Required decrement time to predict time of awaking in effect-site concentration can be estimated by using that in predicted blood concentration displayed on the commercial TCI pump.

摘要

A target-controlled infusion (TCI) pump with a built-in Diprifusor? (Astrazeneca, London, UK) can show the required decrement time (RDT) to a certain concentration of propofol (expected waking concentration, ExWC) for the assistant to estimate the required time to awakening. However, it is not the RDT in effect-site concentration (ESC) but that in predicted blood concentration (pCb). Actually, what we really want to know is the RDT in ESC, not that in pCb.We calculated the differences between RDT in pCb and that in ESC using TIVAtrainer (available at http://www. eurosiva.org/; accessed on 1 May 2010) under 87 conditions. The patient was assumed to be a 40-year-old man with height of 170 cm and weight of 70 kg. It was assumed that anesthetic management was maintained using propofol at one of three target concentrations (low concentration of 2 u.g/ml, medium concentration of 4 jig/ml, or high concentration of 6 mu.g/ml) with one of three durations (short duration of 2 h, intermittent duration of 4 h, or long duration of 6 h). Each concentration of propofol was supposed to decrease with time after stopping administration.