Significant advances in TBI outcome have been achieved over the last 20 years by brasing our management of systemic and cerebrovascular physiology on targets derived from population studies. However, this approach takes no account of interpatient heterogeneity as reflected by varying degrees of autoregulatory reserve in different patients and its time-variability.
There is mounting evidence that including cerebral autoregulation in the ICU management of patients after severe TBI is beneficial to patient’ survival and generally better outcome. Autoregulation based individualisation of therapy thresholds has been included in the recent brain trauma guidelines. However there are still no clinically approved monitors of cerebral autoregulation available.
Crucial to such studies has been the development of techniques for the continuous monitoring of cerebrovascular reactivity [Czosnyka M, Stroke 1996] and cerebral autoregulation [Czosnyka M, Neurosurgery 1997]. These novel methods, based on computer-supported time-series analysis were introduced in 1996-1997 and have demonstrated such methods can be beneficial in the acute stage of management of TBI patients for the individual optimization of management strategies.
This work led to the development of the concept of defining an individual patient’s ‘Optimal Cerebral Perfusion Pressure’, using continuous monitoring of a dynamic index of cerebral autoregulation [Steiner L Critical Care Medicine 1997] – until this work, patients were assumed to require the same cerebral perfusion pressure.