title: Sonographic detection of pneumothorax and hemothorax in microgravity.
abstract: BACKGROUND
  An intrathoracic injury may be disastrous to a crew-member aboard the International Space Station (ISS) if the diagnosis is missed or delayed. Symptomatic or clinically suspicious thoracic trauma is treated as a surgical emergency on Earth, usually with immediate stabilization and rapid transport to a facility that is able to deliver the appropriate medical care. A similar approach is planned for the ISS; however, an unnecessary evacuation would cause a significant mission impact and an exorbitant expense.
  
  
  OBJECTIVE
  The use of ultrasound imaging for the detection of pneumothorax and hemothorax in microgravity is both possible and practical.
  
  
  METHODS
  Sonography was performed on anesthetized pigs in a ground-based laboratory (n = 4) and microgravity conditions (0 G) during parabolic flight (n = 4). Aliquots of air (50-500 ml) or saline (10-200 ml) were introduced into the pleural space to simulate pneumothorax and hemothorax, respectively.
  
  
  RESULTS
  The presence of "lung sliding" excluded pnemothorax. In microgravity, a loss of "lung sliding" was noted simultaneously in the anterior and posterior sonographic windows after 100 ml of air was introduced into the chest, indicating pneumothorax. The presence of the fluid layer in simulated hemothorax was noted in the anterior and posterior sonographic windows after 50 ml of fluid was injected into the pleural space. During the microgravity phase, the intrapleural fluid rapidly redistributed so that it could be detected using either anterior or posterior sonographic windows.
  
  
  CONCLUSIONS
  Modest to severe pneumothorax and hemothorax can be diagnosed using ultrasound in microgravity.
authors.affiliation: Wyle Laboratories, Houston, TX 77058, USA. dhamilton@wylehou.com
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Hamilton
authors.forename: Ashot E
authors.initials: AE
authors.lastname: Sargsyan
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Kirkpatrick
authors.forename: Savvas
authors.initials: S
authors.lastname: Nicolaou
authors.forename: Mark
authors.initials: M
authors.lastname: Campbell
authors.forename: David L
authors.initials: DL
authors.lastname: Dawson
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Melton
authors.forename: George
authors.initials: G
authors.lastname: Beck
authors.forename: Terry
authors.initials: T
authors.lastname: Guess
authors.forename: Jack
authors.initials: J
authors.lastname: Rasbury
authors.forename: Scott A
authors.initials: SA
authors.lastname: Dulchavsky
mesh_terms: D000818:Animals; D005260:Female; D006491:Hemothorax / Q000000981:diagnostic imaging*; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D013026:Space Flight; D013552:Swine; D014463:Ultrasonography; D014893:Weightlessness