technique-Controversial-
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
MechanicalNon Pharamcologic
DVT Prevention
PneumaticCompression
Vena CavaFilter
ElasticStockings
Pharamcologic
DVT Prevention
UnfractionatedHeparin
LMWH Heparin
ElasticStockingsWarfarin
OralAnticoagulants
Pentasacharides
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 PumpsMechanism of Action• Decrease Stasis Fibrinolytic Activity
IVC Filter Indications
• Anticoagulation Prohibited
• High Risk Patients
• DVT Prior to Necessary Surgery
• PE Despite Anticoagulation
IVC Filter
• Prevents Major PE
• Low Morbidity – 96% Patent
– 8% Migration
– 4% PE
• Filter insertion in the ICU
• Expensive
• Invasive
• Does not treat DVT
• Venous Insufficiency
• Filter Occlusion
Advantages Disadvantage
• No Recommendation for Vena Caval Filter
ACCP Recommendation on Vena Cava 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
• No Monitoring
• Increased Efficacy
• Longer 1/2 life
• Predictable Response
• Lower risk of thrombocytopenia
• Parenteral Administration
• Cost
Advantages Disadvantage
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
• Low Cost
• No Monitoring
• Convenient
• Relatively Low Incidence of Bleeding
• Insufficient Efficacy in High Risk Patients
• Unpredictable Responses
• Heparin Induced Thrombocytopenia
Advantages Disadvantage
Aspirin
• Oral Administration• Tolerated well• In-expensive• No Monitoring
• ? Efficacy when used alone
• GI Intolerance• Prolonged anti-platelet
effect
Advantages Disadvantage
Aspirin
• Inhibits cyclooxygenase
• Decreases Platelet Adherence
• ? Effectiveness in Musculoskeletal Trauma– Venous clots not typically found to have
Platelet aggregates
• No Recommendation For The Use of Aspirin
• Recommend Against The Use of Aspirin For Any Indication
ACCP Recommendation on Aspirin
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
• Effective• Oral Administration• Inexpensive
• Requires Monitoring• Difficult to Reverse• Increased Bleeding
Complications in Elderly
Advantages Disadvantage
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
• Recommend Routine Thromboprophylaxis
• Fondaparinux• LMWH• Warfarin (INR 2.5)• LDUH
ACCP Guidelines on Hip Fractures
• Recommend Routine Thromboprophylaxis
• LMWH Once Hemostasis Obtained
• IPC and/or GCS– While Obtaining
Hemostasis
ACCP Guidelines on Spinal Cord Injury
• No Routine Thromboprophylaxis
ACCP Guidelines on Isolated Injuries Distal To The Knee
Duration of Prophylaxis
• 10 to 35 Days
• Agents– LMWH
– Fondaparinux
– Warfarin
ACCP Guidelines Duration of Therapy Hip Fractures
• Up to Hospital Discharge
• Agents– LMWH
– Fondaparinux
– Warfarin
ACCP Guidelines on Duration of Therapy for Trauma Patients
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
E-mail OTA about
Questions/Comments
If you would like to volunteer as an author for the Resident Slide Project or recommend updates to any of the following slides, please send an e-mail to [email protected]
Return to General/Principles
Index