Serial chest computed tomography imaging in a freediver with a case of pulmonary barotrauma of descent (lung squeeze) showing the time course of resolution.

Freedivers can suffer respiratory symptoms indicative of freediving induced pulmonary syndrome (FIPS). Aetiology includes immersion pulmonary oedema and barotrauma of descent in the tracheobronchial or pulmonary parenchyma, also colloquially called 'squeeze'. The pathophysiology and natural history are still largely unknown. This case report describes a freediver who developed haemoptysis following a 49 m personal best constant weight bi-fin dive, presenting with two episodes of haemoptysis within 24 hours post-dive. This style of diving entails finning down to the desired depth, turning with a single pull on the rope, and then finning up to the surface without use of the arms. The diver exhibited no other symptoms and remained haemodynamically stable. Computed tomography (CT) imaging performed two days post-dive showed ground-glass opacities in the right upper and middle lobes. Treatment involved hospitalisation, high-dose corticosteroids, and antibiotics. Follow-up CT scans post-dive revealed almost complete resolution (six days) followed by complete resolution of pulmonary abnormalities (21 days). This case is unique for its documentation of changes in lung findings over three sequential CT scans, providing a timeline of anatomical recovery. Serial CT scanning would not be routinely recommended from a radiation safety perspective but yielded interesting data into the time course of this trauma. The findings raise questions about the underdiagnosis of squeeze injuries, as this diver displayed minimal symptoms despite radiographic evidence of ground-glass opacities. This case highlights the need for standardised imaging and management protocols, as well as further research into the natural history and clinical significance of FIPS.