(See also Overview of Thoracic Trauma.)
Pulmonary contusion is a common and potentially lethal chest injury that results from significant blunt or penetrating chest trauma. Patients may have associated rib fracture, pneumothorax, or other chest injuries. Larger contusions can impair oxygenation. Late complications include pneumonia and sometimes acute respiratory distress syndrome (ARDS).
Symptoms of pulmonary contusion include pain (mainly due to injury to the overlying chest wall) and sometimes dyspnea. The chest wall is tender; other physical findings are those of any associated injuries.
Diagnosis
Pulmonary contusion should be suspected when respiratory distress develops after chest trauma, particularly when symptoms worsen gradually. Chest x-ray is typically done, along with pulse oximetry. Contusions cause opacification of affected lung tissue on imaging, but opacification may not be apparent for 24 to 48 hours because opacification increases with time. CT is highly sensitive but is usually done only when other injuries are also under consideration.
Patients should be monitored for respiratory failure with serial clinical assessments and pulse oximetry. If hypoxemia or dyspnea is noted, capnometry or arterial blood gas measurement is indicated.
Treatment
Analgesics are given as needed to facilitate deep respirations in patients with pulmonary contusions. Supplemental oxygen (O2) is given for mild hypoxemia (SaO2 91 to 94%). Usual indications for mechanical ventilation are moderate or severe hypoxemia (usually PaO2 < 65 or SaO2 < 90% while breathing room air) and hypercarbia. Patients with chronic obstructive pulmonary disease (COPD) or chronic kidney disease are at increased risk of the need for mechanical ventilation.
