Post-Traumatic Abnormal Breathing Pattern

Correct answer: B. Intercostal pulmonary herniation.

In this case, the ability to be freely mobile implies that the protrusion is a herniation. Since there is no pain or gangrene, we know that the hernia is not incarcerated and instead reduces as shown in the video.

Flail chest is a condition where multiple adjacent ribs have at least two fractures each, causing a chest segment to move paradoxically.¹ This answer can be eliminated because as shown in the video, the chest wall is not moving paradoxically but rather in sync with the lung movement.

The protrusion varies in rhythm to the respiratory cycle, so roughly 14-16 times/min. As it does not align with the cardiac cycle, we can further eliminate cardiac issues as a potential cause.

Subcutaneous emphysema is a condition where air becomes trapped under the skin.² It can be clearly diagnosed via a CT scan, but by physical observation it is identified via symptoms such as swelling, neck and chest pain, or breathing difficulties. In a large pneumothorax, the air trapped in the extra-pulmonary space may expand and slightly retract, but not to this degree. In this video, the protrusion both retracts and expands dramatically which is not consistent with the signs of a subcutaneous emphysema or a tension pneumothorax.

Treatment and management. As this patient did not experience pain and was not at risk for the hernia worsening, a conservative treatment approach was preferred over more invasive options. The drainage of blood via the chest tube reduced the pressure in the thoracic cavity and allowed the lung to naturally reposition itself properly.

Outcome and follow-up. The chest tube was removed successfully after a week of improved breathing. The patient was discharged to a rehab facility and made a full recovery.

Discussion. Intercostal pulmonary herniations are rare phenomena first classified by Morel-Lavallée in 1847.³ Roughly 80% of cases are acquired, either due to pathological, spontaneous, or traumatic incidents.^4,5 They are commonly associated with chest pain and dyspnea,⁵ but it is not uncommon for less severe cases to present as asymptomatic. The best way to identify a pulmonary herniation is a CT scan,⁶ which gives more accurate information about location and severity than other imaging techniques.

Ideally, these herniations are treated non-surgically with pain medications or chest tubes.⁷ In more urgent cases such as those at risk of growth, sepsis, or tissue strangulation, surgical intervention is required.⁸ Surgical intervention includes, but is not limited to, mesh placements or approximating sutures.

Pulmonary herniations are incredibly rare occurrences with minimal literature published. They most often arise after thoracic trauma. Guidelines for treatment require further evaluation to establish when conservative or surgical management should be preferred. We advocate for a conservative approach, and believe that with better diagnostic and treatment criteria, surgical intervention would be less necessary.