Table 3.
Peak changes and response dynamics comparing preflight to postflight posture (SUPINE-SIT) and preflight to inflight leg cuff deflation (CUFF), respectively
| Pre-SUPINE-SIT | Post-SUPINE-SIT | Pre-CUFF | Inflight CUFF | |
|---|---|---|---|---|
| Heart rate | ||||
| Change to peak (Δ bpm) | 23.7 ± 7.6 | 25.2 ± 7.0 | 18.6 ± 7.2 | 16.4 ± 3.3 |
| Time to peak (s) | 9.1 ± 4.8 | 12.5 ± 1.1 | 10.3 ± 1.8 | 9.3 ± 3.4 |
| Response rate (bpm/s) | 4.4 ± 5.6 | 2.0 ± 0.5 | 1.9 ± 1.0 | 2.0 ± 0.9 |
| Recovery rate (bpm/s) | −1.7 ± 1.3 | −2.2 ± 1.0 | −2.6 ± 1.2 | −2.5 ± 2.8 |
| Systolic blood pressure | ||||
| Change to peak (Δ mmHg) | −25.8 ± 19.0 | −37.1 ± 25.9 | −16.4 ± 3.7 | −16.4 ± 5.6 |
| Time to Nadir (s) | 11.0 ± 7.2 | 15.8 ± 7.5* | 7.8 ± 1.3 | 5.4 ± 3.5 |
| Response rate (mmHg/s) | −3.5 ± 2.9 | −2.9 ± 2.1 | −2.2 ± 0.7 | −4.7 ± 4.1 |
| Recovery rate (mmHg/s) | −1.0 ± 0.4 | −2.7 ± 2.5 | −3.7 ± 1.3 | −3.2 ± 1.4 |
| Diastolic blood pressure | ||||
| Change to peak (Δ mmHg) | −15.2 ± 11.4 | −23.8 ± 11.9* | −15.8 ± 3.4 | −14.4 ± 3.2 |
| Time to Nadir (s) | 11.6 ± 7.3 | 13.9 ± 8.3 | 8.6 ± 1.4 | 5.9 ± 2.7 |
| Response rate (mmHg/s) | −2.0 ± 2.1 | −2.8 ± 3.0 | −1.9 ± 0.5 | −2.9 ± 1.3 |
| Recovery rate (mmHg/s) | −2.6 ± 4.8 | −1.8 ± 0.9 | −1.8 ± 2.3 | −3.2 ± 1.2 |
| Mean blood pressure | ||||
| Change to peak (Δ mmHg) | −19.4 ± 16.5 | −31.1 ± 17.9* | −18.9 ± 2.3 | −17.9 ± 4.5 |
| Time to Nadir (s) | 9.9 ± 5.1 | 13.8 ± 8.8 | 7.5 ± 1.2 | 5.5 ± 3.5 |
| Response rate (mmHg/s) | −2.4 ± 2.4 | −3.6 ± 3.4 | −2.6 ± 0.5 | −5.5 ± 5.9 |
| Recovery rate (mmHg/s) | −1.7 ± 2.0 | −2.4 ± 1.4* | −3.1 ± 0.8 | −3.9 ± 1.7 |
| Cardiac output | ||||
| Change to peak (Δ L/min) | 2.7 ± 1.8 | 2.4 ± 1.9 | 2.4 ± 1.1 | 2.8 ± 1.2 |
| Time to peak (s) | 8.9 ± 4.1 | 8.6 ± 4.9 | 10.1 ± 1.5 | 9.1 ± 4.0 |
| Response rate (L/min/s) | 0.3 ± 0.2 | 0.3 ± 0.2 | 0.3 ± 0.1 | 0.4 ± 0.2 |
| Recovery rate (L/min/s) | −0.2 ± 0.2 | −0.1 ± 0.1 | −0.4 ± 0.2 | −0.5 ± 0.2 |
| Stroke volume | ||||
| Change to peak (Δ mL) | −30.2 ± 6.2 | −24.3 ± 11.0 | −9.4 ± 17.7 | −5.6 ± 4.2 |
| Time to Nadir (s) | 21.3 ± 9.8 | 11.6 ± 10.4 | 9.0 ± 4.7 | 9.4 ± 8.7 |
| Response rate (mL/min/s) | −2.3 ± 2.7 | −4.5 ± 3.7 | −1.3 ± 1.6 | −1.7 ± 2.0 |
| Recovery rate (mL/min/s) | −4.2 ± 3.9 | −2.1 ± 1.9 | −1.5 ± 2.2 | −0.4 ± 1.2 |
| Total peripheral resistance | ||||
| Change to peak (Δ mmHg/L/min) | −7.5 ± 6.6 | −7.6 ± 2.6 | −8.7 ± 2.0 | −5.4 ± 1.1* |
| Time to Nadir (s) | 12.6 ± 6.7 | 16.8 ± 10.6 | 8.6 ± 0.9 | 6.5 ± 3.9 |
| Response rate (mmHg/L/min/s) | −0.8 ± 1.0 | −0.8 ± 0.8 | −1.0 ± 0.3 | −1.2 ± 1.1 |
| Recovery rate (mmHg/L/min/s) | −0.9 ± 1.1 | −0.8 ± 0.2 | −1.1 ± 0.3 | −0.8 ± 0.2 |
Values are means ± SD. SUPINE-SIT is the peak/nadir during the 30 s sit period of the posture trial, CUFF is the maximal or minimal value after leg cuff deflation. Change to peak = Δ from baseline; negative values indicate a decrease. Response rate = Δ from baseline/time to nadir; recovery rate = 50% Δ/time for recovery
*Different from preflight, p < 0.05