Narrative review of the role of intravenous fluid in critically sick patients

Intravenous fluid administration is regarded as a universal therapy in critical care. It is the mainstay of treatment in patients with dehydration, blood loss, sepsis, electrolyte imbalance, and shock. Crystalloids (for example, normal saline, lactated Ringer’s, Hartmann’s, Normosol, Isolyte, and PlasmaLyte solutions) and colloids (for example, albumin, or synthetic dextrans, gelatins, and starches) are the two types of commonly used IV fluids.

Resuscitation, replacement, and maintenance are the three main indications for intravenous fluid administration. Despite their widespread use, there is no standard therapeutic dose for IV fluids and clinicians are less familiar with the indications to stop IV fluid administration. Appropriate fluid management to maintain tissue perfusion while avoiding potentially harmful effects of IV fluid administration such as fluid overloading, metabolic acidosis, acute kidney injury, and electrolyte imbalance should be the core principle of treatment.

This review will focus on the role of different types of intravenous fluid in critically ill patients, including their side effects and applications in various types of shock.