This manual is aimed at all healthcare practitioners, from novice to expert, who care for the critically ill patient, recognising that different disciplines contribute to the provision of effective care and that essential knowledge and skills are shared by all practitioners. It provides evidence-based guidelines on core critical care procedures and includes a comprehensive competency framework and specific competencies to enable practitioners to assess their abilities and expertise. Each chapter provides a comprehensive overview, beginning with basic principles and progressing to more complex ideas, to support practitioners to develop their knowledge, skills and competencies in critical care.