This has long been the focus of fundamental research which this oral will not have time to explore in depth. The subject matter is complex, and although selective effects on CNS proteins appear to offer the most complete explanation, much remains unexplained. Some of the now discounted theories are described briefly here in order to give some context to the continued search for an answer.

Pneumothorax is an important complication in anaesthesia, trauma and medicine. This oral will concentrate both on the precise mechanisms by which pneumothoraces occur and on details of recognition and treatment. A pneumothorax can develop rapidly into a life-threatening emergency, and so you must ensure that your management is competent.

This is a standard question, but one which contains a lot of anatomical detail. It may be useful to practise drawing a simple explanatory diagram. The oral may be linked to intracranial aneurysms and their management, and it may also include physiological aspects of cerebral perfusion, the problem of cerebral vasospasm following subarachnoid haemorrhage or briefly the subject of intracranial pressure (ICP).

The discovery of anaesthesia transformed the human condition, and unplanned awareness returns a patient to the nightmare that was surgery before anaesthesia and effective analgesia. Significant advances in the pharmacology and technology of anaesthesia have still not brought reliable means of monitoring its depth much closer, although because awareness is such a serious complication, considerable research effort has been dedicated to the search for methods of detection. Some of these remain research tools or are not yet in widespread use, but you should have some idea about which of them may in due course find their way into clinical practice. Most current interest centres around bispectral index (BIS) monitoring, with recommendations both from the Association of Anaesthetists and from NICE, which are summarised in this section, and it is likely that the oral will focus more on BIS than on the other technologies.