We all recall the elegant curves that ostensibly show the neat relationship between mean arterial blood pressure (or CPP) and cerebral blood flow. This relationship classically has its lower and upper limits, beyond which CBF will vary passively with the systemic pressure. Stay within these limits and all is good, the mantra goes. However, as often is the case with physiological “truths”, the realities are slightly more complicated, especially in pathological conditions such as TBI. This is hardly surprising to most neuro-clinicians but we still find it hard to shake off our old dogmatic thinking in daily practice. This might help….
The two following articles comprehensively review the subject of cerebral autoregulation, its clinical implications and its assessment. Both are well worth your time if, like me, you feel the need to catch up on what we know so far.