Table 2. Main cardiovascular and FOT parameters at control (room air) and during O2 (5 L∙min-1) breathing conditions.
| Control (Room air) | Quiet breathing (O2 5 L∙min-1) | Paired t-test | |
|---|---|---|---|
| Mean RR interval, ms | 814 (109) | 872 (98) | < 0.001 |
| RR-SD, ms | 50 (28) | 44 (24) | 0.204 |
| RMSSD, ms | 47 (26) | 40 (18) | 0.172 |
| SBP, mm Hg | 133 (26) | 121 (25) | 0.051 |
| DBP, mm Hg | 75 (13) | 72 (15) | 0.173 |
| BRS, ms∙mmHg-1 | 12.2 (6.8) | 13.0 (7.7) | 0.582 |
| SaO2, % | 98 (1) | 99 (1) | < 0.001 |
| TO2I, % | 65 (10) | 65 (12) | 0.959 |
| R5, cm H2O∙s∙L-1 | 1.70 (0.55) | 2.12 (0.82) | 0.006 |
| R19, cm H2O∙s∙L-1 | 1.87 (0.61) | 2.45 (0.88) | < 0.001 |
| VT, L | 0.93 (0.17) | 0.76 (0.17) | 0.209 |
| E, L∙min-1 | 9.98 (2.01) | 8.06 (2.60) | 0.020 |
| CO2-ET, mm Hg | 40.5 (4.02) | 34.69 (5.35) | < 0.001 |
RR interval: interval between two RR wave peaks; RR-SD: standard deviation of RR interval; SBP and DBP: systolic and diastolic pressures, respectively; SaO2: oxygen saturation; TO2I: Tissue Oxygen Index; R5 and R19, inspiratory resistance at 5 and 19 Hz, respectively; VT: tidal volume; E: minute ventilation; CO2-ET: carbon dioxide end-tidal. Data are mean ± SD.