This manual covers the working procedures of MICU, the diagnosis and treatment of common critical illnesses, commonly used monitoring and treatment methods, and adds relevant content on “ECMO and ventricular assist devices”. The content is up-to-date, detailed, and practical, enabling readers to quickly grasp the diagnosis and treatment of common critical illnesses in ICU, greatly improving clinical efficiency. This book ranges from the construction of RICU to the common clinical symptoms and treatment principles in RICU, the diagnosis and treatment processes of common diseases in RICU, routine diagnosis and treatment techniques in RICU, prevention and control of nosocomial infections, as well as respiratory therapy and nursing sections. It covers everything from the construction to the use of RICU, from basics to clinical practice, from bedside care to clinical thinking, and is applicable to medical staff in RICU and medical ICU.