Since the first edition of the Oxford Textbook of Critical Care was published there have been many advances in in our understanding and management of critical illness. The first edition was prefaced with a note on the exacting nature of critical care—the holistic complexity of the patient with multisystem dysfunction, the out-of-hours commitment, the often stressful and highly charged situations requiring considerable agility of brain and hand, and the continuing evolution (and occasional revolution) in perceived ‘best practice’. These challenging demands are precisely what attract the critical care practitioner to the specialty. The importance of strong support mechanisms—from colleagues, national and international societies, and robust educational and research outputs—is paramount to sustain and enhance the quality of care patients receive. The format used in the first edition with system-orientated sections continues. Each section has been subdivided into short topics grouped according to clinical problems, facilitating manageable and relevant searches in electronic media. It is a single-volume major reference book aiming to cover the breadth of clinical and organizational aspects of adult critical care medicine in readable chunks. The editors acknowledge that every single topic cannot possibly be covered in detail, but hope the book’s comprehensive nature will be found useful by all health care providers who look after critically-ill patients. There are often local, national, and international differences in philosophy and management strategy. Some of these differences are seemingly contradictory and it is often difficult for physicians in one country to assimilate information produced for another. This is an international text attempting to give a balanced view where international differences exist. The book informs, rather than dictates.