Intravenous fluid therapy: essential components and key considerations.

Introduction: Intravenous (IV) fluid therapy plays a vital role in modern medical practice, particularly in critical care management. This review aims to summarize the composition, indications, and contraindications of IV fluids, serving as a useful resource for healthcare professionals. Methods: Review of the literature published in MEDLINE using PubMed and Web of Science, between 2009 and 2024. Systematic reviews, meta-analyses, expert reviews, and guidelines were preferred for analysis. Results: IV fluids can be administered for various reasons, including resuscitation, correction of electrolyte imbalances, or more critical cases. They can be divided into 2 categories: crystalloids and colloids. Crystalloids, in turn, can be subdivided into unbalanced solutions, such as salines (0.45%, 0.9%, 3%, and 20%) and dextrose 5%, or balanced solutions, such as Ringer lactate and polyelectrolytic solutions. Colloids can be derived from plasma, such as 5% albumin, or semisynthetic, such as 4% modified fluid gelatin. Crystalloids are generally more cost-effective, have a lower risk of allergic reactions, and are more readily available than colloids. However, the use of each solution should be individualized based on the patient's specific needs and corresponding conditions. Conclusions: It is essential to have a thorough understanding of available IV fluid solutions to select the best option for each patient's condition at any given time. This review summarizes the most relevant information to guide these decisions. Future research should develop IV fluids that combine the benefits of colloids and crystalloids for safer, more personalized, and cost-effective treatments.