54-year-old man is involved in a moderate-speed motor vehicle collision

pulmonary contusion

Educational Objective:

Recognize the clinical course of and causes for delayed respiratory failure after trauma.

Key Point:

Pulmonary contusions can occur in any type of thoracic trauma and can cause delayed noncardiogenic pulmonary edema.

Explanation:

Areas of lung opacification within roughly 6 hours of blunt chest trauma are diagnostic of pulmonary contusion, which is a bruise of the lung caused by thoracic trauma. Although it is classically described in the setting of flail chest, it can also occur with rib fractures without a flail segment or even (particularly in children) with chest trauma in the absence of fractures. Pulmonary contusion can lead to noncardiogenic pulmonary edema several hours after the preceding injury and is the most common chest injury that is potentially lethal.

CT is more sensitive than plain x-ray for detecting pulmonary contusion because it shows the fact that the lung remains inflated around the bleeding (see above CT image) and that the bleeding/contusion therefore must be located WITHIN the parenchyma, thus excluding a pneumothorax or hemothorax from the diagnosis 9this is similar to the concepts of a subdural versus epidural bleed in the brain). Treatment is primarily aimed at maintaining adequate ventilation and, if necessary, using mechanical ventilation. Overly aggressive fluid resuscitation in the emergency department worsens the clinical course of pulmonary contusion.

References:

American College of Surgeons Committee on Trauma. Advanced Trauma Life Support (ATLS) Student Course Manual. 10th ed., 2018.

Gross EA, Martel ML. Multiple trauma (chapter 33). In: Walls R, et al. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed., 2018:287-300.