The 4-indications of Fluid Therapy: Resuscitation, Replacement, Maintenance and Nutrition Fluids, and Beyond

The administration of intravenous (IV) fluids in critically ill patients remains a major therapeutic challenge. While there are many questions regarding the type, properties, speed, dose, and timing of fluid administration, there are only four major indications for their use: resuscitation, replacement, maintenance, and nutrition. In addition to these indications, IV fluids can also be used as carriers for medications. This chapter not only discusses the major indications for fluid therapy but also delves into different fluid management strategies, including early adequate goal-directed fluid management (EAFM), late conservative fluid management (LCFM), and late goal-directed fluid removal (LGFR). The concept of the six D’s of fluid therapy (diagnosis, drug, dosing, duration, de-escalation, and discharge) is also explored. This chapter aims to provide clinicians with a comprehensive understanding of IV fluid therapy beyond the traditional four indications.