Pulmonary barotraumaJoe Segen2016-11-17T08:03:53+00:00
A term of art referring to alveolar rupture due to elevated transalveolar pressure–defined as alveolar pressure minus the pressure in the adjacent interstitial space.
Pulmonary barotrauma formerly occurred in up to 10% of patients undergoing mechanical ventilation, a rate which is lower as low tidal volume mechanical ventilation has become the standard of care.
Consequences of pulmonary barotrauma Pneumothorax, pneumomediastinum, pneumoperitoneum, subcutaneous emphysema
Life-threatening barotrauma* may affect in scuba and deep sea divers, due to breath holding during ascent.
*Tissue injury resulting from the failure of a gas-filled body space–e.g., the lungs, middle ear, sinuses to equalize its internal pressure to correspond to changes in ambient pressure
Clinical findings Mediastinal and subcutaneous emphysema produces changes in voice, dysphagia, and supraclavicular crepitus, typical findings on chest and neck films*.
*Nonbranching, fixed-caliber radiolucencies radiating from the hilum to the periphery, air in interlobular septa suggestive of pulmonary interstitial emphysema or subpleural air cysts. Pneumomediastinum outlines the great vessels—superior vena cava and left subclavian, common carotid, and innominate arteries; pneumopericardium causes outlining of the pericardium and contiguous diaphragm.Pneumothorax may cause abrupt pain, dyspnoea
Sequelae Arterial air embolism caused by passage of gas into pulmonary veins and thence to the systemic circulation; gas bubbles lodged in small arteries may occlude segments of the cerebral, coronary, and other systemic vascular beds, resulting in a stroke-like syndrome ranging from mild neurologic defects to collapse, unconsciousness, and death once the diver surfaces