barotrauma: one construct, many systems

In critical-care medicine, barotrauma is injury that occurs when the pressure driving gas into the lungs overdistends and ruptures alveoli, letting air escape into the interstitium, mediastinum, or pleural space, a recognised hazard of mechanical ventilation. Macklin and Macklin's 1944 Malignant interstitial emphysema of the lungs and mediastinum traced the pathway by which alveolar rupture tracks along airway sheaths to produce pneumothorax and pneumomediastinum, and Slutsky and Ranieri's 2013 Ventilator-induced lung injury locates it within modern lung-protective ventilation. The referent is pressure-gradient tissue injury in the lung, the same construct a diver meets in a blocked sinus or ear, here produced by a ventilator rather than by depth.[1][2]

Unit

The transpulmonary or airway pressure gradient at which lung tissue fails

Recovery means

Air leaks resolve and tissue heals once the damaging pressure gradient is removed

Measured by

Recognised by pneumothorax, pneumomediastinum, or interstitial emphysema and related to peak and plateau airway pressures

In diving medicine, barotrauma is tissue injury that occurs when a gas-filled body space cannot equalise with changing ambient pressure, so the trapped gas expands or contracts and damages the surrounding tissue: the ears, sinuses, lungs, and mask space most often. Because a trapped gas volume varies inversely with pressure (Boyle's law), the steepest risk sits near the surface, and Diving and subaquatic medicine catalogues the ear, sinus, and pulmonary forms along with their management. It is the identical pressure-gradient injury construct seen on a ventilator, realised by a change in depth rather than by a machine, which is why pulmonary barotrauma of ascent mirrors ventilator-induced alveolar rupture.[3]

Unit

The pressure difference across a non-equalised gas space before tissue damage

Recovery means

Milder forms heal once equalisation is restored; pulmonary forms can need urgent care

Measured by

Diagnosed by the affected space (ear, sinus, lung) and graded against the pressure change left unequalised