Measurement of inferior vena cava diameter for evaluation of venous return in subjects on the 10th day of bed rest experiment

We evaluated the usefulness of measurements of the inferior vena cava (IVC) diameters on abdominal echograms as an indicator of changes of venous return in subjects with orthostatic intolerance (OI) induced by simulated microgravity. We performed a standing test and recorded the IVC diameters on abdominal echograms in 12 subjects placed on a 20-day 6 degree head-down tilting bed rest experiment. We found that different patterns of changes in IVC diameter occurred in the standing test on Day 10 of the experiment; in five subjects with a marginal decrease in pulse pressure, IVC diameters in the upright position were markedly decreased compared with those in the supine position. In five subjects with feelings of discomfort, the IVC diameters in the upright position distended or did not decrease from those in the supine position. These results suggested that the changes in IVC diameter on the standing test indicated the presence of various types of hemodynamic responses of OI caused by simulated microgravity. In this study we also evaluated changes in body-water compartments by conducting multi-frequency bioelectrical impedance analysis. Longitudinal data analysis showed that the total body water/fat-free mass and extracellular fluid/fat-free mass decreased during the experiment period and recovered thereafter, and that the intracellular fluid/fat-free mass decreased during the experiment. No significant difference in changes in body-water compartments was seen among subjects with different patterns of changes in IVC diameters.

[1]  H. Fukuoka,et al.  Effect of Bed Rest on the Intestinal Environment and Microflora in Healthy Young Men , 2003 .

[2]  Yasuo Kawakami,et al.  Resistance training during unweighting maintains muscle size and function in human calf. , 2003, Medicine and science in sports and exercise.

[3]  Victor A Convertino,et al.  Mechanisms of microgravity induced orthostatic intolerance: implications for effective countermeasures. , 2002, Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology.

[4]  Rong Zhang,et al.  Cardiovascular and sympathetic neural responses to handgrip and cold pressor stimuli in humans before, during and after spaceflight , 2002, The Journal of physiology.

[5]  Janice V Meck,et al.  Postspaceflight orthostatic hypotension occurs mostly in women and is predicted by low vascular resistance. , 2002, Journal of applied physiology.

[6]  D. Watenpaugh,et al.  Fluid volume control during short-term space flight and implications for human performance. , 2001, The Journal of experimental biology.

[7]  T. Fukunaga,et al.  Leg-press resistance training during 20 days of 6° head-down-tilt bed rest prevents muscle deconditioning , 2000, European Journal of Applied Physiology.

[8]  R. Seagrave,et al.  Human water, sodium, and calcium regulation during space flight and exercise. , 1999, Acta astronautica.

[9]  S. Kibira,et al.  Does Central Venous Pressure Reflect the Circulating Blood Volume for the Decrement of Compliance Just After Esophagectomy? , 2000, Surgery Today.

[10]  D. Robertson,et al.  The epidemic of orthostatic tachycardia and orthostatic intolerance. , 1999, The American journal of the medical sciences.

[11]  D F Doerr,et al.  Application of acute maximal exercise to protect orthostatic tolerance after simulated microgravity. , 1996, The American journal of physiology.

[12]  C. G. Blomqvist,et al.  Orthostatic intolerance after spaceflight. , 1996, Journal of applied physiology.

[13]  J I Leonard,et al.  Regulation of body fluid compartments during short-term spaceflight. , 1996, Journal of applied physiology.

[14]  E. Ritz,et al.  Vena cava diameter measurement for estimation of dry weight in haemodialysis patients. , 1996, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[15]  N. Battistini,et al.  The prediction of extracellular and total body water from bioelectric impedance in a non-Caucasian population from central Asia. , 1995, Annals of human biology.

[16]  Cole A. Giller,et al.  Cerebral Versus Systemic Hemodynamics During Graded Orthostatic Stress in Humans , 1994, Circulation.

[17]  J. Charles,et al.  Orthostatic Hypotension in Patients, Bed Rest Subjects, and Astronauts , 1994, Journal of clinical pharmacology.

[18]  M. Van Loan,et al.  Use of multi-frequency bioelectrical impedance analysis for the estimation of extracellular fluid. , 1992, European journal of clinical nutrition.

[19]  F Baisch,et al.  Effects of head-down tilt for 10 days on the compliance of the leg. , 1992, Acta physiologica Scandinavica. Supplementum.

[20]  P. Grøttum,et al.  Ultrasonic Assessment of Abdominal Venous Return , 1986, Acta radiologica: diagnosis.

[21]  L. I. Kakurin,et al.  Antiorthostatic hypokinesia as a method of weightlessness simulation. , 1976, Aviation, space, and environmental medicine.

[22]  A. Thomasset,et al.  Determination of body fluid compartments by electrical impedance measurements. , 1975, Aviation, space, and environmental medicine.

[23]  D. C. Simpson,et al.  Correlation of whole-body impedance with total body water volume. , 1969, Journal of applied physiology.

[24]  P. Stevens,et al.  Cardiovascular dynamics during orthostasis and the influence of intravascular instrumentation. , 1966, The American journal of cardiology.