Pharmacology and clinical use of plasma expanders: a 2026 update

Abstract

Plasma expanders are colloidal solutions that expand the circulating blood volume more than isotonic crystalloids. Though this physiologic effect is typically transient, colloids remain commonly though variably used in critical care and perioperative medicine worldwide. Our review of these agents begins by introducing the modified Starling model, which incorporates the fundamental physiologic role of the endothelial glycocalyx in transcapillary fluid movement. Next, we discuss each fluid's pharmacological properties and evidence base for use. Multiple trials suggest that albumin is a safe, albeit more expensive, alternative to crystalloids in intensive care, with secondary analyses suggesting harm in traumatic brain injury and possibly benefit in septic shock. Data to support the routine perioperative use of albumin are lacking, with recent trials in cardiac surgery showing no benefit or harm. Trials on hydroxyethyl starch in critical care demonstrate increased risk of kidney injury, coagulopathy, and possibly mortality. Recent trial data indicate that these harms may not equally apply to low-risk surgical patients, but, while an area of ongoing debate and study, no compelling evidence exists to support the routine perioperative use of hydroxyethyl starch. Finally, human trials on gelatins and dextrans are relatively scarce, making their use difficult to justify in most settings.