title: Correction of target-controlled infusion following wrong selection of emulsion concentrations of propofol.
abstract: BACKGROUND
  We investigated the correction methods following wrong-settings of emulsion concentrations of propofol as a countermeasure against erroneous target-controlled infusions (TCI).
  
  
  METHODS
  TCIs were started with targeting 4.0 µg/ml of effect-site concentration (Ceff) of propofol, and the emulsion concentrations were selected for 2.0% instead of 1.0% (FALSE1-2, n = 24), or 1.0% instead of 2.0% (FALSE2-1, n = 24). These wrong TCIs were corrected at 3 min after infusion start. During FALSE1-2, the deficit was filled up while injecting after equilibrium (n = 12), or while overriding (n = 12). During FALSE2-1, the overdose was evacuated while targeting Ceff (n = 12) or targeting plasma concentration (Cp) (n = 12). The gravimetrical measurements of TCI reproduced the Cp and Ceff using simulations. The reproduced Ceff at 3 min (Ceff-3min) and the time to be normalized within ± 5% of target Ceff (T±5%), were compared between the correction methods.
  
  
  RESULTS
  During the wrong TCI, Ceff-3min was 1.98 ± 0.01 µg/ml in FALSE1-2, and 7.99 ± 0.05 µg/ml in FALSE2-1. In FALSE1-2, T±5% was significantly shorter when corrected while overriding (3.9 ± 0.25 min), than corrected after equilibrium (6.9 ± 0.05 min) (P < 0.001). In FALSE2-1, T±5% was significantly shorter during targeting Cp (3.6 ± 0.04 min) than targeting Ceff (6.7 ± 0.15 min) (P < 0.001).
  
  
  CONCLUSIONS
  The correction methods, based on the pharmacokinetic and pharmacodynamic characteristics, could effectively and rapidly normalize the wrong TCI following erroneously selections of the emulsion concentration of propofol.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Chae
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Han Bum
authors.initials: HB
authors.lastname: Joe
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Won-Il
authors.initials: WI
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jin-A
authors.initials: JA
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Sang-Kee
authors.initials: SK
authors.lastname: Min
keywords: Drug delivery systems; Infusion pumps; Intravenous infusion; Propofol