Propofol context sensitive half life

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Soparklion

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I'm interested in published data regarding the context sensitive half life of propofol at different infusion rates... I believe that there is a limit, below which there is zero accumulation. But I don't know that limit.

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The maximum context sensitive half time is 40 minutes. Don’t have literature on hand for that sorry.
 
Have you searched any of this? There's lots published on this.

And what do you mean by different infusion rates? Csht's definition implies steady state not increasing or decreasing infusions

I have 20 mins in my head for propofol csht but thats UK anesthesia and we're usually drunk and haven't a notion what's going on
 
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Propofol has a context-sensitive half-time that varies between 3 min for a very short infusion to about 18 min after a 12-h infusion. This relatively small variation in context-sensitive half-time, despite a large V3, occurs because excretion is rapid compared with redistribution

 
Not quite sure what you're asking, maybe this helps though:

There is no mathematical "limit" (floor effect) when it comes to the CSHT of propofol, because by definition CSHT is a PK model where the infusion of any amount of drug will produce a positive value (>0 time units). Unless you're actually measuring plasma concentration and not modelling it, in which case, why? Doesn't seem to have any clinical application?
From a clinical perspective: The CSHT is dependent on the effect-site concentration that is being targetted. I assume this is what you're talking about re: lowest infusion rate where the effect-site concentration will approach 0/awake independent of the context (time/duration) of the infusion?
From that, it depends if you want the CSHT of propofol for hypnosis; or the CSHT of propofol for amnesia; or the CSHT of propofol for anxiolysis, etc, etc. You won't find any published data on this because it is too broad and irrelevant when you can do a standardised, high concentration model, and then extrapolate from there. The existing studies only really assess the CSHT of propofol for "MAC" equivalency/BIS scores.

Have a play around with this: Effect Site Concentrations to see if it answers your question.
 
What you should study, which has not been elucidated well, is how multi drugs effect this multi-compartment model.
In other words, does adding precedex change the pharmacokinetics of propofol? Or visa Versa?
 
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