TABLE 3.
Aquanaut waking peripheral and cerebrovascular hemodynamic parameters.
| Aquanaut Waking Peripheral and Cerebrovascular Hemodynamics | ||||
| Pre-Saturation | Saturation | Post-Saturation | P-value | |
| Prone | ||||
| MAP, mmHg | 85.4 ± 18.6 | 73.2 ± 10.2 | 67.3 ± 3.7 | 0.125 |
| SBP, mmHg | 128.5 ± 24.2 | 107.5 ± 20.1 | 95.0 ± 10.8 | 0.150 |
| DBP, mmHg | 66.9 ± 18.4 | 57.3 ± 6.0 | 53.9 ± 2.1 | 0.217* |
| HR, bpm | 73.0 ± 14.0 | 69.3 ± 15.7 | 77.0 ± 13.9 | 0.369 |
| MCAv, cm/s | 47.9 ± 7.3 | 43.6 ± 5.3 | 44.5 ± 8.6 | 0.224 |
| Static Change from Prone when Standing (30 s After Stand) | ||||
| ΔMAP, mmHg | −3.7 ± 2.9 | −5.6 ± 7.3 | −5.5 ± 7.4 | 0.805 |
| ΔHR, bpm | 12.8 ± 8.0 | 30.1 ± 9.5 | 32.3 ± 16.3 | 0.012 |
| ΔMCAv, % | −8.4 ± 6.5 | −16.1 ± 21.5 | −12.8 ± 3.1 | 0.475** |
| Prone-to-Stand Cerebral Autoregulatory Response (During Stand) | ||||
| Cerebral Autoregulatory Index | 4.5 ± 0.9 | 3.9 ± 0.5 | 3.7 ± 0.8 | 0.434* |
| ΔMAP, mmHg | −39.0 ± 3.9 | −35.4 ± 7.2 | −31.7 ± 9.4 | 0.117 |
| ΔMCAv, % | −31.8 ± 8.1 | −38.7 ± 2.1 | −40.7 ± 13.9 | 0.624 |
| Time to MAP nadir, s | 7.5 ± 1.2 | 8.3 ± 1.2 | 7.3 ± 0.5 | 0.275 |
| Time to MCAv nadir, s | 4.4 ± 1.2 | 5.5 ± 1.7 | 4.2 ± 3.0 | 0.272 |
Waking heart rate, blood pressure, and cerebral blood flow velocity values across pre-saturation, saturation, and post-saturation timepoints during the prone-to-stand protocol. Prone values are the average of the 25 s window before the stand. The static change from prone when standing is the difference between values before the stand and 30 s after the stand. The prone-to-stand autoregulatory response reflects the drop in blood pressure and cerebral flow velocity during the stand and the time it took to reach the lowest values (nadirs). N = 3 (male, n = 3). Data: Mean ± SD. MAP, mean arterial pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; MCAv, middle cerebral artery flow velocity. *Values were logarithmically transformed prior to analyses due to non-normal distribution; **values had a positive constant value [34.1; “33.1” (maximum negative number value multiplied by −1) plus “1”; original value + “33.1 + 1 = 34.1] added prior to logarithmic transformation prior to analyses due to negative values and non-normal distribution. ns, p > 0.05 across comparisons.