AbstractsMedical & Health Science

Maintenance of anaesthesia using the intravenous agent propofol has increased following development of pharmacokinetic models. An analyser capable of determining propofol concentrations at the point of care may lead to an improved accuracy of drug delivery. Validation work on a novel analyser measuring propofol concentration in near real time demonstrate a high level of precision for samples in the clinical range. Further work in the clinical setting was carried out using the novel propofol analyser to further research its potential use in a diverse patient cohort. Studies were performed in intensive care correlating blood propofol concentrations with depth of sedation, demonstrating a correlation with organ failure. The Marsh model of Target Controlled Anaesthesia was poorer at predicting propofol concentration in patients with significant organ dysfunction than in those without organ failure (correlation coefficient 0.36 vs. 0.73 respectively). Studies in the operating room were performed in which measured propofol concentrations were compared with those predicted using the Marsh model. Results demonstrated significant inaccuracies of the model (bias 32%, precision -8.7 to 72.6%). A method of Marsh model bias correction using a single blood propofol measurement was tested. Results demonstrated insufficient predictability to allow a single point calibration.