Management of trauma and emergency surgery in space.

Trauma may cause morbidity or mortality in expeditionary spaceflight settings. Physiologic and mechanical changes related to microgravity may increase susceptibility to and complicate the management of injuries in spaceflight. Limited surgical experience in microgravity suggests that special apparatuses and techniques will be needed to maintain the stability of patients, surgeons, and equipment, and to control fluids. A prototype microgravity surgical workstation and suction unit and modifications of standard procedures were devised to address these needs. Using these devices and methods and selected surgical supplies during repeated 25-second intervals of microgravity generated by parabolic arc flight, the "ABCs" of trauma management, limb traction and immobilization, and minor surgical procedures were performed in flight and problems were identified. Convincing "qualification" of spaceflight surgical equipment and protocols will require evaluations in continuous microgravity. As on Earth, the major determinant of emergency surgical care in spaceflight may be the presence or absence of a well-trained surgeon.

Variability in measurements of pressure-volume curves in normal subjects.

Changes in lung elasticity as measured by the pressure-volume curve are used in clinical investigative studies to diagnose abnormalities in lung function and to evaluate changes in a patient either over time or with an acute intervention. To assess the intrinsic variability of parameters derived from this technique, 4 static deflation curves per day on 5 separate days during a 2-month period were constructed for 10 healthy adults. The pressure-volume data were fitted to the exponential equation: V = A-Be-KP. The coefficients of variation for maximal elastic recoil pressure, transpulmonary pressures at 90, 80, 70, and 60% total lung capacity, static expiratory compliance, and the constants A, B, and k were determined. No significant correlation was found between the variability of daily curves and that of curves performed on separate occasions. The natural log of the exponential constant showed the lowest coefficient of variation, indicating that this parameter is the most reproducible.