title: Stability of a sufentanil-ropivacaine mixture in a glass and a PVC reservoir.
abstract: OBJECTIVE
  Drug mixtures containing sufentanil may be unstable owing to absorption into the drug reservoirs of patient-controlled epidural analgesia systems that contain polyvinylchloride. The stability of sufentanil in a mixture of ropivacaine 0.2% in a 750 mL reservoir was therefore investigated.
  
  
  METHODS
  During simulated epidural infusions of 5 mLh(-1) at 25 degrees C, sufentanil concentrations were measured for 96 h. Samples were taken from the reservoir and from the end of the epidural catheter under the following conditions: into glass or polyvinylchloride reservoirs containing ropivacaine 0.2% with sufentanil 1, 0.75 or 0.5 microg mL(-1); and into polyvinylchloride reservoirs with ropivacaine 0.2% and sufentanil 1 microg mL(-1) which were stored for 4 weeks at 8 degrees C.
  
  
  RESULTS
  The different solutions remained stable over the observation period of 96 h. Using the same solutions, independent samples' ANOVA showed no difference in the sufentanil concentrations between the glass and polyvinylchloride reservoirs, or between the polyvinylchloride reservoirs when stored for 4 weeks. Correlations between the concentrations at the different measurement times were extremely high for the reservoir (r(min) = 0.98, r(max) = 1.00) and the catheter end (rmin = 0.86, r(max) = 1.00).
  
  
  CONCLUSIONS
  Sufentanil citrate at 0.5-1.0 microg mL(-1) in an admixture of ropivacaine 0.29 for 5 days, which is the usual period for postoperative epidural analgesia, remains stable in a polyvinylchloride reservoir. There is no change in the drug concentration even if the reservoir is stored for 4 weeks at 8 degrees C.
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Anästhesiologie und operative Intensivmedizin, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Brodner
authors.forename: T
authors.initials: T
authors.lastname: Ermert
authors.forename: H
authors.initials: H
authors.lastname: Van Aken
authors.forename: M
authors.initials: M
authors.lastname: Westphal
authors.forename: M A E
authors.initials: MA
authors.lastname: Marcus
authors.forename: W
authors.initials: W
authors.lastname: Gogarten
authors.forename: C
authors.initials: C
authors.lastname: Goeters
authors.forename: H
authors.initials: H
authors.lastname: Bürkle
mesh_terms: D000577:Amides / Q000737:chemistry*; D016058:Analgesia, Patient-Controlled / Q000295:instrumentation; D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous / Q000737:chemistry*; D000779:Anesthetics, Local / Q000737:chemistry*; D004338:Drug Combinations; D004355:Drug Stability; D006801:Humans; D010149:Postoperative Pain / Q000188:drug therapy; D011143:Polyvinyl Chloride; D000077212:Ropivacaine; D012449:Safety; D017409:Sufentanil / Q000737:chemistry*
chemical_list: D000577:Amides; D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D004338:Drug Combinations; D000077212:Ropivacaine; D011143:Polyvinyl Chloride; D017409:Sufentanil