Table 3.
Linear random-slope mixed models for PbtO2, ICP, CPP, PI, and FVm
| PbtO2 (mm Hg) | ICP (mm Hg) | CPP (mm Hg) | PI | FVm (cm/s) | |
|---|---|---|---|---|---|
| Measurements (n) | 167 | 158 | 158 | 167 | 167 |
| Fixed effects parameters | |||||
| Exp2 | 2.6 (0.7 to 4.5)** | 0.8 (− 1.9 to 3.5) | − 0.2 (− 3.1 to 2.6) | 0.0 (− 0.1 to 0.1) | 18.1 (13.1 to 23.0)** |
| Exp3 | 4.8 (− 1.4 to 11.0) | 4.6 (− 5.3 to 14.5) | − 1.1 (− 7.4 to 5.3) | 0.2 (0.0 to 0.4)* | 3.7 (− 7.5 to 14.9) |
| 30° to 15° to 0° order | − 2.2 (− 5.7 to 1.3) | 4.3 (− 1.2 to 9.9) | 7.8 (1.7 to 13.8)* | 0.1 (− 0.0 to 0.3) | − 4.6 (− 25.6 to 16.5) |
| 0° position | 1.2 (0.2 to 2.3)* | 7.4 (6.3 to 8.6)** | − 0.4 (− 2.9 to 2.0) | − 0.1 (− 0.1 to − 0.0)** | 4.1 (0.0 to 8.2)* |
| 15° position | 0.6 (− 0.5 to 1.6) | 2.6 (1.4 to 3.7)** | 0.0 (− 2.5 to 2.5) | − 0.0 (− 0.1 to 0.00)* | 2.3 (− 1.8 to 6.4) |
| Decompressive craniectomy | − 2.9 (− 6.4 to 0.6) | − 4.0 (− 9.7 to 1.6) | 5.0 (− 1.1 to 11.2) | 0.0 (− 0.2 to 0.2) | − 4.6 (− 25.8 to 16.6) |
| Constant | 25.7 (21.7 to 29.7) | 12.9 (8.0 to 17.8) | 61.7 (55.9 to 67.5) | 1.0 (0.8 to 1.2) | 71.3 (51.6 to 91.1) |
Each model includes covariate fixed effects, i.e., the experiments (exp2 or exp3 versus exp1), the sequential order of the three head postures (30° to 15° to 0° versus 30° to 0° to 15°), the degree of head elevation (0° or 15° versus 30°), and the decompressive craniectomy (present versus absent). Covariance coefficients are expressed as mean (95% confidence interval)
CPP, cerebral perfusion pressure, exp1, performed 24 h after admission to the ICU, exp2, repeated 24 h later, exp3, repeated 96 h later; ICP intracranial pressure; FVm, mean blood flow velocity; PbtO2, oxygenation pressure, PI, pulsatility index
*P < 0.05 compared to covariate at baseline; **P < 0.001 compared to covariate at baseline