title: Patient-maintained propofol sedation. Assessment of a target-controlled infusion system.
abstract: We have developed a system which allows patients to operate a target-controlled infusion of propofol to provide sedation and we have studied its use in 36 unpremedicated patients undergoing local and regional anaesthetic procedures lasting 10-280 min. An intravenous propofol infusion was started at a target plasma level of 1 microgram.ml-1. The patient was able to increase the target propofol concentration in 0.2- microgram.ml-1 increments by pressing a demand button. There was a lockout interval of 2 min and a maximum permissible target concentration of 3 micrograms.ml-1. There was considerable interindividual variability in propofol consumption (mean 39.3 micrograms.kg-1.min-1, range 3-131 micrograms.kg-1.min-1), no cardiovascular instability and little oversedation. Eight patients required supplementary oxygen. Optimal sedation was provided at median target concentrations of 0.8-0.9 microgram.ml-1. The target-controlled infusion system bias was-47% and the inaccuracy was 48%. Patient satisfaction was high and 89% said that they would definitely use the technique again. This technique combines the benefits of target-controlled infusion with patient-controlled feedback and produces safe intra-operative sedation.
authors.affiliation: Department of Anaesthesiology, University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: M G
authors.initials: MG
authors.lastname: Irwin
authors.forename: N
authors.initials: N
authors.lastname: Thompson
authors.forename: G N
authors.initials: GN
authors.lastname: Kenny
mesh_terms: D000328:Adult; D000368:Aged; D000765:Anesthesia, Conduction; D001794:Blood Pressure / Q000187:drug effects; D016292:Procedural Sedation / Q000379:methods* / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000494:pharmacology; D007262:Infusions, Intravenous; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D015742:Propofol / Q000008:administration & dosage* / Q000494:pharmacology; D012119:Respiration / Q000187:drug effects; D012646:Self Administration
chemical_list: D006993:Hypnotics and Sedatives; D015742:Propofol