Health Encyclopedia

Flail Chest

What is Flail Chest?

Flail chest describes a situation in which a portion of the rib cage is separated from the rest of the chest wall, usually due to a severe blunt trauma, such as a serious fall or a car accident. This affected portion is unable to contribute to expansion of the lungs, which creates some obvious problems for the patient (hampered breathing) and can contribute to some not-so-obvious ones. Flail chest is a serious condition that can lead to long-term disability and even death.

When facing someone with flail chest, the goal of emergency room personnel is to stabilize the chest wall, followed by identification and treatment of all injuries in and around the chest. The significance of flail chest is it suggests the presence of underlying cuts and bruises on the lungs. After all, broken ribs have pointed, sharp or jagged edges. The injured ribs probably were knocked out of place and possibly against or into the lungs by the trauma. And proper breathing, of course, remains a critical consideration.

The Mechanics of Flail Chest

For a person to draw a breath, the muscles around the rib cage and the diaphragm have to move to expand the chest cavity. This creates a vacuum that is filled as air enters the lungs. If this expansion is hindered, the ability to draw air into the lungs is diminished. A flail chest is a chest in which sections of broken ribs are isolated from, and interfering with, normal chest movements. That means the chest cannot expand properly and cannot properly draw air into the lungs.This is why stabilization after blunt trauma is important. Not only are the ribs themselves in need of attention, but their condition, position and inability to function properly is causing other, potentially more serious matters that must be addressed quickly. Doctors agree that it is the potential underlying injury to the lungs, and not the flail chest segment itself, that is the most pressing and life-threatening concern.

Symptoms of Flail Chest

The strict requirement for a diagnosis of flail chest—at least three ribs close together broken in two or more places—can be confirmed only by taking an x-ray. But all other significant symptoms can be observed through a simple physical exam.The most telling symptom is paradoxical movement of a portion of the chest wall—that is, the affected area draws in when the patient breathes in and the rest of the chest expands, and the affected area moves outwards as the patient exhales and the rest of the chest contracts. Paradoxical movement is an obvious sign that the portion of the chest wall is not assisting with the breathing function.

Other symptoms of flail chest can include:

  • Bruises, grazes, and/or discoloration in the chest area
  • Telltale markings from a seat belt
  • Chest pain
  • Difficulty drawing breath

Causes of Flail Chest

Flail chest is almost always linked to severe blunt trauma, such as a serious fall or car accident, in terms of cause. But it can develop as a result of less severe impacts. There are cases of flail chest occurring as a result of bone disease or deterioration in older patients, but these are very rare.

Diagnosing Flail Chest

Flail chest is identified using a chest x-ray. Doctors look for evidence in the condition of the ribs themselves, but some fractures are not easily seen. So they also look at the surrounding organs and structures. A punctured blood vessel or contusions on the lungs, for example, are solid indications of flail chest.

It might be necessary to take several chest x-rays to fully examine all damage to the chest area. CT (computed tomography) scans have been found to provide very little additional useful information for initial evaluations of chest wall injuries.

Treating Flail Chest

Treatment of flail chest has changed over the years. Doctors today have a good understanding of the secondary influence of flail chest on respiratory failure and survival, compared to the more significant influence of actual injuries to the lungs (such as pulmonary contusions) on those critical outcomes. Management of chest wall injuries is now directed more toward protecting the underlying lungs. Doctors also want to prevent the onset of pneumonia, which is the most common complication of flail chest.

All patients are immediately placed on 100% oxygen using a facemask. Doctors might intubate or insert a chest tube as part of critical care. Stabilization treatment options include:

  • Mechanical ventilation to achieve chest cavity stabilization is the standard treatment for patients with both flail chest and lung damage. This treatment has a demonstrated ability to reduce mortality rates, but the possibility of developing pneumonia increases the longer it is in place. Mechanical ventilation might also be employed in severe cases where the chest cavity is unstable and threatens to collapse, or where head or abdomen injuries require its use anyway. But for most chest flail cases that are less complicated, or do not significantly involve the lungs, it is considered unnecessary.
  • Corrective surgery currently elicits varying opinions from doctors about its advisability. Usually it is recommended on a case-by-case basis. There are issues concerning effectiveness and timing for patients on mechanical ventilation. Patients requiring prolonged ventilation may not be good candidates for early surgical stabilization. On the other hand, patients whose dependence on the ventilator doesn’t diminish even after lung injuries begin to heal might be good surgery candidates.
  • Analgesic pain medications are a common treatment for flail chest and other rib injuries. Opioid pain medications in high does can produce respiratory depression, especially in the elderly, although they can be helpful at lesser doses. Ideally, the patient will receive a local anesthetic medication via an epidural.

The Good Old Days?
Treatments for flail chest and other chest wall injuries have come a long way. It wasn’t that long ago that patients were taped up, or propped up with sand bags, or subjected to “fracture fixation,” in which a series of external rods and braces were used to force the affected area outwards. There isn’t much of that going on today. Now doctors have modern, improved treatments for flail chest.



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