Rare pulmonary barotrauma after explosive decompression: a case report

Abstract

Background Pneumothorax as a consequence of pulmonary barotrauma during explosive decompression military crew training in a hypobaric chamber is an extremely rare and sparsely diagnosed complication. Extensive bilateral tissue damage is even more unexpected. Case presentation A 26-year-old active duty Air Force pilot was performing an explosive decompression simulation from 8000 ft. (2438.4 m) to 25,000 ft. (7620 m) in a 1.5 s interval. The training was interrupted due to the pilot’s apparent health complications. After transfer to the emergency department, a CT scan showed bilateral lung barotrauma with emphysema. Conclusions The case report shows extensive emphysema and pneumothorax after a rapid decompression done for training purposes. It is a possible but rare complication. The cause remains unclear, with suspicion of a predisposed lung disease.

Characterizing candidate decompression rates for hypobaric hypoxic stunning of pigs. Part 2: Pathological consequences

“…The damage to the nasal cavities including nasal conchae, frontal sinuses and cranium was consistent with lesion scores observed in birds which had undergone decompression at faster commercial rates than those conducted here and this damage was absent in birds killed by anesthetic overdose via intravenous injection of pentobarbital sodium (15). As already discussed here and in the poultry work, the timing of this damage is not known and evidence suggests that rapid recompression is associated with trauma in mammals rather than gradual decompression (27)(28)(29)(30). However, given the unknowns about when damage is occurring and the known vulnerability of pigs to suffer from respiratory problems it is important to be prudent and assume there could be the potential for welfare detriments.…”

“…However long hold times at low absolute vacuum and subsequent recompression may also affect pathological outcomes. Rapid recompressions are associated with more trauma to mammals, including humans (27)(28)(29)(30). Even though neurophysiological measurements indicated that the pigs were in a non-recoverable state upon recompression further damage to tissue by expediting this process could have negative effects on meat quality.…”

“…Encouragingly, studies in poultry have demonstrated that LAPS has no detrimental impact on meat quality (21)(22)(23) and that there is no compromise to organ integrity (15), but these effects are likely to be species specific and the rate of decompression as well as the final vacuum pressure is crucial for mitigating pathological and clinical issues (24)(25)(26). In humans, slow rates of decompression may be associated with clinical signs such as tooth and middle ear pain, abdominal discomfort and joint pain but these are more common with descent of aircraft than ascent (27)(28)(29)(30). Commercial LAPS for poultry achieves an absolute vacuum pressure of ∼20 kPa, which means ebullism is highly unlikely to occur (11,31), and it should be noted that in birds, gases are unlikely to be trapped in the lungs or abdomen during LAPS because of the unique anatomic structure of the avian respiratory system (32).…”