Figure 4.

Changes of rCBF and metabolic variables during clusters of SDs in the injured brain. Left panel: regional cerebral blood flow (rCBF in %), brain tissue partial pressure of oxygen (PbtO₂ in mmHg), cerebral metabolic rate of oxygen (CMRO₂ in µmol/100 g/min), and local field potentials (LFPot in mV), during a cluster of SDs (original traces). Black circles describe the points for calculations of baseline and inter-SD values of rCBF and CMRO₂. Gray triangles and circles, respectively, describe the points for the calculations of the area under the curve (AUC) (rCBF increase) and the maximum (Max) of CMRO₂. Right panel: rCBF AUC and inter-SD rCBF (median and IQR, n = 12) are presented as percentage change from baseline (precluster). Note that rCBF AUC decreased while the inter-SD rCBF level increased during the cluster. In the right lower panel, maximum (Max) and inter-SD CMRO₂ (Median and IQR, n = 6) relative to baseline show a constant peak with a gradual increase of inter-SD CMRO₂ during the cluster. ** p ≤ 0.01: effect of “SD number” factor in a repeated measures ANOVA.