35 year-old male unrestrained driver following motor vehicle crash presents with blunt chest injury. There are multiple injuries on CXR (can you find them all?), but what's up with his right lung?
Answer: Pulmonary contusion
Blunt chest trauma may result in pulmonary contusion, a parenchymal lung injury resulting in blood and edema within the alveolar spaces.
The pathophysiologic effects result in reduced lung compliance and gas exchange (i.e., dead space ventilation and/or shunting), increased risk of ARDS, and increased pulmonary vascular resistance. The full pathophysiologic effects may take up to 48 hours to develop. Resolution usually occurs within 3-5 days.
Diagnosis is typically made on CXR, although early CXR may underestimate the severity of injury. CT scan is much more sensitive for diagnosis (see green arrows below).
Management is supportive and requires strict attention to oxygenation. Positive pressure ventilation is occasionally required for respiratory failure and is sometimes recommended prophylactically for elderly patients, because their pulmonary status can rapidly decline secondary to their reduced lung reserve.
Aggressive control of chest wall pain is also required. Pain reduces both the frequency and depth of respirations leading to atelectasis, a reduction in mucus clearance, and an increased risk of pneumonia. Analgesia should be administered systemically, by epidural, or by local nerve block at the level of injury.
Lively, M. Pulmonary contusion in a collegiate diver: a case report. J Med Case Rep. 2011 Aug 10;5:362.
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