title: Patient-controlled Analgesia with Target-controlled Infusion of Hydromorphone in Postoperative Pain Therapy.
abstract: BACKGROUND
  Patient-controlled analgesia (PCA) is a common method for postoperative pain therapy, but it is characterized by large variation of plasma concentrations. PCA with target-controlled infusion (TCI-PCA) may be an alternative. In a previous analysis, the authors developed a pharmacokinetic model for hydromorphone. In this secondary analysis, the authors investigated the feasibility and efficacy of TCI-PCA for postoperative pain therapy with hydromorphone.
  
  
  METHODS
  Fifty adult patients undergoing cardiac surgery were enrolled in this study. Postoperatively, hydromorphone was applied intravenously during three sequential periods: (1) as TCI with plasma target concentrations of 1 to 2 ng/ml until extubation; (2) as TCI-PCA with plasma target concentrations between 0.8 and 10 ng/ml during the following 6 to 8 h; and (3) thereafter as PCA with a bolus dose of 0.2 mg until the next morning. During TCI-PCA, pain was regularly assessed using the 11-point numerical rating scale (NRS). A pharmacokinetic/pharmacodynamic model was developed using ordinal logistic regression based on measured plasma concentrations.
  
  
  RESULTS
  Data of 43 patients aged 40 to 81 yr were analyzed. The hydromorphone dose during TCI-PCA was 0.26 mg/h (0.07 to 0.93 mg/h). The maximum plasma target concentration during TCI-PCA was 2.3 ng/ml (0.9 to 7.0 ng/ml). The NRS score under deep inspiration was less than 5 in 83% of the ratings. Nausea was present in 30%, vomiting in 9%, and respiratory insufficiency in 5% of the patients. The EC50 of hydromorphone for NRS of 4 or less was 4.1 ng/ml (0.6 to 12.8 ng/ml).
  
  
  CONCLUSIONS
  TCI-PCA with hydromorphone offered satisfactory postoperative pain therapy with moderate side effects.
authors.affiliation: From the Department of Anesthesiology, University of Erlangen-Nuremberg, Erlangen, Germany. Current affiliation: Department of Anesthesiology and Intensive Care, University of Turku and Turku University Hospital, Turku, Finland (T.I.S.).
authors.forename: Christian
authors.initials: C
authors.lastname: Jeleazcov
authors.forename: Harald
authors.initials: H
authors.lastname: Ihmsen
authors.forename: Teijo I
authors.initials: TI
authors.lastname: Saari
authors.forename: Doris
authors.initials: D
authors.lastname: Rohde
authors.forename: Jan
authors.initials: J
authors.lastname: Mell
authors.forename: Katharina
authors.initials: K
authors.lastname: Fröhlich
authors.forename: Ljubica
authors.initials: L
authors.lastname: Krajinovic
authors.forename: Jörg
authors.initials: J
authors.lastname: Fechner
authors.forename: Helmut
authors.initials: H
authors.lastname: Schwilden
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schüttler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D004091:Hydromorphone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D004091:Hydromorphone