Anesthesia is an induced state of temporary and controlled loss of awareness and sensation. It includes paralysis or muscle relaxation, prevention and relief from pain, and unconsciousness. It allows the painless performance of medical procedures, which could cause intolerable pain in an unanesthetized patient. It can be administered such that it leads to a total lack of sensation, or to partial loss of sensation, or inhibit anxiety and the creation of long-term memories. Safe anesthesia administration requires a holistic understanding of the effects of anesthetic drugs, organ support techniques, hemodynamic monitoring, advanced airway management and diagnostic techniques. The practice of anesthesia is known as anesthesiology. This book discusses the fundamentals as well as modern approaches of anesthesiology. It presents researches and studies performed by experts across the globe. The extensive content of this book provides the readers with a thorough understanding of the subject.