Kate Leslie, Ornella Clavisi, Joshua Hargrove

Continuous infusions of the intravenous anaesthetic propofol are commonly used to induce and maintain sedation and general anaesthesia. Infusion devices can be manually controlled (MCI) where the anaesthetist makes each change to the infusion rate or target-controlled (TCI) where the anaesthetist sets a target blood or effect-site concentration and the computerised infusion device makes the necessary changes to the infusion rate. Randomized trials have explored the differences in quality of anaesthesia, adverse event rate and cost between TCI and MCI but the effectiveness of TCI compared with MCI remains controversial. As TCI is in widespread international use, and potentially may be more expensive without added benefit, a systematic review of randomized controlled trials comparing TCI and MCI is warranted. To assess whether TCI of propofol is as effective as MCI of propofol with respect to quality of anaesthesia or sedation, adverse events and propofol drug cost. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 3); PubMED (1950 to July week 2 2007); and EMBASE via OVID (1980 to week 28 2007). We also searched LILACS, CINAHL, ISI Web Knowledge, Panteleimon, KoreaMed and IndMed. We searched for ongoing trials via the National Research Register and metaRegister of Controlled Trials. We planned to include all published and unpublished randomized controlled trials that compared TCI of propofol with MCI of propofol for general anaesthesia or sedation in adult surgical patients. Only published studies were included as no unpublished studies were identified. Two authors independently assessed trial quality and extracted outcome data. We contacted study authors and the pharmaceutical industry for additional information. Twenty trials of poor quality that involved 1759 patients were included. Heterogeneity was high (that is the trials were not comparing the same things). TCI was associated with higher total doses of propofol than was MCI resulting in marginally higher propofol drug costs. However, fewer interventions were required by the anaesthetist during the use of TCI compared with MCI. No clinically significant differences were demonstrated in terms of quality of anaesthesia or adverse events. This systematic review does not provide sufficient evidence for us to make firm recommendations about the use of TCI versus MCI in clinical anaesthetic practice.