a pulmonary pummelling…

The Case.

This patient has been in your ED for over 24 hours waiting for a CCU bed. He presented with vomiting and syncope, but acquired left sided rib fractures during his collapse. He has been comfortable for most of the day on nasal-prong oxygen and a morphine PCA.

You are asked to see him as he has sudden worsening of his left-sided chest pain. He has become clammy and hypoxic.

This is what you see….

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What’s going on ?
What are you going to do now ??

Flail Chest

Defined as segmental fractures (two or more locations on the same rib) of three or more adjacent ribs, resulting in an unstable chest wall. It is one of the most serious chest wall injuries due to its common association with pulmonary contusion and, along with massive haemothorax, tension & open pneumothorax, should be suspected and diagnosed during the primary survey of trauma victims.

The hallmark of this condition is the paradoxical inward movement of the affected chest wall during spontaneous inspiration.

The physiology of respiration is adversely affected by the flail chest in a number of ways;

• Greatly increased work of breathing
• Worsening hypoxia secondary to the underlying developing pulmonary contusion
• Muscular splinting due to pain
• Atelectasis secondary to poor ventilatory effort
• Decreased cardiac output.

Clinical Features & Diagnosis.

Usually diagnosed on physical examination by paradoxical chest wall motion. Pain, tenderness, crepitus or subcutaneous emphysema may also assist in localising the lesion. This may be incredibly difficult to see if the patient is already intubated and receiving positive-pressure ventilation at the time of examination.

A flail segment may be seen on CXR, however CT is more sensitive & provide information regarding the extent of underlying pulmonary contusion and other associated injuries.

* Sometimes they're obvious...

Management.

The patient with a flail chest should be treated as though a pulmonary contusion exists. The outcome of a flail chest injury is directly related to the underlying and associated injuries.

• Supplemental Oxygen.

• Close observation for respiratory decompensation.

• Chest Physiotherapy.

• Cautious fluid management.

• Analgesia.
  • multimodal (paracetamol, NSAIDS, opiates)
  • PCA
  • intercostal nerve blocks
  • high segmental epidurals (never seen these…)

• Respiratory Support
  (obvious problems such as haemopneumothorax or exacerbation of pain should be treated prior to instituting positive pressure ventilation).

• CPAP / BiPAP
  • for awake & cooperative patients
  • may avoid intubation
• Intubation & mechanical ventilation
  • demand-based ventilation (pressure-support) is most beneficial.
  • severe cases may need to proceed to high-frequency oscillation

Indications for early ventilatory support:
* Shock
* Severe head injury
* Comorbid pulmonary disease
* ≥ 8 rib fractures
* Age > 65 years.

• Surgery 
  • Controversial !!!
  • involves fixation of rib or sternal fractures
  • often reserved for when thoracotomy is undertaken to manage other injuries.

The Result.

Upon reviewing his PCA, there is a 3-fold discrepancy between dose-demands and delivery & it is clear that he is under-analgesed. He receives two boluses of IV Fentanyl and additional face-mask oxygen.

Bed-side USS excluded a new pneumothorax and an ABG shows a moderate oxygen requirement. His repeat CXR demonstrates a more confluent lower basal consolidation (?contusion or atelectasis).

He is admitted to HDU for observation, but avoids the need for positive-pressure ventilation following good pain control.