5.4 : Flail Chest-I

Overview of Flail Chest

Flail chest is a severe and potentially life-threatening condition characterized by the fracture of three or more adjacent ribs in multiple places. It is most commonly caused by direct impacts and trauma, such as motor vehicle accidents or injuries from a steering wheel impact. It can also occur due to falls in elderly individuals with osteoporosis, or assaults involving sharp objects.

Pathophysiology

The pathophysiology of flail chest is complex, involving fractures of the ribs, costal cartilage, or sternum, leading to an unstable chest wall. This instability results in paradoxical breathing movement, significantly impairing normal respiratory function. During inspiration, the diaphragm's downward movement creates negative pressure that exacerbates the inward movement of the flail segment, reducing ventilation efficiency. Conversely, during expiration, the flail segment moves outward, impeding exhalation.

Clinical Manifestations

Patients with flail chest may experience:

• Chest Pain: Ongoing due to the fractures and movement of the chest wall.
• Dyspnea: Difficulty breathing caused by compromised lung expansion.
• Hypoxemia: Low oxygen levels in the blood.
• Tachypnea: Rapid breathing as the body attempts to compensate for reduced lung function.
• Compromised Gas Exchange and Increased Dead Space: Ventilated areas not involved in gas exchange increase, leading to inefficient oxygen delivery.
• Cyanosis: The skin appears bluish, discolored due to poor oxygenation in the blood.

Complications

Severe cases of flail chest can lead to:

• Crepitus: A grating or crackling sound or sensation produced by the fractured bone ends rubbing against each other.
• Pneumothorax: Accumulation of air in the pleural space due to chest wall instability.
• Poor Tissue Perfusion and Metabolic Acidosis: Reduced cardiac output can lead to these conditions.
• Atelectasis: Collapsed lung tissue, further complicating respiratory efforts.
• Infection Risk: This is particularly significant if open fractures or the respiratory system is compromised for an extended period.