Table 1.
Measures before, during, and after long-duration spaceflight
| Preflight |
Spaceflight |
Postflight |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Supine | Seated | HDT | HDT + LBNP | FD45 | FD45 + LBNP | FD150 | FD150 + LBNP | R + 40 Supine | R + 40 Seated | R + 180 Supine | R + 180 Seated | |
| JVvol, cm3 | 1.73 (0.62) n = 14 |
0.42 (0.22)* n = 14 |
3.42 (1.56)* n = 12 |
1.06 (0.78)† n = 12 |
2.38 (0.79)* n = 14 |
1.55 (0.71)† n = 13 |
2.45 (0.76)* n = 12 |
1.24 (0.59)† n = 11 |
1.85 (0.91) n = 13 |
0.40 (0.31)* n = 10 |
1.63 (0.45) n = 11 |
0.26 (0.11)* n = 10 |
| PV, cm2 | 0.87 (0.23) n = 14 |
0.76 (0.39) n = 8 |
1.06 (0.29) n = 8 |
0.70 (0.16)† n = 7 |
1.03 (0.35) n = 11 |
0.64 (0.19)† n = 8 |
1.25 (0.40)* n = 12 |
0.72 (0.23)† n = 10 |
0.88 (0.26) n 8 |
n/a | 0.75 (0.26) n = 7 |
n/a |
| MCV velocity, cm/s | 9.30 (3.10) n = 14 |
n/a | n/a | 7.33 (1.68) n = 5 |
14.27 (4.00)* n = 9 |
9.28 (2.40)† n = 10 |
17.13 (5.34)* n = 13 |
9.72 (2.25)† n = 12 |
10.06 (3.53) n = 12 |
n/a | 10.16 (3.21) n = 9 |
n/a |
Mean values (SD) and the number of measures (n) are presented for each of the measurement time point. Symbols are as follows: *different from preflight supine (P < 0.05); and †LBNP value different from respective value without LBNP (P < 0.05). FD45, 45th day of spaceflight; FD150, 150th day of spaceflight; HDT, head-down tilt; JVvol, jugular vein volume; LBNP, lower body negative pressure; MCV, middle cerebral vein velocity; n/a, not applicable; PV, portal vein cross-sectional area; R + 40, 40th day after returning to Earth from spaceflight; R + 180, 180th day after returning to Earth from spaceflight.