Knowledge of pharmacodynamic interaction of opioids and volatile and intravenous anaesthetics is a prerequisite for rational drug dosing in general anaesthesia. Whereas dosing of volatile anaesthetics according to MAC (minimum alveolar concentration) and end-tidal anaesthetic gas (ETAG) rules is as effective as EEG monitoring in prevention of awareness and recall, a similar concept is not available for total intravenous anaesthesia. The utility of depth-of-anaesthesia monitoring devices is under debate.
We are working on interaction models using laryngoscopy and verbal/tactile stimulation instead of skin incision to extend the MAC concept by integrating opioids and propofol. Recently developed interaction models are used to visualize the potency of a given drug combination in anaesthesia display systems and may help the practitioner to optimise the combination of hypnotics and opioids in general anaesthesia. We are currently validating interaction models and investigating the clinical utility of the SmartPilot® View (Dräger Medical, Lübeck, Germany), and are working on new interaction models for loss and return of consciousness.
Our research is performed in cooperation with the Department of Anesthesia at Groningen University Medical Center in the Netherlands, under Prof. MMRF Struys, and is supported by Dräger Medical, Lübeck, Germany.
We are grateful for an unrestricted educational grant from Dräger Medical, Lübeck, Germany