10 Nov

Flail chest

Definition

Flail chest is defined as two or more rib fractures at two or more segment. This causes the segment to become afloat and separated from the ribcage.

The occurrence of this condition is associated with high impact injury to the chest. It is common to have other associated injuries such as contusion or pneumohaemothorax.

Mortality is attributed to either respiratory failure or associated injuries.

Clinical features

History

A diagnosis of flail chest should be suspected in patients with this histories.

  • a high impact mechanism
  • chest pain
  • dyspnoea
  • haemoptysis

Physical examination

  • tachypnoea
  • tachycardia
  • hypoxia; it may lead to respiratory failure
  • paradoxical movement of the flail segment
  • presence of subcutaneous emphysema and crepitus
  • reduced air entry, dullness or percussion due to the presence of pneumohaemothorax

Investigation

Chest x-ray

First radiograph to assess rib fracture, pulmonary contusion, pneumohaemothorax and emphysema.

CT scan

Radiograph has less sensitivity compared to a CT scan. A pulmonary contusion may be not apparent on radiograph alone but appear larger on CT. It also allows an assessment of other structures within the thoracic cavity.

Management

Pain

Pain control is important in the management of any rib fracture. This is to ensure adequate ventilation and reduce work of breathing especially in conscious patients. Choices of analgesia depend on the severity and surgeons judgement. NSAIDs and opiate may help in most cases although occasionally, a stronger opioid (morphine) or an epidural may be needed.

Ventilation

Flail chest causes paradoxical movement of the chest which leads to hypoxia and increase work of breathing. Oxygen therapy should be administered to all patients with evidence of inadequate ventilation. The option of therapy depends on the severity of the injuries. This includes non-invasive therapy (CPAP), and mechanical ventilation.

SPO2 and arterial blood gases (ABG) should be monitored closely and treatment is stepped up if required.

Fluid management

Intravenous fluid should be administered judiciously in flail chest and contusions. This is to prevent pulmonary oedema which will cause worsening of the current state.

Rib deformity

Any fracture or deformity will cause pain upon movement and friction. This will lead to increased work of breathing and inadequate ventilation. Without treatment, the patient will be exhausted and may develop respiratory failure. Rib fixation is used in to stabilise the deformity and improve the morbidity. However, the routine use remains debatable due to cost and efficacy. In Malaysia, rib fixation is still new and uncommon procedure.

Caveats:

  • Chest physiotherapy plays a big role in any thoracic trauma.
  • Any polytrauma may worsen the condition.
  • A fracture ribs especially the 1st and 2nd signify a high impact mechanism. The patient should be assessed for other concomitant injuries.

More reading on thoracic trauma here

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