Approaches to neuroprotection in pediatric neurocritical care

Figure 3 Example of identification of optimal cerebral perfusion in a 2-year-old male with severe traumatic brain injury. Here, the PRx is plotted across a range of CPP values over a four-hour window, demonstrating a parabolic curve which suggests that the lowest point of the curve (51.72 mmHg; CPPopt) represents the CPP at which cerebrovascular pressure reactivity is most efficient. By using cutoffs of greater than 0.2, the lower limit of cerebrovascular pressure reactivity is estimated at 37.86 mmHg and the upper limit of cerebrovascular pressure reactivity is estimated at 66.35 mmHg. PRx: Pressure reactivity index; CPP: Cerebral perfusion pressure; CPPOpt: Optimal cerebral perfusion pressure; ICP: Intracranial pressure; PRXopt: Optimal pressure reactivity index; UL: Upper limit of cerebrovascular pressure reactivity; LL: Lower limit of cerebrovascular pressure reactivity.