Flail Chest

Definition

• Flail chest is traditionally described as the paradoxical movement of a segment of chest wall caused by fractures of 3 or more ribs anteriorly and posteriorly within each rib

Aetiology

• If a rib is broken in two places, then the free-floating section will no longer be able to support the underlying lung or move with the usual expansion of the ribs.
• Such damage means the underlying lung will not expand or contract, and therefore not take part in gas exchange this is called a flail segment. The flail segment moves in the opposite direction to the rest of the chest wall: because of the ambient pressure in comparison to the pressure inside the lungs, it goes in while the rest of the chest is moving out, and vice versa. This so-called "paradoxical breathing" is painful and increases the work involved in breathing resulting in hypoventilation. There may also be underlying lung damage and bruising due to the trauma.

Associations

• Elderly but can be seen in children and all ages, Road traffic accidents
• Weakened bones: inherited conditions, osteoporosis, total sternectomy, and multiple myeloma

Investigations

• CXR is diagnostic or CT scan if unsure

Management

• ABCDE, Pain relief, Chest drain if needed
• May need intubation and ventilation usually needed.
• Surgical fixation can reduce the duration of ventilatory support
• Chest physiotherapy