The Child With Chest Injury

Question 1

Are isolated chest injuries common or uncommon in children?

Answer 1

Uncommon. Usually associated with multisystem injury.

Question 2

What consequences of severe trauma may compromise respiratory function?

Answer 2

CONSEQUENCES OF SEVERE TRAUMA

COMPROMISING RESPIRATORY FUNCTION

1. gastric dilatation
2. pulmonary aspiration (after vomiting/ regurgitation)

Question 3

What physiological and anatomical differences in children need to be considered in chest injury?

Answer 3

CHEST INJURY

1. Elastic tissues
   
   • kinetic energy transferred through chest wall to deep structures with little/ no external injury
   • CXR - lack of rib fractures does not mean no thoracic visceral disruption; rib fractures mean high-energy transfer
2. Little respiratory reserve
   
   • high metabolic rate
   • small FRC
   • horizontal ribs
   • underdeveloped resp muscles
     
     • => desaturate more rapidly
     • => tolerate chest wall disruption e.g. flail chest poorly
3. Iatrogenic chest problems
   
   • short trachea - ETT can be displaced into main stem bronchus or oesophagus
   • BVM ventilation
     
     • gastric distension
     • PTX from overinflation of lungs (esp if intubated and ETT migrates beyond carina) –> tension PTX if ventilation cont’d

Question 4

At which stage are thoracic injuries treated?

Answer 4

• Life threatening injuries - treated immediately after PRIMARY SURVEY during RESUSCITATION
• Other injuries identified during SECONDARY SURVEY managaed during EMERGENCY Rx

Question 5

What chest injuries pose an immediate threat to life and must be managed during resuscitation?

Answer 5

LIFE-THREATENING CHEST INJURIES

ATOM FC

• Airway obstruction
• Tension PTX
• Open PTX
• Massive haemothorax
• Flail chest
• Cardiac tamponade

Question 6

Describe the mechanism of tension PTX, its signs and resuscitation management.

Answer 6

TENSION PTX

• Mechanism
  
  • air accumulates under pressure in the pleural space
  • mediastinum is pushed across the chest
  • great vessels are kinked
  • venous return to the heart is compromised
  • cardiac output is reduced
  • diagnosed clinically
• Signs
  
  • B
    
    • obs: hypoxia
    • LOOK
      
      • respiratory distress (unless deeply unconscious)
      • asymmetrical movement
    • LISTEN
      
      • decreased air entry
    • FEEL
      
      • hyper-resonant to percussion (on side of PTX)
      • trachea deviated away from PTX
  • C
    
    • shock
    • distended neck veins (sometimes)
• RESUS
  
  • High flow O2 through reservoir mask
  • needle thoracocentesis or thoracostomy (GREY cannula into the 2nd intercostal space in the mid-clavicular line - just above the 3rd rib)
  • chest drain - prevents:
    
    • recurrence
    • progression to tension PTX

Question 7

Describe the mechanism of open PTX, its signs and resuscitation management.

Answer 7

OPEN PTX

• Mechanism
  
  • penetrating wound in the chest wall assoc. w/ PTX
  • actively look for this esp. in the back
• SUCKING CHEST WOUND =
  
  • penetrating chest wound
  • > 1/3 diameter of the trachea
  • upon inspiration, air enters the pleural space via the defect instead of being drawn into the lungs via trachea
• Signs
  
  • Obs: Hypoxia
  • LOOK
    
    • respiratory distress (unless deeply unconscious)
    • asymmetrical movement
  • LISTEN
    
    • decreased air entry
    • may hear sucking and blowing through the wound
  • FEEL
    
    • hyper-resonant to percussion (on side of PTX)
    • trachea deviated away from PTX
  • +/- associated haemothorax i.e. haemopneumothorax
• RESUS
  
  • High flow O2 via reservoir mask
  • occlude the wound site
    
    • 3-sided dressing
    • ported chest seal
      
      • allows air to escape from the pleural cavity without being sucked back in
      • ensure defect not larger than the base of the device
  • chest drain – NB not via defect (contamination spreads + bleeding restarts)

Question 8

Describe the mechanism of massive haemothorax, its signs and resuscitation management.

Answer 8

MASSIVE HAEMOTHORAX

• Mechanism
  
  • blood accumulates in the pleural space from damage to:
    
    • blood vessels in the lung (arteries/ veins from pulmonary/ systemic vessels)
    • mediastinum
    • chest wall
    • may be a ​combination
  • more of a circulatory problem than resp
  • hemithorax can hold substantial blood volume =>
    
    • haemorrhagic shock
    • local pressure effects
• Signs
  
  • B
    
    • obs: hypoxia despite added O2 Tx
    • LOOK
      
      • decreased chest wall movement
    • LISTEN
      
      • decreased air entry
    • FEEL
      
      • dullness to percussion
  • C
    
    • shock
• Diagnosis - USS
• RESUS
  
  • ​High flow O2 via reservoir mask
  • 2 x IV access + Volume replacement
  • chest drain

Question 9

Describe the mechanism of flail chest, its signs and resuscitation management.

Answer 9

FLAIL CHEST

• Mechanism
  
  • major force to the chest
  • a number of adjacent ribs get fractured in 2 or more places
  • a segment of the chest wall becomes free floating = FLAIL SEGMENT
  • the segment has paradoxical movement - it moves OUTWARD with EXPIRATION and in INWARD with INSPIRATION
  • rare in children because they have elastic chest wall - requires massive force => expect serious lung + mediastinal injury
  • if no history of massive force –> consider:
    
    • NAI
    • osteogenesis imperfecta
• Signs
  
  • Obs: hypoxia despite added O2 Tx
  • LOOK
    
    • pain
    • paradoxical chest movement
  • FEEL
    
    • crepitus on palpitation (rib #)
• RESUS
  
  • PAIN RELIEF
    
    • IV opioids - titrated
    • Nerve block - local or regional (avoids resp depression of opioids)
      
      • intercostal blocks
        
        • hazardous if uncooperative
        • may need to be sedated
      • epidural
        
        • as above
        • R/O SPINE INJURY first
  • B
    
    • high flow O2 via reservoir mask – minor cases
    • CPAP - nasal or facial – intermediate cases
    • I+V – severe cases
      
      • ​immediately if the child is compromised
      • may need to cont for 2 weeks until flail segment becomes sticky and stabilises

Question 10

Why may flail segments not be noticed on initial examination?

Answer 10

MISSED FLAIL SEGMENT

• Splinting of the chest wall due to pain (unmasked with analgesia)
• PPV (positive pressure ventilation) in an intubated child causes the segment to move in unison with the rest of the chest wall
• posterior flail segment - examine the BACK!
• NB – CXR - rib fractures not always obvious so careful clinical examination needed

Question 11

What is paradoxical breathing?

In which groups may it be normal?

Answer 11

PARADOXICAL BREATHING

• Reversal of normal pattern of breathing
• Chest
  
  • moves IN during INSPIRATION
  • moves OUT during EXPIRATION
• Abdomen
  
  • moves IN during INSPIRATION
  • moves OUT during EXPIRATION
• May be normal in infants and children < 2-3 yo, as long as - stomach move OUT during INSPIRATION
• Because they have underdeveloped resp muscles and elastic chest wall

Question 12

Describe the mechanism of cardiac tamponade, its signs and resuscitation management.

Answer 12

CARDIAC TAMPONADE

• Mechanism
  
  • penetrating or blunt injury (more common after penetrating)
  • blood accumulates in the fibrous pericardial sac
  • reduced volume for cardiac filling during diastole
  • cardiac output progressively reduced
• Signs
  
  • shock
  • muffled heart sounds
  • distended neck veins – blood backed up from right side of heart (not if hypovolaemic)
• RESUS
  
  • high flow O2 reservoir mask
  • IV access x 2 + volume replacement (temporarily increases cardiac filling)
  • emergency thoracotomy (in centres with cardiothoracic surgery) OR
  • needle pericardiocentesis
    
    • removing even a small amount of fluid from the pericardial sac dramatically increases CO

Question 13

What conditions should be sought during the secondary survey wrt to chest injury?

Answer 13

CHEST INJURY

SECONDARY SURVEY CONDITIONS

Please Please Be Very Delicate!

• Pulmonary contusion
• PTX (simple)
• Bronchial & tracheal rupture
• Vessels - disruption of great vessels
• Diaphragm - ruptured

• Pulmonary contusion
  
  • high incidence
  • usually blunt but also penetrating trauma
  • ribs are elastic and transmit energy to the lung causing bruising - do not fracture easily, releasing energy
  • may occur with or without rib fracture
  • can WORSEN with time - ongoing clinical review and continuous pulse ox monitoring + frequent ABG
  • Microscopic level
    
    • oedema
    • haemorrhage (interstitial & intra-alveolar)
  • Usually resolve w/i 36 hours
  • Clinical features
    
    • hypoxia
    • SOB
    • haemoptysis
  • CXR - non-segmental opacification (may not be present initially)
  • CT scan
    
    • may distinguish from consolidation/ collapse/ aspiration/ haemothorax
    • only if needed for other indications
  • Emergency Rx
    
    • high flow o2
    • I+V
    • physio - reduces the risk of
      
      • pulmonary collapse
      • secondary infection
• PTX (simple)
  
  • ​air in the pleural space
  • some degree of lung collapse
  • not under pressure yet (tension)
  • Signs - may be subtle or barely perceptible compared to tension PTX
    
    • Obs: hypoxia
    • LOOK
      
      • decreased chest wall movement
    • LISTEN
      
      • diminished BS
    • FEEL
      
      • normal or increased resonance to percussion
  • Diagnosis
    
    • CXR - lung edge with no lung marking beyond it
    • difficult if anterior
    • CT
  • Emergency Mx = chest drain
    
    • may not resolve spontaneously
    • URGENT if I+V as may progress to tension
• Bronchial & tracheal rupture
  
  • Presents as
    
    • PTX
    • haemoPTX
    • persistent & vigorous air leak after chest drain inserted
    • S/C emphysema
  • Emergency Rx
    
    • refer to cardiothoracic surgeons for definitive repair (if v. small may close spontaneously)
    • insertion of 2 or more chest drains + suction
    • If I+V needed, limit pressure + be aware passed of ETT may cause further disruption
• Vessels - disruption of great vessels
  
  • high speed motor vehicle crash
  • usually fatal
  • if not - aortic rupture has tamponaded itself with intact adventitial (outermost) layer
  • Presentation
    
    • shock Vs. relative hypertension (if leak seals itself with little blood loss)
    • peripheral pulse poorly palpable
  • Diagnosis
    
    • CXR - mediastinum WIDENED or abnormal profile - differentiate from:
      
      • AP film
      • thymus - prominent in small children
      • sternal/ spinal fractures
    • Arch angiography = DEFINITIVE
    • multi-slice CT
  • Emergency Mx
    
    • control BP - avoid surges that can pptate re-bleeding
    • cardiothoracic surgery
• Diaphragm - ruptured
  
  • ​rare with blunt injury
  • may occur with penetrating injury e.g. knife/ stab wounds
  • may be more common on L side
  • Presentation
    
    • asymptomatic - unless other structures damaged may present years later as diaphragmatic hernia
    • B: Hypoxia - due to:
      
      • diaphragmatic dysfunction
      • pulmonary compression from a herniated viscus
    • C: Shock
      
      • mediastinal distortion affecting venous return
      • haemorrhage from adjacent structures
  • CXR
    
    • raised hemidiaphragm
    • abdominal contents e.g. bowel or NGT seen in the chest
  • Emergency Mx
    
    • surgical repair (via abdomen)
    • thoracotomy rarely needed

Question 14

What are the indications for cardiothoracic surgical referral in chest injury?

Answer 14

CARDIOTHORACIC SURGICAL REFERRAL

CHEST INJURY

Cardiothoracics Are Very Helpful

1. Cardiac tamponade
2. Air leak - massive, continuing after chest drain insertion
3. Vessels - Disruption of Great
4. Haemorrhage - continuing after chest drain insertion

Question 15

How should children receive oxygen in chest injury?

Answer 15

High concentration oxygen

• Breathing Spontaneoulsy - reservoir mask
• Assisted ventilation - mask and self-inflating bag with an oxygen reservoir
• Intubated - via ventilator