TABLE 2.
End-tidal CO2 and cerebral blood flow responses to air mixed with CO2 to induce hypercapnia for cerebrovascular reactivity testing. N = 21 participants. Data presented as mean ± standard deviation.
| Variable | Mean ± standard deviation |
|---|---|
| Resting end-tidal CO2 (mmHg) | 38.8 ± 3.2 |
| Hypercapnia end-tidal CO2 (mmHg) | 46.7 ± 3.4 |
| Change in end-tidal CO2 (mmHg) | 8.0 ± 0.7 |
| Resting GM CBF (ml/100 g/min) | 55.0 ± 11.0 |
| Hypercapnia GM CBF (ml/100 g/min) | 75.0 ± 14.4 |
| Change in GM CBF (ml/100 g/min) | 20.1 ± 10.8 |
| GM CBF cerebrovascular reactivity (%) | 4.8 ± 2.6 |
| Resting WM CBF (ml/100 g/min) | 32.9 ± 4.8 |
| Hypercapnia WM CBF (ml/100 g/min) | 40.2 ± 6.4 |
| Change in WM CBF (ml/100 g/min) | 7.3 ± 6.7 |
| WM CBF cerebrovascular reactivity (%) | 2.9 ± 2.5 |
| Resting hippocampal CBF (ml/100 g/min) | 51.7 ± 8.7 |
| Hypercapnia hippocampal CBF (ml/100 g/min) | 63.5 ± 13.5 |
| Change in hippocampal CBF (ml/100 g/min) | 11.8 ± 13.2 |
| Hippocampal CBF cerebrovascular reactivity (%) | 3.1 ± 3.4 |