What is the diagnosis?

This patient is diagnosed with flail chest. It is largely a clinical diagnosis based on the classic paradoxical chest movements that result when multiple ribs are broken in two or more places [1].

Image 2: Plain radiograph of the chest. Annotation by author. (Case courtesy of Ian Bickle, Radiopaedia.org, rID: 37961)

What is the mechanism of injury?

It occurs most commonly due to significant blunt trauma, such as motor vehicle accidents, although falls in osteoporotic and elderly patients is another mechanism [1]. In addition to impaired generation of negative intrathoracic pressure, pulmonary contusions caused by the injury can also impede oxygenation and ventilation [1]. 

• Pearl: Patients can have worsening respiratory distress due to decreased inspiratory effort as a direct result of the pain from the fractures [1]. Reminder to treat their pain! 

What physical exam findings are expected?

On examination, patients will present with increased respiratory rate and work of breathing. Patients are frequently hypoxic and require supplemental oxygen [2]. On the side of the rib fractures, you will notice paradoxical movement of the chest wall during respiration, as the chest wall will move inward during inspiration and outward during expiration. Many patients also present with chest wall ecchymosis on gross examination [1,2]. 

• Pearl: Pay attention to breath sounds! Hemothoraces and pneumothoraces can be seen with this injury. 

• Pearl: The paradoxical movement seen in this injury affects the negative intrathoracic pressure required during inspiration, causing increased work of breathing.

Which imaging modalities can be used?

Plain radiographs of the chest should be ordered for initial assessment and evaluation of hemothorax and pneumothorax. However, chest x-ray is less sensitive than CT for diagnosis of rib fractures and flail chest (Image 3) [2].

Image 3:  CT chest image that demonstrates multiple overlying depressed right rib fractures (1st - 9th) with subcutaneous emphysema. Extensive right pulmonary contusion is seen. Case courtesy of RMH Core Conditions, Radiopaedia.org, rID: 26294)

What is the management in the ED?

These patients present with severe respiratory distress and should be placed on supplemental oxygen. Severe cases will require positive pressure ventilation and possible intubation [1]. Analgesics should also be administered. These patients should be admitted for further monitoring and management. 

• Pearl: Surgical fixation in flail chest is uncommon, but may be required depending on degree of bony and pulmonary injury [3]. In some studies, surgery within the first 48 hours resulted in a shorter ICU stay, shorter invasive ventilatory period, decreased risk of pneumonia, and shorter overall hospital stay [3, 4].

When do you consult Orthopedics?

Most of these patients will be managed and admitted by trauma surgery. Orthopedics can be consulted in conjunction with the trauma surgery team as these patients generally have multiple injuries.