This book is dedicated to the management of the critically ill patient, in particular, the one affected by infectious diseases. The book, thanks to its structure, can be useful both to health professionals already operating within health facilities, and to those who have to take the anesthesiology exam for the health professions. The book also contains brief reviews on bacteremia, innate immunity, hemostasis, the coagulation cascade, activation of the complement system and the mechanism of the inflammatory response.