General anaesthesia: practical recommendations and recent advances

General anaesthesia has become, thanks to recently developed drugs, monitoring devices and delivery systems, a very well tolerated method of making the great surgical opportunities of the last few years available to all ages of patient. With a balanced and rational use of drug profiles, general anaesthesia allows even frail and very ill patients a margin of tolerability inconceivable just a few years ago. For the vast majority of patients, the risk from the general anaesthetic technique is so small it can be considered negligible. However, the majority of general anaesthetic drugs are both highly potent and very toxic, with many of the volatile agents still having a therapeutic ratio of about 4:1. The anaesthetic staff have to continually upgrade their skills and knowledge to ensure that harm does not result. It is, however, reasonable to offer some practical guidelines from the current literature on when to choose a general anaesthetic technique, either alone or with a regional local anaesthetic method, and when to avoid loss of consciousness. The complications expected from the use of general anaesthesia are reviewed, and the basis for these complications investigated. The currently available drugs and their place in anaesthetic practice are also assessed. Recent developments in the area of total intravenous anaesthesia and monitoring for potential awareness using bispectral analysis suggest that this technique should now be included in the choice of anaesthetic. Recommendations are made on both the selection of the technique, and the appropriate agents for a given group of patients.