Critical care medicine is a type of medical specialty that deals with the diagnosis and management of critical health risks and issues. It requires advanced life support and invasive monitoring. The aim of such monitoring is to support life as well as evaluate and treat the diseases. Some of the varied therapies and techniques used in critical care are mechanical ventilation, dialysis, resuscitation, defibrillation, etc. Several hospitals have specifically designed critical care areas for different specialties. Some examples of such units are coronary intensive care unit, surgical intensive care unit, neurological critical care unit, pediatric intensive care unit, neonatal intensive care unit, etc. This book traces the progress of this field and highlights some of its key concepts and applications. It provides significant information of this discipline to help develop a good understanding of critical care and related fields. This book will help the readers in keeping pace with the rapid changes in this field.