Critical care medicine is a branch of medicine that is concerned with the diagnosis and management of critical health issues, which may require advanced life support and dedicated monitoring. The ultimate goal of life support is to sustain life, while the underlying diseases or injury is being evaluated or treated. Some of the diverse therapies and techniques involved in the care of patients in intensive care are mechanical ventilation, defibrillation, cardiopulmonary resuscitation, dialysis, total parenteral nutrition, etc. The care of premature or ill newborn infants is undertaken in a neonatal intensive care unit. Administration of high-risk medications and antibiotics, management of infants requiring ventilator support, surgical care and resuscitation, etc. are crucial to neonatal critical care. There are psychiatric intensive care units in psychiatric wards. These are designed to care for patients who pose a degree of risk to themselves or others. Patients are cared for in such units until their mental state is stable. Critical care is an upcoming field of medicine that has undergone rapid development over the past few decades. This book aims to shed light on some of the unexplored aspects of critical care and the recent researches in this field. It will help new researchers by foregrounding their knowledge in this field.