Table 1.
Basal ventilatory, cardiovascular, cerebral tissue oxygen and heart rate variability variables during eupnoea
| Day 1 | Day 3 | Day 5 | Day 8 | Day 10 | Day 12 | Day 15 | Day 17 | CV (%) | |
|---|---|---|---|---|---|---|---|---|---|
 (l min−1) |
11.1 ± 2.4 | 11.8 ± 2.1 | 11.9 ± 2.3 | 12.4 ± 2.4 | 12.1 ± 2.6 | 11.7 ± 2.2 | 11.7 ± 1.9 | 11.8 ± 1.9 | 9.7 ± 0.5 |
| Fb (breaths min−1) | 16.8 ± 3.8 | 18.1 ± 3.6 | 17.8 ± 4.0 | 18.4 ± 3.2* | 18.7 ± 3.4* | 17.7 ± 2.7 | 17.6 ± 3.1 | 17.9 ± 3.0 | 8.6 ± 4.5 |
| Vt (l) | 0.69 ± 0.12 | 0.67 ± 0.11 | 0.69 ± 0.10 | 0.69 ± 0.11 | 0.67 ± 0.13 | 0.68 ± 0.12 | 0.69 ± 0.07 | 0.68 ± 0.10 | 10.6 ± 0.7 |
| PET,CO2 (mmHg) | 43.6 ± 3.8 | 43.2 ± 3.0 | 43.6 ± 3.6 | 43.0 ± 3.3 | 42.4 ± 2.6 | 43.6 ± 3.3 | 43.6 ± 3.1 | 43.1 ± 3.0 | 3.2 ± 1.2 |
| SBP (mmHg) | 124 ± 9 | 120 ± 11 | 121 ± 9 | 121 ± 10 | 118 ± 9 | 122 ± 7 | 123 ± 11 | 121 ± 12 | 5.4 ± 2.0 |
| DBP (mmHg) | 71 ± 7 | 70 ± 7 | 71 ± 6 | 71 ± 8 | 70 ± 8 | 70 ± 6 | 70 ± 9 | 70 ± 9 | 6.5 ± 1.9 |
| MAP (mmHg) | 89 ± 7 | 87 ± 8 | 87 ± 6 | 88 ± 9 | 86 ± 8 | 88 ± 6 | 88 ± 9 | 87 ± 10 | 5.7 ± 1.8 |
| HR (beats min−1) | 66 ± 11 | 66 ± 12 | 68 ± 13 | 67 ± 13 | 71 ± 11 | 70 ± 12 | 68 ± 13 | 68 ± 11 | 8.9 ± 3.2 |
| ScO2(%) | 70 ± 5 | 68 ± 7 | 69 ± 4 | 69 ± 5 | 69 ± 6 | 70 ± 6 | 70 ± 5 | 69 ± 4 | 4.7 ± 2.1 |
Values are means ±s.d.
*
Significantly different from day 1 (P < 0.05). 
, inspired minute ventilation; Fb, breathing frequency; Vt, tidal volume; PET,CO2 end-tidal partial pressure of CO2; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; ScO2, cerebral tissue O2 saturation; CV, coefficient of variation.