Changes with postnatal age in Doppler velocity measures in the middle cerebral artery
| 5 hours (n=124) | 12 hours (n=123) | 24 hours (n=117) | 48 hours (n=114) | p Value* | |
|---|---|---|---|---|---|
| Data are given as median and range. | |||||
| *Analysis of variance. | |||||
| MCA, Middle cerebral artery; ACA, anterior cerebral artery. | |||||
| Mean blood pressure (mm Hg) | 31 (15–46) | 33 (20–51) | 36 (23–50) | 38 (24–54) | <0.0001 |
| MCA diameter (mm) | 1.4 (0.9–2.2) | 1.4 (0.9–2.3) | 1.4 (0.8–2.3) | 1.4 (0.7–2.2) | 0.632 |
| MCA systolic velocity (m/s) | 0.23 (0.09–0.43) | 0.26 (0.08–0.53) | 0.32 (0.09–0.7) | 0.34 (0.08–1.09) | <0.0001 |
| MCA diastolic velocity (m/s) | 0.04 (0–0.21) | 0.06 (0–0.23) | 0.08 (0–0.22) | 0.09 (0–0.32) | <0.0001 |
| MCA mean velocity (m/s) | 0.11 (0.04–0.29) | 0.14 (0.02–0.33) | 0.17 (0.06–0.36) | 0.19 (0–0.68) | <0.0001 |
| MCA pulsatility index | 1.77 (0.7–15.9) | 1.48 (0.77–12.28) | 1.38 (0.24–2.71) | 1.31 (0.76–2.66) | <0.0001 |
| MCA velocity time integral (m) | 0.047 (0.013–0.102) | 0.06 (0.011–0.12) | 0.076 (0.03–0.17) | 0.087 (0.032–0.222) | <0.0001 |
| MCA mean velocity minus ACA mean velocity (m/s) | 0.03 (−0.07–0.1) | 0.04 (−0.05–0.18) | 0.05 (−0.05–0.27) | 0.06 (−0.06–0.5) | <0.0001 |