Table 2

Secondary cerebral injury definitions

Definition
HypoxemiaOxygen saturation<90% for ≥ 5 min on pulse oxymetry
HypotensionSystolic blood pressure<90 mm Hg for≥5 min
Intracranial hypertensionIntracranial pressure>25 mm Hg for≥5 min
Brain tissue hypoxiaBrain tissue oxygen tension(PbtO2)< 15 mm Hg for≥5 min or
Brain tissue oxygen saturation(SbtO2)> 20% below baseline for≥5 min or
SbtO2<60% for ≥ 5 min