Interactive Tutorial: Chest Trauma And Lung Transplant Flashcards
Classification of Chest trauma
- Common
- Account for ~25% of trauma deaths
- Overall chest trauma mortality is 10%
- <15% of patients with chest trauma require surgical intervention
- Inadequate / Delayed treatment —> Death
- Mortality
—> Immediate deaths
—> Deaths within a few hours
—> Late deaths (days - weeks)
Classification based on ***Mechanism:
- Blunt trauma
- High velocity impact (e.g. RTA)
- Low velocity impact (e.g. falling on level ground)
- Crush injury (e.g. industrial accident) - Penetrating trauma
- Sharps (e.g. knife)
- Gun shot
Classification based on ***Anatomy:
- Chest wall injury
- Rib fracture
- Sternal fracture
- Clavicular fracture
- Vertebral fracture
- Scapular fracture
- Soft tissue injury - Pleural cavity injury
- Haemothorax
- Pneumothorax - Parenchymal lung injury
- Contusion
- Laceration
- Haematoma - Airway injury
- Heat and Great vessel injury
- Cardiac tamponade - Others
- Diaphragmatic injury
- Esophageal injury
Investigations of Chest trauma
- CXR
- CT thorax
- Angiography
- Echocardiography
- Bronchoscopy
- MRI
Management of Chest trauma
Initial management:
- ABC
- Early detection of life-threatening injuries
- Assess as a whole
- Identify indications for immediate operation
Treatment:
- Simple therapeutic procedures (Non-operative)
- majority of patients
- Analgesia, Pulmonary hygiene, ETT intubation, Chest drain insertion, Physiotherapy - Thoracotomy / Sternotomy
- <10% of blunt chest injuries
- 15-30% of penetrating chest injuries
***Indications for Immediate operation
- Massive haemothorax
- Ongoing bleeding from chest
- Cardiac tamponade
- Penetrating transmediastinal chest wounds
- Chest wall disruption / Impalement wounds to chest
- Massive air leak from chest tube
- Major tracheobronchial injury
- Great vessel injury with unstable haemodynamics
Major thoracic injuries
- Tension pneumothorax
- Massive haemothorax
- Flail chest
- Pulmonary contusion
- Tracheobronchial injuries
- Cardiac tamponade
- Traumatic aortic disruption
- Tension pneumothorax
- Air enters pleural space without a means of exit —> “one-way-valve” air leak
- Gradual increase in volume of air in pleural cavity
—> Ipsilateral collapse of lung
—> Pressure continue to develop
—> Mediastinum displaced to opposite lung
—> Impairing venous return (∵ kinking of SVC / IVC) + relaxation of heart
—> Decreasing cardiac output
Causes:
- Penetrating injury to chest
- Blunt trauma with parenchymal lung injury
- Mechanical ventilation with high airway pressure (Barotrauma)
- Spontaneous pneumothorax
Diagnosis:
-
**Clinical (NOT wait for CXR)
- Severe respiratory distress
- **Unilateral absence of breath sounds
- **Tracheal deviation
- **Tachycardia / Hypotension
- ***Neck vein distension
- Cyanosis (late manifestation) - CXR
- Large pneumothorax (from radiopaedia: visible visceral pleural edge seen as white thin line, no lung markings seen peripheral to this lung, radiolucent peripheral space)
- Mediastinal shift
Treatment:
1. Immediate decompression
- Insertion of ***large bore needle into 2nd ICS along MCL
—> Convert Tension pneumothorax into Simple open pneumothorax
- Chest drain insertion (Definitive)
- After stabilisation by decompression
Algorithm:
Traumatic pneumothorax
—> Simple pneumothorax —> **Observation / **Chest drain insertion (depend on size)
—> Tension pneumothorax —> ***Urgent needle decompression followed by Chest drain insertion
- Massive haemothorax
- Common in penetrating trauma
- Each hemithorax can hold up to 3L of blood
- Intercostal / Internal mammary vessels most commonly injured
- Neck veins can be flat (hypovolaemia) / distended (mediastinal compression)
- Hilar / Great vessel disruption —> Severe shock
Diagnosis:
- Clinical
- Haemorrhagic shock
- Flat neck veins
- Unilateral absence / diminution of breath sounds
- Unilateral dullness - CXR
- Unilateral “white out” on CXR
Treatment:
- Rapid fluid resuscitation
- Decompression of chest cavity
- Intubate a patient in shock / respiratory difficulty
- Thoracotomy (Operative intervention)
- if 1.5L blood evacuated initially
- ongoing bleeding from chest drain of >200ml/hr for 2-4 hours
- failure to achieve complete drainage / clotted haemothorax
- Flail chest
- Results from direct high energy impact (blunt force)
- Multiple rib fracture
—> >=2 ribs fractured in >=2 places
—> A segment of chest wall separated from rest of bony chest wall
—> Paradoxical motion of chest wall segment with inspiration and expiration
—> Segment of lung not moving as intended (Inspiration —> alveoli collapse, Expiration —> alveoli expansion)
—> Inefficient respiratory movement
—> Effective lung volume reduced (patient has to take deeper / more rapid breaths —> more work for breathing)
Complications:
- High risk for pneumothorax / haemothorax
- Respiratory failure ∵
- Paradoxical motion of chest wall
- Underlying lung injury
- Severe pain with restricted chest wall movement
Treatment:
- Analgesia
- Mechanical ventilation (usually necessary)
- Immediately intubate for respiratory distress
- Consider intubation for haemodynamic instability - Early surgery to restore integrity of ribcage
- Pulmonary contusion
- Most common potentially lethal chest injury
- Caused by haemorrhage into lung parenchyma
- Commonly associated with fractured ribs
Natural progression:
- Worsening hypoxaemia for first 24-48 hours
Diagnosis:
- Clinical (can be difficult)
- Few respiratory symptoms —> Main problem in diagnosis
- Mainly Chest pain, SOB
- Haemoptysis (rare) - CXR
- Haziness in lung / Infiltration of lung segments + Rib fractures
- Can be ***delayed (within 24-48 hours) - ***CT thorax
- More accurate
Treatment (mainly ***supportive):
- Supportive with supplemental O2
- Physiotherapy
- Mild analgesic
- Broad spectrum antibiotics
- Mechanical ventilation when necessary
- Tracheobronchial injuries
- Unusual (1%) but potentially fatal
- Frequently missed injury
- Result from Penetrating / Blunt trauma
- Most patients die at scene
- High mortality from associated injuries (in posterior mediastinum)
Classification:
- Cervical tracheal injuries
- ***Upper airway obstruction, Cyanosis
- Dysphagia, Cough, Haemoptysis
- Subcutaneous emphysema - Thoracic tracheal / bronchial injuries
- **Intrapleural laceration
—> Persistent SOB
—> Massive air leak
—> Massive pneumothorax
- **Pneumomediastinum / Subcutaneous emphysema
CXR signs:
- ***Peri-bronchial air
- Deep cervical emphysema
- Subcutaneous emphysema
- Lung collapsed ***laterally with pneumomediastinum
- Pneumothorax
- Pleural effusion
- Fallen lung sign
CT signs:
- Fallen lung sign
- bronchial fracture —> causing lung to collapse (∵ air leak) + fall to dependent part of chest
- hanging onto hilum by vascular connections only
Treatment:
- Secure airway
- Intubation
- Cricothyroidotomy / Tracheostomy - Immediate operation to primary repair
- Cardiac tamponade
- Penetrating (more common) / Blunt injury
- 75 to 100ml of blood can produce tamponade physiology in adult
Clinical features:
- Beck’s triad
- Hypotension
- Distended neck vein
- Muffled heart sound - Shock / Ongoing hypotension without obvious blood loss (more common) (i.e. Obstructive shock)
Diagnosis:
1. Transthoracic echocardiography
Treatment:
- Emergency pericardiocentesis
- catheter inserted subxiphoid area —> 45o from midline —> aiming left shoulder - Surgical pericardial drainage
- through median sternotomy / subxiphoid incision
- Traumatic aortic disruption
- Tear in wall of aorta
- Mechanism: ***Rapid deceleration
- Usually located near ***ligamentum arteriosum
- Most die before reaching the hospital
Clinical signs:
- Asymmetry in upper extremity BP
- Widened pulse pressure
- Chest wall contusion
- Posterior scapular pain, intrascapular murmur
CXR:
- Widened mediastinum (>8cm)
- ***Loss of aortopulmonary window (notch between aortic arch and pulmonary artery)
- ***Blurring of aortic knob
- Deviation of trachea to right
- Depression of left main stem bronchus
- Fracture of first 3 ribs / scapula / sternum
- Left pleural effusion
Diagnosis:
- CT thorax with contrast
- Valuable diagnostic tool for aortic injury - Aortography
- Good standard for diagnosis
- Useful for indeterminate cases / more detailed planning required
Treatment:
- Urgent surgical repair
- Endovascular aortic stent grafts (definitive treatment / buy time until definitive surgical repair)
Pitfalls in Chest trauma
- Simple pneumothorax can progress to Tension pneumothorax
- Simple haemothorax can progress to a Clotted haemothroax —> ***Empyema
- Undiagnosed diaphragmatic injury can result in Pulmonary compromise + Strangulation of peritoneal contents
Lung transplantation
- Removal of one / both diseased lungs from patient —> Replacement with healthy lungs from a donor
- Accepted modality of treatment for ***End stage lung disease that is refractory to maximal medical treatment
- Poorest 5 year survival among all organ transplants: ~50%
Types:
- Double transplant
- Single transplant
- Lobar transplant
- Part of Heart-Lung transplant
Indications of Lung transplant
- Obstructive lung disease
- ***COPD
- Alpha 1 antitrypsin deficiency - Restrictive lung disease
- ***Idiopathic pulmonary fibrosis
- ILD - Septic lung disease
- ***Cystic fibrosis
- Bronchiectasis - Pulmonary vascular disease
- Pulmonary hypertension
Morbidity of Lung transplant
- Use of Immunosuppressant / Steroid
- Hypertension
- DM
- Hyperlipidaemia - Renal dysfunction
- Bronchiolitis obliterans syndrome (after 5 years)
- ∵ chronic rejection
Candidacy considerations
- High risk of death (>50%) due to lung disease within 2 years if lung transplantation not performed
- High likelihood (>80%) of surviving >=90 days after lung transplantation
- High likelihood (>80%) of 5-year post-transplant survival from a general medical perspective provided there is adequate graft function
CI of Lung transplantation
Absolute CI:
- Recent history of malignancy
- 5-year disease free interval is prudent - Untreatable significant dysfunction of another major organ system (unless combined organ transplantation)
- Uncorrected atherosclerotic disease with end-organ ischaemia / dysfunction / CAD not amenable to revascularisation
- Acute medical instability
- Uncorrectable bleeding diathesis
- Chronic infection with highly virulent / resistant microbes that are poorly controlled pre-transplant
- Active TB infection
- Significant chest wall / spinal deformity expected to cause severe restriction
- Class 2/3 obesity (BMI >35)
- Current non-adherence to medical therapy / history of repeated / prolonged episodes of non-adherence
- Psychiatric / Psychological conditions associated with inability to cooperate
- Absence of an adequate / reliable social support system
- Severely limited functional status with poor rehabilitation potential
- Substance abuse / dependence (e.g. alcohol, tobacco, marijuana, other illicit substances) within last 6 months
Relative CI:
- Age >65
- Class 1 obesity (BMI 30-34.9)
- Progressive / Severe malnutrition
- Severe, symptomatic osteoporosis
- Extensive prior chest surgery with lung resection
- Mechanical ventilation / ECLS
- however, carefully selected candidates without other acute / chronic organ dysfunction may be successfully transplanted
Mechanical bridges to Lung transplantation
ECLS (Extracorporeal life support) recommended:
- Young age
- Absence of multiple-organ dysfunction
- Good potential for rehabilitation
ECLS not recommended:
- Septic shock
- Multi-organ dysfunction
- Severe arterial occlusive disease
- Heparin-induced thrombocytopenia
- Prior prolonged mechanical ventilation
- Advanced age
- Obesity
Currently accepted “Ideal” donor
- Age <55
- ABO compatibility
- Clear chest radiograph
- PaO2 >300 on FiO2=100%, PEEP 5 cmH2O (P:F ratio —> reflect ability of oxygenation by lung)
- Tobacco history <20 pack years
- Absence of chest trauma
- No evidence of aspiration / sepsis
- No prior cardiopulmonary surgery
- Sputum gram stain - absence of organisms
- Absence of purulent secretions at bronchoscopy
Only 49% of donor lung satisfy above criteria, 51% are ***extended criteria donor lungs
Absolute CI for donor lungs
- Age >65
- History of lung disease
- History of prior cardiopulmonary surgery
- History of severs chest trauma
- Evidence of pulmonary edema
- Long smoking history >20 pack years
- Abnormal CXR
- Fulminant pneumonia
- HbsAg +ve, HCV Ab +ve
- P/F radio <300 on FiO2=100%, PEEP 5 cmH2O
- Evidence of aspiration clinically, on CXR / bronchoscopy
Potential donor lungs are prone to injury
Inside in donor: 1. Cold ischaemia 2. Brain death 3. Hypotension 4. Trauama 5. Mechanical ventilation 6. Pneumonia 7. Aspiration —> Activation of inflammation + coagulation in donor —> ***Ischaemia-reperfusion induced lung injury after transplantation
Method to resolve:
- Normothermic Ex Vivo lung perfusion (EVLP)
- opportunity to salvage borderline lungs
- increase donor lung supply
- reduce transplant waiting list morbidity and mortality - Living donor lobar lung transplant (LDLLT)
- possible serious complications in donor lobectomy —> LDLLT indicated only for critically ill patients who are unlikely to survive the long wait for cadaveric lungs
Monitor:
- CXR of explanted lung