Implications for the anaesthesiologist
cerebral hypoperfusion, cerebrovascular vasodilation
A unique feature of the present study is that it compared the effects of propofol and sevoflurane on both static as well as dynamic CA. The observations corroborate existing (circumstantial) evidence that propofol leads to cerebrovascular vasoconstriction and improved CA, while sevoflurane induces cerebrovascular vasodilation and impaired CA. Against the backdrop of this other evidence, a plausible explanation for these observations could be the different effects on cerebrovascular tone with both agents.The results of this study further elucidate fundamental differences between propofol and volatile anaesthesia on cerebral haemodynamics. Importantly, there are two main implications. Firstly, while it has been recognised that there is a difference in cerebral vasomotor tone between anaesthetics, the behaviour of (dynamic) CA appears to depend on this very same difference. As far as we are aware, this relationship is rarely explicitly suggested. Secondly, the dogmatic view that the lower limit of CA is the inflection point under which cerebral hypoperfusion starts to occur is challenged. In fact, this is in accordance with earlier work,