Definition

The ribcage is made up of twelve pairs of curved bones that extend from the spine to the front of the chest. It forms a protective cage for vital organs such as the lungs and heart. Trauma or severe injuries, such as falls from heights or car accidents, can result in rib fractures.

Flail chest, a distinct rib fracture type, involves three or more consecutive ribs breaking in at least two places, creating a disconnected segment of the rib. This results in a visibly disjointed chest wall that appears to float, particularly during inhalation and exhalation, significantly compromising breathing. Flail chest typically stems from severe blunt force impact to the chest and constitutes a life-threatening emergency due to potential severe lung injury.

While rare, flail chest has profound effects on breathing and poses significant health risks when it occurs.

Causes

Blunt chest wall trauma stands as a common instigator of flail chest. Termed as such due to its genesis from the impact of blunt or flat objects upon the chest wall, it induces rib fractures that detach from the chest wall, rendering it unstable and seemingly "floating."

Roadway accidents constitute a frequent milieu for chest trauma occurrences, ranging from minor bruises to rib fractures of varying severity. These incidents typically involve blunt or flat objects, like steering wheels, colliding with the chest wall sans skin penetration. Flail chest can also stem from activities such as CPR or accidents like animal kicks in sports or animal-involved endeavors.

Additionally, falls from significant heights exceeding 8-10 feet and participation in contact sports like football, rugby, or hockey may precipitate flail chest. Certain predisposing factors, including specific bone diseases, age-related bone degradation, or select cancer types, heighten susceptibility to this condition.

Rib fractures engendered by blunt trauma often manifest excruciating pain and can provoke additional injuries, such as punctured lungs or compromised blood vessels due to bone fractures. Consequently, a flail chest is regarded as the most severe consequence of blunt trauma to the chest wall.

Risk factor

The risk factors for flail chest align with those for trauma in general, given its genesis from injury. These factors include:

• Male gender and substance abuse/misuse rank among the most prevalent risk factors.
• Motor vehicle collisions contribute to 75% of trauma leading to flail chest.
• Falls, notably among the elderly demographic, constitute 15% of cases.
• Specific occurrences such as direct blows to the chest are more predisposed to causing two distinct rib fractures.
• Roll-over and crush injuries predominantly result in single-point rib fractures, thus seldom resulting in flail chest.
• Metabolic bone diseases and conditions like osteogenesis imperfecta during childhood amplify susceptibility.
• The elderly demographic is particularly vulnerable to flail chest due to chest wall rigidity stemming from aging and osteoporosis. Moreover, this group often presents a history of lung ailments, heightening the risk of flail chest complications.

Elderly individuals are more susceptible to flail chest, facing more pronounced complications. In contrast, flail chest occurrences in children are rare owing to their intact chest wall elasticity. Should a child encounter a flail chest, it signals an exceptionally severe trauma necessitating meticulous examination and care.

Symptoms

The symptoms of flail chest can vary depending on the severity of the injury. If you've sustained a severe chest injury, be vigilant for the following symptoms:

• Intense chest pain
• Tenderness in the chest area where the ribs are fractured
• Difficulty breathing
• Bruising
• Irregular movement of the chest wall during breathing

A hallmark indication of flail chest is the uneven movement of the chest between the separated segment and other regions. During inhalation, the injured section of the chest may retract inward while other areas expand outward. Conversely, the injured portion may protrude outward during exhalation while other areas contract inward.

Diagnosis

To diagnose flail chest, the physician conducts a physical examination akin to assessing other rib fractures. If irregular chest wall movements are noted during breathing, it suggests flail chest.

Subsequently, a chest X-ray is typically recommended to corroborate the diagnosis gleaned from the physical examination. While some rib fractures may not be discernible on standard X-rays, severe blunt trauma injuries like flail chest often manifest in multiple points. Multiple X-rays may be necessary to evaluate the extent of the injury comprehensively.

Management

Given its severity, prompt treatment of flail chest is imperative. In initial management, it is paramount to ensure the patient's ability to breathe adequately while safeguarding lung function. Vital signs are monitored, and oxygen therapy via a mask is administered to facilitate breathing. Pain management medications are also provided.

In severe instances accompanied by lung injury, mechanical ventilation might be necessary to stabilize the chest cavity. Depending on the extent of the injury and the associated risks and benefits, surgical intervention may be warranted.

Complications

There is a greater risk of long-term disability in individuals who experience flail chest. Other long-term issues include persistent chest wall pain, changes in chest shape, and shortness of breath after activity. In some cases, lung function may return to normal despite abnormalities in the chest.

If rib fractures puncture the lungs or blood vessels, more severe and life-threatening complications can arise.

Prevention

The prevention of flail chest involves avoiding factors that increase the risk of chest injury, such as:

• Handling vehicles carefully, using seat belts while driving, and adhering to traffic regulations.
• Avoid the use of illicit drugs, alcohol, or medications that cause drowsiness before driving.
• Providing a safe environment for the elderly to prevent falls, such as non-slip and step-free floors and installing handrails.
• Avoid fights or sports that involve blows to the chest area.
• Promptly consult a doctor if you have a condition that may affect your ribs.
• Regular medical check-ups for the elderly with a history of lung disease.
• Immediate management of flail chest cases can prevent worsening and complications leading to death.

When to see a doctor? 

If you experience the signs and symptoms mentioned above after sustaining an injury or blow to the chest area, seek assistance immediately. First aid is administered, and then the patient is taken to the emergency unit for further treatment.

Perera TB, King KC. (2021). Flail chest. StatPearls Publishing. Retrieved 16 February 2022, from https://www.ncbi.nlm.nih.gov/books/NBK534090/