Pathophysiology and management of the flail chest.

Flail chest occurs when a series of adjacent ribs are fractured in at least 2 places, anteriorly and posteriorly. This section of the chest wall becomes unstable and it moves inwards during spontaneous inspiration. The physiological impact of a flail chest depends on multiple factors, including the size of the flail segment, the intrathoracic pressure generated during spontaneous ventilation, and the associated damage to the lung and chest wall. Treatment varies with the severity of the physiologic impairment attributable to the flail segment itself. Immediate surgical fixation may decrease morbidity, but conservative treatment with positive pressure ventilation is preferred when multiple injuries to the intrathoracic organs are present.