Controversies in fluid therapy: Type, dose and toxicity

Area of Science:

• Critical Care Medicine
• Nephrology
• Pharmacology

Background:

• Fluid therapy is a ubiquitous intervention for acutely ill hospitalized patients.
• Significant questions persist regarding the optimal type, dose, and safety of fluid administration.
• Recent randomized trials offer new insights into fluid therapy's efficacy and toxicity.

Purpose of the Study:

• To review recent randomized trial data on fluid type, dose, and toxicity in critically ill patients.
• To discuss the context-specific nature of fluid therapy prescription.
• To highlight the clinical importance of fluid load and composition.

Main Methods:

• Review of recent randomized controlled trials on fluid therapy in acutely ill patients.
• Analysis of fluid efficacy, safety, and toxicity, including fluid type and dose.
• Discussion of fluid therapy phases: resuscitation, homeostasis, and recovery.

Main Results:

• Differences in efficacy between crystalloids and colloids are modest, but safety differences are significant.
• Chloride load and strong ion difference are clinically important factors in fluid solutions.
• Fluid overload (quantitative toxicity) is linked to adverse outcomes and can be managed with hemodynamic monitoring.
• Concerns exist regarding qualitative toxicity, such as acute kidney injury from synthetic colloids and metabolic acidosis from isotonic saline.

Conclusions:

• Fluid therapy prescription is context-specific and analogous to drug prescription in critically ill patients.
• Physiologically balanced crystalloids may serve as the default fluid choice.
• The role of colloids, particularly hydroxyethyl starch, in fluid therapy is diminishingly clear due to safety concerns.