Table 3.
Transcranial color-coded duplex sonography variables measured in middle cerebral arteries bilaterally
| n = 11 | A Baseline |
C Moderate hyperventilation |
D 50 min of moderate hyperventilation |
E Return to baseline |
|---|---|---|---|---|
| CBFV right (cm/s) | 81 (23) | 69 (21)* | 71 (20)* | 77 (28) |
| CBFV left (cm/s) | 80 (22) | 66 (17)* | 63 (15)* | 75 (24)¶Ŧ |
| PSV right (cm/s) | 136 (37) | 117 (34)* | 120 (33)* | 129 (42) |
| PSV left (cm/s) | 131 (35) | 110 (25)* | 107 (24)* | 126 (37)¶Ŧ |
| EDV right (cm/s) | 56 (20) | 45 (16)* | 46 (16)* | 51 (22)¶ |
| EDV left (cm/s) | 54 (16) | 43 (13)* | 41 (11)* | 52 (17)¶Ŧ |
| PI right | 1.03 (0.17) | 1.08 (0.16) | 1.05 (0.23) | 1.05 (0.17) |
| PI left | 0.96 (0.15) | 1.06 (0.10) | 1.07 (0.14)* | 1.02 (0.14) |
Abbreviations: A Baseline, B Increasing minute ventilation, C Begin moderate hyperventilation with target PaCO2 4–4.7 kPa, D After moderate hyperventilation for 50 min, E Return to baseline. CBFV Mean flow velocity of the middle cerebral artery (cm/s), PSV Peak systolic velocity (cm/s), EDV End-diastolic velocity (cm/s), PI Pulsatility index
* p < 0.05 compared with A
¶ p < 0.05 compared with C
Ŧ p < 0.05 compared with D
N = 11 patients, + = 10 patients. Data are expressed as mean (SD)