Radiologic signs of barotrauma.

An otherwise healthy 22-year-old woman was admitted to our burn intensive care unit with deep dermal flame burns of upper limbs, thorax, neck, and head because of a civil-bus deflagrating crash. Fibrobronchoscopy revealed carbon particles attached to the injured mucous membrane of main trachea, confirming the presence of inhalation injury. She was intubated and supported by mechanical ventilation with synchronized intermittent mandatory ventilation mode. Fluid replacement therapy based on a burn formula was performed. During the first 24 hours after admission, her blood pressure was maintained within normal range; however, blood oxygen saturation remained at relatively low levels. Subsequent chest radiography disclosed a right-sited pneumatocele 8 cm in diameter (Fig. 1, large white arrow) associated with right pneumothorax (Fig. 1, small white arrowheads point out “pneumothorax line” of compressed right lung) and left-sided emphysema (Fig. 1, black arrow). It was noticed that lung damage was located mainly in the lower lobes of both lung and that the lesions of the right lung were more severe than those of the left, suggesting that the right lung was exposed to greater barotrauma, because, anatomically, the right main bronchus forms a lesser angle with the trachea than does the left main bronchus, which allows airflow to go through more smoothly to the right bronchus segments. Decreased chest wall compliance can contribute to hyperinflation of the lower lobes as a result of abdominal compensation.1 An emergency thoracic escharotomy was performed to allow the thoracic cage to increase in size with inhalation, following which the tidal volume was lowered from 10 mL/kg to 8 mL/kg. A right percutaneous tube thoracostomy was placed and continuous negative pressure aspiration applied. Her blood oxygen saturation then returned to normal levels. The radiographic features mentioned above disappeared in 3 days without recurrence in a 3-month follow-up study. Her inhalation injury also healed by repeated airway flushing and local use of basic fibroblast growth factor2 through a fibrobronchoscope, and by local and systemic use of mucosolvan (ambroxol).3 Pneumatocele and pneumothorax are not common manifestations of smoke inhalation unless there is a secondary complication, whereas patients exposed to relatively high airway pressure may be at greater risk for developing barotrauma or volutrauma. The radiologic signs of barotrauma can be produced by sufficiently high inspiratory pressures, even in the absence of decreased chest wall compliance.