Central venous pressure in space.
Buckey, Jay C., Jr, F. Andrew Gaffney, Lynda D. Lane, Benjamin D.
Levine, Donald E. Watenpaugh, Sheryl J. Wright, Clyde W. Yancy, Jr.,
Dan Meyer, and C. Gunnar Blomqvist.
Departments of Internal Medicine and Physiology, Division of
Cardiology, University of Texas Southwestern Medical Center, Dallas,
Texas
APStracts 2:0302A, 1995.
Gravity affects cardiac filling pressure and intravascular fluid
distribution significantly. A major central fluid shift occurs when
all hydrostatic gradients are abolished on entry into microgravity
([mu]G). Understanding the dynamics of this shift requires continuous
monitoring of cardiac filling pressure; central venous pressure (CVP)
measurement is the only feasible means of accomplishing this. We
directly measured CVP in three subjects; one aboard the Spacelab Life
Sciences-One Space Shuttle flight and two aboard the Spacelab Life
Sciences-Two Space Shuttle flight. Continuous CVP measurements, using
a 4 fr. catheter, began 4 hours before launch and continued into
[mu]G. Mean CVP was 8.4 cmH2O seated before flight, 15.0 cmH2O in the
supine, legs elevated posture in the Shuttle, and 2.5 cmH2O after 10
minutes in microgravity. Although CVP decreased, left ventricular end
diastolic dimension measured by echocardiography increased from a
mean of 4.60 cm supine preflight to 4.97 cm within 48 hours in
microgravity. These data are consistent with increased cardiac
filling early in microgravity despite a fall in CVP, suggesting that
the relationship between central venous pressure and actual
transmural left ventricular filling pressure is altered in
microgravity.
Received 23 December 1994; accepted in final form 30 May 1995.
APS Manuscript Number A1309-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.