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.

As the prefaces to successive editions of this book suggest, the Final Fellowship of the Royal College of Anaesthetists (FRCA) examination has continued to evolve since its inception in 1996, now almost three decades ago. The perception that the basic science components were little different from those examined in the Primary FRCA led to a change in emphasis from ‘basic’ to ‘clinical’ science. Some saw the change as little more than cosmetic, albeit that the College asserted that the structured orals were intended to test ‘the understanding of basic science to the practice of anaesthesia, intensive therapy and pain management’. The College has always included the proviso that ‘it is accepted that candidates will not have acquired a detailed knowledge of every topic during the period of recognised training’, and the examination is linked specifically to the curriculum, but hitherto this statement on occasion contrasted uneasily with the bitter perception of some candidates that they had been examined almost to destruction on scientific minutiae. This perception, against a background of muted unease about this section of the exam, has long since been acknowledged by the College, which decided therefore to introduce greater clinical emphasis into the science oral. The change of emphasis initially was relatively subtle, but in the current iteration of the SOE, it is much more explicit, with a clinical scenario usually prefacing discussion of a basic science topic. That change notwithstanding, you will be expected to discuss the clinical science subject in some depth because both the College and its examiners are reluctant to dilute the rigour of what for most candidates will be the last examination in anaesthesia that they are likely to take.

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.