Flail Chest Flashcards
What is flail chest?
A flail chest occurs when a segment of the thoracic cage is separated from the rest of the chest wall. This is usually defined as at least two fractures per rib (producing a free segment), in at least two ribs. A segment of the chest wall that is flail is unable to contribute to lung expansion. Large flail segments will involve a much greater proportion of the chest wall and may extend bilaterally or involve the sternum. In these cases the disruption of normal pulmonary mechanics may be large enough to require mechanical ventilation.
Multiple rib fractures will often be associated with an underlying _______.
pulmonary contusion
which may not be immediately apparent on an initial chest X-ray
Fractures of the lower ribs may be associated with ___, ___, or ____ injuries.
diaphragmatic tears and spleen or liver injuries.
Injuries to upper ribs are less commonly associated with injuries to _____.
adjacent great vessels.
This is especially true of a first rib fracture, which requires a significant amount of force to break and indicates a major energy transfer. A fracture of the first rib should prompt a careful search for other injuries
Note also that the rib cage and sternum provide a significant amount of stability to the thoracic spine.
Severe disruption of this ‘fourth column’ may convert what would otherwise be a stable thoracic spine fracture into an unstable one.
How do we manage flail chest?
The main significance of a flail chest however is that it indicates the presence of an underlying pulmonary contusion. In most cases it is the severity and extent of the lung injury that determines the clinical course and requirement for mechanical ventilation. Thus the management of flail chest consists of standard management of the rib fractures and of the pulmonay contusions underneath.
Most significant chest wall injuries will be identified by physical examination. Bruising, grazes or seat-belt signs are visible on inspection, and palpation may reveal the crepitus associated with broken ribs. Awake patients will complain of pain on palpation of the chest wall or on inspiration.
A flail chest is identified as paradoxical movement of a segment of the chest wall - ie indrawing on inspiration and moving outwards on expiration. This is often better appreciated by palpation than by inspection.
Management of chest wall injury is directed towards protecting the underlying lung and allowing adequate oxygenation, ventilation and pulmonary toilet.
This strategy is aimed at preventing the development of pneumonia, which is the most common complication of chest wall injury.
Note that while a young fit patient will easily manage one or two rib fractures with simple analgesia,
the same injury in an elderly patient is regarded as major and will frequently lead to pneumonia and respiratory failure if not appropriately managed (and even then).
What should you do initially when you suspect a chest wall injury?
All patients should initially be placed on 100% oxygen via a non-rebreathing facemask.
