OBJECTIVETo evaluate the predictive performance of 'Diprifusor' TCI (target-controlled infusion) system for its better application in clinical anesthesia.

METHODSThe predictive performance of a 'Diprifusor' TCI system was investigated in 27 Chinese patients (16 males and 11 females) during upper abdominal surgery under total intravenous anesthesia (TIVA) with propofol/fentanyl. Measured arterial propofol concentrations were compared with the values predicted by the TCI infusion system. Performance was determined by the median performance error (MDPE), the median absolute performance error (MDAPE), the divergence (the percentage change of the absolute PE with time), and the wobble (the median absolute deviation of each PE from the MDPE).

RESULTSThe median (range) values of 14.9% (-21.6%-42.9%) for MDPE, 23.3% (6.9%-62.5%) for MDAPE, -1.9% h(-1) (-32.7%-23.0% h(-1)) for divergence, and 18.9% (4.2%-59.6%) for wobble were obtained from 227 samples from all patients. For the studied population, the PE did not increase with time but with increasing target propofol concentration, particularly following induction. conclusions: The control of depth of anaesthesia was good in all patients undergoing upper abdominal surgical operation and the predictive performance of the 'Diprifusor' target controlled infusion system was considered acceptable for clinical purposes. But the relatively bigger wobble showed that the pharmacokinetic model is not so suitable and requires improvement.