A 47-year-old man is brought by ambulance from the scene of a bus bombing in respiratory distress. His examination is significant for many minor abrasions, partial thickness burns on the extremities, dyspnea, poor air movement, dullness to percussion bilaterally, and a superficial crackling sensation noted on palpation of the chest. His chest x-ray shows subcutaneous emphysema and bilateral patchy infiltrates in a butterfly pattern. After intubation, management of his pulmonary injuries should include:
Hyperbaric oxygen treatment.
+Aggressive positive end-tidal expiratory pressure for alveolar recruitment.
+Intravenous corticosteroids to reduce secondary inflammatory lung injury.
+Extracorporeal membrane oxygenation.
+Permissive hypercapnia with reduced tidal volumes and peak inspiratory pressures.
The patient has sustained blast lung injury (BLI). BLI occurs as part of a spectrum of overpressure injuries of which the hollow, air-containing organs are especially susceptible. The traumatic process of compression and expansion disrupts alveolar membranes and interalveolar septa resulting in separation of lung parenchyma from the vascular structures. The subsequent hemorrhage from the distal vasculature tree results in ventilation–perfusion mismatch and reduced lung compliance. The clinical picture is not dissimilar to ARDS or pulmonary contusion. Additional complications, including hemopneumothorax, pneumomediastinum, subcutaneous emphysema, air emboli, and foreign body impaction often accompany and complicate BLI. Recent successes have been found by utilizing permissive hypercapnea and limiting peak inspiratory pressures. Additional treatment modalities include prophylactic bilateral chest tubes and early attempts to stimulate spontaneous breathing with intermittent mechanic ventilation and continuous positive airway pressure.