The complexity of the anaesthesia and intensive therapy of the critically ill patient has imposed in the recent years intense research and perfecting a series of clinical methods used by physicians. Thus, were developed a series of new techniques in the management of the general anaesthesia, regional anaesthesia and mechanical ventilation. Also significant progresses were made regarding the modulation of the intensive therapy in severe infections, haemorrhagic shock, critically ill polytruama patient, neurocritic patient and so on. Another essential progress was made regarding the evaluation, diagnosis and monitoring of the critically ill patient both by introducing new diagnostic techniques, and through the use of new molecular biomarkers. In the present work, the authors wanted to make an important contribution in terms of some basic information but also of actuality specific for the critical patient. This book unites numerous personalities from the world of anaesthesia and intensive care all over the world.